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William, Kevin Hendra, and Kristoko Dwi Hutomo. "The Natural Disaster Prone Index Map Model in Indonesia Using the Thiessen Polygon Method." INTENSIF: Jurnal Ilmiah Penelitian dan Penerapan Teknologi Sistem Informasi 5, no. 2 (2021): 148–60. http://dx.doi.org/10.29407/intensif.v5i2.14612.
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Natural Disasters are natural phenomena that occur at any moment that can cause loss. Indonesia is an archipelagic country located at the meeting of four tectonic plates and volcanic belts. This condition causes Indonesia to be prone to natural disasters. Therefore, it is necessary to make a natural disaster-prone index map model minimize the impact of natural disasters. In this research, the researchers used a Polygon Thiessen method for it was one of the mapping methods to determine a natural disaster based on Indonesia's vast surface and many disasters. The BNPB and Polygon Thiessen data comparison shows that BNPB data has a low level of vulnerability of 302, a moderate level of vulnerability of 148, and a high level of vulnerability of 58. In contrast, the Thiessen polygon has a low level of vulnerability of 297, a moderate vulnerability of 158, and a high vulnerability of 59. Comparing BNPB data and the Thiessen Polygon method found five differences from 40 data in the Papua region. Suggestions for further research to create an application-based information system so that it can be accessed in real-time.
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Akgül, Mehmet Ali, and Hakan Aksu. "Areal Precipitation Estimation Using Satellite Derived Rainfall Data over an Irrigation Area." Turkish Journal of Agriculture - Food Science and Technology 9, no. 2 (2021): 386–94. http://dx.doi.org/10.24925/turjaf.v9i2.386-394.4061.
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The average precipitation on the irrigation field can be estimated from the Meteorology Observation Stations by using spatial interpolation methods such as Thiessen polygon and isohyetal curves. However, the fact that precipitation doesn't occur homogenous in spatial scales, spatial interpolation methodologies need a large number of meteorology stations for more accurate results. In recent years, remote sensing methods have diversified to estimate precipitation. In this study, performance of the satellite-based precipitation data was assessed to determine areal precipitation over an irrigation area. This study was conducted over left bank irrigation area located in the Çukurova Plain of Turkey. Relationship between CHIRPS satellite based on monthly precipitation data and 4 meteorology stations’ data were analyzed. Determination coefficients (R2) of the stations were found between 0.64 and 0.77, for point based comparison, R2 was calculated as 0.84 with Thiessen polygon method. It is concluded that the precipitation amount in the irrigated area can be estimated as accurately as classical methods such as Thiessen polygon with satellite-based precipitation data.
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Wei, Liu, Hai Yan Chen, Li Li, Hai Ming Fu, and Li Wei. "Application of Thiessen Polygon Algorithm in Cellular Network Simulation System." Advanced Materials Research 532-533 (June 2012): 1851–56. http://dx.doi.org/10.4028/www.scientific.net/amr.532-533.1851.
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Cellular mobile communication system divides the service area into several adjacent cells; each cell sets up a base station. In the traditional cellular representation, we always use regular hexagon to represent the cell. In the practical engineering applications and wireless network planning simulation systems, as the programming environment is complex and diverse, using the regular hexagon to represent the cellular network has limitation. This paper used Thiessen polygon and spatial analysis method to describe the cell service area with a polygon. This method intuitively displayed the relationship between the scope of service and its place with each other in space. For the Pre-construction and later optimization of wireless network planning it has a positive role.
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Wang, Shuwei, Lishan Sun, Jian Rong, and Zifan Yang. "Transit Traffic Analysis Zone Delineating Method Based on Thiessen Polygon." Sustainability 6, no. 4 (2014): 1821–32. http://dx.doi.org/10.3390/su6041821.
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Jordan, L. "APPLYING THIESSEN POLYGON CATCHMENT AREAS AND GRIDDED POPULATION WEIGHTS TO ESTIMATE CONFLICT-DRIVEN POPULATION CHANGES IN SOUTH SUDAN." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-4/W2 (October 19, 2017): 23–30. http://dx.doi.org/10.5194/isprs-annals-iv-4-w2-23-2017.
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Recent violence in South Sudan produced significant levels of conflict-driven migration undermining the accuracy and utility of both national and local level population forecasts commonly used in demographic estimates, public health metrics and food security proxies. This article explores the use of Thiessen Polygons and population grids (Gridded Population of the World, WorldPop and LandScan) as weights for estimating the catchment areas for settlement locations that serve large populations of internally displaced persons (IDP), in order to estimate the county-level in- and out-migration attributable to conflict-driven displacement between 2014-2015. Acknowledging IDP totals improves internal population estimates presented by global population databases. Unlike other forecasts, which produce spatially uniform increases in population, accounting for displaced population reveals that 15 percent of counties (<i>n</i> = 12) increased in population over 20 percent, and 30 percent of counties (<i>n</i> = 24) experienced zero or declining population growth, due to internal displacement and refugee out-migration. Adopting Thiessen Polygon catchment zones for internal migration estimation can be applied to other areas with United Nations IDP settlement data, such as Yemen, Somalia, and Nigeria.
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Yang, Guang, and Wei Li Jiao. "An Optimization Method on Ground Control Point Distribution." Advanced Materials Research 268-270 (July 2011): 1092–95. http://dx.doi.org/10.4028/www.scientific.net/amr.268-270.1092.
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With the development of remote sensing, the data quantity of remote sensing image is increasing tremendously. It brings a huge workload to the image geometric correction through manual ground control point (GCP) selection. GCPs automatically selected based on software is one of the effective methods to cut down manual operation. The GCPs obtained from that way is generally redundant. This paper deeply comprehends some existing methods about automatic optimization of GCP, and puts forward a new method of automatic optimization of GCP based on Thiessen Polygon to filter ground control points from the overfull ones without manual subjectivity for better accuracy. Experiments in this paper also demonstrated the relationship between the accuracy of geometric correction and the distribution of GCP. It advances the conception of single GCP’s importance value based on Thiessen Polygon. The paper gives the theory and the flow of automatic optimization of GCPs as well. It also presents an example of the application of this method. In the conclusion, this paper points out the advantages of this method .
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Argamosa, R. J. L., E. C. Paringit, K. R. Quinton, et al. "FULLY AUTOMATED GIS-BASED INDIVIDUAL TREE CROWN DELINEATION BASED ON CURVATURE VALUES FROM A LIDAR DERIVED CANOPY HEIGHT MODEL IN A CONIFEROUS PLANTATION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B8 (June 23, 2016): 563–69. http://dx.doi.org/10.5194/isprsarchives-xli-b8-563-2016.
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The generation of high resolution canopy height model (CHM) from LiDAR makes it possible to delineate individual tree crown by means of a fully-automated method using the CHM’s curvature through its slope. The local maxima are obtained by taking the maximum raster value in a 3 m x 3 m cell. These values are assumed as tree tops and therefore considered as individual trees. Based on the assumptions, thiessen polygons were generated to serve as buffers for the canopy extent. The negative profile curvature is then measured from the slope of the CHM. The results show that the aggregated points from a negative profile curvature raster provide the most realistic crown shape. The absence of field data regarding tree crown dimensions require accurate visual assessment after the appended delineated tree crown polygon was superimposed to the hill shaded CHM.
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Argamosa, R. J. L., E. C. Paringit, K. R. Quinton, et al. "FULLY AUTOMATED GIS-BASED INDIVIDUAL TREE CROWN DELINEATION BASED ON CURVATURE VALUES FROM A LIDAR DERIVED CANOPY HEIGHT MODEL IN A CONIFEROUS PLANTATION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B8 (June 23, 2016): 563–69. http://dx.doi.org/10.5194/isprs-archives-xli-b8-563-2016.
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The generation of high resolution canopy height model (CHM) from LiDAR makes it possible to delineate individual tree crown by means of a fully-automated method using the CHM’s curvature through its slope. The local maxima are obtained by taking the maximum raster value in a 3 m x 3 m cell. These values are assumed as tree tops and therefore considered as individual trees. Based on the assumptions, thiessen polygons were generated to serve as buffers for the canopy extent. The negative profile curvature is then measured from the slope of the CHM. The results show that the aggregated points from a negative profile curvature raster provide the most realistic crown shape. The absence of field data regarding tree crown dimensions require accurate visual assessment after the appended delineated tree crown polygon was superimposed to the hill shaded CHM.
