Готові списки джерел за темами / Water repellent soil

Добірка наукової літератури з теми "Water repellent soil"

Автор: Grafiati
Опубліковано: 19 червня 2021
Оновлено: 1 лютого 2022

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Water repellent soil".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Зміст

  1. Статті в журналах
  2. Дисертації
  3. Книги
  4. Частини книг
  5. Тези доповідей конференцій
  6. Звіти організацій

Статті в журналах з теми "Water repellent soil":

1

Xing, Xin, and Sérgio D. N. Lourenço. "Water-entry pressure in water repellent soils: a review." E3S Web of Conferences 195 (2020): 02030. http://dx.doi.org/10.1051/e3sconf/202019502030.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Water repellent soils can be naturally promoted (e.g. after wildfires) or synthetically induced by mixing with hydrophobic compounds (e.g. polydimethylsiloxane). The study of soil water repellency has lasted for over one century which implied the significant effect of soil water repellency on water infiltration, evaporation, soil strength, and soil stability. Water repellent soils can also be exploited by geotechnical engineers to offer novel and economical solutions for ground infrastructure. This paper synthesizes different methods for assessing soil water repellency based on varied indexes (e.g. contact angle, time for a drop to infiltrate) and with a focus on water entry pressure. Measurements of these parameters in synthetic water- repellent sands were taken, some results of which are summarized with discussion of key factors affecting water repellency. A comparison of these methods shows that water entry pressure can be more representative for assessing the water repellency of bulk samples.
2

Sepehrnia, Nasrollah, Mohammad Ali Hajabbasi, Majid Afyuni, and Ľubomír Lichner. "Soil water repellency changes with depth and relationship to physical properties within wettable and repellent soil profiles." Journal of Hydrology and Hydromechanics 65, no. 1 (March 1, 2017): 99–104. http://dx.doi.org/10.1515/johh-2016-0055.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
AbstractThis study explored the effect of soil water repellency (SWR) on soil hydrophysical properties with depth. Soils were sampled from two distinctly wettable and water repellent soil profiles at depth increments from 0-60 cm. The soils were selected because they appeared to either wet readily (wettable) or remain dry (water repellent) under field conditions. Basic soil properties (MWD, SOM, θv) were compared to hydrophysical properties (Ks, Sw, Se, Sww, Swh, WDPT, RIc, RImand WRCT) that characterise or are affected by water repellency. Our results showed both soil and depth affected basic and hydrophysical properties of the soils (p <0.001). Soil organic matter (SOM) was the major property responsible for water repellency at the selected depths (0-60). Water repellency changes affected moisture distribution and resulted in the upper layer (0-40 cm) of the repellent soil to be considerably drier compared to the wettable soil. The water repellent soil also had greater MWDdryand Ks over the entire 0-60 cm depth compared to the wettable soil. Various measures of sorptivity, Sw, Se, Sww, Swh, were greater through the wettable than water repellent soil profile, which was also reflected in field and dry WDPT measurements. However, the wettable soil had subcritical water repellency, so the range of data was used to compare indices of water repellency. WRCT and RImhad less variation compared to WDPT and RIc. Estimating water repellency using WRCT and RIm indicated that these indices can detect the degree of SWR and are able to better classify SWR degree of the subcritical-repellent soil from the wettable soil.
3

Roy, Julie L., William B. McGill, and Marvin D. Rawluk. "Petroleum residues as water-repellent substances in weathered nonwettable oil-contaminated soils." Canadian Journal of Soil Science 79, no. 2 (May 1, 1999): 367–80. http://dx.doi.org/10.4141/s97-040.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Some soils develop severe water repellency several years or decades following oil contamination. We previously reported on the characteristics of three such soils. Here we report on the characteristics of putative water-repellent substances in them. We examined the effectiveness of various polar, nonpolar and amphiphilic solvents for removal of water-repellent substances in three nonwettable soils. Only the amphiphilic solvent mixture isopropanol/14.8 M ammonia (7:3, vol/vol) (IPA/NH4OH) completely eliminated soil water repellency in all three soils. We thus define putative water-repellent substances as those substances whose removal from soil by IPA/NH4OH removes water repellency. High-resolution CPMAS 13C-NMR spectroscopy and thermal desorption followed by conventional gas chromatography/mass spectroscopy with electron impact ionization (GC/EI/MS) and GC/MS with chemical ionization (GC/CI/MS) were used to characterize extracted putative water-repellent substances. We conclude that: (i) the identified representatives of these substances consist mostly of homologous series of long-chain and polycyclic aliphatic organic compounds; namely, n-fatty acids, n-alkanes, and cycloalkanes, and that (ii) they are of petroleum origin rather than plant or microbial origin. Key words: Soil hydrophobicity, petroleum hydrocarbons, soil water repellency, amphiphilic solvents, crude oil, nonwettable soil
4

