Rainwater availability in the Vietnamese Mekong Delta Region
| Meeting | VIWC2026 |
| Topic | OS11:Groundwater, Soil and Surface Water Exchange |
| Author | Roderick van der Linden | Andreas H. Fink | Tran Anh Duc | Patrick Laux | Joël Arnault | Harald Kunstmann |
| Organization | Research Associate Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research | Professor Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research 76128 Karlsruhe, Germany | PhD student Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research Campus Alpin, 82467 Garmisch-Partenkirchen, Germany | Senior Scientist Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research Campus Alpin, 82467 Garmisch-Partenkirchen, Germany | Senior Scientist Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research Campus Alpin, 82467 Garmisch-Partenkirchen, Germany | Professor Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research Campus Alpin, 82467 Garmisch-Partenkirchen, Germany |
| DOI | 2022.1669969812 |
Abstract
Large amounts of groundwater are abstracted in the Vietnamese Mekong Delta region for the use in agriculture (including aquaculture) and as drinking water. Previous analyses suggest that the excessive groundwater abstraction might be one of the main causes for the observed strong land subsidence, which is a threat to the livelihood of millions of people. Rainwater could more intensively serve as an alternative source of water for irrigation and as drinking water. This requires a quantitative assessment of rainwater availability throughout the year, which is particularly important during the dry season to overcome water shortages.<br> Since rainwater availability is mainly determined by the difference between precipitation and evapotranspiration, the main focus of this study lies on the comparison of rainfall and evapotranspiration variability as represented by different datasets. The rainfall datasets used in this comparison are point measurements (station data), station–based gridded datasets (VnGP, APHRODITE and REGEN datasets), and satellite–based estimates (CHIRPS v2.0 and GPM IMERG V06B datasets). For the estimation of evapotranspiration, in general much fewer data sources are available. Therefore, in addition to the global, multi-source GLEAM and TerraClimate datasets, simulations with the coupled atmosphere–hydrology model WRF-Hydro will be used to determine actual evapotranspiration over the Mekong Delta region. WRF-Hydro simulations will additionally be used to investigate the sensitivity of the simulation results to changes in land use/land cover types and DEM. Ultimately, observations and model simulations will be used to quantify rainwater availability and to discuss uncertainties that arise from the different data sources.
Keywords: rainwater availability, rainfall, evapotranspiration, intra- to interannual variability
