Groundwater recharge sources and processes in northwest India: Evidence from high frequency water isotope observations

• DOI: 10.1016/j.ejrh.2023.101570
• Publication Date: 2023-11-14T16:11:48Z
• Authors: G. Krishan; D.J. Lapworth; A.M. MacDonald; M.S. Rao
• Keywords: Depression-focused recharge; Environmental isotopes; δ18O

Bist-Doab, Punjab, northwest India. Water isotopes and specific electrical conductivity (SEC) are used in this paper to investigate groundwater recharge sources processes a catchment with history of high abstraction for irrigation canal irrigation. High frequency (every 10 days) samples water stable isotope analysis (δ18O δ2H) were sampled from dense network shallow (<50 m) deep (>100 hand pumps tube wells northern Punjab between 2009 2014. The study indicates that is dominated by meteoric intensity events. However, small proportion sites located close proximity some canals rivers have significant surface inputs. Isotope observations indicate rapid changes linked post-monsoon pumping seasonal connectivity inputs, even at sites. Rapid likely poor well integrity, highlighting the risk ingress. Shallow groundwaters had significantly higher SEC compared deeper (p = 0.0002). Overall still relatively low (<2000 μS/cm). based on previously published mean residence time years) rate change salinity (2.5–10% per year) potential concern.