Development of groundwater management system in Thorthongdaeng Irrigation Project of Thailand -

Abstract

Thorthongdaeng irrigation project is water storage pond type, located in the upper central region of Thailand.  It was found that there was groundwater pumping during the period that the surface water resource is insufficient in the dry seasons. However, the development of groundwater management system for estimating groundwater quantities in various scenarios does not exist for the irrigation project. This study was done to develop the groundwater management system containing the groundwater modeling and monitoring. The groundwater pumping test data was analyzed to determine the hydraulic conductivity, transmissivity and storativity. The groundwater model was calibrated, verified and applied to estimate the annual groundwater use, potential and recharge in the dry, normal and wet years, within the 3 aquifer layers and the 3 irrigation zones. The average annual potential groundwater of 171 million cu.m. was nearly 3 times more than the average annual groundwater uses of 66.5 million cu.m. The average annual groundwater recharge of 64 million cu.m. was almost equal to the annual groundwater uses of 65 million cu.m. However, there should be caution in using and monitoring groundwater in the irrigation zone 1 and zone 2 due to the groundwater use exceeding the groundwater recharge. The groundwater levels in Khampaengphet province had the trend to be rather constant while the groundwater levels in Sukhothai province and Phitsanulok province had the trend to decrease. The groundwater management criteria and the measures to manage the groundwater appropriately and sustainably were set up and presented.