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Lewandowicz, Elżbieta, Przemysław Lisowski, and Paweł Flisek. "A Modified Methodology for Generating Indoor Navigation Models." ISPRS International Journal of Geo-Information 8, no. 2 (2019): 60. http://dx.doi.org/10.3390/ijgi8020060.
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Automatic methods for constructing navigation routes do not fully meet all requirements. The aim of this study was to modify the methodology for generating indoor navigation models based on the Medial Axis Transformation (MAT) algorithm. The simplified method for generating corridor axes relies on the Node-Relation Structure (NRS) methodology. The axis of the modeled structure (corridor) is then determined based on the points of the middle lines intersecting the structure (polygon). The proposed solution involves a modified approach to the segmentation of corridor space. Traditional approaches rely on algorithms for generating Triangulated Irregular Networks (TINs) by Delaunay triangulation or algorithms for generating Thiessen polygons known as Voronoi diagrams (VDs). In this study, both algorithms were used in the segmentation process. The edges of TINs intersected structures. Selected midpoints on TIN edges, which were located in the central part of the structure, were used to generate VDs. Corridor structures were segmented by polygon VDs. The identifiers or structure nodes were the midpoints on the TIN edges rather than the calculated centroids. The generated routes were not zigzag lines, and they approximated natural paths. The main advantage of the proposed solution is its simplicity, which can be attributed to the use of standard tools for processing spatial data in a geographic information system.
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Nganro, Sudirman, Slamet Trisutomo, Roland A. Barkey, and Mukti Ali. "Rainfall Analysis of the Makassar City using Thiessen Polygon Method Based on GIS." Journal of Engineering and Applied Sciences 15, no. 6 (2020): 1426–30. http://dx.doi.org/10.36478/jeasci.2020.1426.1430.
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Tatalovich, Zaria, John P. Wilson, and Myles Cockburn. "A Comparison of Thiessen Polygon, Kriging, and Spline Models of Potential UV Exposure." Cartography and Geographic Information Science 33, no. 3 (2006): 217–31. http://dx.doi.org/10.1559/152304006779077318.
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Joewono, Tri Basuki, and Marco Andrianto. "KAJIAN SPASIAL LOKASI BERBELANJA DI KOTA BANDUNG." Jurnal Transportasi 19, no. 2 (2019): 121–32. http://dx.doi.org/10.26593/jt.v19i2.3480.121-132.
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Abstract Shoppers consider many aspects in choosing specific location from variety of shopping location. Spatial analysis is used to determine the catchment area of shopping location based on the location of shoppers’ residence along with the correlation with shoppers’ activity and characteristic. The purposes of this study are to analyze the catchment area of shopping location in Bandung based on shopper’s preferences and to analyze the shopping travel pattern. The questionnaire data about the grocery shopping trip is analyzed using Thiessen Polygon and Buffering Method. The analysis shows that there is a mismatch between the market service coverage and the preferences of respondent destination. Analysis shows that shoppers will choose the shopping location by considering the distance of shopping location from home, travel costs, and travel duration in selecting any type of shopping location. Keywords: shopping location, spatial analysis, GIS, catchment area, shopping trip characteristics Abstrak Ada banyak hal yang dipertimbangkan oleh pelaku belanja dalam memilih lokasi berbelanja yang beragam. Analisis spasial dipergunakan untuk menjelaskan daerah cakupan lokasi belanja berdasarkan lokasi tempat tinggal serta keterkaitannya dengan aktivitas dan karakteristik pelaku belanja. Tujuan penelitian ini adalah menganalisis daerah cakupan lokasi berbelanja pilihan pelaku belanja di Kota Bandung dan menganalisis pola perjalanan berbelanja. Data hasil penyebaran kuisioner mengenai perjalanan berbelanja kebutuhan sehari-hari dianalisis menggunakan Metode Thiessen Polygon dan Metode Buffer. Hasil analisis menunjukkan bahwa terdapat ketidaksesuaian antara luas cakupan layanan suatu lokasi belanja dengan luas jangkauan layanan lokasi pilihan pelaku belanja. Analisis menunjukkan bahwa pelaku belanja memilih lokasi belanja dengan mempertimbangkan jarak dari tempat tinggal, durasi, dan biaya perjalanan. Kata-kata kunci: lokasi berbelanja, analisis spasial, GIS, daerah cakupan, karakteristik perjalanan berbelanja
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Hartati. "Analisa Karakteristik Dan Distribusi Hujan Pada Kawasan DAS Batang Hari Kabupaten Dharmasraya." Jurnal Ilmiah Poli Rekayasa 14, no. 2 (2019): 15. http://dx.doi.org/10.30630/jipr.14.2.123.
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Batang Hari is the 2nd biggest DAS in Indonesia. About 76% of Batang Hari DAS is located in Jambi Province, the entire 24%is in West Sumatera Province. Batang Hari dam which was built on 1997 is one of infrastrcture at Public Work ministery under management at Balai Wilayah Sungai Sumatera V (BWSS V) his high potential of water stock. Optimum discharge of Batang Hari Dam is about 86 m3/sec. In the recently years DAS Batang Hari has been disturbed by some changes like catchment area utilized fot other purpose, change on global climate done to greenhouse effectwhich causingintensity of rain as well as flood. This climate change then will affected standard for engineering design for making a water control buiding which may injuireaccurate waterfall intensity data. Study of rainfall intensity obtained from 3 (three) nearby stations will show the characteristic dam trend of distribution with reperted period. Cousistency of data using Mass Curve method and local rain analysis to be done by Arithmatic & Thiessen Polygon method. To analysis trend of rainfall distribution. We use : Normal, Log Normal, Log Person type III and Gumbel methods. For complaince test of distribution, we use Chi-Kuadrat and Smirnov-Kolmogorov methods. Refer to result of distribution using Chi-Kuadrat and Smirnov-Kolmogorov methods for Arithmatic methods it is adviced to use Gumbel method to evaluate distribution trend; because critical deviation is smell comparing to available in table, with rainfall with repeating period 2,5,10,25,50 and 100 years are 124,08 mm, 1168,56 mm, 198,01 mm, 235,22 mm, 262,83 mm, 290,23 mm and Thiessen Polygon 106,93 mm, 138,22 mm, 158,94 mm, 185,11 mm, 204,53 mm, 223,81 mm
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Seman, Busiai Bin, and Tarmiji Masron. "HOTSPOT ANALYSIS OF HAND FOOT AND MOUTH DISEASE (HFMD) USING GIS IN KUCHING, SARAWAK, MALAYSIA." Humanities & Social Sciences Reviews 7, no. 2 (2019): 36–44. http://dx.doi.org/10.18510/hssr.2019.725.
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Purpose of the study: The main objective of this study was to identify the hotspot area of HFMD reported cases within two local councils, namely, Kuching North City Council and Kuching South City Council, by using Geographic Information System (GIS) technique.
 Methodology: Two methods, namely, Getis-Ord GI* and Thiessen polygon, were used in this study. Getis-Ord GI* statistics was used to identify the hotspot areas and Thiessen polygon method was used to create an influencing boundary for each village. The analysis was conducted from 2014 to 2018 on the basis of the cases reported and registered with Sarawak Health Department by using ArcGIS Software.
 Main Findings: The hotspot areas were confined to the Western area of Kuching North City Council, which is located at Rampangi Fasa II and Semariang Pinggir villages. Subsequently, in Kuching South City Council, there were two villages were identified as hotspot areas at Kampung Stampin and Kampung Stutong Baru.
 Applications of this study: The findings from this study will help local authorities, public health officers, epidemiologists, and the public to identify the hotspot areas of HFMD occurrences and therefore, the information obtained in this study will be of a great help to them in coming up with the necessary mitigation plan to control this disease before it spreads to other locations.
 Novelty/Originality of this study: Previous studies conducted in Sarawak on HFMD were based on divisional boundaries, which were too broad to be used as a guide for mitigation planning. Therefore, the outcome from this study, which was based on the village boundary, provides more information on the hotspot areas of HFMD at a micro level.
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Pradana, Alvin, and Ratna Septi Hendrasari. "ANALISIS NERACA AIR PADA SUB DAERAH ALIRAN SUNGAI CODE YOGYAKARTA." PROKONS Jurusan Teknik Sipil 15, no. 1 (2021): 8. http://dx.doi.org/10.33795/prokons.v15i1.276.
