河西走廊近50年来地表水资源时间序列的小波分析

Wavelet Analysis on the Temporal Series of Surface Water Resources in the Hexi Corridor of Gansu Province since Recent 50 Years

小波分析(waveletAnalysis)是时间一频率分析领域近年来迅速发展的一种新技术,具有多时间尺度、多层次和多分辨的特性。应用小波分析原理对甘肃河西走廊近50a来的径流、降水、气温等影响地表水资源时间序列的因素进行了分析,结果表明,水资源具有多尺度振荡的特点,具有2-4a,5-9a,12-15a,以及20a左右的周期变化。径流与降水和气温具有同步的时间序列,但是它们的主要周期尺度不同。小波分析的应用对河西走廊水资源趋势和预测研究提供了一个新的方法和思路。

Wavelet Analysis is a newly and rapidly developed technology in the field of time-frequency analysis recently, and it has the characteristics of multiple temporal scales, multiple hierarchical analyses, and multiple solution powers. In this paper, the wavelet analysis is used to analyze the factors affecting the temporal series of water resources in the Hexi Corridor since recent 50 years, and the factors include mainly the annual precipitation, air temperature, ice-snow melt water volume in the Qilian Mountains and annual volume of water resources in the Hexi Corridor. The Hexi Corridor is located in a narrow level zone between the Qilian Mountains in the south and the North Mountains in the north, Gansu Province, it is about 1 000 km in length from the western piedmont of the Wusaoling Mountain in the east to the place near Yumenguan in the west, its elevation varies in a range of 1 100～1 500 m a.s.l. The corridor is gently sloped northward, and it is composed of the gravel Gobi deserts, sand-gravel Gobi deserts, soil Gobi deserts and the fixed, semi-fixed and mobile sandlands. The Hexi Corridor is divided into three inland basins due to the uplift of the Heishan Mountain in Jiuquan and the Dahuangshan Mountain in Minle, and from east to west the three basins belong to the Shiyang River Watershed, Heihe River Watershed and Shule River Watershed respectively. The Hexi Corridor is rich in water resources, it is estimated that the annual volume of surface water flowing from the northern piedmont of the Qilian Mountains into the corridor is 6.512×10^9 m^3, in which the proportions of the Shiyang River, Heihe River and Shule River stream systems occupy 23%, 57% and 20% respectively. The study results show that the volume of water resources fluctuates at multiple temporal scales, i.e., the periodical changes of 2～4 years, 5～9 years, 12～15 years and about 20 years. The temporal series of annual volume of water resources, precipitation and air temperature are synchronous, however, their main periodical scales are different. Wavelet analysis can provide a new method and conception for predicting the trend of water resources in the Hexi Corridor.