Change Trends of the Annual Runoff in the Upper Yellow River and Time Series Markov-Chain Forecast Model
LAN Yong-chao 1 ,\ DING Yong-jian\+1,\ KANG Er-si 1 ,\ ZHANG Ji-shi 1 ,\ LIU Gen-sheng 2 (1.Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou Gansu 730000,China; 2.Administrative Office of Hydrology and Water Resources of the Upper Reaches of the Yellow River, Lanzhou Gansu 730030, China)
The upper Yellow River above Tangnag is located in the northeast between 95\^5°～103\^5° E and 32\^5°～36\^0° N of the Tibetan Plateau, with a drainage area of 12\^19×10 4 km 2 , accounting for 1/6 of the total area of the Yellow River basin, which is the main area for runoff formation in the upper reaches of the Yellow River. The runoff from the basin accounts for 95% of the inflow into the Longyangxia Reservoir, the largest reservoir in the upper Yellow River. However, the runoff in the upper Yellow River has decreased since the end of the 1990s owing to the global climate warming and human activity, which not only greatly impacts the economy and peoples living in the upper Yellow River areas, but also restrains the economic development of the whole Yellow River Basin. So accurately predicting the variation of runoff in the upper Yellow River is indispensable for adequate and reasonable exploitation of the water resources in the basin. The long-period evolvement characteristics of the runoff in the Upper Yellow River is analyzed, by using the time series analysis method combined with dispersal stochastic process theory. A new long-period trend forecast model, time series-Markov chain forecast model, is presented based upon the study on the evolvement characteristics of the annual runoff in the Upper Yellow River. The result shows that the model possesses the strongpoint of both time series analysis method and Markov chain model. It can well and truly forecast the evolvement and changing trend of the annual runoff sequence in the Upper Yellow River. It is expected that runoff in the upper Yellow River is at the bottom of the fifth low since the end of the 1980s and it will appear an upward undulate trend in the future decade with the mean runoff less than the long-period mean.
【Fund】： 中国科学院寒区旱区环境与工程研究所知识创新工程项目(CACX2 10 10 0 CACX2 100 16);; 中国科学院知识创新工程项目(KZCX1 1003 KZCX1 0 6 KZCX2 3 0 1)资助
【CateGory Index】： P338
【CateGory Index】： P338