Geomorphology refers to the study of the Earth’s physical land surface features. Digital Elevation Model (DEM) is a digital imagery where each pixel represents elevation value above or below mean sea level. The availability of DEM allows analysis of landscape morphology and related processes in terms of geomorphometry. DEM of Difference (DoD) techniques are used to estimate the elevation variations and volumetric changes over time. The volumetric change of terrain in the Cauvery delta (CD) for the past two decades is estimated using DoD algorithm by utilizing freely available moderate spatial resolution SRTM, PALSAR and Sentinel 1A DEMs which are derived by radar remote sensing technique. A detailed assessment of individual DEM’s errors and propagating errors into the DoD are estimated using the field elevation points measured by Real-Time Kinematic (RTK) Global Positioning System (GPS). The default errors in the SRTM, PALSAR and Sentinel 1A DEMs are observed with Root Mean Square Error (RMSE) of 3.33, 3.11 and 3.04 m respectively. The erosion and accretion rates determined are 25 and 30 million m³ / decade correspondingly. The total volume of sediment load due to erosion and accretion is 50 and 60 million m³ respectively during 2000–2020. Further the net area affected due to deposition (69 %) is higher than the total area affected due to erosion (30%). This study presents decadal sediment budget and rate of annual change due to erosion/accretion in the CD.

地貌学是指对地球物理地表特征的研究。数字高程模型 (DEM) 是一种数字图像，其中每个像素代表高于或低于平均海平面的高程值。DEM 的可用性允许在地貌学方面分析景观形态和相关过程。差分 DEM (DoD) 技术用于估计随时间的海拔变化和体积变化。过去 20 年 Cauvery 三角洲 (CD) 地形的体积变化是利用 DoD 算法通过利用雷达遥感技术导出的免费提供的中等空间分辨率 SRTM、PALSAR 和 Sentinel 1A DEM 估计的。使用实时运动学 (RTK) 全球定位系统 (GPS) 测量的场高程点估计单个 DEM 误差和传播到国防部的误差的详细评估。SRTM、PALSAR 和 Sentinel 1A DEM 的默认误差分别为 3.33、3.11 和 3.04 m 的均方根误差 (RMSE)。确定的侵蚀和吸积率分别为 25 和 3000 万米³ /十年相应。2000-2020 年，由于侵蚀和吸积造成的泥沙总量分别为 50 和 6000 万立方米^。此外，受沉积影响的净面积（69%）高于受侵蚀影响的总面积（30%）。本研究介绍了 CD 中由于侵蚀/吸积导致的十年沉积物预算和年变化率。