Authors: Xiao Huang*, University of South Carolina, Cuizhen Wang, University of South Carolina
Topics: Hazards, Risks, and Disasters, Cartography, Geographic Information Science and Systems
Keywords: flooding, dasymetric mapping, GIS, building footprint, exposure
Session Type: Paper
Presentation File: No File Uploaded
Floods are among the most common natural hazards on earth. Given the rising threat in the U.S., it is of great importance to obtain baseline information by quantifying the general exposure of floods and assessing its impact on those who are likely to bear the eventual cost of flooding. Previous works in estimating flood exposure in the U.S., however, failed to capture the great heterogeneity of population distribution and did not compare multiple floodplain products. The objective of this study is to conduct a comprehensive assessment of exposed population within the 100-year floodplains issued by three different agencies: Federal Emergency Management (FEMA), European Commission Joint Research Center (EC-JRC), and United Nations (UN). To better capture the heterogeneity of population distribution at micro-level, U.S. national building footprint dataset, a newly open-sourced dataset that contains more than 125 million buildings (released by Microsoft in June 2018), is utilized to disaggregate population statistics in block groups from the latest ACS 5-year estimates (2013-2017). The disaggregated building-level statistics are further spatially joined with multiple existing floodplain boundaries. The findings from this national assessment provide valuable benchmark information regarding the current flood exposure in the U.S. by answering the following questions: 1) how many people are exposed? 2) who are they? 3) how are they distributed? 4) how do estimations from different agencies differ spatially?