The chosen basin sizes represent an appropriate regional scale at which the effect of local factors on data analyses is minor (Woods 2005). The data used are all officially supplied and were previously successfully used in both research and practical fields (e.g., Xiong et al. 2014; Yu et al. 2014; Du et al. 2015; Jiang et al. 2015). For the Weihe runoff data were provided by the Hydrology Bureau of the Yellow River Conservancy Commission; for the Beijiang – by the Administration of Feilaixia Water Conservancy Project of Guangdong Province; and for the Qingjiang – by the hydrological bulletins of the Yangtze River Water Resources Commission. Daily precipitation and temperature series originated from the National Climate Center of the China Meteorological Administration. Areal average series of precipitation and temperature were used instead of point-scale precipitation (e.g., Szolgayova et al. 2014). Table 1 shows basic information of discharge, precipitation, and temperature records for the three study areas.