Earth, Atmosphere & Environment Sciences
Title : | Experimental and Numerical Study of Saltwater Intrusion Control Measures under Tidal Influence |
Area of research : | Earth, Atmosphere & Environment Sciences |
Focus area : | Environmental Engineering and Hydrology |
Principal Investigator : | Dr. Selva Balaji M, Birla Institute Of Technology and Science (BITS), Pilani, Rajasthan |
Timeline Start Year : | 2023 |
Timeline End Year : | 2026 |
Contact info : | selva.balaji@pilani.bits-pilani.ac.in |
Details
Executive Summary : | Coastal aquifers act as important source of freshwater with the increasing dependence due to population increase. Coastal aquifers consist of interactions between marine system, surface and groundwater hydrological system. Saltwater intrusion contaminates the aquifer freshwater and makes them brackish. Reclamation of contaminated aquifer is near impossible, time consuming and expensive. Hence, prevention is better than mitigation to maintain sustainable freshwater resources in coastal aquifers. Saltwater intrusion can be restricted by optimally designing the pumping rates and pumping well locations. Apart from the optimization of pumping rates to restrict saltwater contaminations, introduction of recharge wells, physical barriers (cut off walls, subsurface barriers), and hydraulic barriers with combination of recharge and abstract are ways to restrict saltwater intrusion (Hussain et al. 2019). Previous studies on saltwater intrusion control measures examined the effectiveness of above-mentioned techniques in laboratory for either constant seawater levels or aquifers with stable salt intrusion zone. There is a gap in literature on experimental analysis of effectiveness of saltwater intrusion control measures under variable head seaside boundary─ tidal fluctuations ─ and interactions of instabilities with the employed control measures. Presently available literature shows that saltwater control measures─ cut off walls, subsurface dams, injection wells for positive hydraulic barriers, extraction wells for negative hydraulic barriers, injection and extraction well combinations, and groundwater circulation wells─ are studied for constant head seaside boundary conditions without considering variable water levels due to low frequency tidal waves, and high frequency waves induced by winds. Present study would perform laboratory scale sand-box experiments for effectiveness of saltwater control measures. The parameters influencing the effectiveness would be identified based on sensitivity analysis by using numerical modelling. Field scale numerical modelling simulations would be performed to understand the scale effects in upscaling the laboratory scale parameters to field scale. The numerical models available with commercial use licensing are expensive. For the present study, open-source software SUTRA (Voss and Provost, 2002) for modelling the variably saturated, variable density saltwater intrusion would be used. |
Total Budget (INR): | 25,78,400 |
Organizations involved