1. 1 CE 549 Computational Watershed Hydrology Jonghun Kam Instructor: Professor Venkatesh Merwade

2. OBJECTIVES 2 To develop a methodology for floodplain map derived from soil data and imply the methodology to multiple study area To evaluate the accuracy of the floodplain maps from SSURGO soil data comparing with the FEMA traditional floodplain Traditional floodplain map (FEMA) vs. Floodplain map derived from soil data. Traditional floodplain map approach has little changes except for using better quality of DEM data. Traditional floodplain maps have been issued for over 19,200 communities at a cost of over $1.5 billion

3. Study Area 3 From: www.floodsafety.com Rural area (River Wabash, W. Lafayette) vs. Urban area (River Oaks, Houston)

4. Soil Data  STATSGO vs. SSURGO  STATSGO maps are made at 1:250000 scale  STATSGO data are not detailed enough to make interpretations at a county level.  SSURGO maps are made at scales ranging from 1:12,000 to 1:63,360  Includes more soil classifications – possible to make noise 4

5. Methodology 5 Develop a method to create floodplain maps from soil data Start Imply the method to the study areas Compare the acquired floodplain maps with traditional maps End Modify the method to improve the accuracy “If it works, we can save a lot of money and time”