Abstract：
This study compared two different methods, the satellite altimetry-based and DEM (digital elevation model)-based, for estimating lake water volume changes. We focused on 34 lakes in China as the testing sites to compare the two methods for lake water volume changes from 2005 to 2020. The satellite altimetry-based method used water levels provided by the DAHITI (Database for Hydrological Time Series of Inland Waters) data and surface areas derived from Landsat imagery. The DEM-based method used the SRTM DEM data in combination with Landsat-derived lake extents. Our results showed a high degree of consistency in lake water volume changes estimated between the two methods (R2 > 0.90), but each method has its limitations. In terms of temporal coverage, the satellite altimetry-based method with the DAHITI data is limited by missing water level data in certain periods. The performance of the DEM-based method in extracting lake shore boundaries in regions with flat terrains (slope <1.5°) is not satisfactory. The DEM-based method has complete regional applicability (100%) in the Tibetan Plateau (TP) Lake Region, yet its effectiveness drops significantly in the Xinjiang and Eastern China Plain Lake Regions, with applicability rates of 50 and 40%, respectively.
摘要：
本研究比较了两种不同的方法，基于卫星测高和DEM(数字高程模型)的，用于估算湖泊水量变化。我们以中国34个湖泊为试验地点，比较了两种方法对2005年至2020年湖泊水量变化的影响。基于卫星测高的方法使用DAHITI（内陆水域水文时间序列数据库）数据提供的水位和从Landsat图像得出的表面积。基于DEM的方法将SRTMDEM数据与Landsat衍生的湖泊范围结合使用。我们的结果表明，两种方法之间估计的湖泊水量变化具有高度的一致性（R2>0.90），但是每种方法都有其局限性。就时间覆盖范围而言，基于卫星测高的DAHITI数据方法受到某些时期水位数据缺失的限制。基于DEM的方法在平坦地形（坡度<1.5°）区域中提取湖岸边界的性能并不令人满意。基于DEM的方法在青藏高原(TP)湖区具有完全的区域适用性(100%),然而，其有效性在新疆和中国东部平原湖区显著下降，适用性为50%和40%，分别。
