The GCC method was verified using data from the Dagutai, Bailianhe and Kaifengyu watersheds, located in the middle reaches of the Han River, the largest tributary of the Yangtze River, China (Figure 4). All watersheds are within the subtropical monsoon climate zone. A digital elevation model (DEM) of each watershed was derived from shuttle radar topographic mission data, obtained from consortium for spatial information (http://srtm.csi.cgiar.org/) at a 90 m grid resolution. The Yangtze River Commission of the Ministry of Water Resources, P.R. China provided 6-hourly rainfall and instantaneous runoff data measured every 6 hours from each watershed. From these data a total of 18 representative storm events were selected for analysis (Table 1), with six events from the Dagutai watershed with four rain gauges, seven events from the Bailianhe watershed with 14 rain gauges and five events from the Kaifengyu watershed with 29 rain gauges.