FLOODFLOWS FROM SMALL DRAINAGE AREAS IN ILLINOIS: PRELIMINARY FLOOD-FREQUENCY RELATIONS

PRELIMINARY TECHNIQUES ARE PRESENTED FOR ESTIMATING FLOOD-FREQUENCY RELATIONS, UP TO THE 50-YEAR RECURRENCE INTERVAL, FOR STREAMS IN ILLINOIS THAT HAVE DRAINAGE AREAS NO GREATER THAN 10 SQUARE MILES. THE DEFINED RELATIONS WILL BE USEFUL FOR THE DESIGN OR IMPROVEMENTS OF HIGHWAY CULVERTS AND OTHER HYDRAULIC STRUCTURES. ANNUAL FLOOD DISCHARGES FOR 61 STATIONS WITH 12 YEARS OF RECORD AND FOR 36 STATIONS WITH 7 YEARS OF RECORD WERE ANALYZED WITH THE RESPECT TO SEVERAL BASIN CHARACTERISTICS. THE DRAINAGE AREAS FOR THESE 97 STATIONS RANGE FROM 0.02 TO 40 SQUARE MILES. TWO ESTIMATING TECHNIQUES ARE PRESENTED: ONE REQUIRES DETERMINATION OF ONLY THE SIZE OF DRAINAGE BASIN AND A REGIONAL FACTOR, AND THE OTHER REQUIRES THE DETERMINATION OF AN ADDITIONAL PARAMETER, CHANNEL SLOPE. THE RELATIVE RELIABILITY OF THE TWO TECHNIQUES IS APPROXIMATED. AN EXAMPLE IS GIVEN TO DEMONSTRATE A STEP-BY-STEP PROCEDURE OF APPLYING THE TECHNIQUES BY COMPUTING THE 25- AND 50-YEAR FLOODS FOR SITE ON CROOKED CREEK IN UNION COUNTY, ILLINOIS. /AUTHOR/

  • Corporate Authors:

    U.S. Geological Survey

    F Street Between 18th and 19th Street, NW
    Washington, DC    20244

    Illinois Department of Transportation

    Division of Highways, 2300 South Dirksen Parkway
    Springfield, IL  United States  62764
  • Authors:
    • Ellis, D W
  • Publication Date: 1968

Subject/Index Terms

Filing Info

  • Accession Number: 00204188
  • Record Type: Publication
  • Report/Paper Numbers: 10 pp
  • Files: TRIS
  • Created Date: Apr 28 1994 12:00AM