Study on the changes of water cycle and its impacts in the source region of the Yellow River

查看全文 作　　者：ZHANG Shifeng1, JIA Shaofeng1, LIU Changming1, CAO Wenbing2, HAO Fanghua3, LIU Jiuyu4 & YAN Huayun5 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;2. China University of Geosciences, Beijing 100083, China;3. Beijing Normal University, Beijing 100875, China;4. Bureau of Hydrology of Yellow River Conservancy Commission, Zhengzhou 450003, China;5. Bureau of Hydrology and Water Resource Investigation of Qinghai Province, Xining 810001, China 出　　处：《Science China(Technological Sciences)》索引2004年第47卷第z1期,共10页 摘　　要：The water cycle in the source region of the Yellow River underwent great changes in the 1990s. The major features of the changes are as follows: the gauged runoff declined significantly while the precipitation increased slightly, and the runoff process was more concentrated on the flood season. Water balance analyses indicate that the pondage was kept in the status of negative equilibrium, causing eco-environmental problems. The runoff decrement is due to evaporation increment in this region. Studies show that the runoff process in this region is closely related to that of the other hydrological stations in the upper reaches. When the runoff declines in the source regions, the amount of water also declines in the whole upper reaches of the Yellow River, affecting the balance between water demand and supply. Meanwhile changes will take place in the water cycle of the river course system when the eco-environment deteriorates. The trend of water cycle change in the source region is that the runoff will keep declining with the increment of evaporation caused by temperature rise in the northwest of China in the 21st century. But the hydraulic engineering in the source region will help to mitigate the deterioration of local eco-environment system, though the impacts to the lower reaches of this project may not be the case. 关 键 词：source region of the YELLOW River, water cycle, evaporation, NEGATIVE equilibrium.