Link to U.S. Geological Survey home page.

In cooperation with the Texas Department of Transportation

Atlas of Interoccurrence Intervals for Selected Thresholds of Daily Precipitation in Texas

By William H. Asquith and Meghan C. Roussel

U.S. Geological Survey
Water-Resources Investigations Report 03–4281


Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Acrobat Reader 5.0 for Windows (English only), which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at http://access.adobe.com/.

pdf (33.1 MB)


CONTENTS

Abstract

Introduction

Data Sources

Previous Studies

Approach

Site-Specific Interoccurrence Intervals

Regionalization of Interoccurrence Intervals

Interoccurrence Intervals for Selected Daily Precipitation Thresholds in Texas

Statewide Interoccurrence Interval Maps

Influence of Elevation on Interoccurrence Intervals West of the Pecos River

Intra-Annual Variations in Interoccurrence Intervals

Example Applications

Site-Specific Median 6-Month Daily Precipitation Threshold

Site-Specific Median Number of Occurrences

Intra-Annual Variations in Interoccurrence Intervals

Regional Estimation of Mean Interoccurrence Interval

Summary

Selected References

Figures

1. 
Map showing locations of 1,306 National Weather Service daily precipitation stations in Texas
2. 
Example of abbreviated time series of daily precipitation for station 428 Austin Camp Mabry
3. 
Example interoccurrence interval computations for a hypothetical data set
4–13. 
Maps showing interoccurrence interval for a:
 
4. 
0.05-inch and greater daily precipitation threshold for Texas
 
5. 
0.10-inch and greater daily precipitation threshold for Texas
 
6. 
0.25-inch and greater daily precipitation threshold for Texas
 
7. 
0.50-inch and greater daily precipitation threshold for Texas
 
8. 
0.75-inch and greater daily precipitation threshold for Texas
 
9. 
1.0-inch and greater daily precipitation threshold for Texas
 
10. 
1.5-inch and greater daily precipitation threshold for Texas
 
11. 
2.0-inch and greater daily precipitation threshold for Texas
 
12. 
2.5-inch and greater daily precipitation threshold for Texas
 
13. 
3.0-inch and greater daily precipitation threshold for Texas
14a–j. 
Graphs showing relation between interoccurrence interval and elevation west of the Pecos River, west Texas
15–24. 
Boxplots showing distribution of ratio of interoccurrence interval for month to mean interoccurrence interval for period of record at station for a:
 
15. 
0.05-inch and greater daily precipitation threshold for Texas
 
16. 
0.10-inch and greater daily precipitation threshold for Texas
 
17. 
0.25-inch and greater daily precipitation threshold for Texas
 
18. 
0.50-inch and greater daily precipitation threshold for Texas
 
19. 
0.75-inch and greater daily precipitation threshold for Texas
20. 
1.0-inch and greater daily precipitation threshold for Texas
21. 
1.5-inch and greater daily precipitation threshold for Texas
22. 
2.0-inch and greater daily precipitation threshold for Texa
23. 
2.5-inch and greater daily precipitation threshold for Texas
24. 
3.0-inch and greater daily precipitation threshold for Texas
25–28. 
Graphs showing:
25. 
Relation between adjusted mean and median interoccurrence ratios and month for 0.05- and 0.10-inch daily precipitation thresholds for Texas
26. 
Relation between adjusted mean interoccurrence ratio and month for 0.25-, 0.50-, 0.75-, 1.0-, 1.5-, 2.0-, 2.5-, and 3.0-inch daily precipitation thresholds for Texas
27. 
Relation between adjusted median interoccurrence ratio and month for 0.25-, 0.50-, 0.75-, 1.0-, 1.5-, 2.0-, 2.5-, and 3.0-inch daily precipitation thresholds for Texas
28. 
Relation between site-specific daily precipitation threshold and mean interoccurrence interval for station 428 Austin Camp Mabry and estimated median 6-month precipitation

Tables

1. 
Summary of National Weather Service daily precipitation stations in Texas with known names, latitudes, and longitudes
2. 
National Weather Service daily precipitation stations in Texas, by county
3. 
Summary of interoccurrence intervals for daily precipitation thresholds of 0.05 and 0.10 inch
4. 
Summary of interoccurrence intervals for daily precipitation thresholds of 0.25 and 0.50 inch
5. 
Summary of interoccurrence intervals for daily precipitation thresholds of 0.75 and 1.0 inch
6. 
Summary of interoccurrence intervals for daily precipitation thresholds of 1.5 and 2.0 inches
7. 
Summary of interoccurrence intervals for daily precipitation thresholds of 2.5 and 3.0 inches
8. 
Example computation steps of interoccurrence intervals for a Poisson process described in text
9. 
Summary of statewide interoccurrence interval statistics and diagnostic statistics of interoccurrence interval maps
10. 
Summary of interoccurrence ratios by month for 0.05-inch and greater daily precipitation threshold
11. 
Summary of interoccurrence ratios by month for 0.10-inch and greater daily precipitation threshold
12. 
Summary of interoccurrence ratios by month for 0.25-inch and greater daily precipitation threshold
13. 
Summary of interoccurrence ratios by month for 0.50-inch and greater daily precipitation threshold
14. 
Summary of interoccurrence ratios by month for 0.75-inch and greater daily precipitation threshold
15. 
Summary of interoccurrence ratios by month for 1.0-inch and greater daily precipitation threshold
16. 
Summary of interoccurrence ratios by month for 1.5-inch and greater daily precipitation threshold
17. 
Summary of interoccurrence ratios by month for 2.0-inch and greater daily precipitation threshold
18. 
Summary of interoccurrence ratios by month for 2.5-inch and greater daily precipitation threshold
19. 
Summary of interoccurrence ratios by month for 3.0-inch and greater daily precipitation threshold
20. 
Regional estimates of mean interoccurrence interval of precipitation for Austin, Texas

CONVERSION FACTORS AND VERTICAL DATUM

Multiply
 
By
 
To obtain
foot (ft)
 
0.3048
  meter (m)
inch (in.)
 
25.40      
  millimeter (mm)
mile (mi)
 
1.609  
  kilometer (km)

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).


Abstract

A Poisson process model is used to define the distribution of interoccurrence intervals of daily precipitation in Texas. A precipitation interoccurrence interval is the time period between two successive rainfall events. Rainfall events are defined as daily precipitation equaling or exceeding a specified depth threshold. Ten precipitation thresholds are considered: 0.05, 0.10, 0.25, 0.50, 0.75, 1.0, 1.5, 2.0, 2.5, and 3.0 inches. Site-specific mean interoccurrence interval and ancillary statistics are presented for each threshold and for each of 1,306 National Weather Service daily precipitation gages. Maps depicting the spatial variation across Texas of the mean interoccurrence interval for each threshold are presented. The percent change from the statewide standard deviation of the interoccurrence intervals to the root-mean-square error ranges from a magnitude minimum of (negative) -24 to a magnitude maximum of -60 percent for the 0.05- and 2.0-inch thresholds, respectively. Because of the substantial negative percent change, the maps are considered more reliable estimators of the mean interoccurrence interval for most locations in Texas than the statewide mean values.


U.S. Department of the Interior, U.S. Geological Survey
Persistent URL: http://pubs.water.usgs.gov/wri034281
Page Contact Information: GS Pubs Web Contact
Last modified: Friday, September 16 2005, 04:23:48 PM
FirstGov button  Take Pride in America button