Geospatial multi-criteria evaluation to identify groundwater potential in a Himalayan District, Rudraprayag, India

The Himalayan region faces significant challenges in groundwater resource management due to the relief, precipitous slope, and rocky surface, leading to a lower infiltration into subsurface groundwater. Moreover, the region faces significant challenges due to the decline in its quantity and deterioration in quality, exacerbated by urbanisation, land-use change, over-abstraction, poor administration, and mismanagement. Therefore, the present study adopted the Analytic Hierarchy Process (AHP) and geospatial techniques to identify groundwater potential sites in the Rudraprayag district, the Indian Himalayan Region. We used expert knowledge to assign weights, then normalised by AHP eigenvector. The final index was developed using the weighted overlay method and specific criteria, including geomorphology, geology, slope, relief, drainage density, lineament density, dissection index, precipitation, and land use/land cover (LULC). We used the receiver operating characteristic (ROC) curve and the estimated area under the curve (AUC) for validation. The groundwater potential results show that the very few areas are potentially good (1.4%, 26.81 km(2)) and moderately good (17.70%, 350.9 km(2)), while 61.35% (1216.61 km(2)) areas are moderate to poor groundwater potential. The results show that plain to the nearly plain surface of the valley floor and the vicinity of perennial river (Alaknanda and Mandakini River valleys) areas are most potentially best sites for groundwater development. The groundwater potential sites proposed in the study can help farmers, regional planners, and local governments make more precise decisions to determine the groundwater development sites for installing hand pumps and tube wells for regular water supply. The study results have implications for developing a sustainable groundwater management plan to reduce the risk of water scarcity, improve the efficiency of water use, and restore and protect water-related ecosystems in the region.