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.

The socio-economic development of the Tashkent region (Uzbekistan) depends largely on natural resources, especially water resources, as in other regions. One of the canals that supply water to the Tashkent province is the Tashkent magistral canal (TMC). In terms of size, the second of the canals receives water from the left bank of the Chirchik River. The TMC has been 82 years since its start of use. Hydrotechnical facilities on the TMC are typical of the II class. There are many hydrotechnical facilities on the canal: one main structure, four water dampening facilities, two destructive water discharges, four duckers in the canal, 45 water dischargers, one waterfall, seven under-canal duckers, two pipes under the canal, nine aqueducts, nine canal access, thirteen road bridges, one railway bridge, one pedestrian bridge. This article presents the technical condition of the TMC and its hydrotechnical facilities and recommendations developed based on the technical condition. On April 9-13, 2022, field observation work was carried out to study the technical condition of the TMC and hydrotechnical facilities. It reviewed the availability of technical documents of TMC facilities, instructions for their use, information on maintenance of mechanical equipment, working drawings, previous inspection reports, and other materials. In addition, the conclusions of the inspection carried out by the State Inspection "Davsuvkhujalikzorat" and the results of the technical inspections carried out by the employees of the TMC administration and project parameters of water facilities were studied.

This study investigates the accuracy of various DEMs (SRTM DEM, ASTER GDEM, and ALOS PALSAR DEM) for the area of the designing Pskom water reservoir (recommended to construction in Pskom River, in Tashkent region. DEMs are compared for the study area using the Global Mapper application and selection Ground Control Points (GCP). The RMSE we calculate is the most easily interpreted statistic as the square root of the mean square error because it has the same units as the quantity drawn on the vertical axis. Results show that SRTM based measurements of ground control points (GCPs) exhibit RMSE of 15.72 m while ASTER DEM based measurements exhibits and RMSE of 18.47 m, ALOS PALSAR exhibit RMSE of 14.02 m for the Water reservoir located in the plain. There are AOS PALSAR outperforms SRTM and ASTER DEM in detecting vertical accuracy. Based on the capabilities of the Global Mapper program, we can build the longitudinal profile of the approximate location where the dam can be built in each DEM and compare. The results obtained show that the dam height is 187 m at ALOS PALSAR DEM, 168 m at ASTER GDEM, and 175 m at SRTM. The study found that using ALOS PALSAR data in the design of the proposed Pskom Reservoir for construction leads to a more accurate result. Comparing the DEMs data shows that there is more difference between the vertical accuracy; the horizontal accuracy level is almost the same. The results were obtained using ALOS PALSAR data in determining the storage volume (W=479368568 m3) and area (F=8.31 sq., km) of the water reservoir.

Nowadays, like many other fields, DEM is widely used in the field of hydraulic engineering. In our studies, we compared the DEMs (SRTM, ASTER GDEM v2, and ALOS PALSAR) for the area recommended for the construction of the Shurbulak water reservoir. Contours were developed for all DEMs and were compared with the contours of a topographic map. The contours of the SRTM and ALOS PALSAR closely match with the contours on the topographic map than ASTER. Vertical differences between SRTM, ASTER GDEM2, and ALOS PALSAR products were computed the root mean squared error (RMSE) compared to Ground Control Point (GCP) data. RMSE results show that 3.53 m for ALOS PALSAR, 6.27 m for ASTER and 4.09 m for SRTM. The longitudinal profiles of dams (No. 1 and No. 2) of all DEMs were compared with the data of the design institute - UzGIP. The results of comparing the longitudinal profile of the dam (No. 1 and No. 2) on digital ALOS PALSAR models correspond to the longitudinal profile of dams (No. 1 and No. 2) developed by the design institutes. Viewed as a result of all comparisons (comparison of DEMs and topographic map, computed RMSE, comparison longitudinal profile of the dam) ALOS PALSAR is more accurate than other DEMs. Therefore, we decided to use ALOS PALSAR for the determination of water reservoir area and volume. The area and volume of the reservoir were determined using the digital model ALOS PALSAR.

The article is devoted to the analysis of the dynamics of the morphometry of the river bed and the hydraulic parameters of the flow under conditions of flow regulation. For the analysis of the dynamics of the bed morphometry and hydraulic elements of the flow, the Nietbaitas hydro-array located in the zone of the sub-flow of the lower reaches of the Amudarya river in Uzbekistan was selected. As a result of the analysis of data from long-term field studies and hydrometric measurements at the Nietbaitas hydrostorm of the Amudarya river, functional relationships were established between the morphometric elements of the channel and the hydraulic parameters of the flow. The dynamics of the Chezy coefficient, hydraulic resistance, and the roughness coefficient of the channel in conjunction with the hydrodynamic characteristic of the flow are established. Adapted formulas are recommended for determining the calculated values of the Chezi coefficients, roughness, and average flow velocity, taking into account the decelerating effect of the banks of the Amudarya river bed