Groundwater vulnerability study using interaction-based model in Musi River Basin, Telangana, Southern India

Abstract

This article aims to develop an interaction-based model for assessing groundwater risks by quantifying uncertainties in hydrological and hydrogeological parameters such as precipitation, soil moisture, evapotranspiration, surface water runoff, and groundwater level. The model is applied to eight sub-basins of the Musi River in Telangana, Southern India, to compare their vulnerabilities. The results indicate that the Musi basin receives substantial annual rainfall, with significant variability in precipitation across its different sub-basins, averaging between 972 to 1125 mm per year. A large proportion of the precipitation occurs during the monsoon season from June to September. Increased rainfall significantly raises water levels, demonstrating a direct correlation between rainfall and groundwater depth. This relationship is crucial for effective water management. Rainfall variability is considerable, leading to significant fluctuations in water levels, reflecting the basin's hydrological responsiveness. Entropy measures reveal the complexity and predictability of hydrological interactions. During the monsoon, the Osman Sagar sub-basin shows significant recharge, accounting for 33.2% of the rainfall, while the Shamirpet sub-basin shows the lowest recharge at 12.1%. Whereas the Hussain Sagar shows a stable recharge pattern year-round. Evapotranspiration and depth to water level interactions vary from 6.9 to 14.9% annually across sub-basins, indicating differences in water availability and atmospheric conditions. The highest soil moisture interaction, observed at 32.9%, occurs with the depth to water level, particularly during the monsoon, in the Osman Sagar sub-basin. Surface runoff and depth to water level interactions also vary, with the Bikkeru sub-basin having the highest interaction at 21.3%, suggesting high responsiveness to runoff. Groundwater vulnerability classifications based on diverse hydrological attributes indicate varying levels of risk across the sub-basins. These findings emphasize the importance of understanding basin-specific interactions for effective water resource management and planning, particularly in regions with varied hydrological responses to rainfall and groundwater resources. This customized approach aids in designing effective strategies for irrigation, water storage, and flood management to each basin's unique characteristics.