A new approach to selecting a regionalized design hyetograph by principal component analysis and analytic hierarchy process

Abstract

Designing storm hyetographs is the essential element of hydrologic modeling analysis and storm water drainage design. In order to reasonably use storm hyetograph design in an un-gauged area, a regional representative hyetograph from an alternative and uniform area must be found. A new approach is proposed in this study to select a regional design storm hyetograph using principal component analysis (PCA) and analytic hierarchy process (AHP). The proposed approach combines both PCA and cluster analysis techniques. Furthermore, the AHP method is also used to establish the regional design hyetograph. A case study applied in the area of northern Taiwan shows that our method can successfully categorize the area into three homogenous zones. A representative regional hyetograph can be obtained by selecting the largest priority vector or by the weighted average of rain gauges in each zone.