Evaluation of ASTER DEM and SRTM DEM data for determining the area and volume of the water reservoir

Nowadays, like many other fields, Digital Elevation Models (DEM) are widely used in the field of hydrotechnical engineering. In this study, the vertical accuracy of the Shuttle Radar Topography Mission (SRTM DEM) was compared to Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER DEM) for the area recommended for the construction of the Kyzylsay and Tashtepa water reservoirs in Tashkent region, Uzbekistan. Vertical differences between SRTM and ASTER products were computed the root mean squared error (RMSE) compared to GPS data. Results show that SRTM based measurements of ground control points (GCPs) exhibit RMSE of 4.262 m while ASTER DEM based measurements exhibits and RMSE of 3.693 m for the Toshtepa Reservoir located in the plain, and for the Kyzylsay reservoir located in the mountains, RMSE results show that 12.82 m for SRTM, 15.77 m for ASTER. There are SRTM DEM outperforms ASTER DEM in detecting vertical accuracy. This indicates that ASTER DEM outperforms SRTM DEM in detecting vertical accuracy for the plane, and SRTM DEM is preferable than ASTER DEM for mountainous areas. The longitudinal profiles of dams (Kyzylsay and Tashtepa) of all DEMs are compared with the geodetic data of the design institute - UzGIP. The area and volume of the reservoir were determined using the digital model were compared with the data of the design institute - UzGIP performed using a geodetic tablet.