Ferreira, A. J. D., C. O. A. Coelho, A. K. Boulet, G. Leighton-Boyce, J. J. Keizer, and C. J. Ritsema. "Influence of burning intensity on water repellency and hydrological processes at forest and shrub sites in Portugal." Soil Research 43, no. 3 (2005): 327. http://dx.doi.org/10.1071/sr04084.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
In addition to the incineration of vegetation and litter layer, fires are also responsible for the formation of a water repellent layer with significantly different severity and spatial distribution patterns following different burning intensities. Those spatial distribution patterns have an enormous influence on soil wetting patterns, and on hydrological processes at different scales. This study attempts to understand the role of water repellence severity and spatial distribution patterns on soil, slope, and catchment water processes, and on the transmission of hydrological processes between different scales. The comparison between microplot (0.24 m2), plot (16 m2), and catchment (<1.2 km2) scales shows that water repellence spatial homogeneity enhances water fluxes transfer between the different scales. In fact, the more intense the fires, the more severe and spatially uniform the soil water repellency became. For burned areas with heterogeneous soil water repellency, overland flow produced in water repellent patches infiltrated downslope at hydrophilic sites, thereby reducing superficial water fluxes at wider scales. For the more severe and homogeneous water repellent areas following forest wildfires, overland flow was enhanced downslope, increasing fast superficial water fluxes at wider scales.
5

Orfanus, Tomas, Abdel-Monem Mohamed Amer, Grzegorz Jozefaciuk, Emil Fulajtar, and Anežka Čelková. "Water vapour adsorption on water repellent sandy soils." Journal of Hydrology and Hydromechanics 65, no. 4 (December 20, 2017): 395–401. http://dx.doi.org/10.1515/johh-2017-0030.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
AbstractSoil sorptivity is considered a key parameter describing early stages of water (rain) infiltration into a relatively dry soil and it is related to build-up complexity of the capillary system and soil wettability (contact angles of soil pore walls). During the last decade an increasing water repellency of sandy soils under pine forest and grassland vegetation has been frequently observed at Mlaky II location in SW Slovakia. The dry seasons result in uneven wetting of soil and up to hundredfold decrease in soil sorptivity in these vegetated soil as compared to reference sandy material, which was out of the reach of ambient vegetation and therefore readily wettable. As far as water binding to low moisture soils is governed by adsorption processes, we hypothesized that soil water repellency detected by water drop penetration test and by index of water repellency should also influence the water vapour adsorption parameters (monolayer water content, Wm, specific surface area, A, maximum adsorption water, Wa, maximum hygroscopic water MH, fractal dimension, DS and adsorption energies, Ea) derived from BET model of adsorption isotherms. We found however, that the connection of these parameters to water repellency level is difficult to interpret; nevertheless the centres with higher adsorption energy prevailed evidently in wettable materials. The water repellent forest and grassland soils reached less than 80% of the adsorption energy measured on wettable reference material. To get more conclusive results, which would not be influenced by small but still present variability of field materials, commercially available homogeneous siliceous sand was artificially hydrophobized and studied in the same way, as were the field materials. This extremely water repellent material had two-times lower surface area, very low fractal dimension (close to 2) and substantially lower adsorption energy as compared to the same siliceous sand when not hydrophobized.
6

Leighton-Boyce, Gemma, Stefan H. Doerr, Richard A. Shakesby, Rory P. D. Walsh, António J. D. Ferreira, Anne-Karine Boulet, and Celeste O. A. Coelho. "Temporal dynamics of water repellency and soil moisture in eucalypt plantations, Portugal." Soil Research 43, no. 3 (2005): 269. http://dx.doi.org/10.1071/sr04082.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
This paper investigates water repellency and soil moisture under 4 different Eucalyptus globulus plantations in Portugal. On 8 occasions over a 16-month period, measurements were made at 3 depths (surface, 0.10 and 0.20 m) at 60 points on four 10 by 18 m grids. The main results are: (i) at all sites and depths, spatial frequency of repellency (defined as percentage of repellent grid points) followed a moisture-related seasonal cycle, its amplitude being greatest for the longest established site, where surface repellency was contiguous in dry late-summer conditions, but was entirely absent after wet winter conditions; (ii) at a few points at 2 sites, repellency persisted during winter; (iii) repellency severity was dichotomously distributed regardless of season (i.e. soils were generally either wettable or highly repellent); and (iv) at the longest established site, when soil moisture was <14% soils were repellent, and when soil moisture was >27% soils were wettable. This may either support the existence of a ‘transition zone’, or be an artefact of the different scales of repellency and soil moisture assessments. Reasons for the observed changes in repellency and their relationship with soil moisture and antecedent rainfall are explored and soil hydrological implications discussed.
7

Dekker, Louis W., Klaas Oostindie, and Coen J. Ritsema. "Exponential increase of publications related to soil water repellency." Soil Research 43, no. 3 (2005): 403. http://dx.doi.org/10.1071/sr05007.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Soil water repellency is much more wide-spread than formerly thought. During the last decades, it has been a topic of study for soil scientists and hydrologists in at least 21 States of the USA, in Canada, Australia, New Zealand, Mexico, Colombia, Chile, Congo, Nepal, India, Hong Kong, Taiwan, China, Ecuador, Venezuela, Brazil, Mali, Japan, Israel, Turkey, Egypt, South Africa, Germany, The Netherlands, Spain, Portugal, United Kingdom, Denmark, Sweden, Finland, Poland, Slovakia, Russia, France, Italy, and Greece. Although, water repellent soils already have been indicated at the end of the nineteenth century, they have been discovered and studied in most countries in the last decades. Water repellency is most common in sandy soils with grass cover and in nature reserves, but has also been observed in loam, heavy clay, peat, and volcanic ash soils. From 1940 to 1970 research was focussed on identifying vegetation types responsible for inducing water repellency and on developing techniques to quantify the degree of water repellency. Of special interest has been the effects of wildfire on the development of soil water repellency and its consequences for soil erosion. Due to increasing concern over the threat to surface and groundwater posed by the use of agrichemicals and organic fertilisers, studies on water repellent soils have also been focused on its typical flow behavior with runoff and the existence of preferential flow paths. Since the end of the 1950s, wetting agents and clay amendments have been studied to ameliorate water repellent soils. Since 1883, more than 1200 articles related to soil water repellency have been published in journals, reports, and theses. An exponential increase in number of publications started in 1960, resulting in an average of 200 publications per 5 years.
8

Ritsema, CJ, and LW Dekker. "Water repellency and its role in forming preferred flow paths in soils." Soil Research 34, no. 4 (1996): 475. http://dx.doi.org/10.1071/sr9960475.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
The role of water repellency in forming preferred how paths, and in accelerating solute transport, is explained on the basis of extensive field measurements in a grass-covered, extremely water-repellent sandy soil in the coastal region of the Netherlands. It was shown that following wetting of the 9-cm-thick humous topsoil to around 20–25 vol.%, preferred how paths, or fingers, were formed in the sandy subsoil. The fingers started at the layer interface at 'weak' spots with a relatively low degree of potential water repellency, and protruded vertically into the sandy subsoil. Flow through the fingers caused water-repellent substances to be leached from the topsoil to the subsoil, progressively fixating the finger positions. Laboratory analysis revealed that wetting of dry, water-repellent soil between the vertically directed fingers is an extremely slow process compared with wetting of dry, non-water-repellent, or slightly water-repellent, soil. Evidence was presented that fingers at the field site disappeared during dry periods and recurred at the same location during new rain events. Vertical solute leaching down the fingers was greater by a factor of 3 than that estimated on a piston flow basis. The development of new simulation models capable of predicting water and solute transport through water-repellent soils is urgently needed.
9

Tillman, RW, DR Scotter, MG Wallis, and BE Clothier. "Water repellency and its measurement by using intrinsic sorptivity." Soil Research 27, no. 4 (1989): 637. http://dx.doi.org/10.1071/sr9890637.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Measurements of intrinsic sorptivity (S*) by using both ethanol and water were used to indicate the extent of water-repellency in soil. Experiments with initially dry, acid-purified sand verified that in a non-repellent, nonswelling porous medium S' was indeed intrinsic to the medium, and independent of the sorbing liquid. For initially water-moist, non-repellent sand, the measured S* was different when ethanol and water were the invading fluids. But a bound can be put on this difference. It was concluded that in structurally stable soils, the ratio of S* from ethanol to that for water may be used as an index of water-repellency. In the laboratory, disturbance of repellent soil by sieving or shaking effectively removed the repellency. Subsequent incubation restored it. Field measurements of sorptivity, at a scaled negative surface potential, into an initially moist, fine, sandy loam were made. While the soil appeared to absorb water normally, the sorptivity for water was an order of magnitude lower than expected from the ethanol data. This was due, we suggest, to repellency. Some possible implications of this unexpected result are discussed.
10

Ziogas, Apostolos K., Coen J. Ritsema, Klaas Oostindie, and Louis W. Dekker. "Soil water repellency in north-eastern Greece with adverse effects of drying on the persistence." Soil Research 43, no. 3 (2005): 281. http://dx.doi.org/10.1071/sr04087.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Many soils may be water repellent to some degree, challenging the common perception that soil water repellency is only an interesting aberration. When dry, water repellent soils resist or retard water infiltration into the soil matrix. Soil water repellency often leads to the development of unstable wetting and preferential flow paths. In the present study the persistence of water repellency was examined on samples from topsoils in Thrace, north-eastern Greece, using the Water Drop Penetration Time (WDPT) test. The soil samples were collected from agricultural fields throughout the prefectures of Xanthi and Rodopi. Six sites were selected for intensive sampling of water repellency and soil moisture content in transects. Water repellency was measured on field-moist soil samples and after drying the samples at increasing temperatures, to study the influence of drying temperature on the persistence of soil water repellency. Measurements of soil samples taken in agricultural fields under different crops, e.g. winter wheat, tobacco, clover, olive groves, kiwi fruit, and vineyards, in the area of Thrace, revealed that 45% of the locations exhibited actual water repellency during dry periods. Drying of samples from the Sostis site resulted in wettable soil, whereas drying of samples from the Mitriko site increased repellency. Therefore, water repellency should preferably be measured on samples taken in the field under dry conditions in order to reveal and determine the highest persistence of water repellency that might occur in the field.
Більше джерел
Також вас можуть зацікавити розширені добірки на тему "Water repellent soil" для конкретних типів джерел:
Статті в журналах Дисертації

Дисертації з теми "Water repellent soil":

1

Barrett, Gary Edward. "Infiltration in water repellent soil." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28618.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Observations made at Goat Meadows - a small sub-alpine basin located near Pemberton, British Columbia -demonstrated that a layer which is either water repellent or has only a limited affinity for water is present at most vegetated sites. The layer is typically a few centimetres in thickness, and is usually located at or near the top of the profile: it was present only in the zone of accumulation of organic matter. The spatial distribution of the layer did not appear to be related to the distribution of any particular species of plant. Sampling of sub-alpine sites in the Cascade, Selkirk, and Purcell Mountains indicated that such layers are common in the alpine - sub-alpine ecotone of southern British Columbia. The relationship between ponding depth and infiltration rate was explored through experiments conducted on samples collected near Ash Lake, in Goat Meadows. These samples were chosen for analysis because the repellent layer was in excess of thirty centimetres thick at this site. Infiltration rates remained below 2x10⁻⁹ m/s for all samples, even given ponding depths of up to forty centimetres. Breakthrough of liquid water was not observed, even after one month, which implies that most of the infiltration occurred as vapour transfer. In order to observe the movement of liquid water through water repellent media, a plexiglas cell was constructed. A synthetic water repellent sand with uniform surface properties was used as the medium. It was found that up to some critical depth, there was no entry of water into the medium. As the ponding depth was increased in steps, the front would advance in steps: it remained stationary between these step-increases in ponding depth. As the front advanced, protuberances or "fingers" began to develop. At some critical ponding depth, a finger would grow without bound. These observations pose a challenge to existing models of infiltration, since it appears that heterogeneity at the scale of individual pores must be invoked to explain them, but it is usually assumed that the properties of a porous medium are continuous at this scale. The thermodynamics of filling and emptying of pores is considered with emphasis on the effects of pore shape and of variations in the physicochemical properties at the scale of the pore. This thermodynamic analysis provides the conceptual basis for development of a model of infiltration in which pore-scale heterogeneity is preserved. Although it was not developed as such, the model follows the approach of cellular automata, in which local relations between pores or "cells" govern the behaviour of the system. The model replicated the observations of infiltration into synthetic water repellent porous media well: both the halting advance of the front as the ponding depth was increased and the development of fingers were simulated. The fact that such complex behaviour was predicted using only a simple set of physically based rules confirms the power of the approach.
Arts, Faculty of
Geography, Department of
Graduate
2

Blume, Theresa, Erwin Zehe, and Axel Bronstert. "Use of soil moisture dynamics and patterns at different spatio-temporal scales for the investigation of subsurface flow processes." Universität Potsdam, 2009. http://opus.kobv.de/ubp/volltexte/2010/4492/.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Spatial patterns as well as temporal dynamics of soil moisture have a major influence on runoff generation. The investigation of these dynamics and patterns can thus yield valuable information on hydrological processes, especially in data scarce or previously ungauged catchments. The combination of spatially scarce but temporally high resolution soil moisture profiles with episodic and thus temporally scarce moisture profiles at additional locations provides information on spatial as well as temporal patterns of soil moisture at the hillslope transect scale. This approach is better suited to difficult terrain (dense forest, steep slopes) than geophysical techniques and at the same time less cost-intensive than a high resolution grid of continuously measuring sensors. Rainfall simulation experiments with dye tracers while continuously monitoring soil moisture response allows for visualization of flow processes in the unsaturated zone at these locations. Data was analyzed at different spacio-temporal scales using various graphical methods, such as space-time colour maps (for the event and plot scale) and binary indicator maps (for the long-term and hillslope scale). Annual dynamics of soil moisture and decimeterscale variability were also investigated. The proposed approach proved to be successful in the investigation of flow processes in the unsaturated zone and showed the importance of preferential flow in the Malalcahuello Catchment, a datascarce catchment in the Andes of Southern Chile. Fast response times of stream flow indicate that preferential flow observed at the plot scale might also be of importance at the hillslope or catchment scale. Flow patterns were highly variable in space but persistent in time. The most likely explanation for preferential flow in this catchment is a combination of hydrophobicity, small scale heterogeneity in rainfall due to redistribution in the canopy and strong gradients in unsaturated conductivities leading to self-reinforcing flow paths.
3

Schonsky, Horst Georg [Verfasser], Andre [Akademischer Betreuer] Peters, Gerd [Gutachter] Wessolek, and Jörg [Gutachter] Bachmann. "Energy and water fluxes at the soil atmosphere interface of water repellent soils / Horst Georg Schonsky ; Gutachter: Gerd Wessolek, Jörg Bachmann ; Betreuer: Andre Peters." Berlin : Technische Universität Berlin, 2015. http://d-nb.info/1156272963/34.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Ghosh, Asit, and Shah Nawaz Muhammad Mehmood. "Coating on viscose fabric with respect to environmental aspect." Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20852.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Cotton as a dominating natural fibre imparts a major contribution in the whole textile market including natural and artificial fibres. The demand of this cellulosic fibre is increasing rapidly day by day, on the other hand supply cannot fulfill its demand, and as a result price goes higher in world market. Now people are looking for alternatives to cotton in different applications. Viscose as cellulosic origin, the cheapest of all cellulosic fibres could be the best alternative. Viscose fibre exhibits some similar properties compared to cotton except its poor wet strength. In this thesis work different chemical finishes were applied to improve the wet strength of viscose fabric. For this purpose water repellent and soil release finishes were applied. Both water repellent and soil release finishes helped in reducing the molecular barrier around the individual fibres that lowered the surface tension of the fibre. It reduces the absorbency of viscose fibre hence leads to higher wet strength. Water repellent finish was applied alone as well as in combination with soil release finish. It was seen that viscose fibre exhibited better wet strength after applying water repellent and soil release finishes on it. This improved property of viscose could replace the cotton fibre in certain applications like bed linen.
Program: Magisterutbildning i textilteknologi
5

Tuinstra, Annejet. "Post-Wildfire Debris Flows: Mapping and Analysis of Risk Factors in Western North America." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-446352.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Climate change is leading to in an increase in frequency and severity of wildfires, which in turn can result in the formation of runoff-initiated post-wildfire debris flows. This type of debris flows is, like most debris flows, triggered by heavy precipitation events. Debris flows have the potential to cause much damage, and therefore it is important to analyse when and where the risk of these flows exists. This study aims to identify shared characteristics of basins that experienced post-wildfire debris flows in order to improve future risk analyses regarding such flows. These characteristics were studied through the analysis of 42 basins in 10 burned areas across western North America, which experienced a total of 67 post-wildfire debris flows between 2000 and 2018. Literature research and existing databases revealed the bedrock, soil texture and the timing of the flows compared to the wildfires. Spatial analysis using ArcMap allowed for the analysis of the burn severity of the basins, the hypsometry of the basins, and the mean slope of the basins. Analysis of these characteristics revealed the importance of the hypsometric integral, the soil texture, and the mean slope angle of the basins. In general, the hypsometric integral tends to fall between 0.50 and 0.60 and only soils with a coarse texture were identified for the basins. The mean slope angle of the basins is commonly between 25-30o, with a wider range of slopes being able to generate debris flows shortly after the fire. If multiple basins in a small area are burned, those with steeper slope angles have a higher potential to generate debris flows, while basins with steeper slopes do not have a higher risk on large regional scales. In order to generate post-wildfire debris flows the basin also needs to be burned at a large extent at low to medium severity, resulting in an extensive and strong water-repellent layer required to generate the runoff that is needed to generate a debris flow. Seasonal wetting during winters and drying of the soil during summers can reduce or enhance runoff respectively as well. As a result, post-wildfire debris flows occur mostly during the late summer months shortly after a wildfire when precipitation is increasing through summer storms, or a year later when the soil is dried and primed during the summer followed by such a summer storm. Fires during winter and thus outside the traditional wildfire season can lead to post-wildfire debris flows during winter as well due to the strength of the fresh water-repellent layer. Climate change which will lead to more fires during late autumn and winter months can thereby result in post-wildfire debris flows during winter, rather than only during the summer months following wildfires in the traditional fire season.
Jordskred uppstår när en sammanhängande jordmassa kommer i snabb rörelse. Det är en typ av naturolyckor som kan skada både infrastruktur och människor. Sannolikheten att ett jordskred inträffar ökar efter skogsbränder. Samtidigt kan klimatförändringar leda till en ökning av skogsbränder vilket i sin tur kan leda till en ökad risk för jordskred i framtiden. Syftet med det här projektet är att bidra till bedömningen av risken av jordskred till följd av skogsbänder i västra Nordamerika och att identifiera andra områden som också har en stor risk att drabbs av skred efter skogsbränder genom att identifiera riskfaktorer. Under projektets gång skapades en databas med områden där jordskred inträffade efter skogsbränder i västra Nordamerika. Den vetenskapliga litteraturen visade några egenskaper av skred och områdena, t.ex. när branden och skredet hände, vilken berggrund finns i området och texturen av jordarten i området. Dessutom användandes GIS (Geographical Information System) med satellitbilder och DEM (Digital Elevation models), som visade information om brandskador samt de geomorfologiska karaktärerna av områden. Resultaten visade att formationen av jordskred kräver omfattande låga till måttliga brandskador som resulterar i ett starkt vattenavvisande jordlager. Detta jordlager minskar infiltrationskapaciteten av jorden och resulterar i mer ytavrinning vilket orsakar skred till följd av brand. Även en grov textur av jordlagret är viktig eftersom den också bidrar till ett starkt vattenavvisande jordlager. Dessutom kan askpartiklar bli fångade in i stora porer i jord med en grov textur vilket minskar infiltrationskapaciteten och ökar ytavrinningen. Det finns alltså två krav för att ett jordskred ska inträffa efter en skogsbrand: i) omfattande låga-måttliga brandskador, och ii) en grov textur av jorden. Vidare finns det några ytterligare egenskaper som ökar risken för skred efter skogsbränder om de två kraven är uppfyllda. Den hypsometriska integralen (ett sätt att uttrycka hypsometrin av en dal) ligger oftast mellan 0.50-0.60 vilket är normal för en geomorfologiskt sett mogna område. Dessutom hade de flesta områdena i projektet en medellutning mellan 25o och 30o. Dock fanns det även tillfällen där värdena låg utanför dessa intervaller. Därför kan dessa värden i sig inte användas som riskfaktorer, utan borde de även kombineras med de övriga egenskaperna som beskrivs i den här undersökningen. Det är också relevant att veta när jordskred inträffar till följd av skogsbränder. Resultaten visade att skred kan hända strax efter skogsbränder i slutet av sommaren när det finns kraftigt regn. Det är då som det vattenavvisande jordlagret är som starkast. Det vattenavvisande lagret minskar i styrkan under året, men det är också möjligt att det inträffar ett jordskred under sommaren året efter en skogsbrand. Då är jorden torr i slutet av sommaren när kraftigt regn inträffar efter torra månader. Torr jorden bidrar även till en minskad infiltrationskapacitet. Regn i vinter gör jorden blöt vilket ökar infiltrationskapaciteten av jorden. Dessutom sker det även skogsbränder utanför den traditionella skogsbrandsäsongen nuförtiden, t.ex. tidigt i vintern. I så fall kan jordskred också inträffa under samma vinter strax efter skogsbranden, därför att det vattenavvisande jordlagret som skapas i branden fortfarande är starkt då. Som nämnts tidigare finns det en riskprofil som kan användas för att identifiera områden som har en hög risk för jordskred efter skogsbränder, men möjligheten att ett jordskred inträffar under vintern istället för (slutet av) sommaren bör även iakttas. Risken växer nämligen i samband med klimatförändringar som leder till mer skogsbränder; inte bara under sommaren, utan även under vintern.
6

