Simulation of groundwater flow under the influence of groundwater abstraction in parts of Narmada River basin in Gujarat State, India

Abstract

An area between Narmada and Heran rivers in Gujarat State, India forms an excellent potential aquifer system wherein the surface water and groundwater are well interconnected. A conceptual model of the study area was developed and was calibrated for transient state for 48 stress period for 16 years between 1986 and 2002. During the calibration, it was observed that model is very sensitive to conductance applied to General Head Boundary (GHB) and some extent of aquifer parameters and recharge.The model developed was used to forecast the groundwater flow for 13 years from June 2002 to June 2015. Three categories of scenarios have been simulated in order to reflect a combination of different parameters/variables which are likely to influence the behavior of groundwater in future. In forecasting scenario, a major design objective of groundwater extraction was tested to site the additional tube wells in alluvium area. Quantify possible increase in groundwater withdrawal from these tube wells in such a way to induce the recharge from the river to the aquifer or to reduce the base flow to river.The various scenarios formulated for devising better aquifer management plan for this aquifer system clearly showed that this aquifer system is safe under the present hydrological stresses. The developed model also indicated that increase or decrease in the stress will have substantial impact on the subsurface flow to stream or rivers bordering the modeled area. Considering the natural base flow in the rivers, the study showed that there is large scope for groundwater development in this area, which can be augmented by additional tubewells.