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Khumalo, Nomcebo, Aloyce W. Mayo, and Subira Munishi. "Modelling Of Food Hazard Susceptibility in Komatipoort, South Africa." Tanzania Journal of Engineering and Technology 37, no. 1 (December 31, 2018): 47–71. http://dx.doi.org/10.52339/tjet.v37i1.483.
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Komatipoort, a small town located at the confluence of Komati and Krokodil rivers, is constantly being hit by floods which affect the residents of this small town as well as the farmers settling along the rivers. This study aimed at mapping the flood hazard and susceptibility through the integration of GIS techniques and hydraulic modeling. Due to inconsistency in the length of streamflow data in the different gauging stations, a Hydrological modeling HBV model, was utilized for modelling runoff in order to extend flow records at station X2HO32 for Komati River. Calibration was conducted using observed data from 1982 to 1993, giving an efficiency value of 65% and validation was done using data from 1993 to 1999, giving an efficiency value of 53%. Flood frequencies were analyzed and flood quantiles were determined at different return periods. HEC-RAS was utilized to simulate the hydraulic parameters of Komati and Krokodil rivers to obtain flood hazard maps. GIS-based multi-criteria analysis techniques were incorporated for flood susceptibility mapping. Hydraulic analysis showed that the floods mostly affect the farms and settlements along the rivers and a small part of the central business district is affected. Flood susceptibility mapping showed that the area is generally highly susceptible to flooding because of a combination of anthropogenic and natural factors.
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Viljoen, MF, and GR Backeberg. "Management of water extremes: A South African perspective on guidelines for policy and strategy development." South African Journal of Economic and Management Sciences 7, no. 4 (November 30, 2004): 693–700. http://dx.doi.org/10.4102/sajems.v7i4.1300.
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This presentation endeavours to present some guidelines for policy and strategy development with regard to the effective management of floods and droughts. Insights are gained from a literature study about the social, economic and political impacts of irrigation droughts, research done on the impacts and management of floods and water restrictions in South Africa as well as analysing the disaster management policy process in South Africa since 1994. The South African experience in terms of the management of water extremes, serves as basis for policy and strategy development and should benefit all involved – including other regions.
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Benito, G., V. R. Thorndycraft, M. T. Rico, Y. Sánchez-Moya, A. Sopeña, B. A. Botero, M. J. Machado, M. Davis, and A. Pérez-González. "Hydrological response of a dryland ephemeral river to southern African climatic variability during the last millennium." Quaternary Research 75, no. 3 (May 2011): 471–82. http://dx.doi.org/10.1016/j.yqres.2011.01.004.
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AbstractA long-term flood record from the Buffels River, the largest ephemeral river of NW South Africa (9250 km2), was reconstructed based on interpretation of palaeoflood, documentary and instrumental rainfall data. Palaeoflood data were obtained at three study reaches, with preserved sedimentary evidence indicating at least 25 large floods during the last 700 yr. Geochronological control for the palaeoflood record was provided by radiocarbon and optically stimulated luminescence (OSL) dating. Annual resolution was obtained since the 19th century using the overlapping documentary and instrumental records. Large floods coincided in the past within three main hydroclimatic settings: (1) periods of regular large flood occurrence (1 large flood/~30 yr) under wetter and cooler prevailing climatic conditions (AD 1600–1800), (2) decreasing occurrence of large floods (1 large flood/~100 yr) during warmer conditions (e.g., AD 1425–1600 and after 1925), and (3) periods of high frequency of large floods (~ 4–5 large floods in 20–30 yr) coinciding with wetter conditions of decadal duration, namely at AD 1390–1425, 1800–1825 and 1915–1925. These decadal-scale periods of the highest flood frequency seem to correspond in time with changes in atmospheric circulation patterns, as inferred when comparing their onset and distribution with temperature proxies in southern Africa.
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Entwistle, N., G. Heritage, S. Tooth, and D. Milan. "Anastomosing reach control on hydraulics and sediment distribution on the Sabie River, South Africa." Proceedings of the International Association of Hydrological Sciences 367 (March 3, 2015): 215–19. http://dx.doi.org/10.5194/piahs-367-215-2015.
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Abstract. Rivers in the Kruger National Park, South Africa, have variable degrees of bedrock and alluvial influence. Pre-2000 aerial imagery for the Sabie River (catchment area 6320 km2) reveals downstream alternations from alluvial single thread or braided, to bedrock anastomosed or mixed anastomosed channel types, with pool-rapids also present locally. In 2000 and 2012, extreme floods resulted in significant alluvial erosion, widely exposing the underlying bedrock. Since the 2012 flood, aerial LiDAR surveys reveal the strong gradient control exerted by the bedrock and mixed anastomosed channel types, which influences hydraulic conditions and sediment dynamics. Two dimensional hydraulic modelling of moderate floods (<1500 m3 s−1) reveals reduced velocities upstream of bedrock or mixed anastomosed channel types, which promotes deposition. During more extreme floods (>3500 m3 s−1), the bedrock or mixed anastomosed channel types are drowned out, resulting in dramatically increased velocities along the entire river and widespread alluvial stripping regardless of initial channel type or location.
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De Villiers, Gawie, Giel Viljoen, and Herman Booysen. "Global warming and climate change with reference to South Africa. Some perspectives." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 27, no. 4 (September 20, 2008): 294–306. http://dx.doi.org/10.4102/satnt.v27i4.98.
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According to the geological history of the earth, climate change is an integral part of environmental changes that occurred over time. Sufficient evidence is provided of recurrent wet and dry and cold and hot periods due to natural circumstances. Since the industrial revolution human activities increasingly contribute to air pollution by releasing huge volumes of carbon dioxide and other gasses into the atmosphere, so much so that it is generally accepted that increase in global warming the past decades is directly linked to human activities. Observable signs of human induced climate change include increasing average temperatures at many places, melting ice caps in polar areas, rising sea levels on a global scale and coastal disturbances and damages due to storm surges on coastal areas in various countries, also in South Africa. Consensus from a number of hydrological-meteorological circulation models show, for South Africa, a rise in average annual winter and summer temperatures of between 1.5 and 3.0 degrees Centigrade the following number of decades with a strong possibility of an increase in rainfall in the eastern parts and a decrease in rainfall in the western parts. Bigger floods and longer droughts should occur more frequently as well as severe sea onslaught activities along the eastern and south-eastern coastal areas. The net impact of the predictions on the community is negative. There is though other scientists who indicate that no concrete proof of climate change in South Africa exists; including changes with regard to river floods and droughts. According to more beneficial than detrimental. Despite the differences in opinion about the relative contribution of natural and human activities to the present global warming, changes in hydrological and characteristics of floods in several parts of South Africa in the immediate past, necessitate modifications to available models and approaches to flood damage management and control. Flood conditions need to be managed with applicable models. Modifications are furthermore essential as a result of meaningful demographic, social, physical and economic changes in the working and living environments of people and communities.
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Heritage, G., S. Tooth, N. Entwistle, and D. Milan. "Long-term flood controls on semi-arid river form: evidence from the Sabie and Olifants rivers, eastern South Africa." Proceedings of the International Association of Hydrological Sciences 367 (March 3, 2015): 141–46. http://dx.doi.org/10.5194/piahs-367-141-2015.
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Abstract. Rivers in the Kruger National Park, eastern South Africa, are characterised by bedrock-influenced "macrochannels" containing variable alluvial thicknesses and riparian vegetation assemblages. Evidence from the Sabie and Olifants rivers suggests that flows up to moderate floods (<3500 m3 s−1) tend to result in net alluviation, with sediments gradually covering the underlying bedrock. More extreme floods strip alluvium and erode bedrock, effectively exerting the primary control over long-term river morphologic development. On the Olifants River, post-flood aerial LIDAR imagery reveals that the 2012 extreme flood (~14000 m3 s−1) resulted in extensive stripping of stored alluvial sediment, exposing and eroding the underlying weathered bedrock. On the Sabie River, preliminary optically stimulated luminescence ages for remnant alluvium are all less than 1000 years, highlighting typical timescales of sediment storage. Together, these results suggest that while periods of general alluviation occur on these systems, long-term river development results from extreme flood-generated bedrock erosion.
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Tandlich, Roman, Mbonisi Ncube, S. M. M. Khamanga, and Bongumusa M. Zuma. "A Case Study on the Health Risks Related to Flood Disasters in South Africa." Journal of Disaster Research 11, no. 4 (August 1, 2016): 732–41. http://dx.doi.org/10.20965/jdr.2016.p0732.
