The development of the Raster-based Probability Flood Inundation Model (RProFIM) approach for flood modelling in the upstream Citarum Watershed, West Java, Indonesia

The Raster-based Probability Flood Inundation Model (RProFIM) approach was proposed in this study as a new model for flood inundation modelling. Scenarios of changes in land use/land cover (LULC) and differences in return periods are used as the basis for flood modelling scenarios in the study area. The aims of this study are: (a) to estimate the discharge volume in the scenario of changing LULC between 1990 and 2050 and the difference in return period between 2 and 100 years; (b) to create and produce flood inundation maps using the RProFIM approach; (c) to analyse the flood-affected area based on the results given by overlaying the flood inundation maps with LULC data. In general, the results of the flood probability modelling from the RProFIM model can provide the same pattern and conditions as indicated by the reference data. The results of the study also found several potential flood-prone areas in the Citarum Watershed, West Java-Indonesia, based on the RProFIM approach in the Districts of Margaasih, Kutawaringin, Margahayu, Katapang, Dayeuhkolot, and Baleendah. Furthermore, the results of overlaying the flood probability model from the RProFIM model with LULC data are used to determine the flood-affected area. These results indicate that in general the greatest impact of flooding occurs on agricultural and built-up lands which continues to increase every year in the return period range of 2–100 years. This study is expected to be used as one of the considerations in managing environmental problems in dealing with flooding in the study area.