Exploitation potential of groundwater in Yangzhuang Basin, China under recharge enhancement

Abstract

This paper aims to determine the exploitation potential of groundwater and the optimal exploitation plan in karst areas. Considering the hydrogeological and boundary conditions of Yangzhuang karst groundwater system, a generalized hydrogeological model of groundwater flow was created and the governing equations were derived for karst groundwater simulation in the study area. Then, the study area was divided into 31,152 rectangular grids by finite difference method. The established model was applied to simulate the groundwater levels in 25 observation wells, and proved to be feasible through the fitting of simulated results with the measured results. Next, several forecast conditions and constraints were laid down, including but not limited to the precipitation calculated by historical series and future series (nonstationary) and the recharge enhancement measures like greening and retaining dam construction. Based on these conditions and constraints, a forecast model was created on Visual MODFLOW and coupled with the established hydrogeological model using the groundwater management (GWM) process to evaluate the maximum exploitation potential of groundwater in the study area, and determine the optimal exploitation plan for all groundwater source fields after implementing the above recharge enhancement measures. The evaluation results show that the exploitation volume calculated by the non-stationary future precipitation series outperforms that by the historical precipitation series in prediction accuracy; the allowable exploitation volume should be determined as 258,000 m 3 /d; by the most conservative estimate, the groundwater exploitation volume of the groundwater source fields can be maximized at 243,500 m 3 /d. The research findings lay the basis for sustainable exploitation and utilization of karst groundwater in the study area and similar regions.

The Development of a Coupled Soil Water Assessment Tool-MODFLOW Model for Studying the Impact of Irrigation on a Regional Water Cycle

“…Groundwater has a significant impact on runoff [23]. The MODFLOW-NWT [24] model is one of the most commonly used three-dimensional, physically based, fully distributed groundwater flow models in the world and was developed by the U.S. Geological Survey. It can effectively solve the scenarios of drying and rewetting in unconfined aquifers [25].…”