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Floods occurred in the Ndlambe Local Municipality in South Africa in October 2012. During various stages of the post-disaster recovery, bacterial concentrations were measured in water and soil samples from the flood zone. All drinking water concentrations ofE. coliwere below 1–3 colony forming units per 100 millilitres (CFUs/100 mL). The flood waters contained between 46500 to more than 100000 CFUs/100 mL ofE. coli. {The concentrations ofSalmonellaspp. in the flood waters varied from 5000 to 250000 CFUs/100 mL. The presumptiveVibriospp. concentrations in flood waters ranged from 1000 to over 150000 CFUs/100 mL. {The soil concentrations forE. coliranged from 1 to above 330 colony-forming units per 1 g of soil dry weight (CFUs/g). The soil concentrations ofSalmonellaspp. varied from below 1 to 22 CFUs/g. The estimated airborne fungal concentrations ranged from 16820 to 28540 colony-forming units per 1 cubic meter. An outbreak of an infectious disease was recorded among the volunteers who assisted with the post-disaster recovery. The likely bacterial causative agents included strains ofAeromonasspp. andVibrio cholerae. Any human contact with either the contaminated flood waters or of flooded dwellings should only occur, if the individuals in questions are equipped with the full-body personal protective gear. Non-governmental stakeholders performed majority of the post-disaster recovery operations, as the local government could only cover 11% of the required costs. Applying sanitation funds to disaster recovery and increased use of the low-cost flood defence products in high risk areas could provide a solution for the future.
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Rapolaki, Ramontsheng S., and Chris J. C. Reason. "Tropical storm Chedza and associated floods over south-eastern Africa." Natural Hazards 93, no. 1 (April 9, 2018): 189–217. http://dx.doi.org/10.1007/s11069-018-3295-y.
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Huang, Yaohuan, Zhonghua Li, Mingxing Chen, Xiaoyang Song, and Ping Kang. "Spatial Variability of Water Resources State of Regions around the “Belt and Road”." Water 13, no. 15 (July 31, 2021): 2102. http://dx.doi.org/10.3390/w13152102.
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Water resource has become a key constraint for implementing the “Belt and Road” initiative which was raised by the Chinese government. Besides the study of spatial and temporal variability of precipitation, this study created a water hazard risk map along the “Belt and Road” zone through combined flood and drought data from 1985. Our results showed that South-Eastern Asia, southern China and eastern Southern Asia are areas with the most abundant precipitations, while floods in these areas are also the most serious. Northwest China, Western Asia, Northern Africa and Southern Asia are areas highly vulnerable to drought. Furthermore, the potential influence of flood and drought were also analyzed by associating with population distribution and corridor map. It reveals that China, South-Eastern Asia, Southern Asia, Western Asia and Northern Africa have the largest population number facing potential high water hazard risk. China–India–Burma Corridor and China–Indo-China Peninsula Corridor have the largest areas facing potential high water hazard risk.
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De Villiers, Gawie, Giel Viljoen, and Herman Booysen. "Standard residential flood damage functions for South African conditions." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 26, no. 1 (September 21, 2007): 26–36. http://dx.doi.org/10.4102/satnt.v26i1.122.
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Disaster risk management is an integral part of a scientific approach to disaster management. It refers to integrated, multi-sectoral, multi-disciplinary, organizational and operational planning processes and skills to mitigate disasters. Application of the approach necessitates disaster risk analysis, requiring flood damage functions in the case of floods. A flood damage function can be described mathematically, tabularly or graphically and refers to the relationship between flood characteristics like depth and/or speed of floodwater and flood damage to a specific land use type. Research conducted at the University of the Free State indicated the value of standard residential flood damage functions and the necessity for periodic updating to secure contemporary relevance. This article focuses on updating of the latter. The article starts with an introduction to put the development, use and maintenance of standard residential flood damage functions in context with regard to the latest views on disaster risk management, risk assessment, disaster management legislation in South Africa and a computer model TEWA, in which the flood damage functions are used. Aspects that can affect flood damage are briefly discussed, followed by sections on the development and upgrading of structural flood damage functions for formal housing as well as functions for determining damage to housing contents. The development of residential flood damage functions that can be applied nationally forms the main part of the paper and is followed by a brief summary statement.
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Spaliviero, M., M. De Dapper, and S. Maló. "Flood risk analysis of the Limpopo River basin through past evolution reconstruction and geomorphological approach." Natural Hazards and Earth System Sciences Discussions 2, no. 2 (February 10, 2014): 1367–404. http://dx.doi.org/10.5194/nhessd-2-1367-2014.
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Abstract. This research reconstructs the past evolution of the Limpopo River, a transboundary system located in south-eastern Africa, and describes its geomorphological settings through literature review and field work activities, with aim to analyse the risk of floods in the basin. Major changes have occurred since the late Jurassic – early Cretaceous period due to successive tectonic events. The paper demonstrates that the apparently abandoned drainage conformation of the palaeo-Limpopo in the upper and middle stretches of the river constitutes today preferential flood-prone areas in case of major rainfall events. An important palaeo-delta is identified in the lower Limpopo, which imposes a particular drainage pattern to the floodplain in Mozambique and influences the floods dynamics at present. The adopted method is helpful in determining flood risk in a data-scarce area showing complex fluvial dynamics, and allows identifying unsuitable locations for human settlements.
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Benito, G., B. A. Botero, V. R. Thorndycraft, M. Rico, Y. Sánchez-Moya, A. Sopeña, M. J. Machado, and O. Dahan. "Rainfall-runoff modelling and palaeoflood hydrology applied to reconstruct centennial scale records of flooding and aquifer recharge in ungauged ephemeral rivers." Hydrology and Earth System Sciences 15, no. 4 (April 8, 2011): 1185–96. http://dx.doi.org/10.5194/hess-15-1185-2011.
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Abstract. In this study we propose a multi-source data approach for quantifying long-term flooding and aquifer recharge in ungauged ephemeral rivers. The methodology is applied to the Buffels River, at 9000 km2 the largest ephemeral river in Namaqualand (NW South Africa), a region with scarce stream flow records limiting research investigating hydrological response to global change. Daily discharge and annual flood series (1965–2006) were estimated from a distributed rainfall-runoff hydrological model (TETIS) using rainfall gauge records located within the catchment. The model was calibrated and validated with data collected during a two year monitoring programme (2005–2006) at two stream flow stations, one each in the upper and lower reaches of the catchment. In addition to the modelled flow records, non-systematic flood data were reconstructed using both sedimentary and documentary evidence. The palaeoflood record identified at least 25 large floods during the last 700 yr; with the largest floods reaching a minimum discharge of 255 m3 s−1 (450 yr return period) in the upper basin, and 510 m3 s−1 (100 yr return period) in the lower catchment. Since AD 1925, the flood hydrology of the Buffels River has been characterised by a decrease in the magnitude and frequency of extreme floods, with palaeoflood discharges (period 1500–1921) five times greater than the largest modelled floods during the period 1965–2006. Large floods generated the highest hydrograph volumes, however their contribution to aquifer recharge is limited as this depends on other factors such as flood duration and storage capacity of the unsaturated zone prior to the flood. Floods having average return intervals of 5–10 yr (120–140 m3 s−1) and flowing for 12 days are able to fully saturate the Spektakel aquifer in the lower Buffels River basin. Alluvial aquifer storage capacity limiting potential recharge by the largest floods is a common problem in arid environments, with the largest infiltration volumes favoured by increasing depth to groundwater levels.
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Benito, G., B. A. Botero, V. R. Thorndycraft, M. Rico, Y. Sánchez-Moya, A. Sopeña, M. J. Machado, and O. Dahan. "Rainfall-runoff modelling and palaeoflood hydrology applied to reconstruct centennial scale records of flooding and aquifer recharge in ungauged ephemeral rivers." Hydrology and Earth System Sciences Discussions 7, no. 6 (December 21, 2010): 9631–60. http://dx.doi.org/10.5194/hessd-7-9631-2010.
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Abstract. In this study we propose a multi-source data approach for quantifying long-term flooding and aquifer recharge in ungauged ephemeral rivers. The methodology is applied to the Buffels River, at 9000 km2 the largest ephemeral river in Namaqualand (NW South Africa), a region with scarce stream flow records limiting research investigating hydrological response to global change. Daily discharge and annual flood series (1965–2006) were estimated from a distributed rainfall-runoff hydrological model (TETIS) using rainfall gauge records located within the catchment. The model was calibrated and validated with data collected during a two year monitoring programme (2005–2006) at two stream flow stations, one each in the upper and lower reaches of the catchment. In addition to the modelled flow records, non-systematic flood data were reconstructed using both sedimentary and documentary evidence. The palaeoflood record identified at least 25 large floods during the last 700 yr; with the largest events reaching a minimum discharge of 255 m3 s−1 (450 yr return period) in the upper basin, and 510 m3 s−1 (100 yr return period) in the lower catchment. Since 1925 AD, the flood hydrology of the Buffels River has been characterised by a decrease in the magnitude and frequency of extreme events, with palaeoflood discharges five times greater than the largest modelled floods during the period 1965–2006. Large floods generated the highest hydrograph volumes, however their contribution to aquifer recharge is limited as this depends on other factors such as flood duration and storage capacity of the unsaturated zone prior to the flood. Floods reaching flows associated with 5–10 yr return periods (120–140 m3 s−1) and flowing for 12 days are able to fully saturate the Spektakel aquifer in the lower Buffels River basin.
