scholarly journals Soil Loss Estimation for Conservation Planning in the Welmel Watershed of the Genale Dawa Basin, Ethiopia

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 777 ◽  
Author(s):  
Yared Mesfin Tessema ◽  
Justyna Jasińska ◽  
Lemma Tiki Yadeta ◽  
Marcin Świtoniak ◽  
Radosław Puchałka ◽  
...  

As a form of environmental degradation, soil degradation directly or indirectly affects many lives through decreased agricultural yields, increased flooding and habitat loss. Soil loss has been increasing in most parts of the world and is most pronounced in tropical developing countries where there is poor or zero soil and water conservation (SWC) planning and management activities. Identifying areas prone to soil erosion has also been inadequate, having not been informed by dedicated scientific studies. This is true of the poorly understood watershed of Welmel in the Oromia region of Ethiopia, where most livelihoods heavily rely upon agriculture. To plan effective SWC management techniques, a solid knowledge of spatial variations across different climate, land use and soil erosion is essential. This study has aimed at identifying potential areas needing SWC practices through conducting a spatial modeling of soil erosion within the Welmel watershed’s Genale Dawa basin using a geographic information system (GIS), remote sensing (RS), multiple factors as land uses and climate. The Welmel catchment is located in southeastern Ethiopia and extends between 5°0′0″ N–7°45′00″ N and 39°0′0″ E–41°15′0″ E. The revised universal soil loss equation (RUSLE), which was previously adapted to Ethiopian conditions, was used to estimate potential soil loss. It used information on interpolated rainfall erosivity (R), soil erodibility (K), vegetation cover (C) and topography (LS) from a digital elevation model (DEM) and that of conservation practices (P) from satellite images. The study demonstrates that the RUSLE using GIS and RS considering different climates and land management practices provides a great advantage in that it allows one to spatially analyze multilayer data in order to identify soil erosion-prone areas and thereby develop the most appropriate watershed management strategy. The mean soil loss was determined to be 31 tons ha−1 year−1 and it varied between 0 and 169 tons ha−1 year−1. About 79% of the watershed lies within the tolerable level of 11 tons ha−1 year−1. However, the remaining 21% has a high soil truncation trait, mainly due to its steeper slope and use as cultivated land. Our study identifies cultivated and deforested areas of the watershed as the potential SWC practice demanding areas. Thus, the application of RUSEL using GIS across different land management practices and climate zones is a potential tool for identifying SWC demanding sites. This remains helpful in efforts towards sustainable land management practices for the sustainable livelihood of the local human population.

Author(s):  
Hammad Gilani ◽  
Adeel Ahmad ◽  
Isma Younes ◽  
Sawaid Abbas

Abrupt changes in climatic factors, exploitation of natural resources, and land degradation contribute to soil erosion. This study provides the first comprehensive analysis of annual soil erosion dynamics in Pakistan for 2005 and 2015 using publically available climatic, topographic, soil type, and land cover geospatial datasets at 1 km spatial resolution. A well-accepted and widely applied Revised Universal Soil Loss Equation (RUSLE) was implemented for the annual soil erosion estimations and mapping by incorporating six factors; rainfall erosivity (R), soil erodibility (K), slope-length (L), slope-steepness (S), cover management (C) and conservation practice (P). We used a cross tabular or change matrix method to assess the annual soil erosion (ton/ha/year) changes (2005-2015) in terms of areas and spatial distriburtions in four soil erosion classes; i.e. Low (<1), Medium (1–5], High (5-20], and Very high (>20). Major findings of this paper indicated that, at the national scale, an estimated annual soil erosion of 1.79 ± 11.52 ton/ha/year (mean ± standard deviation) was observed in 2005, which increased to 2.47 ±18.14 ton/ha/year in 2015. Among seven administrative units of Pakistan, in Azad Jammu & Kashmir, the average soil erosion doubled from 14.44 ± 35.70 ton/ha/year in 2005 to 28.03 ± 68.24 ton/ha/year in 2015. Spatially explicit and temporal annual analysis of soil erosion provided in this study is essential for various purposes, including the soil conservation and management practices, environmental impact assessment studies, among others.


