Landscape approach to detachment of water-securing zone of River Ushaika based on GIS-mapping

The authors offer a technique of detachment of small rivers water-securing zones within large urbanized areas, the basis of which is made by the landscape analysis of apron plains of small rivers with the usage of methods of geoinformation mapping. The object of research is the apron plain of the Ushaika within the limits of Tomsk. The subject of research is the internal-valley differentiation of landscape systems based on the index of the potential environmental impact risk. There are used both the traditional methods of research in physical geography (including field expedition methods) and the newest methods of Geographic Information Systems mapping and complex spatial analysis based on remote sensing data and digital elevation models. At the first stage of activity a large-scale digital landscape map was built on the basis of field researches, topographic maps and high resolution remote sensing data. The digital elevation model of the apron plain of the Ushaika was further built. The digital elevation model was built on the basis of Delone triangulation in format TIN (Triangular Irregular Network) with the help of the module ArcGIS 3D Analyst of GIS-software ArcGIS by ESRI Inc. For the morpho-metric analysis of landscape systems the digital elevation model was converted to the format GRID with the help of the module ArcGIS Spatial Analyst by ESRI Inc. At the second stage a detail morphometric analysis of landscapes on the basis of digital elevation model was conducted. The mean slopes of landscape systems were counted and the scale of mark estimation of steepness of declines was designed. On the basis of the factors of the mean slope of the landscape system, the condition of green and soil substrata the integral parameter of potential ecological danger was counted, by assigning the degree of danger of disturbance. The rules of land use in the given terrain were shown, and in cases these rules are already disturbed by a cardinal mode the necessity was stated of application of a complex of engineering systems adjusting surface sinks. In a computed result of factors of potential ecological danger the map of water-securing zone was built. The designed technique has demonstrated the urgency and necessity of its practical usage in the analysis of consequences of vernal inundations in Tomsk in 2008-2012. In a number of relevant parameters it is more effective and less wasteful than the existing techniques, and actuation of the modern GIS-software in processing of the statistical data has considerably allowed the automation of all the process and made it more impartial.

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