Figure 8 Correlation of parameter α of TFDC, SFDC and FFDC of 224 catchments with catchment physical characteristics BFI ,P max* α p.
As shown in Figure 8 (c), α of FFDC is closely related to the multiplication of maximum daily precipitationPmax and αp . Due to precipitation being a prerequisite for fast flow andPmax basically representing the maximum intensity of daily precipitation. For specific catchments, the maximum fast flow usually occurs when the maximum daily precipitation events happen. Moreover, the probability of exceedance of the fast flow depends on the occurrence of precipitation, as a supplementary condition. Therefore,Pmax*αp is selected as the climatic influencing factors for the shape of FFDC with the Spearman’s rank correlation coefficient of -0.4139. the shape parameters αof FFDC tends to decrease asPmax*αp increases. Based on this, the results of Pmax*αp can be used to predict the spatial variation of FFDC.