Water management using traditional tank cascade systems: a case study of semi-arid region of Southern India

Abstract

Most arid and semi-arid regions of the Southern-Indian peninsula experience frequent drought. To combat this, historically many water recharge structures, such as tank cascade systems, have been constructed. However, in recent years, performance of these tanks, especially for irrigation and groundwater recharge, is limited due to impacts of external factors that are not scientifically understood. This study, for the first time, aimed to explore spatio-temporal variation of water mass balance components and their impact on the Vandiyur tank cascade system (VTCS) in the city of Madurai, India. Study estimated water mass balance components for rural, peri-urban, and urban catchments across VTCS. Catchment-specific algorithms and water budget equation were used to estimate the volume of hydrological parameters. Additionally, land use/land cover maps were developed to understand the significance of using a water balance approach in understanding the behavior of hydrological components governing the water budget of a catchment. Results indicated a rapid increase in the urban area, up to 300%, in peri-urban and urban regions. Urbanization was considered the primary cause of high catchment runoff (40–60% of rainfall). Due to this, seasonal water availability within each tank across catchment was observed inconsistent (0–15%), wherein summer recorded approximately the least tank storage (0–8%). In general, study provided an approach for a practical, water‐focused application demonstrating how the principles of mass balance can help to foster robust water accounting, monitoring, and management. It further emphasized the use of a water balance approach in identifying vulnerable catchments for appropriate tank-rehabilitation-based interventions.