塔里木河流域水资源变化的周期性分析及预测

Analysis and Prediction on the Periodical Change of Water Resources in the Tarim River Watershed

利用塔里木河源流区10个水文站1957-2003年的径流量资料,通过时间序列周期方差分析外推法计算了塔里木河上游三源流出山口径流量的水文周期,根据组间差异与组内差异最大的原则,得出塔里木河三源流的水文周期为17 a;利用周期叠加趋势模型对塔里木河三源流出山口总径流量的变化趋势进行了预测,预报模型为:X(τ)=200.984 439 95+0.513 206 81τ+dt+τ。从预测模型的预测结果看,从2006年起将出现一个源流来水量大幅减少的时段,如果不采取积极的对策和解决措施,塔里木河干流的生态问题将更加严峻。

The Tarim River Watershed is located in an arid and semiarid region, and its mainstream is completely recharged by its headstreams because there is no runoff formation in its mainstream area. Therefore, the runoff volumes of the headstreams at their debouchures and the water consumption in the headstream areas should be mainly considered in analyzing the utilization of water resources in the Tarim River Watershed. In this paper, the hydrological periods of runoff volumes of the headstreams at their debouchures in the upper reaches of the Tarim River are calculated based on the data measured by 10 hydrologic stations during the period from 1957 to 2003 by using the time series periodic variance analysis extrapolation method. According to the maximum principle of the difference between two data groups or the internal difference in one data group, the result reveals that the hydrological period of the three headstreams of the Tarim River is 17 years. Then the periodic superposition trend model is applied to predict the change trend of the total surface runoff volume of the three headstreams. The prediction model is expressed as： X（τ）=200.984 439 95 ＋ 0.513 206 81τ ＋ dt＋τ. The predicted results show that the stream flow from the headstreams to the mainstream of the Tarim River will be sharply reduced from 2006, the annual runoff volume of the mainstream will be 2.78×10^9 m^3 if the water consumption in the headstream areas is maintained at the level during the period of 1994 - 2003, and a shortage of annual runoff volume of 2.0×10^9 m^3 will occur comparing with the planned annual runoff volume of 4.6×10^9 m^3 for conserving and regenerating the ecology in the lower reaches of the Tarim River after 2005. Such situation will not only threaten the ecological safety in the lower reaches of the Tarim River, but also the stream flow of the middle reaches will be possibly cut off if the rational and active measures are not taken.