Modern systems of hydrometeorological monitoring, for the most part, widely use WEB and GIS technology tools. Territorial fragmentation divisions of the World Meteorological Organization (WMO), Roshydromet, Russian Academy of Sciences and other services and departments interested in obtaining data requires creation of unified information environment for exchange of heterogeneous information. Formation field for geospatial data has become possible with the availability of industrial design platforms with high performance, supporting standard data exchange formats suitable of system for building projectoin. The purpose of the study is to develop requirements for geoinformation sup-port of the system necessary for flood forecasting. Methods: GIS mapping, interpretation and analysis of remote sensing data of the Earth. When developing system for hydrological monitoring of rivers in the Southern Sakhalin, we used the experience of operating similar observational network in services of several European countries, as well as the geographically distributed GIS created by Roshydromet. Considering the vast experience of predecessors and requirements for geoinformation support neces-sary for predicting flood zones in the rivers of Southern Sakhalin have been developed. The initial da-ta for creating the correct flood model are satellite images, large-scale topographic maps, digital terrain models, data from long-term hydrometeorological observations, and engineering surveys.

Fault zones on the territory of Nature Sanctuary “Dolinsky” (Sakhalin Island), which are characterized by high geodynamic activity, are generally well distinguished when analyzing satellite imagery materials. In any territory, it is not difficult to identify the various plant communities that occupy it, as well as to determine their state by the content of phytomass determined by the vegetation index NDVI. The aim of the study is to test the validity of the hypothesis about the formation of abundant vegetation cover within the fault zones by analyzing the state of various plant communities by the volume of phytomass. Methods: decryption and analysis of Earth remote sensing data from Sentinel, Landsat and SRTM generation, geoinformation mapping on the ArcGIS platform. Results. In the course of the study, the state of the Nature Sanctuary “Dolinsky” analyzed by Landsat-8, Sentinel-2A satellite sur-veys, as well as SRTM data. Fault zones identified using the software systems ArcGIS, QGIS, and PyLEFA by lineament analysis, vegetation was classified by the maximum likelihood method, and its condition was determined by the values of the NDVI index, which reflects the content of phytomass in the study area. As result of the work carried out, an increase in phytomass revealed, and, consequently, good conditions for the growth of plant communities confined to the zones of distribution of faults of the earth's crust, and the reliability of the working hypothesis confirmed.