Floodplain Modeling in the Kansas River Basin Using Hydrologic Engineering Center (HEC) Models: Impacts of Urbanization and Wetlands for Mitigation
Citation:
Qaiser, K. AND Y. YUAN. Floodplain Modeling in the Kansas River Basin Using Hydrologic Engineering Center (HEC) Models: Impacts of Urbanization and Wetlands for Mitigation. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-11/116, 2011.
Impact/Purpose:
Studies show that the state of Kansas ranks high among the US states with highest losses due to floods (Changnon, 2008). With increasing population growth and urban development, the likelihood of exposure to flood damage is rising. One of the most effective ways of assessing the flood risk to people and property is through the production of flood models, which show areas prone to flooding events of known return periods. The objectives of this study are: 1) to evaluate the impacts of future land use change in the backdrop of 100 year design storms (considered to be the most extreme storm event), on the peak runoff and flood inundation extents for the Kansas River, and 2) to evaluate the potential role of wetlands in flood attenuation. To mitigate flood risk, reservoirs and levees are used. In recent years, wetlands have been studied for flood attenuation and water quality improvement (Mitsch et al., 2001; Crumpton et al., 2007). Wetlands have the capability of short term surface water storage, and can reduce downstream flood peaks. In addition, wetlands have biological, wildlife habitat and water quality benefits. (Lewis, 1995, Hey and Philippi, 1995, Wamsley et al., 2010).
Description:
Flooding is a major natural hazard which every year impacts different regions across the world. Between 2000 and 2008, various types of natural hazards, mainly floods have affected the largest number of people worldwide, averaging 99 million people per year (WDR, 2010). In the United States from 1972 to 2006, the value of property losses due to a catastrophic flood events average about $80 million (Changnon, 2008). In terms of human life, these catastrophic floods on an average kill about 140 people each year in the US (USGS, 2006). Climate change is expected to enhance the risk of extreme storm events (Milly et al., 2002). In addition, the frequency of flash floods and large-area floods in many regions is very likely to increase (Parry et al., 2007 & Alley et al., 2003). These dangers are exacerbated by rapid urbanization occurring across the world (UN, 2010). In the United States, there was a 34% increase in the amount of land devoted to urban and built-up uses between 1982 and 1997 (USDA, 2001). Urbanization generally increases the size and frequency of floods and may expose communities to increasing flood hazards (Parker, 2000; USGS, 2003). These developments have placed a renewed emphasis on the prediction of flood levels and damages, mainly for the purpose of disaster management and urban and regional planning (Milly et al., 2008).