Runoff trend detection in the Minjiang River Basin with TFPW-MK method
Wang Yuefeng, Chen Ying, Chen Xingwei
(1.College of Geographical Science Fujian Normal University,350007,Fuzhou, China;2.Cultivation Base of State Key Laboratory of Humid Subtropical Mountain Ecology,350007,Fuzhou, China;3.Fujian Provincial Engineering Research Center for Monitoring and Assessing Terrestrial Disasters,350007,Fuzhou, China)
Abstract:In order to find the suitable method in analyzing the runoff trend of Minjiang River Basin, TFPW-MK method was used to detect the trend of runoff in Minjiang River Basin based on the monthly runoff data of four main hydrological stations from 1950 to 2010, and the results were also compared with that investigated by the method of MK and PW-MK.The results showed that:First,TFPW-MK method was the most suitable method for runoff trend detection in Minjiang River Basin due to the autocorrelation existing in the runoff sequence, and the autocorrelation coefficient r was the key factor to the results.Second,the annual runoff trend in Minjiang River Basin was on the decrease, and this trend was not significant. The runoff in the flood season was on the decrease, while in the non-flood season it was on the increase. As for the seasonal runoff, the runoff was almost on the increase except in the spring, and the increase of winter runoff was especially significant. Moreover, the maximum monthly runoff was in a downward trend, while the minimum monthly runoff was in an upward trend. And the trends for the most hydrological stations were similar. Additionally, the length of time series had an important effect on the results.