Science and Mathematics Education Commons^™

Flood Frequency Estimation By Neyman-Scott Rectangular Pulse Rainfall Model And Topmodel, Richard Bernatz

Journal of the Iowa Academy of Science: JIAS

A spatial-temporal Neyman-Scott Rectangular Pulse (NSRP) stochastic rainfall model is developed for seasonal-continuous simulation to project annual discharge probabilities from a relatively small watershed, the 1395 km2 Upper Iowa River watershed upstream from Decorah, Iowa. NSRP rainfall data is used as rainfall input to TOPMODEL, a conceptual, semidistributed rainfall runoff model, to calculate river discharge at a site common to the United States Geological Survey (USGS) gauging station in Decorah, Iowa. Annual peak flows based on simulated rainfall are used to fit a log-Pearson type III distribution to project 1 %-, 0.2%-, and 0.1 %-annual discharges. These results are compared …