2013 ◽  
Vol 864-867 ◽  
pp. 2799-2803
Author(s):  
Wei Li ◽  
Wen Yi Fan ◽  
Xue Gang Mao ◽  
Lin Zhao

Uses 2011 years TM/ETM images classification were land uses/cover type figure, combination Great Khinggan area digital elevation model (DEM), and soil type distribution figure and research regional rainfall information, we got all factors values of space distribution in the USLE model, got soil erosion volume estimates data and soil erosion strength distribution figure based on grid cell data. Result indicate that the micro-absolute percentage of erosion throughout the study area, with increasing slope, area of erosion and erosion gradually reduce trend increases with the elevation increases, reduced erosion area after, generally good soil and water conservation in the region.


Author(s):  
Gizachew Tiruneh ◽  
Mersha Ayalew

Accelerated soil erosion is a worldwide problem because of its economic and environmental impacts. Enfraz watershed is one of the most erosion-prone watersheds in the highlands of Ethiopia, which received little attention. This study was, therefore, carried out to spatially predict the soil loss rate of the watershed with a Geographic Information System (GIS) and Remote Sensing (RS). Revised Universal Soil Loss Equation (RUSLE) adapted to Ethiopian conditions was used to estimate potential soil losses by utilizing information on rainfall erosivity (R) using interpolation of rainfall data, soil erodibility (K) using soil map, vegetation cover (C) using satellite images, topography (LS) using Digital Elevation Model (DEM) and conservation practices (P ) using satellite images. Based on the analysis, about 92.31% (5914.34 ha) of the watershed was categorized none to slight class which under soil loss tolerance (SLT) values ranging from 5 to 11 tons ha-1 year-1. The remaining 7.68% (492.21 ha) of land was classified under moderate to high class about several times the maximum tolerable soil loss. The total and an average amount of soil loss estimated by RUSLE from the watershed was 30,836.41 ton year-1 and 4.81 tons ha-1year-1, respectively.Int. J. Agril. Res. Innov. & Tech. 5 (2): 21-30, December, 2015


2021 ◽  
Vol 14 ◽  
pp. 117862212098581
Author(s):  
Ajanaw Negese ◽  
Endalkachew Fekadu ◽  
Haile Getnet

Soil erosion by water is the major form of land degradation in Chereti watershed, Northeastern Ethiopia. This problem is exacerbated by high rainfall after a long period of dry seasons, undulating topography, intensive cultivation, and lack of proper soil and water conservation measures. Hence, this study aimed to estimate the 23 years (1995-2018) average soil erosion rate of the watershed and to identify and prioritize erosion-vulnerable subwatersheds for conservation planning. The integration of the revised universal soil loss equation (RUSLE), geographic information system, and remote sensing was applied to estimate the long-term soil loss of the watershed. The RUSLE factors such as rainfall erosivity ( R), soil erodibility ( K), topography ( LS), cover and management ( C), and support and conservation practices ( P) factors were computed and overlayed to estimate the soil loss. The result showed that the annual soil loss rate of the watershed ranged up to 187.47 t ha−1 year−1 in steep slope areas with a mean annual soil loss of 38.7 t ha−1 year−1, and the entire watershed lost a total of about 487 057.7 tons of soil annually. About 57.9% of the annual watershed soil loss was generated from 5 subwatersheds which need prior intervention for the planning and implementation of soil conservation measures. The integrated use of RUSLE with GIS and remote sensing was found to be indispensable, less costly, and effective for the estimation of soil erosion, and prioritization of vulnerable subwatersheds for conservation planning.


