基于卫星测高和实测数据的博斯腾湖水位变化分析

Analysis of Bosten Lake water level change based on satellite altimetry and measured data

湖泊水位是湖泊水文观测必不可缺的要素,直接关系到湖泊物质交换和能量平衡,对研究湖泊运动和区域气候环境变化至关重要。为了掌握内陆湖泊水位的变化过程和空间特征,以新疆博斯腾湖为例,综合Jason-1&2、ENVISat&ERS、ICESat-1、ICESat-2等卫星测高资料,提取博斯腾湖湖泊水域瞬时水位和日均水位,并根据Hydroweb水位记录和1975-2020年博斯腾湖湖泊水位观测及水域面积数据,检验Jason-1&2、ENVISat&ERS、ICESat-1、ICESat-2测高数据的估计精度。借助趋势面分析方法,分析博斯腾湖水域水位变化的空间差异和特征。结果表明:Hydroweb水位记录、Jason-1&2、ENVISat&ERS、ICESat-1、ICESat-2卫星资料估计湖泊日均水位的绝对误差分别为0.24、0.34、0.28、0.18、0.08 m;2020年博斯腾湖年均水位为1048.10±0.12 m,与1975年年均水位相比增加了0.70±0.15 m;湖泊瞬时水位在空间尺度上存在一定水位差,ICESat-2测高数据能准确地描述博斯腾湖水域表面高程和水位变化速率的空间异质性。

The lake water level is an important element of lake hydrological observation,which directly reflects the mass exchange and energy balance of the lake.Moreover,the analysis of lake water level is vital to the study of lake movement and regional climate and environmental change.In order to grasp the change process and spatial characteristics of the water level of inland lakes,both instantaneous and daily mean water level of Xinjiang Bosten Lake were extracted from Jason-1&2,ENVISat&ERS,ICESat-1 and ICESat-2 satellite altimetry data,which were then compared with the water level record of Hydroweb and the measured data of water level and water extent area of Bosten Lake from 1975 to 2020 to ascertain the estimation accuracy of the satellite altimetry data.Furthemore,the trend-surface analysis was used to analyze the spatial difference and characteristics of water level change in Bosten Lake.The results showed that the absolute error of the daily mean lake water level of the Hydroweb water level record,Jason-1&2,ENVISat&ERS,ICESat-1,ICESat-2 satellite altimetry data was 0.24,0.34,0.28,0.18 and 0.08 m,respectively.The annual mean water level of Bosten Lake in 2020 reached 1,048.1± 0.12 m,which had an increase of 0.70 ± 0.15 m,compared with that in 1975.The fluctuation of instantaneous water level showed that there was a water level difference on the spatial scale,and ICESat-2 satellite altimetry data accurately described the spatial heterogeneity of lake water surface elevation and change rate of Bosten Lake.