Real-Time Flood Forecasting and Information System for the State of Iowa

Abstract

The Iowa Flood Center (IFC), established following the 2008 record floods, has developed a real-time flood forecasting and information dissemination system for use by all Iowans. The system complements the operational forecasting issued by the National Weather Service, is based on sound scientific principles of flood genesis and spatial organization, and includes many technological advances. At its core is a continuous rainfall–runoff model based on landscape decomposition into hillslopes and channel links. Rainfall conversion to runoff is modeled through soil moisture accounting at hillslopes. Channel routing is based on a nonlinear representation of water velocity that considers the discharge amount as well as the upstream drainage area. Mathematically, the model represents a large system of ordinary differential equations organized to follow river network topology. The IFC also developed an efficient numerical solver suitable for high-performance computing architecture. The solver allows the IFC to update forecasts every 15 min for over 1,000 Iowa communities. The input to the system comes from a radar-rainfall algorithm, developed in-house, that maps rainfall every 5 min with high spatial resolution. The algorithm uses Level II radar reflectivity and other polarimetric data from the Weather Surveillance Radar-1988 Dual-Polarimetric (WSR-88DP) radar network. A large library of flood inundation maps and real-time river stage data from over 200 IFC “stream-stage sensors” complement the IFC information system. The system communicates all this information to the general public through a comprehensive browser-based and interactive platform. Streamflow forecasts and observations from Iowa can provide support for a similar system being developed at the National Water Center through model intercomparisons, diagnostic analyses, and product evaluations.

Leveraging a Participatory Process for Restoration Return on Investment: The Nature Conservancy's Floodplain Investment Tool

“…The landscape was decomposed into hillslopes and channel links in the stream using a methodology similar to that of Krajewski et al. (). Segments where floodplain longitudinal connectivity supports ecological functioning allowing unimpeded movement of water, sediment, and organisms were defined using stream confluences and these channel links to provide natural break points for further comparison.…”

Cyberinfrastructure and Web Apps for Managing and Disseminating the National Water Model

“…The massive amount of new information being produced by the NWM presents a new challenge in water data management. Besides the NWM, other high‐resolution hydrologic model outputs are already being produced from global land surface models and continue to improve the ability to forecast hydrologic events (Gochis et al ., ; Snow et al ., ; Krajewski et al ., ). With the advent of new and more comprehensive hydrologic models, the scientific community is now starting to close the second gap: providing timely, continuous, and freely accessible water intelligence.…”

A Case Study for the Application of an Operational Two-Dimensional Real-Time Flooding Forecasting System and Smart Water Level Gauges on Roads in Tainan City, Taiwan

“…To prevent flood disasters by increasing the response time, many countries have developed their own flood forecasting systems, such as the Watershed Simulation and Forecasting System (WSFS) of Finland [1], the Melbourne Water's Flood Integrated Decision Support System (FIDSS) of Melbourne, Australia [2], the Ensemble Streamflow Prediction (ESP) of Sweden [3], the Mekong Flood Forecasting System of the Mekong River Commission [4], the National Flood Forecasting System (NFFS) of UK [5], and the Iowa Flood Information System (IFIS) of Iowa State, USA [6]. In Taiwan, the Water Resources Agency has developed the FEWS_Taiwan platform based on the structure of the Delft-FEWS platform.…”