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Muofhe, Tshimbiluni Percy, Hector Chikoore, Mary-Jane Morongwa Bopape, Nthaduleni Samuel Nethengwe, Thando Ndarana, and Gift Tshifhiwa Rambuwani. "Forecasting Intense Cut-Off Lows in South Africa Using the 4.4 km Unified Model." Climate 8, no. 11 (November 7, 2020): 129. http://dx.doi.org/10.3390/cli8110129.
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Mid-tropospheric cut-off low (COL) pressure systems are linked to severe weather, heavy rainfall and extreme cold conditions over South Africa. They occur during all the above and often result in floods and snowfalls during the winter months, disrupting economic activities and causing extensive damage to infrastructure. This paper examines the evolution and circulation patterns associated with cases of severe COLs over South Africa. We evaluate the performance of the 4.4 km Unified Model (UM) which is currently used operationally by the South African Weather Service (SAWS) to simulate daily rainfall. Circulation variables and precipitation simulated by the UM were compared against European Centre for Medium-Range Weather Forecast’s (ECMWF’s) ERA Interim re-analyses and GPM precipitation at 24-hour timesteps. We present five recent severe COLs, which occurred between 2016 and 2019, that had high impact and found a higher model skill when simulating heavy precipitation during the initial stages than the dissipating stages of the systems. A key finding was that the UM simulated the precipitation differently during the different stages of development and location of the systems. This is mainly due to inaccurate placing of COL centers. Understanding the performance and limitations of the UM model in simulating COL characteristics can benefit severe weather forecasting and contribute to disaster risk reduction in South Africa.
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Mohamed, Mostafa A., and Mohamed El-Sayed El-Mahdy. "Impact of sunspot activity on the rainfall patterns over Eastern Africa: a case study of Sudan and South Sudan." Journal of Water and Climate Change 12, no. 5 (February 26, 2021): 2104–24. http://dx.doi.org/10.2166/wcc.2021.312.
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Abstract The relation between sunspots and rainfall patterns is still obscure in Africa, especially for Sudan and South Sudan. This research explores the response of rainfall to solar activity in eastern regions of Africa, with a case study in Sudan and South Sudan. Rainfall varies with time; therefore, skillful monitoring, predicting, and early warning of rainfall events is indispensable. Severe climatic events, such as droughts and floods, are critical factors in planning and managing all socioeconomic activities. Similar trends for the sunspot activity (sunspot number and sunspot groups) changes and rainfall variations for different stations in East Africa during the years 1910–2018 were not found. Correlation analysis carried out for the above period indicated a weak negative correlation between the total rainfall and the average number of sunspots over the long-term scale for selected stations in Sudan and South Sudan. The overall result of the paper indicated no significant relationship between sunspot numbers and rainfall in temporal and spatial scales in Sudan and South Sudan.
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Goldin, Jacqueline, Cobus Botha, Thabiso Koatla, Kobus Anderson, Germaine Owen, and Ally Lebese. "Towards a gender sensitive vulnerability assessment for climate change: Lambani, Limpopo Province, South Africa." Human Geography 12, no. 1 (March 2019): 19–32. http://dx.doi.org/10.1177/194277861901200102.
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Women's limited access to resources and decision-making processes increases their vulnerability to impacts of climate change. Despite their own vulnerability, women are often responsible for caring for close relatives, extended families and friends during hazardous and traumatic events (whether its famine, floods, drought or forced displacements). Based on experience and knowledge it is believed that women are more vulnerable to the effects of climate change than men, primarily as they constitute the majority of the world's poor and are more dependent for their livelihood on natural resources that are threatened by climate change. The paper proposes a gender sensitive vulnerable assessment framework that is scaffolded by three key concepts: exposure, temporality and resource base. Because the study is grounded in the Capability Approach Framework it captures multi-dimensionality and intangible goods which are emotions such as fear, anger, shock or shame. It seeks to better understand the differentiated responses of men and women to climate variations and stress such as extreme heat, cold, droughts or floods in a specific site, Lambani, in the Limpopo Province of South Africa. The main aim is to understand different responses of men and women to climate change in order to design and populate a vulnerability assessment (VA) framework. In order to do so the Capability Approach (CA) is applied as a theoretical frame with its lens on diversity and social justice. The CA thus provides an expanded notion of human well-being that taps into the emotional life of women and men in Lambani.
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Ionita, Monica, Viorica Nagavciuc, and Bin Guan. "Rivers in the sky, flooding on the ground: the role of atmospheric rivers in inland flooding in central Europe." Hydrology and Earth System Sciences 24, no. 11 (November 5, 2020): 5125–47. http://dx.doi.org/10.5194/hess-24-5125-2020.
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Abstract. The role of large-scale atmospheric circulation and atmospheric rivers (ARs) in producing extreme flooding and heavy rainfall events in the lower part of the Rhine catchment area is examined in this study. Analysis of the largest 10 floods in the lower Rhine, between 1817 and 2015, shows that all these extreme flood peaks have been preceded up to 7 d in advance by intense moisture transport from the tropical North Atlantic basin in the form of narrow bands also known as atmospheric rivers. Most of the ARs associated with these flood events are embedded in the trailing fronts of the extratropical cyclones. The typical large-scale atmospheric circulation leading to heavy rainfall and flooding in the lower Rhine is characterized by a low pressure center south of Greenland, which migrates toward Europe, and a stable high pressure center over the northern part of Africa and the southern part of Europe and projects on the positive phase of the North Atlantic Oscillation. On the days preceding the flood peaks, lower (upper) level convergence (divergence) is observed over the analyzed region, which indicates strong vertical motions and heavy rainfall. Vertically integrated water vapor transport (IVT) exceeds 600 kg m−1 s−1 for the largest floods, marking these as very strong ARs. The results presented in this study offer new insights regarding the importance of moisture transport as a driver of extreme flooding in the lower part of the Rhine catchment area, and we show, for the first time, that ARs are a useful tool for the identification of potentially damaging floods in inland Europe.
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Fitchett, J. M., G. Hoogendoorn, and A. M. Swemmer. "Economic costs of the 2012 floods on tourism in the Mopani District Municipality, South Africa." Transactions of the Royal Society of South Africa 71, no. 2 (April 13, 2016): 187–94. http://dx.doi.org/10.1080/0035919x.2016.1167788.
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Owen, R. K., and A. T. Forbes. "SALINITY, FLOODS AND THE INFAUNAL MACROBENTHIC COMMUNITY OF THE ST LUCIA ESTUARY, KWAZULU-NATAL, SOUTH AFRICA." Southern African Journal of Aquatic Sciences 23, no. 1 (January 1997): 14–30. http://dx.doi.org/10.1080/10183469.1997.9631385.
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Bangira, Tsitsi, Ben H. P. Maathuis, Timothy Dube, and Tawanda W. Gara. "Investigating flash floods potential areas using ASCAT and TRMM satellites in the Western Cape Province, South Africa." Geocarto International 30, no. 7 (April 10, 2015): 737–54. http://dx.doi.org/10.1080/10106049.2014.997302.
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Milan, David, George Heritage, Stephen Tooth, and Neil Entwistle. "Morphodynamics of bedrock-influenced dryland rivers during extreme floods: Insights from the Kruger National Park, South Africa." GSA Bulletin 130, no. 11-12 (May 14, 2018): 1825–41. http://dx.doi.org/10.1130/b31839.1.
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Botai, Christina M., Joel O. Botai, Nosipho N. Zwane, Patrick Hayombe, Eric K. Wamiti, Thabo Makgoale, Miriam D. Murambadoro, et al. "Hydroclimatic Extremes in the Limpopo River Basin, South Africa, under Changing Climate." Water 12, no. 12 (November 24, 2020): 3299. http://dx.doi.org/10.3390/w12123299.
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This research study evaluated the projected future climate and anticipated impacts on water-linked sectors on the transboundary Limpopo River Basin (LRB) with a focus on South Africa. Streamflow was simulated from two CORDEX-Africa regional climate models (RCMs) forced by the 5th phase of the Coupled Model Inter-Comparison Project (CMIP5) Global Climate Models (GCMs), namely, the CanESM2m and IPSL-CM5A-MR climate models. Three climate projection time intervals were considered spanning from 2006 to 2099 and delineated as follows: current climatology (2006–2035), near future (2036–2065) and end of century future projection (2070–2099). Statistical metrics derived from the projected streamflow were used to assess the impacts of the changing climate on water-linked sectors. These metrics included streamflow trends, low and high flow quantile probabilities, the Standardized Streamflow Index (SSI) trends and the proportion (%) of dry and wet years, as well as drought monitoring indicators. Based on the Mann-Kendall (MK) trend test, the LRB is projected to experience reduced streamflow in both the near and the distant future. The basin is projected to experience frequent dry and wet conditions that can translate to drought and flash floods, respectively. In particular, a high proportion of dry and a few incidences of wet years are expected in the basin in the future. In general, the findings of this research study will inform and enhance climate change adaptation and mitigation policy decisions and implementation thereof, to sustain the livelihoods of vulnerable communities.
