Variance spectra of short duration rainfall in time and space


  • David M. Hershfield


Variance spectra for rainfall amounts were determined for time series composed of 5-, 10-, 30-, and 60-minute rainfalls from selected storms at individual gages in dense networks. Space series were developed from rainfalls at fixed intervals along transects in the direction of storm movement. The areas considered in the analysis range in size from less than 1 mi2 to 1000 mi2 and cover several rainfall regimes. Diagrams display such relationships as the correlation coefficient as a function of distance between rain gages and time series duration, the autocorrelation coefficient as a function of lag and time series duration, and the power spectral density as a function of wave number for both the time and the space series.