【摘要】 湖底地形数据是湖泊流域规划与治理、湖区冲淤变化研究、水资源利用和生态环境保护的重要基础。但传统的大型湖泊湖底地形数据获取手段耗时长、投入大,因此,有必要研究一种基于遥感影像快速获取湖底地形数据的方法。本文以洞庭湖为研究对象,采用Landsat和MODIS系列遥感影像提取湖区边界,基于趋势面分析法和克里金插值法,反演湖区边界各点对应的水位,将带有水位信息的边界点作为高程点实现湖底地形反演,进一步用实测湖底地形验证反演方法的可靠性。研究结果表明,克里金插值法水位反演效果较好,交叉验证的误差标准平均值在0.2 m以内,水位样本点分布较多处,基于克里金法的地形反演绝对误差在1 m以内。本文利用湖泊淹没区域变化的特点快速获取湖底地形,对湖区演变分析、综合治理与保护等具有重要意义。更多还原

【Abstract】 Lake bathymetry can provide abundant information for basin planning and governance, watershed erosion and siltation management, water resource utilization, as well as environmental protection. In particular, lake bathymetry is essential for lake development and conservation, and is also closely related to sediment deposition and removal. A number of sounding techniques, such as single-beam sonar sounding, multi-beam sonar sounding, and unmanned ship sounding, have been applied to extract underwater topography of lakes. These techniques, albeit with high measurement accuracy, are time-consuming and costly. Therefore,it is of great need to develop a simple and cost-effective method. To reach this goal, recent advances of remote sensing technologies provide an alternative means of accurately measuring lake bathymetry information. Taking Dongting Lake as the study area, this paper estimated the lake bathymetry through extracting the boundaries of lake areas using multi-temporal Landsat and MODIS image series. In particular, the water level corresponding to each reference point of the lake boundary is retrieved based on trend surface analysis and kriging interpolation technology. Then the water levels of these points are regarded as the elevation points to retrieve the landform of the lakebed of the Dongting Lake. The reliability and accuracy of the developed methods were assessed through the comparsion with the actual measurements.Results indicate that the kriging interpolation technology performs well, with the average of cross-validated error target less than 0.2 meter, and the retrieval error of lake boundary with more reference points less than 1 meter. This paper suggests that an improved method for accurately and rapidly extracting lake bathymetry information can be achieved through examining the changes of water levels. This method might be of great significance for further study on lake evolution, lake development planning, and water ecological protection.更多还原