Evaluating the impacts of soil and water conservation practices on soil moisture dynamics in the Dengora and Keritwuha watersheds in Central Gondar Ethiopia

Abstract

The Ethiopian highlands are experiencing issues such as water scarcity, land degradation, deforestation, and overgrazing, all of which negatively impact soil productivity. The study examines the effects of soil and water conservation practices on soil moisture dynamics in the Dengora and Keritwuha watersheds of Central Gondar, Ethiopia, from 2015 to 2020. It focuses on how it improves water retention and controls soil erosion. The required data included time-domain reflectometry, passive microwave satellites, in situ soil moisture, and thermal and optical remote sensing analysis, specifically Sentinel-2 data from the European Space Agency. It utilized a mixed research design to evaluate soil–water conservation practices through an optical trapezoidal model, incorporating tools such as ArcGIS and SPSS software. This study examines the impact of various land management techniques, including terracing, contour plowing, cover cropping, and agroforestry. The optical trapezoidal model and the soil moisture estimation showed low root mean square errors and good coefficients of determination, with bias levels ranging from 1 to 8%. It shows a strong correlation between satellite and in situ soil moisture measurements. Also, Sentinel-2 satellite image analysis showed a strong correlation between vegetation and soil moisture content. The soil–water conservation coverage of the Keritwuha, Megachoch, and Washkayna watersheds increased by 19.33, 11.16, and 28.05 hectares, respectively, from 2015 to 2020. Similarly, it covers 40.03%, 56.98%, and 30%, respectively. Consequently, by 2020, the watershed's soil moisture increased by 0.18, 0.27, and 0.24 cm3/cm3. Therefore, sustainable land management practices are crucial for soil moisture content.