Impact of climate change on groundwater levels in Sirhind Canal Tract of Punjab, India

Abstract

Changing global climate predicts a warmer future which may alter the hydrological cycle, surface water as well as groundwater resource. Groundwater plays an ineradicable role in supplying its water needs to the arid and semi-arid parts of Punjab, region susceptible to the issue of diminishing groundwater resources and the effects of climate change. Thus, a study was performed to simulate the outcomes of the climate change on groundwater levels in Sirhind Canal Tract of Punjab using MODFLOWfor two future time spans, i.e. mid-century (MC) (2020–2050) and end century (EC) (2065–2095) based on CSRIO-Mk 6-CM model, under RCP 4.5 and RCP 6.0 climate scenarios. Two pumping conditions were considered-Condition A assumes that the number of tube wells till EC, would remain same as that of 2018 and Condition B considers that the number of tube wells are expected to increase till 2050, in accordance to the augmenting trend of years 2013–14 to 2017–18. The mean temperature of the tract is predicted to increaseby1.9 °C in MC and 3.6 °C in EC in RCP 4.5, and by 1.6 °C in MC and 3.5 °C in EC in RCP 6.0. The rainfall is also predicted to increase by 17.7 % and 18.2 % under RCP 4.5 and RCP 6.0. The projected change in climate is expected to have positive influence of groundwater recharge with an average increase by 30 % in Condition A and 174 % in Condition B by EC. A fall in water table fall by 5.7 m and 4.3 m by EC under RCP 4.5 and RCP 6.0, respectively for pumping Condition A is predicted, whereas higher fall of 45 m and 57.5 m by EC under RCP 4.5 and RCP 6.0, was predicted for Condition B.