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Abstract Water is one of the sources of human life. Population growth continues to increase and results in higher utilization of water sources. This will certainly affect the availability of water in the city of Yogyakarta. Water balance is a comparison between the water availability potential and the water demand of a place in a certain period. Water balance analysis is useful for knowing the amount of excess water (surplus) or lack of water (deficit) so that water use can be managed as well as possible. The calculation was done by analyzing the 10-year rainfall data using the Thiessen Polygon method to obtain the mean rainfall value. The available debit was calculated using the F.J. Mock method. The dependable discharge was calculated with 80% reliability from the 10-year debit data. The debit data was sorted from the largest to the smallest value, so that a probability value of 80% was obtained from the interpolation of the data sequence. Water demand was calculated based on the irrigation planning standard (KP-01). The results of the study show that the average water availability in the sub-watershed of Code River Yogyakarta was 527.92lt/sec. Based on the results of the analysis, the highest water deficit occurred in the first October at 278.40 l/sec and the lowest deficit was in the second July at 73.01 l/sec. However, the availability of water in certain months was quite abundant. Therefore, it is necessary to do a special study so that water is not wasted and can be used to cover water shortages in dry months. Keywords: Water balance, Water availability, Water demand, Code river, Thiessen polygon, FJ mock
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Mushtaha, Ashraf M., Marc Van Camp, and Kristine Walraevens. "Quantification of Recharge and Runoff from Rainfall Using New GIS Tool: Example of the Gaza Strip Aquifer." Water 11, no. 1 (2019): 84. http://dx.doi.org/10.3390/w11010084.
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The Gaza Strip forms a transition zone between the semi-humid coastal zone in the north, the semi-arid zone in the east, and the Sinai desert in the south. Groundwater is the only water source for 1.94 million inhabitants, where the only fresh replenishment water for the aquifer comes from rainfall. This study focuses on testing a newly developed GIS tool to estimate the spatial and temporal distribution of runoff and recharge from rainfall. The estimation of surface runoff was made using the Soil Conservation Services Curve Number Method, while groundwater recharge was estimated using Thornthwaite and Mather’s Soil Moisture Balance approach. The new tool was applied to the Gaza aquifer for the year 1935 and for the period from 1973 to 2016. A comparison was made between the results obtained with the developed GIS tool and the frequently used Thiessen polygon method for rainfall distribution. Runoff and recharge were estimated for the year 1935 (prior to development) to compare with the current developed conditions. It was found that the built-up and sand dune areas stand in an inverse relationship, where the former is replacing the latter (built-up area expanded from 30.1 km2 in 1982 to 92.1 km2 in 2010). Recharge takes place in the sand dune area, whereas runoff increases in the built-up area. Due to development, runoff almost tripled from 9 million m3 in 1982 to 22.9 million m3 in 2010, while groundwater recharge was reduced from 27.3 million m3 in 1982 to 23 million m3 in 2010, even though the rainfall increased between 1982 and 2010 by 11%. Comparison between the newly developed GIS tool and the Thiessen polygon-based estimation shows that the former leads to higher values of runoff and recharge for dry years.
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Kiš, Ivana Mesić, та Tomislav Malvić. "The Universal Kriging Mapping of the Neogene EL-markers Rs5 and Δ, Northern Croatia". Materials and Geoenvironment 65, № 4 (2018): 187–98. http://dx.doi.org/10.2478/rmzmag-2018-0022.
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AbstractThe area of the Bjelovar Subdepression in Northern Croatia, which represents the southwestern part of Drava’s depression, has been analysed. More than 700 depth data were collected in a regular grid covering the existing structural maps of e-log markers Rs5, Z’ and Δ, with cells 2 x 2 km in size. For zonal assessment, Thiessen polygon method was used as introductory analysis preceding Kriging interpolation on regional scale. The emphasis was on OK and UK interpolation, their comparison and selection of most appropriate method for mapping. Crossvalidation results proved UK technique to be the most appropriate in mapping of e-log markers Rs5 and Δ, thus acquiring the most accurate maps so far of the analysed Neogene area.
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Shope, Christopher L., and Ganga Ram Maharjan. "Modeling Spatiotemporal Precipitation: Effects of Density, Interpolation, and Land Use Distribution." Advances in Meteorology 2015 (2015): 1–16. http://dx.doi.org/10.1155/2015/174196.
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Characterization of precipitation is critical in quantifying distributed catchment-wide discharge. The gauge network is a key driver in hydrologic modeling to characterize discharge. The accuracy of precipitation is dependent on the location of stations, the density of the network, and the interpolation scheme. Our study examines 16 weather stations in a 64 km2catchment. We develop a weighted, distributed approach for gap-filling the observed meteorological dataset. We analyze five interpolation methods (Thiessen, IDW, nearest neighbor, spline, and ordinary Kriging) at five gauge densities. We utilize precipitation in a SWAT model to estimate discharge in lumped parameter simulations and in a distributed approach at the multiple densities (1, 16, 50, 142, and 300 stations). Gauge density has a substantial impact on distributed discharge and the optimal gauge density is between 50 and 142 stations. Our results also indicate that the IDW interpolation scheme was optimum, although the Kriging and Thiessen polygon methods produced similar results. To further examine variability in discharge, we characterized the land use and soil distribution throughout each of the subbasins. The optimal rain gauge position and distribution of the gauges drastically influence catchment-wide runoff. We found that it is best to locate the gauges near less permeable locations.
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N, Sivakarun, Chidambaram S, Thivya C, et al. "GIS based approach to understand the factors influencing the water level of the coastal aquifers in the ramnad district, Tamilnadu, India." International Journal of Advanced Geosciences 4, no. 2 (2016): 54. http://dx.doi.org/10.14419/ijag.v4i2.6228.
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An attempt has been made in this study to understand the factors influencing the variation in water level of the groundwater of the Ramnad district. The different factors considered for study were average water level, Land use pattern, tanks and rainfall pattern of the study area. The water level contours were spatially plotted for four months interval and their average was considered for comparison. The rainfall trend of the district was obtained by the Thiessen polygon method. Further the Average water level contour was overlaid over the land use, tanks and rainfall distribution maps to understand the spatial influencing factor and it was identified that the agricultural return flow and the tank intensity play a major role in the recharge of the groundwater of this coastal aquifers.
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Ha Trang, N., and N. K. Tripathi. "Spatial Correlation Analysis between Particulate Matter 10 (PM10) Hazard and Respiratory Diseases in Chiang Mai Province, Thailand." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-8 (November 27, 2014): 185–91. http://dx.doi.org/10.5194/isprsarchives-xl-8-185-2014.
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Every year, during dry season, Chiang Mai and other northern provinces of Thailand face the problem of haze which is mainly generated by the burning of agricultural waste and forest fire, contained high percentage of particulate matter. Particulate matter 10 (PM10), being very small in size, can be inhaled easily to the deepest parts of the human lung and throat respiratory functions. Due to this, it increases the risk of respiratory diseases mainly in the case of continuous exposure to this seasonal smog. MODIS aerosol images (MOD04) have been used for four weeks in March 2007 for generating the hazard map by linking to in-situ values of PM10. Simple linear regression model between PM10 and AOD got fair correlation with R<sup>2</sup> = 0.7 and was applied to transform PM10 pattern. The hazard maps showed the dominance of PM10 in northern part of Chiang Mai, especially in second week of March when PM10 level was three to four times higher than standard. The respiratory disease records and public health station of each village were collected from Provincial Public Health Department in Chiang Mai province. There are about 300 public health stations out of 2070 villages; hence thiessen polygon was created to determine the representative area of each public health station. Within each thiessen polygon, respiratory disease incident rate (RDIR) was calculated based on the number of patients and population. Global Moran's I was computed for RDIR to explore spatial pattern of diseases through four weeks of March. Moran's I index depicted a cluster pattern of respiratory diseases in 2nd week than other weeks. That made sense for a relationship between PM10 and respiratory diseases infections. In order to examine how PM10 affect the human respiratory system, geographically weighted regression model was used to observe local correlation coefficient between RDIR and PM10 across study area. The result captured a high correlation between respiratory diseases and high level of PM10 in northeast districts of Chiang Mai in second week of March.
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Ahmad, Mustaffa Anjang, Putera Agung Maha Agung, Muhamad Arif Arsad, and Saiful Azhar Ahmad Tajudin. "Database Development of Site Investigation Using GIS (A Case at Pulau Indah, Klang, Malaysia)." Applied Research on Civil Engineering and Environment (ARCEE) 2, no. 02 (2021): 45–51. http://dx.doi.org/10.32722/arcee.v2i02.3113.