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Ubisi, Nomcebo R., Unathi Kolanisi, and Obert Jiri. "The Role of Indigenous Knowledge Systems in Rural Smallholder Farmers’ Response to Climate Change: Case Study of Nkomazi Local Municipality, Mpumalanga, South Africa." Journal of Asian and African Studies 55, no. 2 (September 28, 2019): 273–84. http://dx.doi.org/10.1177/0021909619874824.
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Climate change and variability have direct negative impacts on rural smallholder farmers. These impacts involve extreme climatic events such as excessive temperatures, prolonged droughts and floods which affect people’s livelihoods. This study was conducted in Nkomazi Local Municipality, Mpumalanga, South Africa. The main objective of the study was to investigate indigenous weather and climate indicators used by smallholder farmers and the role of indigenous knowledge in their farming systems. The research used qualitative methods, including focus group discussions and key informant interviews. The findings indicated that farmers observed animal behaviour, plants, atmospheric indicators and human ailments to predict weather.
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Peltzer, K., M. J. Seakamela, L. Manganye, K. G. Mamiane, M. S. Motsei, and T. T. M. Mathebula. "Trauma and Posttraumatic Stress Disorder in a Rural Primary Care Population in South Africa." Psychological Reports 100, no. 3_suppl (June 2007): 1115–20. http://dx.doi.org/10.2466/pr0.100.4.1115-1120.
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The aim of this study was to assess trauma events experienced and PTSD among 250 consecutive rural primary clinic patients (all Black Africans, 24% male and 76% female; M age 31.1 yr., SD = 11.8; range 18–65 years) in South Africa using the Trauma History Questionnaire and the PTSD Checklist-Civilian Version, interview administered. Results indicated that the mean number of traumatic events reported was 3.5 ( SD = 2.9, range = 0–19) and was significantly higher among men ( M = 4.9, SD = 3.5) than women ( M = 3.0, SD = 2.6). Among the most frequently endorsed traumas among men were seeing someone seriously injured or killed (60%), serious accident (43.3%), and seeing dead bodies (43.3%), and among women natural disaster (mostly floods) (51.6%), news of a serious injury, life-threatening illness or unexpected death of someone close (31.1%), and seeing someone seriously injured or killed (30%). A current diagnosis of PTSD was found in 12.4%) of the sample. Trauma incidence figures were high ( M = 3.5) and were comparable with an urban Xhosa primary care population in South Africa ( M = 3.8). A current indicative diagnosis of PTSD of 12.4%) also compares with other studies; 19.9% among urban Xhosa primary care patients and 11.8% among American primary care patients.
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Adugu, Emmanuel. "Determinants of Support for Climate Change Efforts in the Global South." European Journal of Sustainable Development 9, no. 1 (February 1, 2020): 455–68. http://dx.doi.org/10.14207/ejsd.2020.v9n1p455.
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This paper addresses determinants that underpin support for climate change efforts. The study is based on Pew Research Center (USA), Spring 2015 Global Attitudes survey dataset, with a primary focus on climate change, collected from March 25 to May 27, 2015. Drawing on the new ecological paradigm and ecological modernization perspectives, the paper utilizing logistic regression, examines the relationship between individuals’ perception or awareness of the severity of climate change and their support for limiting greenhouse emissions; the extent to which individuals’ views on whether developing countries should do as much as the rich countries in addressing climate change predict the likelihood of their (individuals’) support for limiting greenhouse emissions. The logistic regression models reveal that people’s rational insight into the following consequences of climate change positively predicts support for limiting greenhouse emissions: severe weather like floods or severe storms; long periods of unusually hot weather; rising sea levels; years of schooling and age positively predict support for limiting greenhouse emissions. In general, knowing an individual’s country of residence offers no predictive value in determining whether the individual will support limiting greenhouse emissions. The notable exceptions are: South Africa, Nigeria, Ghana and Kenya. These four countries display positive and statistically significant coefficients in the logistic regression model predicting support for greenhouse emissions. Keywords: climate change; environmental concern; greenhouse emissions; ecological crisis; Africa
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Fox, R. C., and K. M. Rowntree. "Extreme weather events in the Sneeuberg, Karoo, South Africa: a case study of the floods of 9 and 12 February 2011." Hydrology and Earth System Sciences Discussions 10, no. 8 (August 19, 2013): 10809–44. http://dx.doi.org/10.5194/hessd-10-10809-2013.
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Abstract. Two destructive flood events occurred in rapid succession in the semi-arid Sneeuberg Mountains of the Karoo, South Africa in February 2011. The temporal and spatial characteristics of these two extreme events are examined in this paper through analysis of data from an unusually dense, and reliable, network of farm rain gauges. These analyses add to our understanding derived from existing rain gauge information. Comparisons are then made with patterns from a range of modeled products derived from remote sensed information: the Modern-Era Retrospective Analysis for Research and Applications (MERRA), the Tropical Rainfall Measuring Mission (TRMM) and the Global Land Data Assimilation System (GLDAS). We found that the first flood event was widespread and precipitation was related strongly to altitude. The second was highly localised, with no relationship to altitude. Both had very sharply peaked rainfall intensities. These findings are of significance to the studies of flooding and landscape change in the area as such events have become more pronounced over the past 50 yr and it is likely that this trend will accelerate. The modeled patterns are derived largely from remote sensing and we found that they are reliable for drawing out monthly and annual variations but they make noticeable underestimates. They are poor estimates, however, both for the spatial distribution of precipitation, and the short term trends as they struggle to estimate the impact of topography and other local forcing factors. This finding corroborates information derived from other analyses at broader spatial scales using more widely spread, established rain gauge stations. Ten percent of southern Africa has been classified as mountainous and these areas provide much of our water resources so our findings are significant to water managers throughout this and similar mountainous regions.
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Lwasa, Shuaib. "Drought and Flood Risk, Impacts and Adaptation Options for Resilience in Rural Communities of Uganda." International Journal of Applied Geospatial Research 9, no. 1 (January 2018): 36–50. http://dx.doi.org/10.4018/ijagr.2018010103.
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Climate change is affecting many rural resource-poor communities unequivocally with differing magnitude, severity and frequency of drought risk from one locale to another especially in Africa. At micro spatial scale of households and villages, climate change risk trends and hazards vary spatially, coupling with social, economic and locational conditions. This paper analyzes vulnerability and impacts of climate change from droughts and floods in a rural community with varied geographies across social, economic and environmental profiles in Uganda. In recent years, studies have shown that droughts have increased form 1 in 10 years to 1 in 6 years and the worst affected area is the semi-arid zone of Uganda that spans from south western through central parts to the north-eastern parts of the country. In the study area of Pallisa, located in the eastern central part of the semi-arid zone, droughts and floods impacts on livelihoods, people and assets are eroding the asset-base for the households. Yet the household assets are important in adaptation and resilience of the community. As a natural resource dependent community like many others, evidence strongly suggests increasing climate risks of droughts and floods the impacts of which are worsening the already grim conditions of community well-being. This paper analyses the climate risks utilizing the vulnerability assessment framework. A scenario-based analysis that integrates community evaluation of vulnerability with climate data to analyze current and future vulnerabilities in a spatial context is conducted to examine spatial differences in vulnerability. Various multi-scale adaptation strategies are analyzed in respect to the climate change risks to assess the resilient capacity of the community to current and future vulnerabilities.
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Mussá, F. E. F., Y. Zhou, S. Maskey, I. Masih, and S. Uhlenbrook. "Groundwater as an emergency source for drought mitigation in the Crocodile River catchment, South Africa." Hydrology and Earth System Sciences 19, no. 2 (February 26, 2015): 1093–106. http://dx.doi.org/10.5194/hess-19-1093-2015.
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Abstract. Global climate change has received much attention worldwide in the scientific as well as in the political community, indicating that changes in precipitation, extreme droughts and floods may increasingly threaten many regions. Drought is a natural phenomenon that causes social, economical and environmental damage to society. In this study, we assess the drought intensity and severity and the groundwater potential to be used as a supplementary source of water to mitigate drought impacts in the Crocodile River catchment, a water-stressed sub-catchment of the Incomati River catchment in South Africa. The research methodology consists of three parts. First, the spatial and temporal variation of the meteorological and hydrological drought severity and intensity over the catchment were evaluated. The Standardized Precipitation Index (SPI) was used to analyse the meteorological drought and the Standardized Runoff Index (SRI) was used for the hydrological drought. Second, the water deficit in the catchment during the drought period was computed using a simple water balance method. Finally, a groundwater model was constructed in order to assess the feasibility of using groundwater as an emergency source for drought impact mitigation. Results show that the low-rainfall areas are more vulnerable to severe meteorological droughts (lower and upper crocodile). Moreover, the most water stressed sub-catchments with high level of water uses but limited storage, such as the Kaap located in the middle catchment and the Lower Crocodile sub-catchments, are more vulnerable to severe hydrological droughts. The analysis of the potential groundwater use during droughts showed that a deficit of 97 Mm3 yr−1 could be supplied from groundwater without considerable adverse impacts on the river base flow and groundwater storage. Abstraction simulations for different scenarios of extremely severe droughts reveal that it is possible to use groundwater to cope with the droughts in the catchment. However, local groundwater exploitation in Nelspruit and White River sub-catchment will cause large drawdowns (> 10 m) and high base flow reduction (> 20%). This case study shows that conjunctive water management of groundwater and surface water resources is necessary to mitigate the impacts of droughts.
