Classification of microtopographical features along the shore of Balkhash Lake by ALOS/PRISM DSM

The purpose of this study is to analyze the distribution and the classification of gravel bar along the shore of Balkhash Lake by using the high precision DSM newly produced from the stereo pair data of PRISM carried in ALOS, and to consider the age and environment of formation of every classified gravel bar, and the long-term environmental change based on water level fluctuation of the lake. The classification of gravel bar distribution pattern based on the characteristics such as height, number and direction of the ridge line was carried out through extraction and comparative analysis of the DSM data and ALOS pan-sharpened image in eighteen areas along the shoreline. The result of this study showed that the distribution pattern of the gravel bars along the shore was classified into three typical groups. The difference in distribution of three groups is based on the influence of the waves with the strong prevailing wind. Moreover, according to the feature of the classified group, the water level change situation of Balkhash Lake was divided into three stages in the past about 26,000 years, and the tendency of drawdown was shown as the whole.