GIS based annual soil loss estimation with revised universal soil loss equation (RUSLE) in the upper Meki sub-catchment, rift valley sub-basin, Ethiopia

Abstract

Soil erosion is the most challenging and major environmental problems in the Upper Meki Sub catchment. Therefore, this work aims to determine the relative influences of erosion governing factors and to estimate the annual soil loss in the sub catchment area using RUSLE model. The model variables including rainfall erosivity (R), soil erodibility (K), topography (LS), cover and management (C), and support practices (P) were implemented into the GIS environment and a layer of each of these factors was prepared. The estimated value of R, K, LS, C, and P for the sub catchment area ranges from 512 to 604 MJ mm ha^-1 h^-1yr^-1, 0.137 to 0.169 tons/ha, 0 to 59, 0.001 to 0.4 and 0.10 – 1.00 respectively. The raster values of all these factors were multiplied by using GIS calculator. Based on the results from GIS raster calculation and RUSLE model, the total annual potential soil loss from the sub catchment area is about 2,756,540 tons per year with a mean estimated soil loss rate of 28.12 + 34.77 t/ha/yr and the total actual annual soil loss is 492929 tons with an estimated erosion rate of 37.05 + 46.7 t/ha/yr. Rainfall is identified as the most sensitive factor of soil erosion in the sub catchment area. Our estimation of soil erosion provides notional basses that the area needs immediate action to sustain the soil. Nevertheless, further research on severity analysis and area prioritization, and sediment loss estimation in this watershed is highly recommended to develop practical way of conserving practices.

Keywords:

• Soil loss
• revised universal soil loss equation
• GIS and remote sensing
• Meki catchment

REVIEWING EDITOR:

• Manuel Tejada, University of Seville, Spain

SUBJECTS:

• Soil Sciences
• Conservation - Environment Studies
• Landscape Conservation
• Maintenance and Management
• GIS
• Remote Sensing & Cartography

Disclosure statement

The authors declare there is no Complete of Interest at this study.

Authors’ contributions

Degfie Teku: Design the research, data collection and writing original draft. Nega Kesete: Methodology, interpretation of data and analysis. Abebaw Abebe: literature review, data coding, writing and editing final draft.

Disclosure of interest

This research has no any conflict of interest.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request. Author address can be found from the abstract page.

Additional information

Funding

No funding was received.

Notes on contributors

Degfie Teku

Degfie Teku obtained his BSc. degree in Geology from University of Gonder and his MSc. degree in Environmental Geology in university of Gonder. He is a lecturer and a researcher in the Department of Geology at Mekdela Amba University. He is now engaged in teaching, research and community service. His special research interests are geological hazard, climate and land degradation.

Nega Kesete

Nega Kesete obtained his MSc. degree in surface hydrology. He is now a PhD candidate at Bahir Dar university in climatology. He has worked in lecturer and researcher position at Ambo university and Mekdela Amba university in department of natural resource management. His primary research interests are land degradation, climate, environmental hazard, water resource management and GIS.

Abebaw Abebe

Abebaw Abebe obtained his BSc. degree in Agricultural economics from Jimma University and his MSc. degree in Agricultural information and communication management from Haramaya university. He is a lecturer and a researcher in the Department of Rural Development and Agricultural Extension at Mekdela Amba University. He is now engaged in teaching, research and community service. His special research interests are agricultural and environmental information analysis, risk and uncertainty analysis, socio-economic, agricultural market analysis, value chain analysis and food security.