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Mussá, F. E. F., Y. Zhou, S. Maskey, I. Masih, and S. Uhlenbrook. "Groundwater as an emergency source for drought mitigation in the Crocodile River catchment, South Africa." Hydrology and Earth System Sciences Discussions 11, no. 3 (March 6, 2014): 2719–57. http://dx.doi.org/10.5194/hessd-11-2719-2014.
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Abstract. Global climate change has received much attention worldwide in the scientific as well as in the political community, indicating that changes in precipitation, extreme droughts and floods may threaten increasingly many regions. Drought is a natural phenomenon that may cause social, economical and environmental damages to the society. In this study, we assess the drought intensity and severity and the groundwater potential to be used as a supplement source of water to mitigate drought impacts in the Crocodile River catchment, a water-stressed sub-catchment of the Incomati River catchment in South Africa. The research methodology consists mainly of three parts. First, the spatial and temporal variation of the meteorological and hydrological drought severity and intensity over the catchment were evaluated. The Standardized Precipitation Index (SPI) was used to analyse the meteorological drought and the Standardized Runoff Index (SRI) was used for the hydrological drought. Second, the water deficit in the catchment during the drought period was computed using a simple water balance method. Finally, a groundwater model was constructed in order to assess the feasibility of using groundwater as an emergency source for drought impact mitigation. Results show that the meteorological drought severity varies accordingly with the precipitation; the low rainfall areas are more vulnerable to severe meteorological droughts (lower and upper crocodile). Moreover, the most water stressed sub-catchments with high level of water uses but limited storage, such as the Kaap located in the middle catchment and the Lower Crocodile sub-catchments are those which are more vulnerable to severe hydrological droughts. The analysis of the potential groundwater use during droughts showed that a deficit of 97 Mm3 yr−1 could be supplied from groundwater without considerable adverse impacts on the river base flow and groundwater storage. Abstraction simulations for different scenarios of extremely severe droughts reveal that it is possible to use groundwater to cope with the droughts in the catchment. However, local groundwater exploitation in Nelspruit and White River sub-catchment will cause large drawdowns (> 10 m) and high base flow reduction (> 20%). This case study shows that conjunctive water management of groundwater and surface water resources is the necessary to mitigate the impacts of droughts.
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Marais, S. S., E. J. Ncube, T. A. M. Msagati, B. B. Mamba, and T. I. Nkambule. "Investigation of natural organic matter (NOM) character and its removal in a chlorinated and chloraminated system at Rand Water, South Africa." Water Supply 17, no. 5 (March 9, 2017): 1287–97. http://dx.doi.org/10.2166/ws.2017.028.
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In its natural environment, natural organic matter (NOM) is not problematic. However, during water treatment NOM does affect water quality specifically during the disinfection step, where if NOM is present it reacts with disinfectants resulting in the formation of disinfection by-products. To emphasize the importance of NOM monitoring during potable water treatment this study aimed to characterize NOM and evaluate NOM removal by a conventional water treatment plant considering seasonal trends. NOM was characterized by making use of NOM polarity and specific ultraviolet absorbance. NOM removal was monitored with high-performance size exclusion chromatography, dissolved organic carbon (DOC) and UV254 analyses. The polarity rapid assessment method indicated that the hydrophobic and hydrophilic NOM fractions within the surface water increased during a period of heavy rain when floods occurred, but conversely decreased during an average rain season. Although NOM character showed variability during the 5-year study period, seasonal relationship during high and low flow seasons between aromatic NOM and total trihalomethane (TTHM) formation was not evident. Aromatic NOM was not the only precursor to TTHM formation, which stresses the need to implement advanced NOM characterization techniques during NOM monitoring to study reactivity of the individual NOM fraction with the disinfectant used at the water treatment plant.
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Insua-Costa, Damián, Gonzalo Miguez-Macho, and María Carmen Llasat. "Local and remote moisture sources for extreme precipitation: a study of the two catastrophic 1982 western Mediterranean episodes." Hydrology and Earth System Sciences 23, no. 9 (September 24, 2019): 3885–900. http://dx.doi.org/10.5194/hess-23-3885-2019.
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Abstract. Floods and flash floods are frequent in the south of Europe resulting from heavy rainfall events that often produce more than 200 mm in less than 24 h. Even though the meteorological conditions favourable for these situations have been widely studied, there is a lingering question that still arises: what humidity sources could explain so much precipitation? To answer this question, the regional atmospheric Weather Research and Forecasting (WRF) model with a recently implemented moisture tagging capability has been used to analyse the main moisture sources for two catastrophic flood events that occurred during the autumn of 1982 (October and November) in the western Mediterranean area, which is regularly affected by these types of adverse weather episodes. The procedure consists in selecting a priori potential moisture source regions for the extreme event under consideration, and then performing simulations using the tagging technique to quantify the relative contribution of each selected source to total precipitation. For these events we study the influence of four possible potential sources: (1) evaporation in the western Mediterranean; (2) evaporation in the central Mediterranean; (3) evaporation in the North Atlantic; and (4) advection from the tropical and subtropical Atlantic and Africa. Results show that these four moisture sources explain most of the accumulated precipitation, with the tropical and subtropical input being the most relevant in both cases. In the October event, evaporation in the western and central Mediterranean and in the North Atlantic also had an important contribution. However, in the November episode tropical and subtropical moisture accounted for more than half of the total accumulated rainfall, while evaporation in the western Mediterranean and North Atlantic played a secondary role and the contribution of the central Mediterranean was almost negligible. Therefore, remote sources were crucial: in the October event they played a similar role to local sources, whereas in the November case they were clearly dominant. In both episodes, long-distance moisture transport from the tropics and subtropics mostly occurred in mid-tropospheric layers, via well-defined moisture plumes with maximum mixing ratios at medium levels.
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Otim, Daniel, Jeffrey Colin Smithers, Aidan Senzanje, and Rianto van Antwerpen. "Investigation of System Design Criteria and the Capital Cost of Varying Design Return Periods for Soil and Water Conservation Structures." Applied Engineering in Agriculture 36, no. 4 (2020): 511–23. http://dx.doi.org/10.13031/aea.13714.
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Highlights Very few sediment yield events contribute to annual sediment yield. Any rainfall, runoff, and peak discharge event has the potential to generate the most extreme sediment yield event. Twenty year return period recommended for design of conservation structures. Abstract . Design of conservation structures includes both hydrologic and hydraulic designs. Hydrologic design involves estimation of design floods which are required for the sizing of the hydraulic structures. The minimum recommended return period for the design of conservation structures is 10 years but due to the projected levels of risk, and the fact that a few large events are likely to be responsible for the majority of the erosion, the 10-year return period currently recommended may be inadequate. This study investigated system design criteria and the capital cost of varying design return periods for soil and water conservation structures in the sugar industry of South Africa. Observed rainfall data and results of runoff, peak discharge and sediment yield simulated using the Agricultural Catchments Research Unit (ACRU) model were utilized in this study. Relationships between extreme events of sediment yield and the rainfall, runoff and peak discharge events associated with them were analyzed and the capital cost of varying design return periods was also investigated. The results showed that only 0.2% of sediment yield events contributed up to 95% of the annual sediment yield simulated in the sugar production areas in South Africa and that any event of rainfall, runoff and peak discharge had the potential to generate an extreme sediment yield event provided the soil surface was not adequately protected. Based on a sustainable soil loss of 5 t ha-1, the 20-year return period was recommended for the design of soil and water conservation structures. Furthermore, the capital cost implication of varying design return periods from the minimum 10-year return period ranged from an increase of 16% to 35% across the sugar industry. Therefore, given that soil erosion is associated with adverse effects on sustainable crop production and also increases in costs of replanting destroyed crops, the 20-year return period is recommended for the design of soil and water conservation structures in the sugar industry in South Africa. Keywords: Capital cost, Design criteria, Erosion, Return perioW, Risk, Soil and water conservation.
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Huntjens, Patrick, C. Pahl-Wostl, X. Jun, J. Camkin, and N. Kranz. "Comparison of the processes for developing climate change adaptation strategies for dealing with floods and droughts in the Netherlands, South Africa, China and Australia." IOP Conference Series: Earth and Environmental Science 6, no. 29 (February 1, 2009): 292013. http://dx.doi.org/10.1088/1755-1307/6/29/292013.
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Calder, I. R. "Forests and water - closing the gap between public and science perceptions." Water Science and Technology 49, no. 7 (April 1, 2004): 39–53. http://dx.doi.org/10.2166/wst.2004.0411.
