Regional Precipitation-Frequency Analysis and Spatial Mapping of 24-Hour Precipitation for Oregon [Report and Data files]

Details

• Creators:
  Schaefer, Melvin G. ; Barker, Bruce L. ; Taylor, George H. ; Wallis, James R.
• Corporate Creators:
  Oregon. Dept. of Transportation. Research Unit
• Subject/TRT Terms:
  Measuring Methods Precipitation (Meteorology) Precipitation (Meteorology)--Oregon--Measurement Rainfall Rainfall Frequencies--Oregon--Measurement
• Publication/ Report Number:
  OR-RD-FHWA-08-05
• Resource Type:
  Tech Report
• Geographical Coverage:
  Oregon
• OCLC Number:
  742685369
• Edition:
  Final report
• Corporate Publisher:
  Oregon. Dept. of Transportation. Research Unit
• NTL Classification:
  NTL-ENERGY AND ENVIRONMENT-ENERGY AND ENVIRONMENT
• Abstract:
  For this study regional frequency analyses were conducted for precipitation annual maxima in the state of Oregon for the 24-hour duration. A total of 693 precipitation gages in Oregon, southern Washington, western Idaho, northern California and northern Nevada were included in the study, representing 34,062 station-years of record. A regional analysis methodology was utilized that pooled data from climatologically similar areas to increase the dataset and improve the reliability of precipitation-frequency estimates. The regional analysis methodology included L-moment statistics, and an index-flood type approach for scaling the annual maxima data. L-moment statistics were used to: characterize the variability, skewness and kurtosis of the data; measure heterogeneity in proposed homogeneous sub-regions; and assist in identification of an appropriate regional probability distribution.
  
  Spatial mapping techniques were employed for mapping of the precipitation-frequency information. This included spatial mapping of at-site means, L-moment ratio values of L-Cv and L-Skewness, and mapping of precipitation for selected recurrence intervals. Procedures were employed to minimize differences between mapped values and observed station values in a manner that was consistent with the regional behavior of the data and also recognized uncertainties due to natural sampling variability.
  
  Color-shaded isopluvial maps were developed for the 6-month, 2-year, 10-year, 25-year, 50-year, 100-year, 500-year, and 1000-year precipitation recurrence intervals. Electronic gridded datasets are available for use in creation of GIS applications that utilize precipitation-frequency information. Please see the "Supporting Files" tab for the zip of the data files.
  
  
• Format:
  PDF
• Funding:
  SPR 656
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:ee1e2dfb4f5f9a0e135696615d095549ad2b18c84f1ad42dcca28348ae2a965c
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/21841/dot_21841_DS1.pdf
• File Type:
  [PDF - 1.57 MB ]