From a NEXRAD Rainfall Map to a Flood Inundation Map

Abstract

An application integrating the Hydrologic Engineering Center's ͑HEC͒-Hydrologic Modeling System hydrologic simulation model and the HEC-River Analysis System hydraulic simulation model into a seamless floodplain mapping application is presented. The application is implemented with an ArcGIS 9 workflow model called Map to Map, which converts a map of rainfall data to a flood inundation map. The simulation models are integrated into the application by establishing information exchange points at which time series of information are passed to a model or returned from a model. Communication between simulation models and the Geographic Information System ͑GIS͒ is made possible by interface data models, which provide a one-to-one mapping between data structures within the simulation model and the GIS. A case study is presented for Rosillo Creek in Texas, in which the Map-to-Map model computes flood inundation polygons from rainfall data. Map to Map gives the user a powerful floodplain mapping and real-time flood forecasting tool.

A coupling of hydrologic and hydraulic models appropriate for the fast floods of the Gardon River basin (France)

“…If inflows are obtained by hydrologic modelling, we can call it a hydrologic and hydraulic model coupling. Some examples of coupling have already been detailed in the literature (see, for example, Knebl et al, 2005;Whiteaker et al, 2006;Lian et al, 2007;Biancamaria et al, 2009;Bonnifait et al, 2009;Montanari et al, 2009;Mejia and Reed, 2011;Kim et al, 2012;Lerat et al, 2012). A single application concerns a catchment prone to fast floods: the study of Bonnifait et al (2009), which proposes a coupling of the hydrologic n-TOPMODELs model to the CARIMA hydraulic model.…”

“…Several criteria motivate this choice. Firstly, this type of coupling is more flexible: the models can be easily changed, if it is needed (Whiteaker et al, 2006). This fact is important, because there is still no clear consensus on a preferred approach to hydrologic modelling of flash floods, as stated by Hapuarachchi et al (2011).…”

Sources of uncertainty in flood inundation maps

“…An alternative to the use of the steady‐flow assumption and development of inundation map libraries, as was done for this project, is to estimate inundated areas in real time during, or immediately before, a flood so that the particular characteristics of the rainfall and flood hydrograph are well represented in the hydraulic modelling. Research applications have demonstrated that it is possible to produce reasonable inundation maps from medium‐range weather forecasts (Pappenberger et al ., 2005) or from NWS estimates of rainfall derived from NEXRAD weather radar (Whiteaker et al ., 2006). The limitation of this approach is that the models must be run operationally in real time for each event and that results must be distributed quickly to emergency management officials and all other interested parties.…”

Use of Ground‐based Radar for Climate‐Scale Studies of Weather and Rainfall

“…If many non-geographers are utilizing GIS and radar data in their work, then more geographers should also begin to perform the GIS-based analysis of radar reflectivity data and rainfall estimates. As a GIS facilitates the geospatial analysis of large volumes of data, it has become more widely used for precipitation mapping and hydrologic modeling (Dyras and Serafin-Rek 2005;Fang et al 2008;Knebl et al 2005;Whiteaker et al 2006;Xie et al 2005). The collaboration of geographers specializing in geospatial techniques with those pursuing research in climatology and hydrology could provide specialized tools for the geovisualization and analysis of radar reflectivity and velocity data within a GIS.…”