Research Projects

Inland surface water bodies, viz. lakes, ponds, rivers, and wetlands, are major contributors to the global C and N2 cycle. These water bodies support freshwater ecosystems and aid living communities by reducing floods and drought, recharging groundwater, and augmenting the low flow of rivers. They also store, transport and assimilate pollutants transferred from their sources. Among them, lakes and ponds with a depth of ≤ 5m are static, lack self-cleaning capacity and are prone to eutrophication and harmful algal blooms. N2O accumulates in the water column of these shallow-depth lakes and ponds (lacustrine system) when excess nutrients, especially nitrogen, are loaded within them, intensifying denitrification. Similarly, the excess nutrients discharged into the lacustrine system can cause algal blooming, and its mortality releases a large amount of organic substance, which later decomposes and releases CO2 and CH4. Thus, lacustrine systems are considered the major hotspots for greenhouse gas (GHG) emissions, namely, CO2, CH4, and N2O, which can disrupt the natural geochemical cycle. The sources of organic material (OM) responsible for GHG emission can be autochthonous in lacustrine systems with higher organic production. At the same time, surface runoff is considered as the only primary source of allochthonous OM. Groundwater which significantly impacts the lacustrine system due to its higher total dissolved components, long retention, and decomposition rate are always neglected leading to incomplete nutrient and pollution budgets and GHG emissions. Groundwater supports the stability of the lacustrine system by influencing the water and material balance through surface and groundwater interactions. Though groundwater discharge into the lacustrine system is less than surface runoff, the groundwater profoundly affects lacustrine water quality, eutrophic status and C-N loadings. In the present study, shallow and small-scale lakes located in Uttarakhand, India at high altitude and plain lands will be chosen. This study will aim to give insights on lacustrine groundwater discharge (LGD) and how it influences sediment-water interactions and subsurface contaminant fluxes under varying hydrogeological and anthropogenic conditions. The data that is generated on nutrient flux and GHG emissions due to LGD, whose estimates are undermined in densely populated countries like India, will be used by researchers to create climate models and plans for mitigating GHG emissions that are particular to a region. Hence, the proposed research enables the scientific community to quantify the impact of LGD on sediment-water interactions, biogeochemical processes under oxidizing and reducing conditions, and GHG production under varying conditions.