Analysis on Evolution Characteristics of Irtysh River in Xinjiang Based on RS and GIS

Abstract

Based on multi-spectrum satellite remote sensing (RS) images and GIS, the evolution characteristics of Irtysh River in Xinjiang were analyzed. The results show that the Irtysh River is a composite meander integrated by valley meander and free meander according to the geomorphic features formed by meandering. Judging from the characteristics of this river, the average slope of riverbeds is 0.5188 ‰; the average curvature is 1.72. By observing dry oxbow lake sites, right bank swung more violently than left bank in historical period. Since 1972, 23 reaches were cutoff; 15 reaches’ concave banks expanded; 55 tributaries broke away from the main riverway because of flow cutoff; 94 reaches moved to downstream. These changes increased sharply since 1997 after the construction of key water control project in the upstream of the Irtysh River.