Abstract: The consistency of hydrological sequence might have been changed by human activities and climate change. The daily data in flood season of 6 rainfall gauges during the period of 1963 to 2013 was addressed to analyze the consistency of rainfall-runoff in the upper Huanhe river. The Mann-Kendall rank statistic test and Pettitt change-point statistical methods were applied to trend and abrupt change test in terms of 1 day, 3 days and 7 days. Then the spatial and temporal distribution change of rainfall was quantified with non-uniform coefficient and a gravity center model. The runoff change pattern of different relative duration was analyzed using daily flow duration curve. Finally, the temporal variation of rainfall-runoff relation was explored. The result indicated that the rainfall showd a nonsignificant trend of decrease and non-obvious change in spatial distribution, while the rainfall gravity center mainly located between Guangshui station and Caodian station.The runoff in Huayuan station assumed the reduced tendency, while the maximum average flow in 1 day, 3 days and 7 days have declined significantly. The downward trend of high flow and upward trend of low flow was obvious. The deviation between high flow and median flow reduced, similarly with the deviation between low flow and median flow. The average decline rate of rainfall and runoff was 11.6 mm/10 a、20.8 mm/10 a over the years while the runoff coefficient in flood season descended. The runoff coefficient and runoff had a piecewise linear relationship with the break point of 565 mm for rainfall.
Key words：spatio-temporal evolution; spatial non-uniformity; rainfall gravity center; flow duration curve; rainfall-runoff relationship