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Site investigation works is very essential in every construction design work. Soil type and shear strength are the important parameter to design foundation system of insfrastructure project. Site investigations are not only costly, but also time consuming. There many geotechnical engineers tend to reduce site investigation works to decrease the construction cost. Based on these problems, the study was developed on site investigation database for Pulau Indah, Klang, Malaysia using Geographical Information System (GIS). Research study applied the Thiessen polygon method to obtain existing some informations type of soil and shear strength on this site. The research result was the database and map information. These data can be used for civil engineers to obtain site informations of soil type and shear strength parameter for future construction work related to the area.
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Nganro, Sudirman, Slamet Trisutomo, Roland Alexander Barkey, Mukti Ali, and Nurjannah Nurdin. "Model Spasial Level Dasar Bangunan Kota Tepian Air (Studi Kasus: Kota Makassar)." TATALOKA 22, no. 3 (2020): 418–27. http://dx.doi.org/10.14710/tataloka.22.3.418-427.
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Flooding is a threat to coastal cities such as Makassar City. To Avoid the threat of flooding, it is necessary to determine the ground level of the building. This study aims to develop a spatial model for determining the ground level of buildings for Makassar City based on climate change data and environmental geography. Prediction of sea level rise using MAGICC/SCENGEN application, GIS-based satellite image analysis, rainfall analysis using Thiessen polygon method, surface runoff coefficient value determined by Cook method, and design flood discharge analysis with HSU Nakayasu method. The spatial model of the ground level of Makassar City building for 2030 is a function of sea tides, sea level rise due to climate change, alluvial floods and inflow floods that can occur simultaneously. The model produces a spatial map with attributes of geographic coordinates (x,y,z).
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Harifa, Ayisya Cindy, Moh Charits, Joko Setiono, and Moch Khamim. "Evaluasi Jaringan Stasiun Hujan di Wilayah Sungai Dumoga Sangkub." Reka Buana : Jurnal Ilmiah Teknik Sipil dan Teknik Kimia 5, no. 1 (2020): 37. http://dx.doi.org/10.33366/rekabuana.v5i1.1607.
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Rainfall data always use in analytical process. Errors in monitoring hydrological data in a watershed will result in incorrect analysis and result in inefficient and effective planning, research and management of water resources. The quality and basic data that will be used for an analysis is very dependent on the distribution of existing hydrological posts in monitoring hydrological characteristics accurately and correctly. The purpose of network evaluation is to find out the distribution and condition of rain stations, so that a new rain station recommendation will be obtained, with distributions that already represent each watershed. Rain station distribution analysis uses the WMO (World Meteorological Organization) method, to evaluate the existing rain station using the Kagan rodda method. According to the analysis of WMO density and Polygon Thiessen Map, the distribution of the rain stations in the Dumoga Sangkub river area is quite evenly distributed, but does not yet represent each Watershed. The results of the Kagan Rodda analysis stated that only 7 rain stations met the kagan criteria, i.e: Pusian, Toraut, Andigile Buko, Bolangitan – Paku, Lolak – Solog, Moayat, Buyat – Buyat. The results of the kagan analysis also recommend 19 new station points through each watershed.ABSTRAK Data hujan sangat sering digunakan dalam proses analisa. Analisa hidrologi memerlukan data dasar yang benar, data dasar akan berdampak besar dalam proses perencanaan dan penelitian dalam sumberdaya air, sehingga hasil yang didapat akan lebih optimum.. Sebaran pos hidrologi akan menentukan tingkat kualitas analisa hidrologi. Tujuan evaluasi jaringan adalah mengetahui sebaran dan kondisi pos hujan, sehingga akan didapatkan rekomendasi stasiun hujan yang baru, dengan sebagaran yang sudah mewakili setiap daerah aliran sungai. Dalam penelitian ini Metode WMO (World Meteorological Organization) dirasa tepat untuk menggambarkan sebaran stasiun hujan. Sedangkan untuk mengevaluasi stasiun hujan eksisting menggunakan metode Kagan rodda. Berdasarkan analisa kerapatan WMO dan Peta Polygon Thiessen, Sebaran stasiun hujan di wilayan sungai Dumoga Sangkub sudah cukup merata, akan tetapi belum mewakili setiap Daerah Aliran Sungai (DAS). Hasil analisa Kagan Rodda menyatakan hanya 7 stasiun hujan yang memenuhi kriteria kagan, yaitu stasiun Pusian, Toraut, Andigile Buko, Bolangitan – Paku, Lolak – Solog, Moayat, Buyat – Buyat. Hasil analisa kagan juga merekomendasikan 19 titik stasiun baru yang tersebar diseluruh DAS.Kata kunci : jaringan; stasiun hujan; kagan rodda
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Zhang, Jianhua, and Allan S. Hamill. "Seed weight, intraspecific competition, and plant performance in Abutilon theophrasti." Canadian Journal of Botany 75, no. 9 (1997): 1614–20. http://dx.doi.org/10.1139/b97-873.
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Seed weight of Abutilon theophrasti Medic, varies among populations and with the light conditions of the parent plants. In this study, the impacts of seed weight variation on seed germination and plant growth were investigated. Variations in seed weight did not result in any significant difference in the germination ability of seeds. The enhanced germination associated with large seeds produced by plants in shaded conditions found in previous studies were more likely the result of interpopulational variation or difference in maternal environments. The leaf chlorophyll content of young seedlings and the total leaf area of plants at harvest tended to increase with increasing original seed weight of the plants. Although the aboveground biomass of a plant was not affected by its original seed weight, the performance of the plant depended significantly on the total original seed weight of the neighbouring plants. Key words: seed weight, germination, competition, Thiessen polygon, Abutilon theophrasti.
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Reza, AHM Selim, Quamrul Hasan Mazumder, and Mushfique Ahmed. "Groundwater Balance Study in the High Barind, Bangladesh." Rajshahi University Journal of Science 39 (October 9, 2013): 11–26. http://dx.doi.org/10.3329/rujs.v39i0.16539.
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The annual groundwater recharge and discharge of aquifer of the Sapahar and Porsha Upazillas is estimated by Thiessen polygon method varies from 106.41 to 244 Mm3 and 93.77 to 291 Mm3 respectively. The calculated groundwater recharge of aquifer of the study area shows that the rate of groundwater recharge of aquifer in Porsha Upazilla is higher than that of Sapahar Upazilla and is characterized by very suitable groundwater storage potential. The overall groundwater balance study in the study area indicates that there exists a balance between annual recharge and withdrawal up to 1993 but after period of 1993 discharge exceeds the recharge continuing till today. But hereforth a cumulative annual deficit is found to exist because of progressive annual discharge in Sapahar Upazilla. 23.99 to 42.08 Mm3 of groundwater is discharged by discharging mechanisms. The rest of groundwater is discharged by natural seepage. DOI: http://dx.doi.org/10.3329/rujs.v39i0.16539 Rajshahi University J. of Sci. 39, 11-26 (2011)
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Croke, B. F. W., A. Islam, J. Ghosh, and M. A. Khan. "Evaluation of approaches for estimation of rainfall and the unit hydrograph." Hydrology Research 42, no. 5 (2011): 372–85. http://dx.doi.org/10.2166/nh.2011.017.
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The impact of rainfall interpolation techniques and unit hydrograph estimation has been explored for four gauged locations in the Brahmani basin in east India. The use of ground-based and satellite-based data, coupled with testing two interpolation techniques (Thiessen polygon and inverse distance weighting), can yield improved rainfall estimates and fits to observed flows. Due to the presence of significant errors in the areal rainfall estimate it was found that identification of known errors in rainfall data can assist in focusing model calibration on catchment response, thereby reducing the uncertainty in model parameter values. Similarly, using several approaches to estimate the unit hydrograph can assist in reducing uncertainty. The resulting performance of the model for the gauged sites in the Brahmani basin gave Nash–Sutcliffe efficiency (NSE) values for the calibration period of 0.6–0.7. For this basin, the inverse distance weighting approach corrected for spatial variation in rainfall distribution generally gave the best fits to the observed streamflow. Sensitivity to errors in the rainfall surface limits the applicability for this approach in modelling the flows in ungauged basins, however.
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Cheng, Yang, Hongming He, Nannan Cheng, and Wenming He. "The Effects of Climate and Anthropogenic Activity on Hydrologic Features in Yanhe River." Advances in Meteorology 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/5297158.
