HYDROLOGICAL DROUGHT ASSESSMENT USING GEOSPATIAL TECHNOLOGY OF THE YERLA RIVER BASIN, MAHARASHTRA (INDIA)

Abstract

Hydrological drought poses significant challenges to surface and groundwater resources, impacting agriculture, ecosystems, and water management strategies. This study examines hydrological drought in the Yerla River Basin, Maharashtra, using the Groundwater Drought Index (GWDI) and Standardized Groundwater Index (SGI). Groundwater level data from 32 observation wells (1994–2023) were analyzed to assess temporal drought trends and delineate spatial drought risk zones through Geographic Information System (GIS) techniques. The GWDI quantified groundwater drought by evaluating water table deviations, while the SGI standardized fluctuations for effective monitoring. The findings highlight severe drought periods, notably 2000–2003 and 2011, with significant regional variations in intensity. Post-monsoon GWDI assessments identified acute drought conditions in Kadegaon and Khambale Aundh, while pre-monsoon analysis revealed prolonged drought persistence in Hanmantvadiye and Kadegaon until 2003, followed by partial recovery. SGI results reinforced these trends, pinpointing severe drought hotspots in Kadegaon, Khanapur (Sangli), and Khatav (Satara). Spatial interpolation using Inverse Distance Weighting (IDW) and weighted overlay analysis classified drought severity into five levels, aiding in vulnerability mapping. The study underscores the need for proactive drought mitigation strategies, including early warning systems, enhanced groundwater monitoring, and community-driven water conservation measures. By integrating GIS-based techniques with groundwater data, this research provides critical insights into drought dynamics and supports the formulation of adaptive water management policies tailored to semi-arid regions like the Yerla River Basin.