Potentially dangerous areas of Moscow with a high concentration of geogenic radon potential are highlighted with green on the map. The quantitative results of the analysis of the processed initial cartographic information in the form of tables and diagrams show that the share of a high level of geogenic radon potential among the administrative districts of the capital reaches maximum in the Southern Administrative District, the Western Administrative District and the Northern Administrative District. The most calm situation in the North-West Administrative District and Eastern Administrative District .The methodology for the formation of the semantic data of land monitoring on the basis of processing and analysis of cartographic information on the development and dissemination of negative processes has been successfully tested using the example of the map of the geogenic radon potential of the city of Moscow. Further studies on the example of maps and card-charts of other processes are needed to assess its suitability. Possible approaches to the development of methods for the formation of semantic land monitoring data based on the processing and analysis of cartographic information as well as on the development and dissemination of negative processes are proposed.