AUTOMATED ECOLOGICAL TERRAIN MORPHOLOGY CLASSIFICATION OF STRETCH OF UPPER DNISTER RIVER VALLEY

Abstract

Modern technological developments can induce substantial changes not only in research methods, but also in theoretical concepts and approaches in Earth sciences. Recent developments in the technologies of remote sensing, GIS data processing and mapping now make possible to more directly consider ecologically relevant properties in the process of spatial units delineation. The concept of morphotop has been proposed by author meaning spatial units mapped taking into account ecologically relevant properties of terrain. It is different from the commonly used concept of natural complex in that ecological and not genetic criteria are at the base of spatial units differentiation. The ecological approach for terrain morphology classification has been applied for the 4.5 to 2 km study area located at the upper part of Dnister river valley. The 10 m spatial resolution DEM was obtained for the study area by the interpolation of digitized topographic map layers with ANUDEM algorithm. Three groups of ecologically meaningful factors of landscape differentiation have been taken into account: 1) solar radiation redistribution; 2) water and soil moisture redistribution; 3) erosion potential of terrain. For each of these, the appropriate index was proposed and derived from DEM by the respective formula. The method of iterative cluster analysis with ISODATA algorithm has been applied to these variables complemented with absolute elevation. This method distinguishes a predefined number of classes by revealing the natural groupings of data in attribute space. Arbitrary presetting the number of classes allows to classify data with the different levels of detail and to analyze the changes in classification output as a function of classification scale and detalization. The study area has been successively classified into 12 and 8 classes, with 100 algorithm iteration in each case. Each class has been given a descriptive characteristic; an average values of certain terrain morphometric parameters for each class were also calculated and given in a table. The map of the distribution of the distinguished classes was produced. Key words: terrain morphology, unsupervised classification, morphotop, ecological geomorphology.