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Development of a Framework for Discharge Forecasting Over Iowa
YEAR: 2014
INVESTIGATORS: Gabriele Villarini, Aaron Strong

Iowa is plagued by catastrophic natural hazards on a yearly basis, with the 2008 flood and the 2012 drought being two of the most recent extreme events affecting our state. Unfortunately, the question is not if, but when, the next extreme event will happen. There is little we can do to prevent flooding or droughts but we can improve our preparedness for these events. Improved readiness relies on the availability of information that would allow Iowans to make more informed decision about the most suitable water management strategy. The proposed work aims to develop a framework to provide monthly forecasts of discharge over Iowa with a lead time from one month up to one year. The availability of these forecasts would have major societal and economic impacts on hydrology and water resources management, agriculture, disaster forecasts and prevention, energy, finance and insurance, food security, policy-making and public authorities, and transportation. This proposal will advance our preparedness for flood and drought conditions over Iowa. Our approach follows in two phases: Phase I will focus on development of a forecasting system to provide monthly discharge values for one watershed in Iowa (Raccoon River at Van Meter). The methodology leverages on the use of statistical models to describe discharge from low to high flow. These models use rainfall as well as row crop production acreage (used as a proxy for the characterization of the impacts of agricultural practices) as inputs. Monthly rainfall forecasts will be based on one coupled ocean-atmosphere model, while the forecast of row crop production will be based on the value from the previous year (persistence forecast). The discharge forecast will have a lead time from one month up to one year. Phase II will build on the insights gained during Phase I. During this phase, we will consider a total of four coupled ocean-atmosphere models and examine alternative ways of combining them in order to provide an improved forecast of rainfall. The domain of interest for the rainfall analyses will be expanded to the entire State of Iowa. Moreover, the discharge forecast will include a larger number of watersheds reflecting different geology, agricultural practices and rainfall climatology. The methodologies build on analysis tools and data sets with which the PI and Co-PI have extensive experience, and will be developed further here to address the problem of forecasting discharge over Iowa. The results of the proposed work will provide basic information critical to improving the planning and development of adaptation strategies to mitigate future costs and disruptions arising from flood and drought conditions. The results and data from this project will be made available to federal and state agencies, including the U.S. Geological Survey, the U.S. Army Corps of Engineers, the Federal Emergency Management Agency, National Weather Service, and the Iowa Department of Natural Resources. Moreover, this information will be readily available to local stakeholders and users for their own use. The PI is part of the team of researchers at the Iowa Flood Center (IFC), and will leverage the tools and expertise provided by the IFC to make the results of the proposed work relevant and immediately and directly available to agencies and to the general public. Moreover, the dissemination of the results will be facilitated by means of outreach activities through the IFC and the Iowa Water Center.