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The public perception that forests are, in all circumstances, necessarily good for the water environment, that they increase rainfall, increase runoff, regulate flows, reduce erosion, reduce floods, “sterilize” water supplies and improve water quality, has long been questioned by the scientific community. The evolving “modern” science perception suggests a more complex and generally less advantageous view of forests. It is suggested that the disparity between the two perceptions needs to be addressed before we are in a position to devise and develop land and water policies which are aimed at either improving the water environment, and by doing so improving the livelihoods of poor people by greater access to water, or conserving and protecting forests. Examples are given of “interactive” research projects in different parts of the world including the UK, South Africa, Panama and India where, through the involvement of stakeholder groups, often with representatives comprising both the science and public perceptions, research programmes have been designed and are being implemented, not only to derive new research findings with regard to the biophysical processes, but also to achieve better “ownership” and acceptance of these research findings by the stakeholder groups.
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Cupido, Kim, and Jean-Paul Van Belle. "A Digitally Enabled Strategic Sourcing Process to Mitigate Risk." Journal of Information Technology Education: Discussion Cases 6 (2017): 08. http://dx.doi.org/10.28945/3924.
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A South African insurance company is considering how to automate the process of handling home insurance repair claims in order to make the process more efficient and improve the customer experience. Should they stick with the status quo, develop their own system, purchase existing technology or employ a hybrid solution? ABC Insurance was a leading short-term insurer in South Africa. The FSB (Financial Services Board) of South Africa defined short term insurance cover as indemnification secured by the insurance purchaser over their fixed and movable assets (FSB, n.d.). Such insurable assets could be one’s home (the actual building) or motor vehicle (https://www.fsb.co.za). The purchased insurance cover protected the policyholder (customer) against total loss or accidental damage, as a result of insurable events like fires or floods. In exchange, payment for insurance cover (referred to as the “premium”), was collected by the insurance company from its customers. Andrew Cohen, commodity manager for the Non-Automobile Property and Casualty procurement division at ABC Insurance, was faced with the choice of either digitizing the day to day claims fulfillment procedures within his portfolio, or to continue his business unit’s activities “as is.” The main function of Cohen’s business unit was to ensure that home owners (policyholders) who purchased insurance cover over their fixed assets (i.e., buildings insurance) could access and receive the required repair services as per the provisions set out in their insurance policies. In delivering these services to the policyholders, Cohen’s immediate challenges were that he had to increase efficiency within the claims environment, meet customer demand and enhance operational processes while concurrently accelerating daily business operations. In opposition to maintaining the status quo, his options were to either build an in-house solution, or purchase an existing tool and customize it to his organization’s requirements. His preliminary cost benefit analysis showed that choosing to remain “as is” would cost the firm nothing in terms of immediate cash outflows, but in the long term would expose management to the risk of not capitalizing on opportunities to service their customers quickly and efficiently, infuse transparency into the appointment procedure of suppliers on repair claims, and gain line of sight of interactions between the firm, its service providers, and its customers. He furthermore surmised that whatever the solution was it might require the firm to make initial investments of time for the re-organization of internal processes and new information technology competencies to acquire. To select an ideal solution, he would need to weigh the risks of remaining “as is” against the benefits of infusing mobile technology such as a mobile app into his portfolio, and ultimately, into the core day-to-day operations of the firm as well.
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de Coning, E., and E. R. Poolman. "South African Weather Service operational satellite based precipitation estimation technique: applications and improvements." Hydrology and Earth System Sciences Discussions 7, no. 6 (November 12, 2010): 8837–71. http://dx.doi.org/10.5194/hessd-7-8837-2010.
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Abstract. Extreme weather related to heavy or more frequent precipitation events seem to be a likely possibility for the future of our planet. While precipitation measurements can be done by means of rain gauges, the obvious disadvantages of point measurements are driving meteorologists towards remotely sensed precipitation methods. In South Africa more sophisticated and expensive nowcasting technology such as radar and lightning networks are available, supported by a fairly dense rain gauge network of about 1500 gauges. In the rest of southern Africa rainfall measurements are more difficult to obtain. The availability of the local version of the Unified Model and the Meteosat Second Generation satellite data make these products ideal components of precipitation measurement in data sparse regions such as Africa. In this article the local version of the Hydroestimator (originally from NOAA/NESDIS) is discussed as well as its applications for precipitation measurement in this region. Hourly accumulations of the Hydroestimator are currently used as a satellite based precipitation estimator for the South African Flash Flood Guidance system. However, the Hydroestimator is by no means a perfect representation of the real rainfall. In this study the Hydroestimator and the stratiform rainfall field from the Unified Model are both bias corrected and then combined into a new precipitation field which can feed into the South African Flash Flood Guidance system. This new product should provide a more accurate and comprehensive input to the Flash Flood Guidance systems in South Africa as well as southern Africa. In this way the southern African region where data is sparse and very few radars are available can have access to more accurate flash flood guidance.
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Van Loon, Anne F., Imogen Lester-Moseley, Melanie Rohse, Phil Jones, and Rosie Day. "Creative practice as a tool to build resilience to natural hazards in the Global South." Geoscience Communication 3, no. 2 (December 23, 2020): 453–74. http://dx.doi.org/10.5194/gc-3-453-2020.
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Abstract. Global South communities are increasingly exposed and vulnerable to natural hazards such as floods and droughts. Preparing for future hazards requires developing an idea of an uncertain future, thinking out of the box for possible solutions, enhancing communication between diverse groups, and instigating organisational and behavioural change. In this study, we explore whether art and creativity could support this process by presenting the results of a literature-mapping exercise and a case study. Our search for journal articles, focusing on Global South communities and topics like environmental issues, hazards, and health, yielded 267 papers published between 2000 and 2018. These used a diversity of art forms, including photography and other forms of visual art, music and song, and drama and storytelling. We found that papers on the topic of climate change generally had lower co-creation (62 % medium to high) than those on health (90 % medium to high). A subset of seven papers focusing on drought and flooding fell into the following two categories: those aiming to raise the general public's awareness of these hazards and those aiming to instigate adaptation action by the participants. In our case study, we explored the middle ground between these categories. In a pilot project in South Africa, we designed storytelling workshops in which community members explored scientific data on future droughts, exchanged ideas between groups, and developed narratives about the impacts of and preparedness for future drought. These narratives were filmed and edited and shared both with the community and with governance actors. We found that this approach allowed participants to imagine future droughts, opened up conversations about potential adaptation measures, encouraged intergenerational exchange, and increased awareness of local issues for policy makers. Both in the wider literature and in our case study, the long-term effects of creative interventions are rarely evaluated. Feedback from participants, however, indicates a number of short-term benefits, which shows the potential of combining creative practice approaches and more conventional approaches into a more holistic preparation for future natural hazards.
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Reyers, Belinda, Jeanne L. Nel, Patrick J. O’Farrell, Nadia Sitas, and Deon C. Nel. "Navigating complexity through knowledge coproduction: Mainstreaming ecosystem services into disaster risk reduction." Proceedings of the National Academy of Sciences 112, no. 24 (June 16, 2015): 7362–68. http://dx.doi.org/10.1073/pnas.1414374112.
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Achieving the policy and practice shifts needed to secure ecosystem services is hampered by the inherent complexities of ecosystem services and their management. Methods for the participatory production and exchange of knowledge offer an avenue to navigate this complexity together with the beneficiaries and managers of ecosystem services. We develop and apply a knowledge coproduction approach based on social–ecological systems research and assess its utility in generating shared knowledge and action for ecosystem services. The approach was piloted in South Africa across four case studies aimed at reducing the risk of disasters associated with floods, wildfires, storm waves, and droughts. Different configurations of stakeholders (knowledge brokers, assessment teams, implementers, and bridging agents) were involved in collaboratively designing each study, generating and exchanging knowledge, and planning for implementation. The approach proved useful in the development of shared knowledge on the sizable contribution of ecosystem services to disaster risk reduction. This knowledge was used by stakeholders to design and implement several actions to enhance ecosystem services, including new investments in ecosystem restoration, institutional changes in the private and public sector, and innovative partnerships of science, practice, and policy. By bringing together multiple disciplines, sectors, and stakeholders to jointly produce the knowledge needed to understand and manage a complex system, knowledge coproduction approaches offer an effective avenue for the improved integration of ecosystem services into decision making.
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Lavery, Charne. "Antarctica and Africa: Narrating alternate futures." Polar Record 55, no. 5 (September 2019): 347–50. http://dx.doi.org/10.1017/s0032247419000743.
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AbstractAfrica has been marginalised in the history of Antarctica, a politics of exclusion (with the exception of Apartheid South Africa) reflected unsurprisingly by a dearth of imaginative, cultural and literary engagement. But, in addition to paleontological and geophysical links, Antarctica has increasing interrelationship with Africa’s climactic future. Africa is widely predicted to be the continent worst affected by climate change, and Antarctica and its surrounding Southern Ocean are uniquely implicated as crucial mediators for changing global climate and currents, rainfall patterns, and sea level rise. This paper proposes that there are in fact several ways of imagining the far South from Africa in literary and cultural terms. One is to read against the grain for southern-directed perspectives in existing African literature and the arts, from southern coastlines looking south; another is to reexamine both familiar and new, speculative narratives of African weather – drought, flood and change – for their Antarctic entanglements. In the context of ongoing work on postcolonial Antarctica and calls to decolonise Antarctic studies – such readings can begin to bridge the Antarctica–Africa divide.
