Spatial and temporal trend analysis of groundwater levels and regional groundwater drought assessment of Kabul, Afghanistan

摘要

Groundwater is the dominant source of water supply in Kabul city in Afghanistan, but water levels in the region are steadily declining. This study was undertaken to assess groundwater level trends and examine its drought dynamics in Kabul city. The observation wells were classified using cluster analysis to categorize long-term trends of groundwater water level data. The seasonal and annual variations in groundwater depth have been determined utilizing the Mann-Kendall statistical test. To measure groundwater drought, the Standardized Groundwater Level Index (SGI) was utilized. Based on trend analysis, the water levels in 82 of the observation wells were significantly decreasing. From 2014 to 2020, most of the wells in the study area suffered increasingly severe and persistent drought, as per the SGI results. The analysis of land use and land cover (LULC) indicates that the built-up area is increased from about 15 in 2005 to 32 in 2020 in the study area. Bare land had decreased from about 67 in 2005 to 52 in 2020. The severe decline in groundwater level can be attributed to changes in LULC, overexploitation of groundwater, and declining annual precipitation. The findings of this study indicate that long-term groundwater management measures are required in the city area to maintain groundwater availability.