The use of digital terrain models in the calculation of flood zones

The article presents an integrated approach to the use of computer processing of Earth remote sensing materials for the quantitative assessment of flood-prone areas. It provides the practical experience of using the proposed algorithm with GIS for obtaining data on the boundaries of territories on the example of tree and shrub vegetation. The algorithm can be helpful when calculating possible flooding zones based on 3D terrain models with the necessary adaptation of input information. When calculating the vegetation index, the authors applied the open software products and publicly available remote sensing materials using the NDVI method. The application of a step-by-step approach to the definition of flood zones using unified initial remote sensing data made it possible to eliminate a number of errors (transformation, binding, correction, etc.) related to the peculiarities of obtaining derived elements of remote sensing of the Earth. The calculation of the boundaries of the flood zones was performed by determining the line of intersection of the relief surface with the surface simulating the water level. The paper establishes the dependence of the quality of determining the boundaries of flood zones on the level of forest cover of the territory. It confirms the presence of residual artifacts representing vegetation cover in open digital relief models.