STUDY ON TEMPORAL AND SPATIAL DISTRIBUTION OF SCARCE PRECIPITATION BY DEPTH-AREA-DURATION ANALYSIS

Depth-area-duration (DAD) analysis has been used in a lot of papers about temporal and spatial distribution of heavy rainfall for long years. In this paper, similar analytical method is used in order to clarify characteristics of temporal and spatial distribution of scarce precipitation that is main cause of drought. First, normalized precipitation by mean annual rainfall is defined. Next, depth-duration curve that is linear approximation is obtained. By this approximation and the result of depth-area analysis, DAD curve that represents fairly the data is obtained. Furthermore, the seriousness of drought is evaluated statistically by the similar method as drought-duration curve method.