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Lashkari, Hassan, Neda Esfandiari, and Abbas Kashani. "Identification and Synoptic Analysis of the Highest Precipitation Linked to Ars in Iran." European Journal of Geosciences 3, no. 2 (March 10, 2021): 20–32. http://dx.doi.org/10.34154/2021-ejcc-0020/euraass.
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Atmospheric rivers are long, narrow, concentrated structures of water vapour that are highly associated with rainfall and floods. To identify and introduce the highest rainfall occurring during the presence of atmospheric rivers from November to April (2007-2018) while showing the importance of this phenomenon in creating super heavy rainfall and introducing the areas affected by it, analyzed the synoptic factors affecting them slowly. In order to identify atmospheric rivers, vertical integral data of water vapour flow were used and thresholds were documented on them. The date of occurrence of each atmospheric river with their daily rainfall was examined and ten of the highest rainfall events Station (equivalent to the 95th percentile of maximum rainfall) related to atmospheric rivers was introduced and analyzed. It is found that the South Gram has been directly and indirectly the main source of atmospheric rivers associated with heavy rainfall. The source of most of these atmospheric rivers is at the peak of the Red Sea, the Gulf of Aden and the Horn of Africa. Synonymously, the origins of 7 cases from Atmospheric rivers have been of the Sudanese low pressure and in the remaining three cases have been integrated systems. In Sudanese systems, the predominant structure of the meridional inclination jet and in Integration systems has been oriented. Due to the dominance of a strong upstream current in the vicinity of the highest flux, moisture of heavy convective currents has caused super heavy rainfall and the station with the highest rainfall in the east and North West of the negative omega field or upstream streams.
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de Coning, E., and E. Poolman. "South African Weather Service operational satellite based precipitation estimation technique: applications and improvements." Hydrology and Earth System Sciences 15, no. 4 (April 6, 2011): 1131–45. http://dx.doi.org/10.5194/hess-15-1131-2011.
Full textAbstract:
Abstract. Extreme weather related to heavy or more frequent precipitation events seem to be a likely possibility for the future of our planet. While precipitation measurements can be done by means of rain gauges, the obvious disadvantages of point measurements are driving meteorologists towards remotely sensed precipitation methods. In South Africa more sophisticated and expensive nowcasting technology such as radar and lightning networks are available, supported by a fairly dense rain gauge network of about 1500 daily gauges. In the rest of southern Africa rainfall measurements are more difficult to obtain. The local version of the Unified Model and the Meteosat Second Generation satellite data are ideal components of precipitation estimation in data sparse regions such as Africa. In South Africa hourly accumulations of the Hydroestimator (originally from NOAA/NESDIS) are currently used as a satellite based precipitation estimator for the South African Flash Flood Guidance system, especially in regions which are not covered by radar. In this study the Hydroestimator and the stratiform rainfall field from the Unified Model are both bias corrected and then combined into a new precipitation field. The new product was tested over a two year period and provides a more accurate and comprehensive input to the Flash Flood Guidance systems in the data sparse southern Africa. Future work will include updating the period over which bias corrections were calculated.
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Van der Westhuizen, G. C. A., and A. Eicker. "The mushrooms of Pretoria and surroundings." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 7, no. 1 (March 17, 1988): 15–25. http://dx.doi.org/10.4102/satnt.v7i1.894.
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As a result of an increasing interest in mushrooms and demand for information on South African species, a list is provided of 106 species of the Order Agaricales, excluding the Polyporaceae, that have been recorded to date in the municipal areas of Pretoria, Pretoria North and Verwoerdburg. Twenty of the most common species are briefly described and illustrated. The occurence of mushrooms in this area is compared with their occurrence and distribution in other regions of South Africa. It is hoped that this information may serve as a basis for similar studies of the mushroom floras of other regions in order to extend the knowledge of the mushroom flora of South Africa.
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Adler, Glenn. "Shop Floors and Rugby Fields: The Social Basis of Auto Worker Solidarity in South Africa." International Labor and Working-Class History 51 (April 1997): 96–128. http://dx.doi.org/10.1017/s0147547900002003.
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When 4,000 black workers at Volkswagen South Africa went on strike on the morning of June 16, 1980, their walkout and march through Uitenhage—twenty-five kilometers inland from the Indian Ocean city of Port Elizabeth—did far more than disturb the streets of a conservative industrial town. The Workers struct after an impasse in negotiations between the automobile companies and their union, the National Union of Motor Assembly and Rubber Workers of South Africa (NUMARWOSA) over the union's demand for a “living wage.” Within days the entire town was engulfed in a general strike. The South African Police declared Uitenhage a “security area,” effectively cutting it off from the outside world. The other strikes soon ended or were repressed, most fiercely at the American multinational Goodyear, where the work force was dismissed and then selectively reemployed under police guard. However, Volkswagen workers continued their action for more than three weeks before winning awage increase and returning to work with their jobs intact and their union strengthened (Plates 1, 2, 3).
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Reid, Richard. "Images of an African Ruler: Kabaka Mutesa of Buganda, ca. 1857–1884." History in Africa 26 (January 1999): 269–98. http://dx.doi.org/10.2307/3172144.
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There can be few areas of the world which have been more systematically misrepresented than Africa, especially that part of the continent south of the Sahara. For centuries, and certainly since the Midas-like Mansa Musa sat astride West Africa on the maps of fourteenth-century Spain, the weird and wonderful imagery of Africa has flooded Europe's vision of that continent. Much of this imagery has been generated by Europeans, and even where it has been generated by Africans themselves, the original meaning and intention is often difficult to discover. The imagery has, to the non-African world, become Africa; this is the case to the point where, at the end of the twentieth century, almost every adjective placed before the name “Africa” is loaded, has some ideological or political currency, and indeed has a history of its own.Most famously, perhaps, Africa was for a long time “dark”, and still that image periodically appears in assorted Western media, a comforting crutch to an audience which remains somewhat confused as to what to make of the continent. Africa is often supposed to have a “heart,” in a way that neither Europe nor North America does. This is perhaps related to the continent's geographical shape, for it is rather more self-contained than Europe, Asia, or the Americas. It is more likely, however, that an African “heart” is sought precisely because it cannot, using the clumsy surgical tools of Western culture, be found. In more recent times, Africa's “dark heart” has been replaced by its “troubled heart;” but the idea remains unchanged.
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GEWALD, JAN-BART. "NEAR DEATH IN THE STREETS OF KARIBIB: FAMINE, MIGRANT LABOUR AND THE COMING OF OVAMBO TO CENTRAL NAMIBIA." Journal of African History 44, no. 2 (July 2003): 211–39. http://dx.doi.org/10.1017/s0021853702008381.
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Namibian politics and society are today dominated by people who trace their descent from the settlements and homesteads of Ovamboland in southern Angola and northern Namibia. Yet, prior to 1915, and the defeat by South Africa of the German colonial army in German South-West Africa, very few Ovambo had settled in areas to the south of the Etosha Pan. In 1915, a Portuguese expeditionary army defeated Kwanyama forces in southern Angola, and unleashed a flood of refugees into northern Namibia. These refugees entered an area that was already overstretched. Since 1912 the rains had failed and, on account of the First World War, trade and migration had come to a standstill. As a result the area was experiencing its most devastating famine ever. Unable to find sanctuary in Ovamboland, thousands of people trekked southwards into central Namibia, an area which had only just come under the control of South Africa. The famine allowed for the easy entrance of South African military administrators and labour recruiters into Ovamboland and heralded the demise of Ovambo independence. By focusing on developments in the central Namibian town of Karibib between 1915 to 1916, the article explores the move of the Ovambo into central and southern Namibia. It traces the impact of war and drought on Ovambo societies, and follows Ovambo famine migrants on their route south into areas administered by the South African military administration. Discussion also concentrates on the reception and treatment of Ovambo famine migrants in the Karibib settlement, and argues that the refugee crisis heralded the establishment of Ovambo in modern central and southern Namibia.
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Camacho, V. V., A. M. L. Saraiva Okello, J. W. Wenninger, and S. Uhlenbrook. "Understanding runoff processes in a semi-arid environment through isotope and hydrochemical hydrograph separations." Hydrology and Earth System Sciences Discussions 12, no. 1 (January 22, 2015): 975–1015. http://dx.doi.org/10.5194/hessd-12-975-2015.
