Известия Томского политехнического университета: Инжиниринг георесурсов (Oct 2016)
Generalized histogram of lake size-distribution in permafrost of Western Siberia based on satellite images of high resolution
Abstract
Relevance of the research is caused by the need to clarify the type of law of lakes size-distribution for estimating methane emission from small thermokarst lakes in vast areas of permafrost. Currently, the histograms of the distributions are obtained by satellite images on separate test sites. This causes difficulty in determining the type of lakes distribution law on all the territory of the permafrost zone, due to the lack of methodology of generalizing the empirical histograms of lake distribution, obtained on a limited set of test sites, on the entire territory of research. The main aim of the research is to develop the methodological issues of determining the law of distribution of small thermokarst lakes areas in permafrost in a wide range of sizes based on generalization of the lakes size-distribution histograms obtained by satellite images on a limited set of test sites on the study territory. Methods: remote study of thermokarst lakes fields based on satellite imagery; method of test (key) sites; method for determining the active thermokarst areas using satellite imagery; methods of geographic information systems for spatial analysis of data on thermokarst lakes. Results. The authors have considered the methodical issues of generalizing empirical histograms of lakes size-distribution, obtained by high-resolution images on a limited set of test sites, on the entire territory of studies, to determine the type of law of the generalized lakes size-distribution. The proposed approach to construction of empirical histograms is based on application of high resolution images of Canopus-V, ALOS and BKA, reflecting the distribution of small lakes. Remote study was carried out at 66 test sites located quite evenly on the territory of the permafrost zone of Western Siberia. The linear approximation of generalized histogram of lakes size-distribution in permafrost territory, represented as a graph in double logarithmic scale, providing its compact representation in a very wide range of changes in lake sizes, confirms the power form of generalized size-distribution of lakes in the permafrost zone of Western Siberia.