Ward, Philip R. "Generation of water repellence in sands, and its amelioration by clay addition /." Adelaide, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phw262.pdf.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Roy, Julie L. "Soil water repellency at old crude oil spill sites." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ46912.pdf.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Llewellyn, Christopher Thomas. "Studies of the molecular basis of soil water repellency." Thesis, Swansea University, 2005. https://cronfa.swan.ac.uk/Record/cronfa42740.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
To identify the causes of water repellency in soils, a range of water repellent soils and wettable control soils, sampled from five countries (Australia, Greece, Portugal, The Netherlands, U.K.), were studied. Water repellency was assessed using the water drop penetration time (WDPT) test whilst total organic carbon (TOC) analysis and diffuse reflectance infrared spectroscopy (DRIFT) were used to measure the TOC and aliphatic content respectively in the soils. Water repellency correlated slightly better with aliphatic content than TOC content, although neither correlated well with water repellency. The efficiency of Soxhlet extractions with isopropanol: aqueous ammonia (7:3, v:v) in extracting compounds associated with water repellency was examined. Extraction efficiency was examined by determining: extract mass; severity of water repellency post-extraction; amounts of organic carbon and aliphatic C-H removed; and by assessing the ability of extracts to cause repellency in acid washed sand. Extraction removed repellency completely from 12 of 14 repellent samples and extracts from all soils (including the wettable control samples) were capable of inducing repellency. Samples were rendered wettable regardless of the mass extracted or the quantity of organic carbon removed, suggesting that provided there is some aliphatic material present, the amount is less important than its constitution and/or molecular arrangement. Low polarity solvents caused sample repellency to increase despite the removal of non-polar hydrocarbons, suggesting that compounds such as alkanes are not, in themselves, the main cause of repellency. Kinetics and selectivity of the extraction procedure (using isopropanol: aqueous ammonia) was also examined. Increasing extraction time caused an increase in extract mass and a decrease in soil water repellency. The same compound types were detected by GC-MS in all extracts, but their proportions varied with extraction time. In particular, the removal of alkanes from the soil sample was less rapid than that of more polar compounds.
9

DeBano, Leonard F. "Water-Repellent Soils: What They Are and Why They Are Important." Arizona-Nevada Academy of Science, 1999. http://hdl.handle.net/10150/296535.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Miyata, Shusuke. "Surface runoff and infiltration processes on hillslopes with water repellent soils." Kyoto University, 2007. http://hdl.handle.net/2433/136538.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第13119号
農博第1624号
新制||農||941(附属図書館)
学位論文||H19||N4245(農学部図書室)
UT51-2007-H392
京都大学大学院農学研究科森林科学専攻
(主査)教授 水山 高久, 教授 三野 徹, 教授 谷 誠
学位規則第4条第1項該当
Більше джерел

Книги з теми "Water repellent soil":

1

Robichaud, Peter R. New procedure for sampling infiltration to assess post-fire soil water repellency. Fort Collins, CO: U.S. Dept. of Agriculture, Forest Service, Rocky Mountain Research Station, 2008.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Soil Water Repellency. Elsevier, 2003. http://dx.doi.org/10.1016/c2009-0-13739-x.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

(Editor), C. J. Ritsema, and L. W. Dekker (Editor), eds. Soil Water Repellency: Occurrence, Consequences, and Amelioration. Elsevier Science, 2003.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

H, Cannon Susan, and Geological Survey (U.S.), eds. Fire-induced water-repellent soils: An annotated bibliography. Denver, CO: U.S. Geological Survey, 1997.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

H, Cannon Susan, and Geological Survey (U.S.), eds. Fire-induced water-repellent soils: An annotated bibliography. Denver, CO: U.S. Geological Survey, 1997.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

H, Cannon Susan, and Geological Survey (U.S.), eds. Fire-induced water-repellent soils: An annotated bibliography. Denver, CO: U.S. Geological Survey, 1997.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

H, Cannon Susan, and Geological Survey (U.S.), eds. Fire-induced water-repellent soils: An annotated bibliography. Denver, CO: U.S. Geological Survey, 1997.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

H, Cannon Susan, and Geological Survey (U.S.), eds. Fire-induced water-repellent soils: An annotated bibliography. Denver, CO: U.S. Geological Survey, 1997.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

H, Cannon Susan, and Geological Survey (U.S.), eds. Fire-induced water-repellent soils: An annotated bibliography. Denver, CO: U.S. Geological Survey, 1997.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

H, Cannon Susan, and Geological Survey (U.S.), eds. Fire-induced water-repellent soils: An annotated bibliography. Denver, CO: U.S. Geological Survey, 1997.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Частини книг з теми "Water repellent soil":

