Author:

Keywords:

flood prediction, WetSpa, GIS, karstic Suoimuoi catchment

Abstract:

The major obstacles to modelling flood processes in karstic areas are a lack of understanding and model representations of the distinctive features and processes associated with runoff generation in those regions and a lack of field data. In this study, a distributed flood modelling approach, WetSpa, was performed by modifying model representations of some of the predominant features and processes of the karstic Suoimuoi catchment with complex-terrain and mixed land use in the northwest Vietnam. The model was calibrated based on 15 months of hourly hydrometeorological data, topography, land use and soil types in GIS format, and used to continuously simulate both baseflow and fast-responding overland, conduit and channel flows during stormflow periods. Considerable variability in simulation accuracy was found among storm events and within the catchment. The simulation results showed that the model represents reasonably well stormflows generated by rainfall events in the study catchment, and the potential of using distributed flood simulation for estimating future flood conditions under changing land use conditions. It is argued therefore that the WetSpa approach is suitable for application in karstic areas under human and natural pressure.