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This paper aims to analyze the effects of precipitation and anthropogenic activity on hydrologic features in Yanhe River so as to provide support for regional water management and evaluation of water and soil conservation measures. Thiessen Polygon was created to calculate mean values of watershed, and Mann-Kendall statistic test and Sen’s slop estimator test were adapted to analyze variation trend and interaction between precipitation, runoff, and sediment discharge. When 1961~1970 was set as reference period (ignoring human effects), the double mass curve quantified the effects of precipitation and anthropogenic activity on runoff and sediment discharge in Yanhe River during 1961~2008. The result showed that the monthly distribution of precipitation, runoff, and sediment discharge was extremely uneven. 78.1% of precipitation, 64.1% of runoff, and 98.6% of sediment discharge occurred in the flood season. Precipitation, runoff, and sediment discharge performed significant downward trends during 1961–2008. Therein, anthropogenic factors contributed 66.7% and 51.1% to sediment discharge reduction during 1971–1994 and 1995–2008, respectively. They contributed 103.8% and 82.9% to runoff reduction during these two periods, respectively.
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Lashari, Rini Kusumawardani, and Ferdian Prakasa. "Analisa Distribusi Curah Hujan di Area Merapi Menggunakan Metode Aritmatika Dan Poligon." Jurnal Teknik Sipil dan Perencanaan 19, no. 1 (2017): 39–46. http://dx.doi.org/10.15294/jtsp.v19i1.9497.
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Watershed (DAS) at the peak of Merapi is very interesting to examine in case of the relation with debris flow due to vomit material from Mount Merapi. In this article reveals the pattern of rainfall distribution, the difference in precipitation every month, rainfall for the period of 5 years, 10 years, 25 years, and 50 years in the area of Merapi and its effect on the behavior of a watershed in the Merapi area. In this study, the rainfall data validity test was conducted by RAPS (rescaled Adjusted Partial Sums). Analysis of the region rain is calculated using arithmetic method or average Algebra and Thiessen Polygon. While Gumbel Distribution, Normal Distribution, Log-Normal Distribution and Distribution Log-Pearson III was used to analyze the pattern of rainfall distribution. Furthermore, to determine the appropriate distribution patterns were analyzed using the chi-squared test and test-Kolmogorof Smirnov. Calculate the intensity of rainfall at a specific time duration using the formula Mononobe.Daerah Aliran Sungai (DAS) yang berada di puncak merapi sangat menarik untuk diteliti mengenai keterkaitannya dengan fenomena debris flow material akibat muntahan dari gunung Merapi. Pada artikel ini mengungkapkan mengenai pola distribusi curah hujan, perbedaan curah hujan setiap bulan, curah hujan untuk periode ulang 5 tahunan, 10 tahunan, 25 tahunan, dan 50 tahunan di Area Merapi dan pengaruhya terhadap perilaku DAS di area Merapi. Dalam penelitian ini uji kevalidan data hujan dilakukan dengan metode RAPS (Rescaled Adjusted Partial Sums). Analisis hujan wilayah dihitung menggunakan Metode Aritmatika atau Rata-rata Aljabar dan Poligon Thiessen. Sedangkan Distribusi Gumbel, Distribusi Normal, Distribusi Log-Normal, dan Distribusi Log-Pearson III digunakan untuk menganalisis pola distribusi curah hujan. Selanjutnya untuk mengetahui pola distribusi yang sesuai dianalisa menggunakan Uji Chi Kuadrat dan Uji Smirnov-Kolmogorof. Menghitung intensitas hujan pada durasi waktu tertentu menggunakan rumus Mononobe.
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CASAER, JIM, MARTIN HERMY, POL COPPIN, and RON VERHAGEN. "Analysing space use patterns by Thiessen polygon and triangulated irregular network interpolation: a non-parametric method for processing telemetric animal fixes." International Journal of Geographical Information Science 13, no. 5 (1999): 499–511. http://dx.doi.org/10.1080/136588199241175.
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Ha, Joonhyeok, Heeseong Park, and Gunhui Chung. "Snow Vulnerability Analysis in the Korean Peninsula using RCP Climate Change Scenarios." Journal of the Korean Society of Hazard Mitigation 20, no. 4 (2020): 251–59. http://dx.doi.org/10.9798/kosham.2020.20.4.251.
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Snow vulnerability analysis was implemented using 400 years of controlled RCP 2.6, 4.5, 6.0, and 8.5 scenarios in the following divided periods: the former period (2011-2040), middle period (2041-2070), and later period (2071-2100). Data from a total of 74 meteorological stations were used and the Thiessen polygon method was applied in the areas without stations. The indicators were classified into the Pressure-State-Response (PSR) structure, and the weight for vulnerability analysis was calculated using the entropy method. As snow vulnerability analysis was implemented for the future scenarios, it was difficult to determine social and economic factors as indicators; thus, only predicted weather data and population trends were considered. As a result, the rankings for snow vulnerable areas were determined for each period and scenario. Overall, snow vulnerability would decrease due to the decrease in long-term heavy snowfall in climate change scenarios. However, increased snow vulnerability is also expected in Sejong-si and the western coastal area due to a rise in population and snow depth in the future. Based on this, disaster prevention projects considering the characteristics of the region in the future could be implemented.
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Soo, Eugene Zhen Xiang, Wan Zurina Wan Jaafar, Sai Hin Lai, Tanvir Islam, and Prashant Srivastava. "Evaluation of satellite precipitation products for extreme flood events: case study in Peninsular Malaysia." Journal of Water and Climate Change 10, no. 4 (2018): 871–92. http://dx.doi.org/10.2166/wcc.2018.159.
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Abstract This study aimed at evaluating the three advanced satellite precipitation products (SPPs), i.e. CMORPH, TRMM 3B42V7 and PERSIANN, against the ground observation to evaluate their performance in detecting rain, capturing storms and rainfall pattern during 2014–2015 extreme flood events at three different river basins in Peninsular Malaysia (Kelantan, Langat and Johor river basins). Several spatial interpolation methods, including Arithmetic Mean, Thiessen Polygon, Inverse Distance Weighting, Ordinary Kriging and Spline were applied on the ground observations to transform the point-based precipitation into areal precipitation. Slight variations in the interpolated values were found, but overall it was comparable. Based on the daily rainfall data for the duration of 62 days, this study found that all SPPs performed with acceptable accuracy, as shown by the Kelantan river basin; however, these SPPs did not estimate accurately for Langat and Johor river basins. Overall, TRMM and CMORPH outperformed PERSIANN for the Langat and Johor river basins. In conclusion, all SPPs were capable of predicting heavy rainfall during the northeast monsoon and the level of accuracy is promising for the northern part of Peninsular Malaysia. However, as for the rest of the region, careful consideration should be given when applying the SPPs.
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Xu, Ruichen, Yong Pang, Zhibing Hu, Jianjian Wang, and John Paul Kaisam. "Study on pollution traceability based on the optimized hydrodynamic model of Tai Lake." Water Supply 20, no. 8 (2020): 3014–28. http://dx.doi.org/10.2166/ws.2020.191.
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Abstract This research optimized a hydrodynamic model based on in-situ measurement experiments, which can evaluate the transport process of pollution groups from inflowing lake sources with different wind conditions and their effects on the sensitive area in Tai Lake. The results showed that the wind drag coefficient (Cs) was 0.001–0.0028 when the wind speed was 1–12 m/s, and the particle trajectory is validated well by the methods of Thiessen polygon and Lagrange particle tracking, which proves that this hydrodynamic model was optimized successfully. During the water diversion period, the results showed that the Northwest Area and Gong Bay are the most important pollution flux sources to the sensitive area. Under northwest wind condition, the pollution flux proportion from Northwest Area and Gong Bay is 65 and 17%, respectively. Under southeast wind condition, the pollution flux proportion from Northwest Area and Gong Bay is 48 and 27%, respectively. Namely, pollution control to the upstream watershed of the Northwest Area and improving the water quality (TP &lt; 0.065 mg/L; TN &lt; 1.2 mg/L) from the Wangyu river are the effective methods to reduce the pollution risks for the sensitive area.
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Hong, H. P., K. Goda, and A. G. Davenport. "Seismic hazard analysis: a comparative study." Canadian Journal of Civil Engineering 33, no. 9 (2006): 1156–71. http://dx.doi.org/10.1139/l06-062.