Full textAbstract:
Abstract. The understanding of runoff generation mechanisms is crucial for the sustainable management of river basins such as the allocation of water resources or the prediction of floods and droughts. However, identifying the mechanisms of runoff generation has been a challenging task, even more so in arid and semi-arid areas where high rainfall and streamflow variability, high evaporation rates, and deep groundwater reservoirs increase the complexity of hydrological process dynamics. Isotope and hydrochemical tracers have proven to be useful in identifying runoff components and their characteristics. Moreover, although widely used in humid-temperate regions, isotope hydrograph separations have not been studied in detail in arid and semi-arid areas. Thus the purpose of this study is to determine if isotope hydrograph separations are suitable for the quantification and characterization of runoff components in a semi-arid catchment considering the hydrological complexities of these regions. Through a hydrochemical characterization of the surface water and groundwater sources of the catchment and two and three component hydrograph separations, runoff components of the Kaap Catchment in South Africa were quantified using both, isotope and hydrochemical tracers. No major disadvantages while using isotope tracers over hydrochemical tracers were found. Hydrograph separation results showed that runoff in the Kaap catchment is mainly generated by groundwater sources. Two-component hydrograph separations revealed groundwater contributions between 64 and 98% of total runoff. By means of three-component hydrograph separations, runoff components were further separated into direct runoff, shallow and deep groundwater components. Direct runoff, defined as the direct precipitation on the stream channel and overland flow, contributed up to 41% of total runoff during wet catchment conditions. Shallow groundwater defined as the soil water and near-surface water component, contributed up to 45% of total runoff, and deep groundwater contributed up to 84% of total runoff. A strong correlation for the four studied events was found between the antecedent precipitation conditions and direct runoff. These findings suggest that direct runoff is enhanced by wetter conditions in the catchment which trigger saturation excess overland flow as observed in the hydrograph separations.
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Alexander, William J. R., and William J. R. Emeritus. "Linkages between Solar Activity and Climatic Responses." Energy & Environment 16, no. 2 (March 2005): 239–53. http://dx.doi.org/10.1260/0958305053749462.
Full textAbstract:
Statistically significant 21-year periodicity is present concurrently in South African annual rainfall, river flow, flood peak maxima, groundwater levels, lake levels and the Southern Oscillation Index. This is directly related to the double sunspot cycle. The first years of the periodic sequences are characterised by sudden, regular and therefore predictable, reversals from sequences of well below average rainfall and river flow (droughts) that are suddenly broken by sequences of well above average events (floods). These reversals are directly related to corresponding six-fold increases in sunspot activity at this time. The two sunspot cycles that comprise the double sunspot cycle also have fundamentally different effects on the hydrometeorological responses. These observations are solidly based and will require a re-assessment of the nature of the solar activity that gives rise to them.
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Bell, Gerald D., and Michael S. Halpert. "Climate Assessment for 1997." Bulletin of the American Meteorological Society 79, no. 5s (May 1, 1998): S1—S50. http://dx.doi.org/10.1175/1520-0477-79.5s.s1.
Full textAbstract:
The global climate during 1997 was affected by both extremes of the El Niño-Southern Oscillation (ENSO), with weak Pacific cold episode conditions prevailing during January and February, and one of the strongest Pacific warm episodes (El Niño) in the historical record prevailing during the remainder of the year. This warm episode contributed to major regional rainfall and temperature anomalies over large portions of the Tropics and extratropics, which were generally consistent with those observed during past warm episodes. In many regions, these anomalies were opposite to those observed during 1996 and early 1997 in association with Pacific cold episode conditions. Some of the most dramatic El Niño impacts during 1997 were observed in the Tropics, where anomalous convection was evident across the entire Pacific and throughout most major monsoon regions of the world. Tropical regions most affected by excessive El Niño–related rainfall during the year included 1) the eastern half of the tropical Pacific, where extremely heavy rainfall and strong convective activity covered the region from April through December; 2) equatorial eastern Africa, where excessive rainfall during October–December led to widespread flooding and massive property damage; 3) Chile, where a highly amplified and extended South Pacific jet stream brought increased storminess and above-normal rainfall during the winter and spring; 4) southeastern South America, where these same storms produced above-normal rainfall during June–December; and 5) Ecuador and northern Peru, which began receiving excessive rainfall totals in November and December as deep tropical convection spread eastward across the extreme eastern Pacific. In contrast, El Niño-–elated rainfall deficits during 1997 included 1) Indonesia, where significantly below-normal rainfall from June through December resulted in extreme drought and contributed to uncontrolled wildfires; 2) New Guinea, where drought contributed to large-scale food shortages leading to an outbreak of malnutrition; 3) the Amazon Basin, which received below-normal rainfall during June–December in association with substantially reduced tropical convection throughout the region; 4) the tropical Atlantic, which experienced drier than normal conditions during July–December; and 5) central America and the Caribbean Sea, which experienced below-normal rainfall during March–December. The El Niño also contributed to a decrease in tropical storm and hurricane activity over the North Atlantic during August–November, and to an expanded area of conditions favorable for tropical cyclone and hurricane formation over the eastern North Pacific. These conditions are in marked contrast to both the 1995 and 1996 hurricane seasons, in which significantly above-normal tropical cyclone activity was observed over the North Atlantic and suppressed activity prevailed across the eastern North Pacific. Other regional aspects of the short-term climate during 1997 included 1) wetter than average 1996/97 rainy seasons in both northeastern Australia and southern Africa in association with a continuation of weak cold episode conditions into early 1997; 2) below-normal rainfall and drought in southeastern Australia from October 1996 to December 1997 following very wet conditions in this region during most of 1996; 3) widespread flooding in the Red River Valley of the north-central United States during April following an abnormally cold and snowy winter; 4) floods in central Europe during July following several consecutive months of above-normal rainfall; 5) near-record to record rainfall in southeastern Asia during June–August in association with an abnormally weak upper-level monsoon ridge; and 6) near-normal rainfall across India during the Indian monsoon season (June–September) despite the weakened monsoon ridge.
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Tsampiras, Carla. "Two Tales about Illness, Ideologies, and Intimate Identities: Sexuality Politics and AIDS in South Africa, 1980–95." Medical History 58, no. 2 (April 2014): 230–56. http://dx.doi.org/10.1017/mdh.2014.7.
Full textAbstract:
AbstractThis article focuses on the micro-narratives of two individuals whose responses to AIDS were mediated by their sexual identity, AIDS activism and the political context of South Africa during a time of transition. Their experiences were also mediated by well-established metanarratives about AIDS and ‘homosexuality’ created in the USA and the UK which were transplanted and reinforced (with local variations) into South Africa by medico-scientific and political leaders.The nascent process of writing South African AIDS histories provides the opportunity to record responses to AIDS at institutional level, reveal the connections between narratives about AIDS and those responses, and draw on the personal stories of those who were at the nexus of impersonal official responses and the personal politics of AIDS. This article records the experiences of Dennis Sifris, a physician who helped establish one of the first AIDS clinics in South Africa and emptied the dance floors, and Pierre Brouard, a clinical psychologist who was involved in early counselling, support and education initiatives for HIV-positive people, and counselled people about dying, and then about living. Their stories show how, even within government-aligned health care spaces hostile to gay men, they were able to provide support and treatment to people; benefited from international connections with other gay communities; and engaged in socially subversive activities. These oral histories thus provide otherwise hidden insights into the experiences of some gay men at the start of an epidemic that was initially almost exclusively constructed on, and about, gay men’s bodies.
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Camacho Suarez, V. V., A. M. L. Saraiva Okello, J. W. Wenninger, and S. Uhlenbrook. "Understanding runoff processes in a semi-arid environment through isotope and hydrochemical hydrograph separations." Hydrology and Earth System Sciences 19, no. 10 (October 20, 2015): 4183–99. http://dx.doi.org/10.5194/hess-19-4183-2015.
Full textAbstract:
Abstract. The understanding of runoff generation mechanisms is crucial for the sustainable management of river basins such as the allocation of water resources or the prediction of floods and droughts. However, identifying the mechanisms of runoff generation has been a challenging task, even more so in arid and semi-arid areas where high rainfall and streamflow variability, high evaporation rates, and deep groundwater reservoirs may increase the complexity of hydrological process dynamics. Isotope and hydrochemical tracers have proven to be useful in identifying runoff components and their characteristics. Moreover, although widely used in humid temperate regions, isotope hydrograph separations have not been studied in detail in arid and semi-arid areas. Thus the purpose of this study is to determine whether isotope hydrograph separations are suitable for the quantification and characterization of runoff components in a semi-arid catchment considering the hydrological complexities of these regions. Through a hydrochemical characterization of the surface water and groundwater sources of the catchment and two- and three-component hydrograph separations, runoff components of the Kaap catchment in South Africa were quantified using both isotope and hydrochemical tracers. No major disadvantages while using isotope tracers over hydrochemical tracers were found. Hydrograph separation results showed that runoff in the Kaap catchment is mainly generated by groundwater sources. Two-component hydrograph separations revealed groundwater contributions of between 64 and 98 % of total runoff. By means of three-component hydrograph separations, runoff components were further separated into direct runoff, shallow and deep groundwater components. Direct runoff, defined as the direct precipitation on the stream channel and overland flow, contributed up to 41 % of total runoff during wet catchment conditions. Shallow groundwater defined as the soil water and near-surface water component (and potentially surface runoff) contributed up to 45 % of total runoff, and deep groundwater contributed up to 84 % of total runoff. A strong correlation for the four studied events was found between the antecedent precipitation conditions and direct runoff. These findings suggest that direct runoff is enhanced by wetter conditions in the catchment that trigger saturation excess overland flow as observed in the hydrograph separations.