ESTIMATE GROUND WATER RECHARGE FROM RAINFALL IN DONG NAI RIVER BASIN

Abstract

Ground water recharge estimation is very important for sustainable ground water management. This research shows the results of ground water recharge estimation for Dong Nai River using SWAT model. The results shows ground water recharge in main tributaries of Dong Nai basin varies from 100-500 mm/year. It can be over 700 mm/year at upstream sub basins. Ground water recharge rate compare with total annual rainfall is not uniform due to terrain characteristics, varies from 2-30%. The research indicates the potential of mathematic model application to estimate current stage as well as the changing trend of ground water recharge. Classification map of ground water recharge can be used as basis for identifying and developing ground water exploitation plan. The analysis result in this article is part of the project "Research on the Role of hydrology, land surface and Water Use in the Sai Gon - Dong Nai River Basin in the formation of underground water resources in downstream and proposed solutions to exploit underground water resources stability" implemeted by the Institute of Hydrometeorology and Climate Change.