多源遥感影像和测高数据协同的季节性湖泊水量动态监测研究

Regular and accurate monitoring of water volume in lakes is essential for equitable water allocation to water use sectors, ecological environment protection and regional sustainable development. Satellite imagery and altimetry are now gradually used to calculate water volume in some great lakes. However, the complex water regime of seasonally flooded lake introduce difficulties, particularly with respect to many isolated sub-lake during the low-water season. Therefore, the existing strategies and algorithms to accurately calculate water volume of seasonally flood lakes are difficult, and specific approaches need to be developed. In this project, we select Poyang Lake, the largest freshwater lake in China, as the research area. We plan to integrate multi-satellite images, new altimetry data and field investigations to monitor the water volume of this lake during different seasons. Key objectives in this project include: (1) Combing multi-satellite images to acquire accurate water inundation area through the methods of data fusion, scale transfer, and error analysis; (2) Proposing a set of water level retrieval methodology (including data selection, waveform retracking and combined adjustment ) through combining new altimetry data to suit for the seasonally flooded lake; (3) Developing a quantitative calculating strategy and a uncertainty evaluation methodology for the water volume of seasonally flooded lake, which will promote the understanding of spatio-temporal changes in lake volume. The research results provide insight into water volume calculation for similar lakes, and benefit basin-scale water resource management and regional climate change studies.

湖泊水量是衡量陆表水资源量的重要指标，定量监测湖泊水量及其变化，对于水资源管理、生态环境保护及区域可持续发展等意义重大。针对季节性湖泊的复杂性以及单一遥感数据在监测湖泊水量上的局限性，本项目拟以鄱阳湖为研究区，联合多源遥感影像和卫星测高数据，开展季节性湖泊水量高精度动态监测的关键技术方法研究。首先，综合运用多源遥感和地面实测数据，采用数据融合、尺度转换和误差分析等手段，实现湖泊水面信息的高精度提取；其次，基于多源测高数据，从数据遴选、环境改正、波形重跟踪及联合平差等方面，系统研究适合于季节性湖泊的水位提取方法，实现季节性湖泊水位的时空动态监测；最后，结合获取的面积和水位信息，开展季节性湖泊水量的定量化计算策略研究，进而深化湖泊水量时空变化过程的认识。本研究有望为全球变化趋势下类似湖泊水量的准确估算提供方法上的借鉴，研究成果对于流域水资源管理和区域气候变化研究具有重要的科学价值。

针对季节性湖泊的特殊性及单一遥感数据在监测湖泊水量上的局限性，本项目以鄱阳湖为研究区，在系统收集研究区多源遥感数据的基础上，结合水文/气象/测绘资料以及野外调查与实测数据，综合应用遥感技术、水文学、数理科学和GIS空间分析手段等多学科交叉和多技术方法集成，对季节性湖泊水量遥感定量监测的关键技术及应用开展了系统性研究。首先，综合运用多源遥感和地面实测数据，系统开展了多种水体信息提取方法的对比性研究，采用多源数据融合、尺度转换等手段，实现了水面信息高精度时序数据的构建；进而基于新型测高数据，研究了适合于季节性湖泊的水位提取方法，实现了鄱阳湖湖区水位的遥感制图与定量评估研究；最后，结合获取的面积、水位信息，开展了湖泊水量的定量化计算及不确定性分析，总结并探讨了服务于季节性湖泊水量动态监测的有效途径与集成框架。研究结果有望为全球变化趋势下湖泊水量的准确估算提供方法上的借鉴，同时研究成果对于研究区周边水资源优化配置、生态环境保护以及区域可持续发展研究也具有积极的现实意义。