Soil erosion poses a serious threat over the maintenance activities of a reservoir and its watershed. This study has been taken us to assess the extent of soil erosion in the watersheds of the Siruvani Reservoir located in the district of Kerala. Two methods namely, Universal Soil Loss equation (USLE) and Hypsometric curve methods are adapted in this study. Hypsometry of watersheds (area-elevation analysis) has generally been used to reveal the stages of geomorphic development (stabilized, mature and young). The watersheds of Siruvani Reservoir were delineated from the generated Digital Elevation Model (DEM) using Geographic Information System (GIS). Various set of data like land use map, rainfall and soil map have been used for this analysis to generate five factors namely finally, the soil erosion risk map was created to identify the regions which are susceptible to erosion. Hypsometric analysis deals with measurement of the interrelationships between basin area and altitude of basin which has been used to understand the influence of various factors such as climate, geology and tectonic changes. GIS provides advanced tools to obtain hypsometric information and also helps to estimate the associated parameters of landforms. The entire study area has been sub-divided into 5 watersheds for hypsometric analysis and their area ranges from 1.77 to 6.94 km2. The hypsometric curve of the whole the watersheds reflects the mature geomorphic terrain whereas hypsometric integral indicates that the drainage basin has already eroded per cent of land masses. These findings would emphasize the importance of soil and water conservation measures to be taken up in the Siruvani watersheds for controlling further erosion, reducing the sediment outflows and conserve water.


2021 ◽  
Vol 14 ◽  
pp. 117862212110462
Author(s):  
Meseret Wagari ◽  
Habtamu Tamiru

In this study, Revised Universal Soil Loss Equation (RUSLE) model and Geographic Information System (GIS) platforms were successfully applied to quantify the annual soil loss for the protection of soil erosion in Fincha catchment, Ethiopia. The key physical factors such as rainfall erosivity ( R-factor), soil erodibility ( K-factor), topographic condition (LS-factor), cover management ( C-factor), and support practice ( P-factor) were prepared in GIS environment from rainfall, soil, Digital Elevation Model (DEM), Land use/Land cover (LULC) respectively. The RUSLE equation was used in raster calculator of ArcGIS spatial tool analyst. The individual map of the derived factors was multiplied in the raster calculator and an average annual soil loss ranges from 0.0 to 76.5 t ha−1 yr−1 was estimated. The estimated annual soil loss was categorized based on the qualitative and quantitative classifications as Very Low (0–15 t ha−1 yr−1), Low (15–45 t ha−1 yr−1), Moderate (45–75 t ha−1 yr−1), and High (>75 t ha−1 yr−1). It was found from the generated soil erosion severity map that about 45% of the catchment area was vulnerable to the erosion with an annual soil loss of (>75 t ha−1 yr−1), and this demonstrates that the erosion reduction actions are immediately required to ensure the sustainable soil resources in the study area. The soil erosion severity map generated based on RUSLE model and GIS platforms have a paramount role to alert all stakeholders in controlling the effects of the erosion. The results of the RUSLE model can also be further considered along with the catchment for practical soil loss protection practices.


2021 ◽  
Author(s):  
Mesfin Anteneh ◽  
Dereje Biru

Abstract This research was administered to spatially predict the soil loss rate of kaffa zone using model estimate and GIS. Revised Universal Soil Loss Equation (RUSLE) adapted to Ethiopian conditions was accustomed estimate potential soil losses by utilizing information on rainfall erosivity (R) using interpolation of rainfall data, soil erodibility (K) using DSMW soil map, vegetation cover (C) using Sentinel-2A satellite images, topography (LS) using Digital Elevation Model (DEM) and conservation practices (P ) using DEM and satellite images. supported the analysis, the mean and total annual soil loss potential of the study area was 30 tons ha-1 year-1 and 36264.5tons ha-1 year-1, respectively. The result also showed that about 2.89, 8.02, 15.31 and 73.78% of the study area were classified a slight, moderate, high and very high with values ranging 0 to 15 ,15 to50,50 to 200, and > 200 tons ha-1 year-1, respectively. The study demonstrates that the RUSLE using GIS and RS provides great advantage to spatially analyze multi-layer of knowledge. The expected amount of soil loss and its spatial distribution could facilitate sustainable land use and management.


