Assessment of the Impact of Land Use Changes on Groundwater Recharge Potential: A Case Study of the Hat Yai Basin, Songkhla Province

Abstract

In Thailand’s Songkhla Province, the densely populated and economically vital Hat Yai basin (HYB) experiences high water demand from agriculture, industry, and domestic use. Consequently, effective water resource management is essential for the future development of the area, especially concerning groundwater use and recharge. This study investigates the impact of land use changes (LUC) on groundwater recharge potential in the HYB using the Soil and Water Assessment Tool (SWAT) model. Utilizing land use data from 2000, 2011, and 2018, the model was calibrated with runoff data from three stations, achieving an R² of 0.70. The model revealed that the groundwater recharge potential in HYB in 2000, 2011, and 2018 was approximately 283, 244, and 240 mm, respectively. These figures coincide with a decrease in forest area and an increase in residential areas. Notably, a 10% loss of forest between 2000–2011 contributed to an 8% reduction in recharge, highlighting the significant impact of urbanization on this vital resource. Urbanization, which involves replacing forests with residential areas, diminishes water infiltration by disrupting vegetation and root systems, thereby increasing runoff and reducing groundwater recharge potential. Therefore, the study emphasizes the need for comprehensive land use planning and water management strategies in the HYB, prioritizing the protection of natural ecosystems and promoting sustainable development practices.