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The quantitative seismic hazard maps for the 1970s National Building Code of Canada were evaluated using the Davenport–Milne method. The Cornell–McGuire method is employed to develop recent seismic hazard maps of Canada. These methods incorporate the information on seismicity, magnitude-recurrence relations, and ground motion (or response) attenuation relations. The former preserves and depends completely on details of the historical seismicity; the latter smoothes the irregular spatial occurrence pattern of the historical seismicity into seismic source zones. Further, the Epicentral Cell method, which attempts to incorporate the preserving and smoothing aspect of these methods, has been developed. However, the impact of the adopted assumptions on the estimated quantitative seismic hazard has not been investigated. This study provides a comparative seismic hazard assessment using the above-mentioned methods and simulation-based algorithms. The analysis results show that overall the Davenport–Milne method gives quasi-circular seismic hazard contours near significant historical events, and the Cornell–McGuire method smoothes the transition of contours. The Epicentral Cell method provides estimates approximately within the former and the latter. Key words: epicentral cell method, probability, seismic hazard, Thiessen polygon, Voronoi, uniform hazard spectra.
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Abeysingha, N. S., and U. R. L. N. Rajapaksha. "SPI-Based Spatiotemporal Drought over Sri Lanka." Advances in Meteorology 2020 (January 21, 2020): 1–10. http://dx.doi.org/10.1155/2020/9753279.
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Drought is one of the most significant hazards in Sri Lanka. Status of drought in Sri Lanka was assessed using Standardized Precipitation Index (SPI) at 3, 6, and 12 months’ time scales using monthly rainfall (1970 to 2017) data of 54 weather stations. The frequency of drought events was evaluated using SPI, and trend of SPI was also detected using the Mann–Kendall (MK) test and Sen’s slope estimator. The result based on SPI identified hydrological years 1975-76, 1982-83, 1986-87, 1988-89, 2000-01, 2001-02, 2013-14, and 2016-17 as drought years for 52, 32, 35, 33, 33, 31, 31, and 31% of tested stations (54), respectively, at annual time scale. Comparison of the SPI at different time scales revealed that more drought events (SPI ≤ −1) occurred during Yala season than Maha cropping season. Considering the Thiessen polygon average rainfall, more frequent drought events occurred in the dry zone (57%) than the wet (49%) and intermediate zone (47%) at the annual time scale. SPI trend results showed greater increase in drought (59% of stations) during Yala seasons as compared to the Maha cropping season (15% of stations) in Sri Lanka.
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Wu, Li, Hui Zhou, Jiaoyang Li, et al. "Thiessen polygon analysis and spatial pattern evolution of Neolithic cultural sites (8.0–4.0 ka BP) in Huaibei Plain of Anhui, East China." Quaternary International 521 (June 2019): 75–84. http://dx.doi.org/10.1016/j.quaint.2019.06.005.
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ميسون الزغول, ميسون الزغول. "الخصائص الطبوغرافية وتقدير كمية الحصاد المائي في قاع الجفر". journal of king abdulaziz university arts and humanities 28, № 4 (2020): 207–59. http://dx.doi.org/10.4197/art.28-4.8.
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يُعد قاع الجفر التكتوني الأكبر في هضبة الأردن الجنوبية، ويحتل الجزء الأوسط من محافظة معان، وتبلغ مساحته 12400 كم²، ليشكل ما نسبته 37.7? من المساحة الكلية لمحافظة معان البالغة 32832 كم². وقد تشكل هذا الحوض نتيجة لسلسلة من الحركات التكتونية. وتُعد ظاهرة القيعان، ومناطق الانتشار المائي من أهم الأشكال الأرضية التي تميزه. والأهداف الأساسية لهذه الدراسة تمثلت في تحليل الخصائص الطبوغرافية، وتأثيرها على أنماط الأشكال الأرضية، وتقدير كمية الحصاد المائي في هذه المنطقة. وتم اشتقاق القيعان اعتماداً على الخريطة الطبوغرافية بمقياس 1: 50000، والصورة الفضائية لعام 2018وجاءت أبرز النتائج كما يلي: (1)- تميز التوزع الجغرافي للقيعان بالتركز في ثلاثة مناطق أساسية، على الرغم من انتشار القيعان على مساحة نسبتها 51% من مساحة منطقة الدراسة.(2)- تم اشتقاق 462 قاع جاف بمساحة قدرها 422.2كم²، والتي تُشّكل ما نسبته 3.4% من المساحة الكلية لمنطقة الدراسة، مع وجود اختلافات ذات دلالة في مساحاتها ما بين المساحة الصغيرة جداً حوالي 988,م² إلى الأكبر مساحة والمتمثلة بقاع الجفر والبالغة مساحتها250.1كم².(3)- أوضحت نتائج التحليل المكاني للقيعان أنها تتركز في المناطق ذات الارتفاعات ما بين 833-1047 م وبمتوسط ارتفاع 868.6م، وانحدار تراوح ما بين 0°-13°. Thiessen polygon method (4) تقدير معدل الأمطار المساحية الموزونة اعتماداً على نموذج معدل الأمطار للعام المطري 2016/2017 حوالي 6097.393 ملم، ومعدل عمق المياه في كافة القيعان حوالي 130.255 ملم خلال تلك السنة.
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Zhang, Tao, Baolin Li, Jinfeng Wang, Maogui Hu, and Lili Xu. "Estimation of Areal Mean Rainfall in Remote Areas Using B-SHADE Model." Advances in Meteorology 2016 (2016): 1–13. http://dx.doi.org/10.1155/2016/7643753.
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This study presented a method to estimate areal mean rainfall (AMR) using a Biased Sentinel Hospital Based Area Disease Estimation (B-SHADE) model, together with biased rain gauge observations and Tropical Rainfall Measuring Mission (TRMM) data, for remote areas with a sparse and uneven distribution of rain gauges. Based on the B-SHADE model, the best linear unbiased estimation of AMR could be obtained. A case study was conducted for the Three-River Headwaters region in the Tibetan Plateau of China, and its performance was compared with traditional methods. The results indicated that B-SHADE obtained the least estimation biases, with a mean error and root mean square error of −0.63 and 3.48 mm, respectively. For the traditional methods including arithmetic average, Thiessen polygon, and ordinary kriging, the mean errors were 7.11, −1.43, and 2.89 mm, which were up to 1027.1%, 127.0%, and 358.3%, respectively, greater than for the B-SHADE model. The root mean square errors were 10.31, 4.02, and 6.27 mm, which were up to 196.1%, 15.5%, and 80.0%, respectively, higher than for the B-SHADE model. The proposed technique can be used to extend the AMR record to the presatellite observation period, when only the gauge data are available.
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Pujiastuti, Ratih, and Undayani Cita Sari. "Analisis Multi Kriteria Pos Hujan dan Pos Debit dengan Metode Stepwise pada DAS Bd. Katulampa." BANGUNAN 25, no. 1 (2020): 1. http://dx.doi.org/10.17977/um071v25i12020p1-8.
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Abstrak:Dalam suatu WS/DAS, pos pencatatan curah hujan biasanya lebih banyak ditemui dibandingkan dengan pos pencatatan debit. Banyaknya jumlah pos hujan menimbulkan permasalahan dalam biaya operasi dan pemeliharaan. Penelitian ini bertujuan untuk menentukan pos hujan yang paling berpengaruh pada DAS Bd. Katulampa. Analisis dilakukan dengan metode Stepwise yang merupakan analisis multi correlation, dalam hal ini data hujan bulanan sebagai variabel bebas dan data debit bulanan sebagai variabel tidak bebas. DAS Bd. Katulampa dipengaruhi oleh 13 pos hujan. Akan tetapi karena keterbatasan data, analisis dilakukan pada 5 Pos Hujan yaitu Pos Perkeb. Gn. Mas, Pos Gunung Mas, Pos Panjang, Pos Pasir Muncang dan Pos Katulampa. Hasil analisa dengan multi correlation menunjukkan bahwa pertambahan nilai korelasi bertambah dari kombinasi 2,3 dan 4 pos hujan. Akan tetapi pada kombinasi 5 pos hujan, pertambahan nilai korelasi tidak lagi signifikan. Hal ini bisa disimpulkan bahwa pada DAS Bd. Katulampa, pencatatan pos hujan cukup terwakili dengan kombinasi 4 pos hujan antara lain Pos Perkeb. Gn. Mas, Pos Panjang, Pos Pasir Muncang dan Pos Katulampa. Kombinasi 4 pos hujan ini kemudian di cek dengan standar WMO. Polygon thiessen yang dihasilkan 4 pos hujan hasil analisis, menghasilkan luas pengaruh pos hujan maksimum adalah 50.57 km2 yaitu Pos Pasir Muncang dan minimum 15.46 km2 Pos Katulampa. Artinya dengan 4 pos hujan tersebut, luas pengaruh pos hujan masih masuk dalam ketentuan yang disyaratkan oleh WMO.Kata-kata kunci: pos hujan, pos debit, multi correlation, stepwiseAbstract:In a WS / DAS, the rainfall recording post is usually more common than the debit recording post. The large number of rain stations has caused problems in operating and maintenance costs. This study aims to determine the most influential rainfall items in the watershed Bd. Katulampa. The analysis was carried out using the Stepwise method which is a multi correlation analysis, in this case monthly rainfall data as the independent variable and monthly discharge data as the dependent variable. DAS Bd. Katulampa is affected by 13 rain posts. However, due to data limitations, the analysis was carried out on 5 Rain Posts, namely Perk Perkeb. Mt. Mas, Gunung Mas Post, Pos Panjang, Muncang Sand Post and Katulampa Post. The results of the analysis with multi correlation show that the correlation value increases from the combination of 2.3 and 4 rain posts. However, in the combination of 5 rain posts, the correlation value is no longer significant. It can be concluded that in the watershed Bd. Katulampa, the recording of rain posts is adequately represented by a combination of 4 rain posts, including the Pos Perkeb. Mt. Mas, Long Post, Muncang Sand Post and Katulampa Post. The combination of the 4 rain posts is then checked with the WMO standard. Polygon Thiessen produced by 4 analysis results, the maximum area of influence is 50.57 km2, that is Pasir Muncang Post and minimum 15.46 km2 Katulampa Post. This means that with the 4 rain posts, the broad influence of the rain post is still included in the conditions required by the WMO.Keywords: rain post, debit post, multi correlation, stepwise.
