三峡蓄水前后宜昌–城陵矶水情多尺度变化特征分析

采用Morlet小波分解重构和频谱分析等方法,对宜昌、枝城、沙市、监利和城陵矶1997~2014年水位和流量及三峡水库2003~2014年入库、出库流量和库水位数据进行了统计分析,探究了各水文站在三峡建坝前后水情的变化特征及原因。结果表明:各观测站的水位和流量沿程递减,水位的年内波动处同一水平,研究河段内上游河段流量年内和年际变化比下游河段剧烈;各水文站水位和流量变化的显著周期为6.05、11.78、21.2、30.29和53个月,各水文站水位1 a周期变化幅度均在2 m以上,其他周期上的变化幅度为0.08~0.82 m;三峡水库蓄水活动对下游水文站水位和流量等水情的影响有限,主要反映在对水情趋势项的影响上,三峡大坝蓄水后,各水文站水位和流量受到一定程度影响,呈波动性递减变化。

ANALYSIS OF THE MULTIPLE DIMENSIONAL SPATIAL-TEMPORAL VARIATIONS OF HYDROLOGICAL REGIMES ALONG YICHANG TO CHENGLINGKAI DURING THE WATER STORAGE PROCESS IN THREE GORGES

The water level and river discharges data in Yichang, Zhicheng, Shashi, Jianli and Chenglingji during 1997-2014, and the coupled with inflow, outflow and water level in Three Gorges during 2003-2014 were collected to detect the multiple dimensional spatial-temporal variations of hydrological regimes during the water storage process in Three Gorges. And the Mallat decomposition and reconstruction and spectrum analysis approaches were utilized during the analyses. The results indicate the following:(1) the water level and river discharge decrease along the Changjiang River. The annual fluctuations of water levels in different stations are in the same level, while the annual fluctuations of river discharges in the upstream region are more volatile than those in the downstream region; (2) the water regimes in the hydrological stations have the significant periodicities of 6.05, 11.78, 21.2, 30.29 and 53 months. The amplitude of water level in the peridicity of 1 year is above 2 m, while the amplitudes of water level in the other peridicities ranges from 0.08 to 0.82 m. (3) The water storage process in Three Gorges has limited impact on the water regims in the nearby hydrological stations. And the impact mainly conentrate on the trend variation, the water level and river discharge shows decrease trend after the water storage of the Three Gorges.