1

Novák, Viliam, and Hana Hlaváčiková. "Water Repellent Soils." In Applied Soil Hydrology, 283–91. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01806-1_18.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Bially, Paul T. "Novel Alkyl Polyglucoside Surfactant Derivatives for Improving the Infiltration of Irrigation Water into Repellent Soil." In Pesticide Formulations and Delivery Systems, 31stVolume: Innovative Green Chemistries for the 21stCentury, 95–102. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2011. http://dx.doi.org/10.1520/stp153720120007.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Wallis, M. G., and D. J. Horne. "Soil Water Repellency." In Advances in Soil Science, 91–146. New York, NY: Springer New York, 1992. http://dx.doi.org/10.1007/978-1-4612-2930-8_2.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Ritsema, Coen J., Louis W. Dekker, Klaas Oostindie, Demie Moore, and Bernd Leinauer. "Soil Water Repellency and Critical Soil Water Content." In Soil Science Step-by-Step Field Analysis, 97–112. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2136/2008.soilsciencestepbystep.c8.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Zheng, Shuang, Sérgio D. N. Lourenço, Peter J. Cleall, Stuart W. Millis, Angel K. Y. Ng, and Ting Fong May Chui. "Synthetic Water Repellent Soils for Slope Stabilization." In Advancing Culture of Living with Landslides, 523–28. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-53487-9_61.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Jackson, J. F., and H. F. Linskens. "Determination of Waxes Causing Water Repellency in Sandy Soils." In Essential Oils and Waxes, 291–95. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-84023-4_15.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Savage, S. M. "Occurrence and Phenomenon of Natural and Fire-induced Soil Water Repellency." In SSSA Special Publications, 165–72. Madison, WI, USA: Soil Science Society of America, 2015. http://dx.doi.org/10.2136/sssaspecpub7.c16.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Scott, D. F., and D. B. van Wyk. "The Effects of Fire on Soil Water Repellency, Catchment Sediment Yields and Streamflow." In Fire in South African Mountain Fynbos, 216–39. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-76174-4_12.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

"Water-Repellent Soils." In Encyclopedia of Soil Science, Third Edition, 2546–49. CRC Press, 2017. http://dx.doi.org/10.1081/e-ess3-120006656.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Lal, Rattan, Anna Eynard, and Keith Wiebe. "Water Repellent Soils." In Encyclopedia of Soil Science, Second Edition. CRC Press, 2005. http://dx.doi.org/10.1201/noe0849338304.ch396.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Water repellent soil":

1

Tao, Huanzhuang. "Spatial variation of soil moisture content and soil water repellency in the sugarcane land." In 2017 2nd International Conference on Materials Science, Machinery and Energy Engineering (MSMEE 2017). Paris, France: Atlantis Press, 2017. http://dx.doi.org/10.2991/msmee-17.2017.166.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Flannery, Kelly E., William B. Ouimet, Eli Egan-Anderson, and Sarah A. Vitale. "EXAMINING THE EFFECTS OF 18TH-19TH CENTURY CHARCOAL PRODUCTION ON SOIL-WATER REPELLENCY IN NORTHWESTERN, CONNECTICUT." In 54th Annual GSA Northeastern Section Meeting - 2019. Geological Society of America, 2019. http://dx.doi.org/10.1130/abs/2019ne-328475.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "Water repellent soil":

1

Shillito, Rose, Markus Berli, and Teamrat Ghezzehei. Quantifying the effect of subcritical water repellency on sorptivity : a physically based model. Engineer Research and Development Center (U.S.), July 2021. http://dx.doi.org/10.21079/11681/41054.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Soil water wettability or water repellency is a phenomenon that can affect infiltration and, ultimately, runoff. Thus, there is a need to develop a model that can quantitatively capture the influence of water repellency on infiltration in a physically meaningful way and within the framework of existing infiltration theory. The analytical model developed in this study relates soil sorptivity (an infiltration parameter) with contact angle (a direct measure of water repellency) for variably saturated media. The model was validated with laboratory experiments using a silica sand of known properties treated to produce controlled degrees of water repellency. The measured contact angle and sorptivity values closely matched the model‐predicted values. Further, the relationship between the frequently used water drop penetration time test (used to assess water repellency) and sorptivity was illustrated. Finally, the direct impact of water repellency on saturated hydraulic conductivity was investigated due to its role in infiltration equations and to shed light on inconsistent field observations. It was found that water repellency had minimal effect on the saturated hydraulic conductivity of structureless sand. A quantitative model for infiltration incorporating the effect of water repellency is particularly important for post‐fire hydrologic modeling of burned areas exhibiting water repellent soils.
2

Robichaud, P. R., S. A. Lewis, and L. E. Ashmun. New procedure for sampling infiltration to assess post-fire soil water repellency. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, 2008. http://dx.doi.org/10.2737/rmrs-rn-33.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

До бібліографії