Initial multiscale evaluation of satellite rainfall products for flood prediction in Iowa

During the spring of 2013, NASA and the Iowa Flood center (IFC) conducted the Iowa Flood Studies (IFloodS) field campaign, a hydrological experiment in the State of Iowa designed as a validation activity of the Global Precipitation Measurement mission. A primary goal of IFloodS is to enhance the understanding of flood-related precipitation processes in Iowa and worldwide and the applicability of satellite rainfall products in flood forecasting. We present a preliminary evaluation of several satellite rainfall products including TMPA (TRMM Multi-satellite Precipitation Analysis), PERSIANN (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Network), Hydro-Estimator, and compare them with radar based rainfall products including the IFC product, Stage IV, N-Pol with and without polarization, in the period between April and June of 2013. These products are used as forcing for the IFC hydrological model and produced discharge simulations in a high-resolution drainage network. The IFC hydrological model has been validated using the IFC radar rainfall product and thus, it becomes the benchmark of comparison for the other rainfall products. We evaluated the hydrological performance of the rainfall products at different spatial scales, ranging from 2 to 14,000 square miles using stream discharge information from USGS and the IFC gauges network. We discuss the adequacy of the rainfall products for flood forecasting at different spatial scales.