Impact of atmospheric correction on land use classification and water demand for the Aral-Sea Basin

Abstract

The Aral Sea, once the fourth largest inland sea in surface area in the world, is located at the borders of Kazakhstan and Uzbekistan. It is fed by the two major rivers of the basin, the Amudarya and the Syrdarya. Kazakhstan territory was formerly a part of a Soviet program which included reclamation of the natural Central Asian deserts. In order to expand the area of irrigated land water was taken out from the two major rivers, resulting in desertification of the Aral Sea. The drying part of the Sea remained heavily salted after the evaporation of the water, causing salt and dust storms and therefore aeolian deposition of these components on plants, significantly affecting their productivity and quality. This work presents an overview of some results drawn from a preliminary investigation and analysis on the importance of atmospheric effects in the interpretation of time series images in terms of land characteristics. The images are used to estimate the areas of current cultivation of various types of crops being irrigated in the Syrdarya flood plain, in order that water demand can be determined. This work examines the differences between single image and time series land classification, and the effects of the application of a variety of atmospheric corrections.