Water Reservoirs Bathymetric Mapping Using A GIS-Based Distance Method
Abstract
Accurate knowledge of reservoir bathymetry is fundamental for quantifying water storage, managing irrigation resources, and assessing the long-term impacts of sedimentation. This study presents firstly the results of the bathymetric mapping of the Karkidon Reservoir, located in the Fergana region of Uzbekistan and fed by the Isfaramsay River and other main water reservoirs of Ferghana Valley of Central Asia, using a GIS-based distance method. The approach, originally developed within the framework of the GLOBathy global dataset (Khazaei et al., 2022), translates Euclidean distances from reservoir shoreline pixels to a continuous depth surface without requiring in-situ echo-sounding surveys. Input data comprised the maximum depth value from official reservoirs’ records and the waterbody polygons from the HydroLAKES dataset. Analysis was performed in Python (GDAL/NumPy) and the resulting bathymetric raster was visualised in ArcGIS software. Results indicate that the water surface area of the Karkidon Reservoir as of March, 2022 covers approximately 4.41 km², with an estimated maximum depth of about 30 m and a total water volume of roughly 50 million m³—representing approximately 24% of the reservoir's original design capacity of 211 million m³. The findings underscore the need for systematic monitoring of reservoir morphology in the region and demonstrate the utility of open-source, remotely sensed data products for water resource management in data-scarce environments.