Changing Trend of Water Resources in Qinghai Province from 1956 to 2000
ZHOU Chen-chao 1 , JIA Shao-feng 1 , YAN Hua-yun 2 , YANG Gui-lin 2 (1.Geographical Sciences and Natural Resources Research Institute, Chinese Academy of Sciences, Beijing 100101, China; 2.Qinghai Hydrology and Water Resource Bureau, Xining Qinghai 810001, China)
In this paper the changing trend of water resources in Qinghai Province is studied. The main representative stations in the head area of the three big rivers (Yangtze River, Yellow River, and Lancang River) are selected. Mann-Kendall and Lineal-Correlation methods are applied to analyze the changing trends of hydrologic components. By use of the yearly series of natural runoff and precipitation data acquired from the representative stations (1956 _2000), it is found that the changing trend of water resources in the head area of the three rivers is different from what achieved before. The results calculated by the two significance test methods are both below the standard value, which confirm the changing trend of water resources in Qinghai Province is not obvious. The water resources did not show an obvious variation trend in the past 45 years; however, it is found that the natural runoff has decreased since 1990. The water shortage in the 1990 had taken some bad influence to Qinghai s environment. At the same time, in order to explain the argument from more expansive area in Qinghai Province, three stations are selected from the areas of internal drainages to analyze. From the analysis, the same result is achieved as what achieved from the previous stations, except for Xiangride station. Of the variation of water resources in the areas of internal drainages, also no any obvious changing trend can be seen. But in Xiangride Station, it is found that both precipitation and natural runoff are obviously increasing.