Identifying the Spatial and Community‐Based Hotspots of Drought Within the White Volta Basin of Ghana: A Multi‐Index Approach

This study used a multi‐index approach to identify the hotspots of agricultural drought within the White Volta Basin (WVB) in Ghana. Ground‐based rainfall and temperature data were utilised together with satellite and reanalysis data to calculate multiple drought indices: Standardised Precipitation Index (SPI), Standardised Precipitation Evapotranspiration Index (SPEI), and Soil Moisture Condition Index (SMCI). Various drought characteristics like count, duration, intensity and severity were computed for each grid within the basin to create spatial hotspot maps of drought as well as hotspots at the community level with 30 communities selected across the basin. The analysis was conducted for the full year, the growing season (May to October) and the dry season (November to April) for the period 1991–2020. The Mann‐Kendall test and Sen’s slope estimator were used to identify the trends in the drought characteristics. The results indicate that at the basin scale, drought dominated from 2013 to 2020 with significant events seen in 2002 during the dry season and 2015 during the growing season. The southwestern portion of the basin was identified as the primary hotspot of drought using the combined index. The greatest vulnerability was seen within the savannah region during the growing season while the upper east dominated during the dry season. The research provides crucial information for targeted drought management and adaptation strategies within the basin.