The paper discusses the basic principles of using geoinformation technologies to study relief-forming processes and the ecological state of aquatic ecosystems. The object of the study is the territory of the city of Sevastopol within the valleys of the Chernaya, Kacha and Belbek rivers. To conduct environmental monitoring, it is proposed to use field and chemical-analytical methods. According to the data obtained, information and analytical maps with a geodatabase are produced. Creation of an information and analytical map with a database using GIS toolkit makes it possible to identify factors influencing the deformation of the river bed and changes in the ecological state of aquatic ecosystems. The proposed technology for monitoring the study area allows saving data, using them in projects, and supplementing these data as new information becomes available.