2021 ◽  
Vol 5 (1) ◽  
pp. 9-27
Author(s):  
Meseret Bekele

Water induced soil erosion has been continued to threaten the land resources in sub humid northwestern highlands of Ethiopia. Human-induced land cover (LC) changes due to improper land management practices are contributing factors in deteriorating soil quality. Soil and water conservation measures have been implemented without site-specific scientifically quantified soil erosion data and priority bases in this regard; this study was conducted with a view to quantifying soil erosion in Anka-Shashara watershed. To do this, we have opted to use the RUSLE model based on geographic information systems. By collecting data on rainfall, soils, vegetation, slopes and conservation practices separately as a layer and determining the pixel values for each of these factors, a quantified assessment of erosion in the basin is obtained. The result reveals that the mean annual soil loss (15.22t/ha/yr) of the most parts of study area falls in tolerable levels and almost 66% (1594 ha), moderate level about 23% and 10% at high level of watershed. The soil loss of watershed is classified in to four main classes. None to Slight rates of soil erosion (0-10t/ha) is cover the almost 66% of watershed moderate about 23% and high about 10% of erosion rate as seen from the erosion rate distribution map. The upstream of catchment needs management and protection of those existing resources and the fundamental attention for SWC as recommended bases. Therefore, to reduce sedimentation problem and ensue sustainability of the watershed need to special attention for implementing recommended SWC intervention at the earlier.


2021 ◽  
Vol 11 (9) ◽  
Author(s):  
W. R. Singh ◽  
S. Barman ◽  
G. Tirkey

AbstractMorphologic parameters of a watershed could help in segregating critical sub-watersheds for taking up conservation practices and mitigation interventions. Determination of critical watersheds or prioritization of sub-watersheds is inevitable for efficient and sustainable watershed management programs and allocation of its natural resources. The traditional methods of determination of morphologic parameters are time consuming, expensive and requires huge labor. However, the process becomes easier, cheaper and faster with the advent of Geographical Information System (GIS) and remote sensing technologies. In the present study, a combined approach of using toposheet, remotely sensed digital elevation model and morphometric ArcGIS toolbox has been adopted to determine morphometric parameters in Dudhnai river basin, a sub-basin of river Brahmaputra which is prone to both erosion and sedimentation. Seven sub-watersheds of Dudhnai have been prioritized by using the morphometric parameters and ranked them according to its vulnerability to soil erosion. The results of bifurcation ratio, drainage density, drainage intensity and constant of channel maintenance showed that Dudhnai watershed is a well-dissected watershed with less risk to flooding and soil erosion. However, significantly high values of infiltration number and ruggedness number obtained are indicative of very low infiltration which may result in high surface runoff and soil erosion. The study also revealed that channel erosion is stronger than sheet erosion in the basin. The prioritization of the sub-watersheds implied that Chil sub-watershed is the most susceptible sub-watershed that needs greater attention for soil and water conservation measures. The results of the present study could aid various stakeholders who are involved in the watershed development and management programs.


2017 ◽  
Vol 12 (No. 2) ◽  
pp. 69-77 ◽  
Author(s):  
M. Hrabalíková ◽  
M. Janeček

Geographic Information Systems (GIS) in combination with soil loss models can enhance evaluation of soil erosion estimation. SAGA and ARC/INFO geographic information systems were used to estimate the topographic (LS) factor of the Universal Soil Loss Equation (USLE) that in turn was used to calculate the soil erosion on a long-term experimental plot near Prague in the Czech Republic. To determine the influence of a chosen algorithm on the soil erosion estimates a digital elevation model with high accuracy (1 × 1 m) and a measured soil loss under simulated rainfall were used. These then provided input for five GIS-based and two manual procedures of computing the combined slope length and steepness factor in the (R)USLE. The results of GIS-based (R)USLE erosion estimates from the seven procedures were compared to the measured soil loss from the 11 m long experimental plot and from 38 rainfall simulations performed here during 15 years. The results indicate that the GIS-based (R)USLE soil loss estimates from five different approaches to calculation of LS factor are lower than the measured average annual soil loss. The two remaining approaches over-predicted the measured soil loss. The best method for LS factor estimation on field scale is the original manual method of the USLE, which predicted the average soil loss with 6% difference from the measured soil loss. The second method is the GIS-based method that concluded a difference of 8%. The results of this study show the need for further work in the area of soil erosion estimation (with particular focus on the rill/interrill ratio) using the GIS and USLE. The study also revealed the need for an application of the same approach to catchment area as it might bring different outcomes.


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