Accession Number : ADA130089

Title :   Statistics of Instantaneous Rainfall Rates.

Descriptive Note : Final rept. 30 Oct 81-30 Mar 83,

Corporate Author : ILLINOIS STATE WATER SURVEY DIV URBANA

Personal Author(s) : Jones,Douglas M A ; Wendland,Wayne M

PDF Url : ADA130089

Report Date : Feb 1983

Pagination or Media Count : 56

Abstract : The known sources of data from arrays of instantaneous precipitation intensity recorders were obtained. Data were obtained from Hohenpeissenberg, F.R.G.; East Central Illinois, U.S.A.; northeastern Illinois U.S.A.; and central Florida, U.S.A. These data were analyzed for line averages of the percent frequency of occurrence of exceedance of threshold precipitation intensities. The correlation coefficients of the precipitation intensity at sites at varying distances from a comparison site were determined and found to decrease with distance; the rate of decrease was an inverse function of distance and a function of the type of precipitation: showery or continuous. Showery rains were found to decorrelate about 12 km from the comparison site while continuous rains decorrelated near 50 km. Precipitation events had longer durations when the continuous rains were produced by cyclonic systems with some months experiencing measurable precipitation rates 20% of the time. Autumn tended to be the season with the least percentage of precipitation time. Single-station intensity data collected at Urbana, Illinois, U.S.A.; Paris, France; Inyanga, Zimbabwe; Bogor, Indonesia; Reading, England; U.K.; Island Beach, New Jersey, U.S.A.; Miami, Florida, U.S.A.; Franklin, North Carolina, U.S.A.; and Majuro, Marshall Islands, were compared. The greatest precipitation intensity observed at any one these sites was 6.31 mm/min at Urbana. By comparison, the maximum rate in southern Germany was 0.32 mm/min and in Zimbabwe 5.08 mm/min.

Descriptors :   *RAINFALL INTENSITY, WEST GERMANY, ILLINOIS, FLORIDA, RHODESIA, HAWAII, THRESHOLD EFFECTS, FREQUENCY, SEASONAL VARIATIONS, REGIONS, GROUND STATIONS, RANGE(DISTANCE), CORRELATION

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE