This article presents the 4th stage of the developed methodology, which includes an algorithm for calculating the integrated land use assessment (CSA). A distinctive feature of the CSA method is the refusal to use the method of expert assessments to determine the weight coefficients, instead the method of mathematical justification of the weight coefficients of individual factors was used. This methodology includes a variety of factors that affect rational land use and land monitoring. This set of characteristics allows you to apply this technique not on a specific area, but on any territory under study. All indicators were calculated using the developed software package for assessing rational land use "GeoSi". A great advantage of the created complex is the ability to automatically calculate a large amount of information at the same time. For example, performing calculations of all parameters both for districts of one region and for the entire territory of the Russian Federation, if all the initial data are available.This method is complex in nature, as it involves the use of several approaches, improved taking into account the features of arid territories. The research was conducted on the example of the Astrakhan region. Based on the results of calculations, a cartographic map of the "integrated land use assessment of the Astrakhan region" was compiled. The article presents the main conclusions of the study, offers solutions for rational land use in the studied region, and offers suggestions for improving and stabilizing the geo-ecological situation.