Assessing Human Health and Infrastructure Vulnerability to Groundwater Stress in the Northern Indo-Gangetic Plains

The Satluj-Ghaggar river floodplains comprise a heterogeneous landscape, encompassing urban, agricultural, and industrial regions, which extend across the Punjab, Chandigarh, Haryana, and Himachal Pradesh states of the northern Indo-Gangetic Plains (IGP). Previous studies have reported groundwater quality deterioration with harmful heavy metals such as Mn, Fe, Ni, Zn, As, Tl, U, and Se exceeding WHO/BIS thresholds and associated health impacts, including gastrointestinal and skin issues (Kumar et al., 2024), along with groundwater over-extraction-induced land subsidence in parts of this study region, such as western Lundiana, where reported subsidence rates range from -2 to -21 mm/yr (Shankar et al., 2024). However, integrated assessments linking groundwater stress to both human health risks and infrastructure damage remain limited. 

This study provides a comprehensive evaluation of groundwater-related health hazards and land subsidence-driven infrastructure exposure, utilizing hydro-geochemical observations and satellite-based analysis. Using hydro-chemical analysis, we computed non-carcinogenic health indices (HI) for pre- and post-monsoon seasons based on concentrations of 19 heavy metals measured in groundwater (n = 69) and surface water (n = 11). The results indicate that areas exposed to moderate (HI = 1-4) to severe (HI > 4) health risks increased during the post-monsoon season, with children exhibiting higher vulnerability than adults. By integrating population data into the exposure analysis, we observe that rapidly urbanizing areas exhibit high exposure to health risks.

For assessing land deformation and infrastructure vulnerability resulting from groundwater over-drafting, we use multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) time-series analysis over the period 2016-2023, utilizing Sentinel-1 data from the European Space Agency (ESA). We observed an average vertical land motion rate of approximately -6.1 mm/yr across the floodplain. Such deformation trends correlate with long-term average groundwater-level declines of approximately -0.3 m/yr observed in nearly 150 monitoring wells of Central Groundwater Board (CGWB) across the region.

The ongoing subsidence poses increasing risks to built-up areas, mainly near the Chandigarh, Mohali, Kharar, Rajpura, and Deabassi regions, where surface cracks and structural damage have been reported. Using Land Use Land Cover (LULC) map and subsidence results, it was calculated from ArcGIS that approximately 28% of built-up land is exposed to severe (< -20 mm/yr) subsidence-induced potential infrastructure damage. We are further analysing seasonal variations in both health and infrastructure risks to identify periods of higher vulnerability.