Using "Free Software" to calculate the fractal dimension of hydrographic basins

Recently, when studying river basins, the QGIS system has been widely used to obtain various hydrological factors from a Digital Elevation Model (DEM). This study is aimed at determining the fractal dimension of vector layers of river basins obtained using QGIS. Aim. For a number of hydrological networks, investigate the relationship between the values of the fractal dimensions calculated for the corresponding QGIS layers and used for calculation by the software, as well as the dependence of the fractal dimension on the initial conditions set for the software (the latter only for "shp" files): also determine possible correlations between the resulting dependencies. For 9 hydrological objects (the Aya, Belaya, Sars, Sura, Ufa and Yuryuzan rivers and the mouths of the rivers Volga, Lena and Selenga), the fractal dimension was calculated using the “box-counting” method. Calculations were carried out using free software: Minkowski Dimension Calculator for QGIS, Fractalyse, ImageJ, Frac Lac for ImageJ, Gwyddon, Fractal and FDE. The data reveal that, firstly, the calculation result depends on the initial conditions set for the computer programme, and secondly, there are correlations between the fractal dimensions calculated under both different initial measurement conditions and using different software. Our results suggest the possibility of using all the software under consideration to determine fractal dimension from images of hydrological objects, obtained using QGIS. Moreover, the recommendations proposed in the conclusion will allow more effective use of the special opportunities of each of the programmes for further research.