The rapid growth of geo-information technology capabilities in the field of spatial data processing and analysis has led to a significant growth of the role of geo-information systems in different areas of human activity. Application of approaches to spatial information processing from satellites new for more effective and efficient assessment of the state of plant cover is caused by growing tendency of availability to data of Earth remote sensing. The article offers an information system that allows to quickly and conveniently track changes in the vegetation. The analysis was carried out on the example of the Chornobyl Area between 2000 and 2020. The Chornobyl Disaster coincides with the period of intensive vegetative plant development. During that period, they are most sensitive to radiation. It has been established that for defining the quantitative state of biomass the NDVI index at different time intervals is most often used. But this index becomes ineffective during periods of weakening of active phase of vegetation. This is therefore of practical interest to assess the possibility of using the K-means clustering for the analysis of space images of vegetation cover at different phases of vegetation. As a result of the research, water surface, land with and without vegetation has been correctly interpreted, thus determining the land with a sparse vegetation and dense vegetation cover. The maps of the vegetation cover according to the normalized vegetative index using the K-medium method were constructed, the method by which changes in vegetation over 20 years can be clearly observed. The accuracy results were verified with the Common Method Bias. According to the calculations, despite all natural cataclysms (temperature increase, drought, winter anomalies of precipitations and temperatures, storms, forest fires), as well as human activity (sanitary clear cuttings, illegal logging), vegetation in the Chornobyl zone continues to grow and its areas will increase, although not so quickly.