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Adhikari, Basanta Raj, Naresh Nidal, Bhupendra Kumar Yadav, and Surendra Awasthi. "Landslide Risk Assessment of the Patlekhet Landslide in Myagdi District, Nepal." Journal of the Institute of Engineering 13, no. 1 (2018): 78–89. http://dx.doi.org/10.3126/jie.v13i1.20352.
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Abstract: Nepal Himalaya is one of the most active mountain belts with several kilometers of relief which is very prone to catastrophic mass failure and this region encounter the problem of landslide almost every year during monsoon period causing large scale of devastation. Most of the landslides are caused by river bank erosion, monsoon and earthquakes. Patlekhet landslide, Myagdi district represents the vulnerable condition of the hilly region and therefore it is chosen for study. Hydro-meteorological analysis of the landslide including estimation of the physical characteristics of the landslide and different parameter were used for the study. The Thiessen polygon and arithmetic average methods are used for rainfall analysis of the landslide and high flood level is estimated at the toe of the landslide. The risk is calculated by assessing the vulnerability of different exposure elements such as population, households, agricultural land and water supply through the use of quantitative tools and techniques. It is clear that the landslide was triggered by heavy rainfall and toe cutting by Raghu Ghat Khola. Around fourteen percent households’ lie in the high risk zone and others are in moderate and low risk zone. The level of risk is changing every year with increasing number of population and continuous movement of landslide.Journal of the Institute of Engineering, 2017, 13(1): 78-89
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Singla, Shivika, Raktim Halder, Rakesh Khosa, Rumani Singla, and Rudraksh Rajeev. "Frequency analysis of annual one day to five consecutive days maximum rainfall for Gandak river basin." International Journal of Engineering & Technology 3, no. 2 (2014): 93. http://dx.doi.org/10.14419/ijet.v3i2.1803.
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The present study has been conducted for rainfall intensity and frequency estimation for the Gandak basin, a region prone to high floods with an unrealized and unexplored hydro-potential. The two popular gridded precipitation datasets i.e.: (1) APHRODITE, and (2) IMD, for the years 1969-2005, has been used to calculate the mean basin precipitation through the Thiessen polygon method on the ARC-GIS interface. This computed data was used to find out the 1-day, 2-day to 5-day consecutive maximum precipitation series and hence fitted into various well-known probability distribution functions viz., Normal, Gamma, Exponential, etc. According to the best fit data in these functions, the quantiles were determined corresponding to a return period of 2, 10, 20, 25, 50 and 100 years. The two widely used tests: Chi-square Test and Kolmogorov-Smirnov Test were employed to further check the goodness of fit of the series in the distributions. The results reveal that the best fit for 1-day was achieved with the normal distribution, for 2-day with GEV and with GPAR for the remaining maximum consecutive days rainfall. Such studies have thus proven to be substantially facilitative in planning for the safe and economic design of various engineered structures such as bridges, culverts, levees, canals, irrigation and drainage works and effective reservoir management. Keywords: Floods, Frequency, Hydrology, Probability Distribution, Rainfall.
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Mahmood, Taufique H., Jaakko Putkonen, and Aaron Sobbe. "Spatially Variable Precipitation and Its Influence on Water Balance in a Headwater Alpine Basin, Nepal." Water 13, no. 3 (2021): 254. http://dx.doi.org/10.3390/w13030254.
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The current knowledge of the spatial variability of precipitation in High Mountain Asia is based on the remotely-sensed estimates (coarse spatial and temporal resolution) or data from sparsely-distributed rain gauges. However, as precipitation is strongly affected by topography in mountainous terrain, the spatially varying precipitation and the resulting water balances are currently poorly understood. To fill this gap in knowledge, we studied the spatial variation of the precipitation and its impact on water balance in a small headwater basin located in the foothills of the Himalaya, Nepal. We deployed ten rain gauges and climate stations, spanning the whole elevation range 700–4500 m above sea level (masl) for a period of four years. Our results show a quadratic polynomial relationship between annual precipitation and station elevation, which are used to produce annual precipitation maps. The performance of the elevation-based precipitation estimates is adequate in closing the water balance while the performances of average precipitation and Thiessen polygon method are poor and inconsistent in closing the water balance. We also demonstrate that precipitation estimates from one or two gauges at the lowest basin elevation substantially underestimate the water balance. However, the precipitation from one or two rain gauges at 2000–3000 masl provide a significantly better estimate of the water balance of a small headwater basin.
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Boots, B. N. "Modifying Thiessen Polygons." Canadian Geographer/Le Géographe canadien 31, no. 2 (1987): 160–69. http://dx.doi.org/10.1111/j.1541-0064.1987.tb01636.x.
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Croley, Thomas E., and Holly C. Hartmann. "Resolving Thiessen polygons." Journal of Hydrology 76, no. 3-4 (1985): 363–79. http://dx.doi.org/10.1016/0022-1694(85)90143-x.
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Ariesta, Diana. "The Effect of Initial Groundwater Table and Rainfall Wetting Towards Slope Stability (Case Study of Landslide in Tangkil Hamlet, Banaran Village, Pulung Subdistrict, Ponorogo Regency)." Journal of the Civil Engineering Forum 5, no. 2 (2019): 149. http://dx.doi.org/10.22146/jcef.43804.
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Landslide is a natural phenomenon that can be controlled by a combination of various factors, such as topography, lithological condition, geological structure, water table, etc. Landslide is stated as a natural disaster if it causes casualties, direct losses and subsequent impacts of the initial destruction, as happened in Banaran Village, Ponorogo Regency. This study is aimed to examine the effects of initial groundwater table conditions and rainfall wetting on Banaran Village landslide. This study was conducted by assuming scenarios of initial groundwater table conditions. Soil parameters were obtained by testing soil samples in the laboratory. Infiltration parameters were acquired through permeability tests using the Philip-Dunne method, while areal rainfall was calculated using the Thiessen polygon method. In addition, slope stability modeling was calculated by using SLOPE/W while rainfall wetting analysis was carried out through SEEP/W. The analysis of Banaran Village landslide through these two numerical models was conducted by considering two conditions: 1) without rainfall and 2) with rainfall and infiltration. The analysis results imply that the landslide occurred in the initial groundwater table condition in scenario 3 with a safety factor of 1.008, and in a similar scenario with a safety factor of 0.973 when taking into account rainfall and infiltration. The results from SEEP/W and SLOPE/W indicate that the initial condition of the groundwater table highly influenced the decrease of the safety factor, while the wetting process did not cause a significant decrease of the safety factor.
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Cajucom, E. P., G. Y. Chao Jr., G. A. Constantino, et al. "EVALUATION OF THE SPATIAL DISTRIBUTION OF EVACUATION CENTERS IN METRO MANILA, PHILIPPINES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W8 (August 20, 2019): 79–85. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w8-79-2019.
