Research Projects

This project aims to investigate the contribution of terrestrial evapotranspiration (ET) to local precipitation in the Central Ganga Basin using the stable isotopic composition (d18Oand dD) of atmospheric moisture, rainwater, and surface water. By establishing isotopic linkages between different water pools and atmospheric inputs, the study will delineate the roles of plant transpiration and soil evaporation in regional moisture recycling. While large-scale isotopic studies have emphasized transpiration's dominance in global ET, region-specific moisture recycling estimates especially in intensively cultivated monsoon regions like North India remain sparse. Traditional hydrological approaches struggle to quantify the partitioning of ET into transpiration (T) and evaporation (E). Stable isotope techniques offer a unique means to trace moisture pathways, yet very few studies from the Ganga Basin directly measure ground-level vapor (GLV) or compare its isotopic composition with rainwater and surface water. Moreover, no study has yet addressed the seasonal and spatial controls on ET-derived recycled precipitation using d18O and dD in Lucknow. This research fills the existing knowledge gap by providing d18O and dDmeasurements in GLV, rainfall, and water bodies. The research will apply mixing models to quantify the relative contributions of oceanic advection and local ET to precipitation. The data from the work will help in discriminating between evaporation and transpiration using deuterium excess (d-excess) and Craig–Gordon model. The field site, Lucknow (Uttar Pradesh) falling under the Gomti river catchment, offers an ideal urban-agroecosystem transitional setting, where land-use patterns, vegetation cover, and seasonal monsoon dynamics can significantly influence ET fluxes. The project integrates isotope mass balance models, meteorological observations, and remote sensing data to quantify the local recycling ratio and its seasonal variability. The findings will improve our understanding of land-atmosphere interactions and support water resource planning under climate variability.