Adaptation strategy for climate aberrations on rainfed agriculture through conceptualization of catchment-storage-command area in semi-arid region of India

Rainfed crop production in semi-arid regions is constrained with rainfall variability, dry spell during crop season, largely depends on effective rainwater harvesting and supplemental irrigation. This study assessed rainfall, surface runoff relationships, and farm-pond capacity using long-term experiment from a 1.5 ha catchment during 2009–2024, integrating with regional runoff assessment with QSWAT across Rayalaseema region of India. The SCS–CN method was used to estimate runoff from the experimental catchment. Results showed substantial spatial variability in harvestable runoff, indicating that farm-pond capacity should be planned according to catchment, soil, land-use, topographic and rainfall rather than a uniform value. It was also found that occurrence of dry-spells during the crop season was inevitable and the crop was exposed to water stress conditions. Field observations showed that 20 mm supplemental irrigation from harvested water increased groundnut yield by 22%. The integrated framework supports location-specific rainwater-harvesting and climate-adaptation planning for rainfed agriculture.