Mapping groundwater recharge potential zone using a GIS approach in Hualian River, Taiwan

Hualian River is abundant in runoff and high in sediment transport capacity. Most surface water is utilized for agricultural purposes, whereas domestic and industrial water usage relies on the copious amount of available groundwater. To understand the use of water resources in this basin, the fundamental characteristics and recharge of the groundwater need to be analyzed. In this study, the weight of different factors for potential groundwater recharge and the score under various characteristics were assessed based on the characteristics of the study area. A GIS approach was used to integrate five contributing factors: lithology, land cover/land use, lineaments, drainage, and slope. The results demonstrated that about 1.2% of the study area is designated as excellent potential groundwater recharge. Good, moderate and lower potential groundwater recharge areas cover 11.6, 11.7 and 29.9%, respectively; the area with poor potential groundwater recharge covers 45.6%. The results indicate that the most effective groundwater recharge potential zone is located in the Huatung Valley. In this region, the gravelly stratum and the concentration of drainage also help the streamflow recharge the groundwater system.