Morphometric and land use land cover analysis for the management of water resources in Guder sub-basin, Ethiopia

Abstract

Morphometric analysis is essential for understanding the surface hydrological processes within a watershed. It enables the prediction of runoff and infiltration patterns, assesses soil erosion risks, and helps in the planning of effective water resource management practices. The integrated approach of morphometric analysis and land use land cover (LULC) analysis is vital for addressing water resource challenges and ensuring the sustainable management of watersheds. The present study aims to measure the morphometric and LULC parameters to assess and understand the morphological and hydrological properties of the Guder sub-basin. The Guder sub-basin is an ungauged watershed facing water resource challenges throughout the year. The study used data from the Shuttle Radar Topographic Mission (SRTM) Digital Elevation Model (DEM) to extract the stream network and sub-watershed (SW) through ArcGIS10.4 environment using Arc hydro tools and the SWAT model. Fourteen morphometric parameters including linear, areal, and relief were computed over thirty sub-watersheds for prioritization of watersheds. The land use land cover analysis was conducted using the Google Earth Engine platform to examine how anthropogenic factors affect hydrologic aspects. The Guder sub-basin LULC was divided into seven classes: bare land, built-up, bushland, cropland, forest, grassland, and waterbody, with 93% overall accuracy. Based on the combined results obtained, the sub-watersheds were classified into five priority categories: very low (> 9.23), low (8.82–9.23), medium (8.14–8.58), high (7.66–8.11), and very high (< 7.66). Sub-watersheds SW3, SW7, SW14, SW17, SW22, and SW29 were identified as high priority watersheds with a high probability of runoff and erosion. Sub-watersheds SW6, SW9, SW11, SW13, SW28, and SW30 were identified as low priority watersheds, indicating good infiltration. Therefore, immediate action should be applied for appropriate land and water management to mitigate the risks and optimize the benefits in these areas. The outcome of this research provides knowledge of watershed hydrologic information before planning and implementing land and water management practices.