PRELIMINARY FLOOD-FREQUENCY RELATIONS FOR SMALL STREAMS IN GEORGIA

NEW FLOOD INFORMATION FROM 102 SMALL BASINS (0.1 TO 20 SQUARE MILES), NOT AVAILABLE FOR PREVIOUS FLOOD-FREQUENCY ANALYSES, AND DATA AVAILABLE FROM 120 LARGER DRAINAGE BASINS (20 TO 1,000 SQUARE MILES) HAVE BEEN ANALYZED TO PROVIDE PLANNERS AND DESIGNERS WITH PRELIMINARY RELATIONS FOR ESTIMATING THE MAGNITUDE AND FREQUENCY OF FLOOD PEAK DISCHARGES ON SMALL STREAMS IN GEORGIA. A PROGRAM TO COLLECT AND ANALYZE FLOOD PEAK DATA FROM SMALL NATURAL DRAINAGE BASINS WAS BEGUN IN 1963 BY THE U. S. GEOLOGICAL SURVEY IN COOPERATION WITH THE DEPARTMENT OF TRANSPORTATION OF GEORGIA AND THE U. S. DEPARTMENT OF TRANSPORTATION. THE Q2 (2-YEAR FLOOD) PEAK DISCHARGES WERE DETERMINED FROM FLOOD-FREQUENCY CURVES FOR EACH OF THE SMALL-STREAM STATIONS. MULTIPLE REGRESSION WAS USED TO DEFINE THE RELATION BETWEEN Q2 STATION DATA AND SELECTED PHYSICAL AND CLIMATOLOGICAL BASIN CHARACTERISTICS. STATISTICALLY SIGNIFICANT CHANRACTERISTICS WERE DRAINAGE AREA, SOILS-INFILTRATION-CAPACITY INDEX, AND PRECIPITATION INTENSITY. EQUATIONS WERE DEVELOPED FOR THREE REGIONS IN THE STATE, ROUGHLY DELINEATED BY THREE PHYSIOGRAPHIC PROVINCES. EQUATIONS FOR ESTIMATING Q50 (50-YEAR FLOOD) DISCHARGES WERE DEVELOPED FROM THE Q2 EQUATIONS BY THE RATIO METHOD USING THE STATION FLOOD-FREQUENCY DATA COMPUTED FOR THE LARGER STATIONS. THE EQUATIONS ARE CONSIDERED USABLE FOR ANY SITE IN GEORGIA WHERE THE DRAINAGE AREA IS BETWEEN 0.1 AND 20 SQUARE MILES AND WHERE THE FLOOD FLOW IS VIRTUALLY NATURAL. THE APPROXIMATE STANDARD ERROR OF ESTIMATE OF THE Q50 EQUATION IS 41 PERCENT IN REGION 1 (VALLEY AND RIDGE AND BLUE RIDGE PROVICE), 48 PERCENT IN REGION 2 (PIEDMONT PROVINCE), AND 37 PERCENT IN REGION 3 (COASTAL PLAIN PROVINCE).

  • Supplemental Notes:
    • GDOT RES NO 6303
  • Corporate Authors:

    U.S. Geological Survey

    F Street Between 18th and 19th Street, NW
    Washington, DC    20244
  • Authors:
    • Golden, H G
  • Publication Date: 1973-4

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 29 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00204517
  • Record Type: Publication
  • Report/Paper Numbers: Intrm Rept
  • Files: TRIS
  • Created Date: Jul 16 1974 12:00AM