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Soil erosion risk analysis in Sidama Region, southern Ethiopia
Bizunhe, Getie Balkie ; Martínek, Karel (advisor) ; Hroch, Tomáš (referee)
Soil erosion is one of the most important environmental issues in Ethiopia. Studies on erosional processes and soil loss rates can provide insight into the landscape evolution, climate change, and human activities, as well as on land degradation risk. The soil coverage of the Sidama Region study area, Main Ethiopian Rift, is characterized by Major Reference Soil Groups as follows: Luvisols, Cambisols, Nitisols, Vertisols, Andosols, Fluvisols, Regosols, and Leptosols. Cambisols and Luvisols are more susceptible to erosion. Revised Universal Soil Loss Equation (RUSLE) is most developed and recently widely used algorithm which was used to map and estimate the spatial distribution of soil erosion rates in the study area. Two rainfall datasets and three soil structure datasets were tested for reliability. The resulting 6 RUSLE calculations were validated by field mapped polygons in selected areas. It showed that most reliable input datasets are new more complete rainfall data and soil structure data derived from field mapping and sample analysis. The most susceptible areas of soil loss are mapped and the mean soil loss rate in the study area is 28 t/ha/yr. The mean annual soil loss of Sidama study area is above the tolerable mean soil loss (18 t/ha/yr for Ethiopian highlands). The Revised Universal Soil Loss...
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Porovnání nejnovějších metod pro výpočty vodní eroze
VALENTA, David
The content of this bachelor thesis is an explanation that focuses on erosion, especially water erosion. The introductory part explains water erosion, its origin, the consequence of water erosion and possible anti-erosion measures, which can suppress this type of erosion or at least reduce its impact. The main purpose of this bachelor thesis is to compare the available procedures for calculating water erosion. In this work, the methods of average annual land removal and other selected models are presented, which serve as a basis for calculating the immediate land removal. The primary methods for calculating the average annual soil distribution include the USLE and RUSLE methods. In this work, only the most available models were selected to assess the calculation of the instantaneous soil removal.
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Optimal digital terrain model for erosion analysis
Středová, Kamila ; Brychta, Jiří (advisor) ; Rejha, Vít (referee)
The thesis deals with the question of using available sources of elevation data for the evaluation of topographic factor in estimating the amount of water erosion in the area. Work compares the results with consideration to the origin of the data, the accuracy and resolution of the digital terrain model, which is interpolated from the source data. The calculation of topographic factor in ArcGIS will be confronted with the results of the Universal Soil Loss Equation (USLE). The frequency of compliance will tell us which data source and digital terrain model resolution is the most suitable for determining the topographic factor.
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Comparison of the newest methods for computation of water erosion
ŠESTAUBEROVÁ, Martina
The conspectus of this thesis is to explain erosion matters, especially water erosion problems. The introduction part explains the water erosion, its origins, impacts and some erosion control measures, which can precisely this sort of water erosion or at least limit its consequences. The main goal of this thesis is to compare and contrast available methods for the calculation of water erosion. In this work we can find the basic methods for calculating the average annual erosion of soil and the following selected models provide the basis used to calculate the instantaneous erosion of soils. The basic methods for calculation of average annual erosion of soil are then USLE and RUSLE methods. The most available possible models were selected for the purposes of this thesis.
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Comparison of the latest methods for calculations water erosion
KOVÁŘOVÁ, Kristýna
The substance of this thesis is to explain erosion matters, mainly water erosion matters. The opening part explains the water erosion, its causes and consequences, and also possible antierosion measures, which can partly scumble the water erosion or at least reduce its consequences. The main goal of this thesis is to compare and contrast available methods of water erosion calculation. What is presented here are the methods of calculation of average annual soil wash-away and consequently the selected models which serve for calculation of immediate soil wash-away. Methods for calculation of average annual soil wash-away include USLE method and RUSLE method. Only the most available possible models of calculation the immediate soil wash-away were selected for the purposesof this thesis. The closing part of the thesis evaluates teoretical findings in the particular project of land consolidation. Convenience to a given drainage area was considered for individual models of immediate soil wash-away. While calculating the average annual soil wash-away the individual patterns of the USLE method were used. This method developed gradually and individual results were compared.
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Evaluation of a soil erosion in a project of KPU
HAŇKOVÁ, Kateřina
In the Czech Republic, about 50 per cent of agricultural land is affected by water erosion that adversely influences soil productivity and the environment. That´s why the goal of this work was an evaluation of soil erosion danger in an arbitrary area. And secondly, if high erosion danger found, there was a task to make a proposal of suitable erosion control measures. The chosen area is called Hosín, located northly close to České Budějovice. There were fifteen profiles found in the area which are most likely to be in a danger of increased water erosion. These fifteen profiles were proved by two different methods of soil erosion evaluation. The RUSLE method - revised universal soil loss equation, and SMODERP {--} a simulation model of overland flow and erosion processes. SMODERP method showed all the proved profiles beeing not in a high erosion danger. Which means no erosion control measures are needed. The result gained by the RUSLE method was: by more than one third of examined slopes the estimate average annual soil loss raises above the limits. In this case the erosion control measures are necessary. Four different possibilities were proposed, the final one was combination of two erosion control measures {--} mulching and using a vegetative stabilization while the soil is uncovered. This kind of control measure was found to be the best one because of its low financial costs and easy implementation. On the other hand this control measure doesn´t restrict the farmer´s choise of the crops kind to grow. An objective comparison of the different results gained of the two methods wasn´t possible because of different enter data.
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