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

[AHW24-04] From Adoption to Over-Extraction: Evaluation of the Trade-offs of Solar Irrigation in Rajasthan

*Vanshika Gupta¹、S.P. Singh¹ (1.Indian Institute of Technology Roorkee)

キーワード：Solar Irrigation, Groundwater exploitation, Demand analysis, Impact evaluation

The highest incoming solar incidence, overreliance on groundwater, and being a pioneer in adopting solar irrigation policies make Rajasthan the leading state in the adoption of solar irrigation pumps in India. This study examines the factors affecting the scalability of solar irrigation in Rajasthan by using primary survey data from two districts, i.e., Sikar and Jaipur, having the highest concentration of solar irrigation pumps in the state. A Factor Analysis of Mixed Data (FAMD) was deployed to unveil the first-of-its-kind linkages between qualitative and quantitative variables, providing a holistic picture of adoption trade-offs. The identified factors include high initial cost, capital subsidies, delayed repair services, deep groundwater level, etc. To assess the sustainability and environmental favourability of solar irrigation pumps, Geographic Information Systems and Remote Sensing (GIS-RS) techniques were used to compute the Normalized Difference Vegetation Index (NDVI) time series for the vegetation cover data followed by comparison with respective areas’ groundwater levels. The findings reveal that the adoption of solar irrigation initially expanded the cropping to water-intensive crops and additional seasons, such as Rabi and Zaid, which in turn led to increased groundwater extraction. However, this has eventually caused a significant groundwater depletion in the long term, forcing farmers to switch back to cultivating water-extensive crops or only one season, primarily rain-fed. These results of the alarming groundwater exploitation due to solar irrigation pump adoption put forward the divergent impacts of policymaking on groundwater and highlight the need for improved water governance and sustainable water management strategies to ensure the lasting feasibility of solar irrigation in water-scare areas like Rajasthan and beyond.