Estimating the Impacts of Climate Change and Population Growth on Flood Discharges in the United States

AbstractThis study reflects a portion of the riverine analysis for a Federal Emergency Management Agency initiative to estimate the economic risks associated with climate and land use change to the U.S. National Flood Insurance Program. Specifically, this paper investigates how the 1% annual chance flood discharge, Q1% (equivalent to a 100-year return period flood), may change based on climate change and population projections through the year 2100. Watershed characteristics and observations of climate indicators at 2,357 U.S. Geological Survey gauging stations were used to develop regression relationships to estimate Q1%. Projections of the climate indicators that measure extremes in temperature and precipitation from a suite of global climate models were then used within a Monte Carlo sampling framework to estimate future changes to Q1% throughout the United States, while also translating the uncertainty resulting from multiple climate model projections into uncertainty in estimating the future Q1%. Pop...