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<p><strong>Abstract.</strong> In a densely populated and hazard-prone megalopolis like Metro Manila, the ability to execute a rapid evacuation protocol is crucial in saving lives and minimizing the damage during disastrous events. However, there is no centralized database on the location of evacuation centers (ECs) in Metro Manila and the available lists are not up-to-date. This study geotagged the current list of ECs in Metro Manila obtained from different government agencies to evaluate the spatial distribution using Geographical Information System (GIS). This is important since the immediate evacuation of residents depends on the proximity and safe location of the ECs. A total of 870 ECs were geo-tagged and validated using the street view of Google Earth<sup>TM</sup>. EC-to-population ratios were calculated for each of the 16 cities and one municipality of Metro Manila. Values range from ~3,000 to 81,000 persons per EC. Distance analysis using Thiessen Polygon shows that the ECs are not evenly distributed with proximity areas ranging from 0.0009 to 9.5 km<sup>2</sup>. Out of the total number of mapped ECs, 392 (45%) are situated in flood-prone areas while 108 (12%) are within the 1-km buffer hazard zone of an active faultline. Re-evaluation of the locations and the number of ECs per city or municipality is highly recommended to facilitate prompt evacuation when disasters strike.</p>
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Gunawan, Gusta. "ANALISIS DATA HIDROLOGI SUNGAI AIR BENGKULU MENGGUNAKAN METODE STATISTIK." Inersia, Jurnal Teknik Sipil 9, no. 1 (2019): 47–58. http://dx.doi.org/10.33369/ijts.9.1.47-58.
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Bengkulu municipality as a constituent element of the Air Bengkulu watershed with 51,500 of hectares area bypassed by the stream of Air Bengkulu River which empties into the Teluk Segara District, municipal of Bengkulu. Air Bengkulu River suffered flood at least twice a year of frequency as result of the increase in water discharge (Q) in the rainy season. The purpose of this research is to calculate the amount of peak river discharge of Air Bengkulu and mappingthe distribution of inundation water that may occur in the city of Bengkulu. Analysis of the mean daily maximum rainfall area was conducted by Thiessen Polygon using 15 last years of rainfall datas. Calculation of peak discharge using rational methods for different return period plans Analysis of Rainfall of flood modeling simulation is done by using HEC-RAS 4.1.0 and flood inundation mapping is done by using Hec-GeoRAS 4.3.1 flood modeling. The result of rainfall plan calculations was qualified by Gumbel type 1 method. The results of the Air Bengkulu river peak discharge quantify for return period 5, 10, 25, 50 and 100 years respectively 339.66 m3/sec; 470.38m3/sec; 520.59m3/sec; 557.83m3/sec; 594.79m3/sec; 631.62m3/sec. Results of generated mapping showed the areas affected by flood inundation in Bengkulu City namely Pasar Bengkulu village, Kampung Klawi, Rawa Makmur, Suka Merindu, Tanjung Agung,Tanjung Jaya, and Semarang. The depth value of inundation mapping for every affected village of floodwaters are vary, but in the range of 0 - 110 cm.
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Ly, S., C. Charles, and A. Degré. "Spatial interpolation of daily rainfall at catchment scale: a case study of the Ourthe and Ambleve catchments, Belgium." Hydrology and Earth System Sciences Discussions 7, no. 5 (2010): 7383–416. http://dx.doi.org/10.5194/hessd-7-7383-2010.
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Abstract. Spatial interpolation of precipitation data is of great importance for hydrological modelling. Geostatistical methods (krigings) are widely used in spatial interpolation from point measurement to continuous surfaces. However, the majority of existing geostatistical algorithms are available only for single-moment data. The first step in kriging computation is the semi-variogram modelling which usually uses only one variogram model for all-moment data. The objective of this paper was to develop different algorithms of spatial interpolation for daily rainfall on 1 km2 regular grids in the catchment area and to compare the results of geostatistical and deterministic approaches. In this study, we used daily rainfall data from 70 raingages in the hilly landscape of the Ourthe and Ambleve catchments in Belgium (2908 km2). This area lies between 35 and 693 m in elevation and consists of river networks, which are tributaries of the Meuse River. For geostatistical algorithms, Cressie's Approximate Weighted Least Squares method was used to fit seven semi-variogram models (logarithmic, power, exponential, Gaussian, rational quadratic, spherical and penta-spherical) to daily sample semi-variogram on a daily basis. Seven selected raingages were used to compare the interpolation performance of these algorithms applied to many degenerated-raingage cases. Spatial interpolation with the geostatistical and Inverse Distance Weighting (IDW) algorithms outperformed considerably interpolation with the Thiessen polygon that is commonly used in various hydrological models. Kriging with an External Drift (KED) and Ordinary Cokriging (OCK) presented the highest Root Mean Square Error (RMSE) between the geostatistical and IDW methods. Ordinary Kriging (ORK) and IDW were considered to be the best methods, as they provided smallest RMSE value for nearly all cases.
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Zhao, Shuai, Yangjian Xu, Changliang Pan, Lihua Liang, and Xiaogui Wang. "Microstructural Modeling and Strengthening Mechanism of TiB/Ti-6Al-4V Discontinuously-Reinforced Titanium Matrix Composite." Materials 12, no. 5 (2019): 827. http://dx.doi.org/10.3390/ma12050827.
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A novel modeling method was proposed to provide an improved representation of the actual microstructure of TiB/Ti-6Al-4V discontinuously-reinforced titanium matrix composite (DRTMC). Based on the Thiessen polygon structure, the representative volume element (RVE) containing the complex microstructures of the DRTMC was first generated. Thereafter, by using multiple user-defined subroutines in the commercial finite element software ABAQUS, the application of asymmetric mesh periodic boundary conditions on the RVE was realized, and the equivalent elastic modulus of the DRTMC was determined according to the homogenization method. Through error analyses on the experimental and calculated results regarding the equivalent elastic parameters of the DRTMC, the rationality of generating the DRTMC finite element model by using the present method was validated. Finally, simulations based on four types of network-like models revealed that the present simplifications to the particle shape of the reinforcement phase had less of an influence on the overall composite strength. Moreover, the present study demonstrates that the DRTMC enhancement is mainly attributed to the matrix strengthening, rather than the load-transferring mechanism. The strengthening influences of the distribution forms of the reinforcement phases, including their distribution density and orientation, were studied further. It was found that both the higher distribution density and limited distribution orientation of the particles would increase the probability of overlapping and merging between particles, and; therefore, higher strength could be yielded when the volume fraction of the reinforcement phase reached a certain threshold. Owing to the versatility of the developed methods and programs, this work can provide a useful reference for the characterization of the mechanical properties of other composites types.
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Valimba, Patrick, and Gil Mahe. "Estimating Flood Magnitudes of Ungauged Urban Msimbazi River Catchment in Dar es Salaam, Tanzania." Tanzania Journal of Engineering and Technology 39, no. 1 (2020): 59–71. http://dx.doi.org/10.52339/tjet.v39i1.519.
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More often daily climate data have been used in hydrological models to estimate flood flows in small data scarce urban and rural catchments where flow peaking and recession are quick within short periods of few hours. This study assesses magnitudes of error of using daily climate data to simulate flood flow hydrographs of a small urban river catchment, Msimbazi River. Spot discharge measurements were available for Apr-May 2014 and MarMay 2015 periods.10-minutes climate records were available at one station, daily temperatures at two stations while daily rainfall records at several stations within the catchment. Visual analysis characterise rainfall events during the 2011, 2014 and 2015 floods, Thiessen-polygon was used for catchment rainfall, Hargreave-Samani model for catchment potential evapotranspiration and flow hydrographs were estimated by calibrated HBV model. Length weighted channel slope was estimated from segment slopes established from available topographical maps and used in estimating time of concentration for the catchment using Kirpich method. Results indicated that simulated flood hydrographs using 10-minutes climate inputs produced higher flood peaks for both December 2011 (peak: 471.6 m3 /s) and April 2014 (peak: 393.5 m3 /s) and expected hydrograph recession behaviour reproducing the Kirpich estimate of time of concentration of 7 hours. Simulated flood peaks using daily climate inputs were 252.3 m3 /s for December 2011 and 205 m3 /s for the April 2014 event being 53% and 52% of those simulated from 10-minutes climate inputs. Despite usefulness of 10-minute climate data, these data are required at more stations within the catchment for reliable simulation of fast receding urban floods and therefore more automatic weather stations are needed in Dar es Salaam.
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Rhynsburger, Dierk. "Analytic Delineation of Thiessen Polygons*." Geographical Analysis 5, no. 2 (2010): 133–44. http://dx.doi.org/10.1111/j.1538-4632.1973.tb01003.x.
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