Files and code used to determine which NFIP claims were caused by pluvial flooding. This folder contains (1) the inputs used for the analysis, (2) the code to run the analysis, and (3) outputs from the analysis.
(1) Inputs
outsideClaims.mat
NFIP non SFHA claims
retrieved from https://www.fema.gov/openfema-data-page/fima-nfip-redacted-claims-v2 (web address as of 5/17/2024)
accessed 11/15/2022
includes only claims with listed floodZone of B, C, or X
outsidePolicies.mat
NFIP non SFHA policies
retrieved from https://www.fema.gov/openfema-data-page/fima-nfip-redacted-policies-v2 (web address as of 5/17/2024)
accessed 2/14/2023
includes only policies with listed floodZone of B, C, or X
basinShapefiles folder
USGS Streamgage NHDPlus Watersheds
retrieved from https://www.sciencebase.gov/catalog/item/631405ccd34e36012efa32dc (web address as of 5/17/2024)
allUSGSgages.mat
combined all NHDPlus shapefile information together into a single matlab file
Streamflows folder
USGS Streamflows
retrieved from https://waterdata.usgs.gov/nwis/rt (web address as of 5/17/2024)
generated by DownloadUSGSStreamflows.m code
Frequency factor table for log-Pearson III analysis - "KFreqFact_logp.mat"
retrieved from https://streamflow.engr.oregonstate.edu/analysis/floodfreq/skew.htm (web address as of 5/17/2024)
(2) Code
DownloadUSGSStreamflows.m
Downloads daily discharge data for all USGS gages from the USGS NHDPlus dataset and stores the streamflow as .txt files
Input: allGages
Output: .txt files in Streamflows folder
LogPearson3Analysis.m
Performs the Log-Pearson Type III analysis on the daily streamflows for each USGS to determine the date(s) each gage experienced a 100-yr+ discharge event
Inputs: KFreqFact_logp, Streamflows folder, basinShapefiles folder, allUSGSgages
Outputs: Q100Final, Q100Gages, keptGages
FindingClaimsAndPoliciesWithGageInfo.m
Filters out claims that don't occur inside a USGS gage watershed with flow data for the date of the claim, leaving only claims we can determine if they were caused by a pluvial or 100-yr+ event
Inputs: outsideClaims, outsidePolicies, keptGages
Outputs: goodClaims, goodPolicies
AnalyzingClaims.m
Analyzes if a claim is due to a pluvial or 100-yr+ event
Inputs: Q100Gages, Q100Final, goodClaims
Outputs: analyzedClaims
(3) Outputs
Q100Final.mat
Final table with discharge 100-yr+ events determined from log-Pearson III analysis
generated by LogPearson3Analysis.m code
Q100Gages.mat
List of all gages with a 100-yr+ event determined from log-Pearson III analysis
generated by LogPearson3Analysis.m code
keptGages.mat
Dataset with all the watershed information for gages with sufficient data to perform this log-Pearson III analysis
generated by LogPearson3Analysis.m code
goodClaims.mat
Dataset with all claims with sufficient information to perform our analysis. These claims occur inside a USGS gage watershed with discharge data for the date of the claim.
generated by FindingClaimsAndPoliciesWithGageInfo.m code
goodPolicies.mat
Dataset with all policies with sufficient information to perform our analysis. These claims occur inside a USGS gage watershed with discharge data for the year the policy was active.
generated by FindingClaimsAndPoliciesWithGageInfo.m code
analyzedClaims.mat
Dataset with a new field, "causedBy100yr", indicating if a claim was due to pluvial flooding (0) or a 100-yr+ event (1)
generated by AnalyzingClaims.m code