Spatial analysis of agricultural drought in the Choke watershed region using remote sensing metrics

Agricultural drought in the Choke watershed is driven by precipitation shortages, limited agronomic conditions, and soil moisture deficits throughout the crop-growing season. This study aims to identify the occurrence, distribution, and duration of agricultural drought in the Choke watershed region, upper Blue Nile basin, Ethiopia using integrated satellite imagery, normalized difference vegetation index (NDVI), vegetation health index (VHI), vegetation condition index (VCI), and temperature condition index (TCI). Landsat-8 geo-tiff image data from 2019 to 2023 was analyzed for seasonal crop-growing periods (June to September) using statistical tools in ARC GIS. Moderate drought conditions were observed in June 2022 and August 2023, leading to vegetation stress. In 2020, severe and exceptional droughts were recorded every test month, with August being the most affected. Climate change has driven agricultural drought, impacting crop growth and livestock production. VHI indices showed that a significant portion of the lowland Choke watershed experienced moderate drought, affecting 22.41%, 25.38%, 25.62%, 25.04%, and 24.65% of the area in 2019 and 2023, respectively. NDVI, VHI, and VCI consistently depicted moderate drought and normal to above-average conditions, while TCI tended to overestimate severe drought. VHI indicated that 11.99%, 15.95%, 8.16%, 10.29%, and 18.79% of the region faced severe drought from 2019 to 2023. The Choke watershed region is highly susceptible to drought, necessitating action from government officials, policymakers, and environmentalists to mitigate its effects.