Introduction. Organization and implementation of a special spring release, carried out annually in the interests of the agriculture and fisheries of the Lower Volga, is the most important and complex problem of the Volga-Kama cascade management. The way to increase the efficiency of solving this problem is to use of mathematical models for calculating the movement of water along the Volga-Akhtuba floodplain. However, the currently functioning mathematical hydrodynamic models of the Lower Volga do not provide enough accuracy and speed. It is planned to create an algorithm for modeling the movement of water masses, combining the use of nomograms of dynamic volumes and a tank model. The characteristics of water bodies and streams that form the water system of the Lower Volga should be obtained at the first stage.
Materials and methods. The materials for the work were a raster digital elevation model with 30 m resolution, obtained from Earth remote sensing data. Algorithms for determining the position and boundaries of water bodies and calculating their characteristics are implemented in the Fortran programming language.
Results. The description of algorithms of smoothing the digital elevation model, searching for local minima, and determining the boundaries of floodplain reservoirs developed to prepare information structures using in the created mathematical model of a water system with a developed network of floodplain streams and lakes is given on the example of the Volga-Akhtuba floodplain. The results of testing the developed algorithms are shown.
Conclusions. The results of the algorithms for searching for local minima on the digital elevation model and determining the position and boundaries of floodplain reservoirs make it possible to calculate the characteristics of water bodies, building a model graph, and developing a data storage system at the next stages of work.
