Preliminary Conceptual Model of Hydrogeological System in The Raimanuk and its Surrounding Area on the Timor Island

Abstract

There are several areas with groundwater potential in Timor island, one of which is the Raimanuk and its surrounding area. This study aims to determine the hydrogeological system in the Raimanuk and its surrounding area. The hydrogeological system is determined by the geological conditions, geomorphology, lithology, and groundwater flow patterns. Geological conditions and groundwater flow patterns are provided by conducting a field investigation. Twenty shallow wells and four springs were measured to provide the groundwater contour. The geoelectrical survey was conducted at eleven points to analyze subsurface lithology. The results show that the geology of the study area is dominated by alluvium (west area), carbonate siltstone, and crystalline limestone (middle to the east area). There are two types of aquifers in the study area: unconfined aquifers and confined aquifers with gravel sandstone lithology. The groundwater flow pattern shows that the groundwater movement is from the east to the southwest. Moreover, the groundwater also moved from the northern, southern, and western of the study area. It is implied that the aquifer’s shape at the Raimanuk area is formed as a bowl-like shape influenced by the geological, geomorphological conditions.