| Title | Delineation of Groundwater Recharge Areas in High-Terrain Young Andesitic Volcano Geothermal Systems |
|---|---|
| Authors | Suryantini, Hendro Wibowo |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | High-terrain young andesitic volcano geothermal systems are common in Indonesia. The surficial geology is often dominated by massive, non-fractured lava and welded tuff formations, which can act as aquitards. In contrast, some areas may be covered by unconsolidated tephra, agglomerates, or other reworked materials, forming unconfined aquifers or local recharge zones. Geothermal exploration in Indonesia is often hindered by the assumption that high-elevation areas on volcano flanks are groundwater recharge zones that must be protected. However, not all such areas function as recharge zones. In this paper, we discuss the common characteristics of groundwater recharge areas that may not be associated with the geothermal fluid system, meaning these areas can still be utilized for geothermal development, such as siting well pads for drilling targets. We analyzed slope (using DEMNAS data), morphology, hydrostratigraphy, water chemistry, and stable isotopic composition, integrating these factors in a GIS to identify the most plausible recharge areas. This approach is considered a simple, semi-quantitative method that is sufficiently valid for locating groundwater recharge zones. Consequently, areas outside these recharge zones can be deemed suitable for geothermal development. |