Tight coupling UFMArcGIS for simulating inundation depth in densely area

Abstract. The integration of hydrological models and Geographical Information Systems (GIS) usually takes two approaches: loose coupling and tight coupling. This paper presents a tight coupling approach within a GIS environment that is achieved by integrating the urban flood model with the macro language of GIS. Such an approach affords an uncomplicated way to capitalize on the GIS visualization and spatial analysis functions, thereby significantly supporting the dynamic simulation process of hydrological modeling. The tight coupling approach is illustrated by UFMArcGIS (Urban Flood Model with ArcGIS), which is a realization of an urban flood model integrated with the VBA (visual basic of application) language of ArcGIS. Within this model, major stages of model structures are created from the initial parameter input and transformation of datasets, intermediate maps are then visualized, and the results are finally presented in various graphical formats in their geographic context. This approach provides a convenient and single environment in which users can visually interact with the model, e.g. by adjusting parameters while simultaneously observing the corresponding results. This significantly facilitates users in the exploratory data analysis and decision-making stages in terms of the model applications.