多源卫星测高数据监测太湖水位变化及影响分析

Variation and effect analysis of the water level of the Taihu Lake based on multi-source satellite altimetry data

基于Envisat与Cryosat-2卫星测高数据利用波形重跟踪算法提取2003年1月—2019年4月太湖水位信息,并对测高数据进行粗差剔除、卫星间系统误差消除,结合MODIS光学遥感影像提取太湖边界信息,得到长时间序列太湖水位数据。结合气象观测数据和城市人口变迁数据,讨论太湖水位变化规律及其对气候变化以及人类活动影响的响应。结果表明:2003-2009年期间太湖水位呈上升趋势(0.036 m/a),2009-2019年期间太湖水位呈下降趋势(-0.0144 m/a);地表温度及降水均对太湖水位变化有周期性影响,其中降水的影响更为显著;此外,随着太湖周边城市化进程加快,以2009年为节点,2009年后周边城市人口增长速度加快,城市用水需求加大,导致太湖水位呈下降趋势,表明人类活动对太湖水位变化有整体性影响。

The water level of the Taihu Lake from January 2003 to April 2019 was monitored using the waveform retracking method based on the altimetry data of Envisat and Cryosat-2 satellites.Through gross error elimination and system error correction as well as the boundary extraction of Taihu Lake using MODIS remote sensing images,the long time series of the water level of the Taihu Lake were obtained.Based on these as well as weather observation data and the data on urban population changes,the variation pattern of the water level and its response to climate change and human activities were discussed.The results are as follows.The water level of the Taihu Lake showed an upward trend(0.036 m/a)during 2003—2009 and a downward trend(-0.0144 m/a)during 2010—2019.It was affected by the ground surface temperature and precipitation in a periodic manner,especially the precipitation.In addition,as the urbanization in the cities around the Taihu Lake accelerated,the population growth rate in the cities had increased and the water demand had notably increased accordingly from 2009.This resulted in a distinct downward trend in the water level of the Taihu Lake since 2009,indicating that human activities affected the water level of the Taihu Lake over.