The content of this scientific material reflects the results of the research on the evolution of the hydrographic networks and the surfaces of the river basins Cula and Ciuluc under specific environmental conditions. Cartographic materials and representation of data (number, summed and averaged lengths of river segments, and data regarding the drainage areas of different order basins) in logarithmic coordinates, with reference to the years 1913 and 1988, highlight the changes that occurred over time. The use of quantitative methods such as mathematical modeling of statistical data, allow a profound analysis of time and space changes, and correlation with the impact of environmental factors, highlight the way of drainage processes, the state and evolution of this river basins.