[A-HW24] Human- and Climate-induced variability in water cycle and (sub)surface water resources

[AHW24-06] Modelling Irrigation Strategies to Mitigate Groundwater Depletion in a Water-Stressed Agroecosystem of India

*Divyam Garg¹、Hemant Kumar¹ (1.Department of Civil Engineering, Indian Institute of Technology Roorkee, India)

キーワード：Groundwater sustainability, water use efficiency, hydro-economic modelling, crop switching, climate variability, swarm-based optimization

The intensification of agriculture in North-West India, a key food-producing region, has been predominantly sustained through groundwater irrigation. However, decades of excessive groundwater extraction have led to alarming declines in water tables, turning the region into a critical hotspot of groundwater depletion. In the Anthropocene, climate variability and anthropogenic interventions—such as high cropping intensity and water-intensive cultivation patterns—have exacerbated the imbalance in the terrestrial hydrological cycle. Addressing this challenge requires an integrated assessment of groundwater resources and agricultural water demand under changing climatic conditions. This study employs a multi-objective modelling approach that combines a biophysical crop model with a regional optimization framework to evaluate irrigation strategies aimed at enhancing water use efficiency (WUE) while sustaining agricultural productivity. By incorporating climate variability, soil properties, and field management practices, we assess the hydrological trade-offs associated with crop switching and deficit irrigation in two water-stressed districts of Southern Haryana, where groundwater levels have declined beyond 30 m b.g.l. We further analyse the potential for reducing irrigation water demand by increasing millet cultivation, given its lower water footprint compared to conventional cereal crops. Our results highlight the role of adaptive agricultural strategies in mitigating groundwater depletion and contribute to the broader discussion on sustainable water resource management. By integrating modelling techniques with policy-relevant insights, this study aligns with the need for synergistic assessments of hydrological fluxes to inform climate-resilient agricultural planning.