A publicly available GIS-based web platform for reservoir inundation mapping in the lower Mekong region

Dam construction in mainland Southeast Asia has increased substantially in recent years. Most dams have the potential to generate value, however, potential and existing impacts include alterations in water regimes, loss and degradation of natural forests and bio-diversity. For mapping impacts, we have developed the Reservoir Mapping Tool for the greater Mekong region designed in ArcGIS Desktop 10.5 ModelBuilder, with dam point location and digital elevation model SRTM-30 m on a publicly available web interface which provides inundated area and dam volume based on user inputs. We validate our results and find excellent agreement with ground data from the Lanh Ra dam located in Vietnam. Further validation and error quantification are done comparing results of three different DEMS's and compared with reported values. We also illustrate various application areas using this information in combination with other geospatial layers, which could provide key inputs towards assessing overall social impacts of dams.