The rehabilitation of landscapes along river valleys play an ever more important role in urban management. The first step is evaluation of natural conditions of green areas. We propose a validation method based on analysis of land use changes in the last 200 years, actual vegetation mapping, and the hemeroby concept. The field study was conducted in the Sokołówka River valley in Łódź city (Central Poland). All analyses were performed using the GIS software. The results show that after World War II, during urbanization and industrialization of Łódź, a surprising increase in the forest cover and a decline of agricultural areas have been observed in the study area. The current naturalization of the landscape should be used for rehabilitation projects.