Morphological characteristics of interactions between deserts and rivers in northern China

Abstract

Abstract Arid regions are affected by long-term interactions between various factors including water and wind. Recent research has concentrated on aeolian–fluvial interactions in dryland environments, including the important role of rivers in providing sand and spaces for deserts development, as well as the influences of aeolian activity upon river landforms. However, there is still a lack of comprehensive data at the large watershed scale to support such research. In this study, we analyzed statistically the morphological parameters related to twelve deserts and ten watersheds in dryland regions of northern China using remote sensing data, maps of desert and watershed distributions, and classification of aeolian landforms. Results indicate that, in view of the relationship between deserts and rivers, the geomorphic structures of drainage basins in northern China can be overall divided into five large drainage zones: northwestern drainage (ND), western drainage (WD), drainage of northern Qinghai-Tibet Plateau (PD), middle drainage (MD) and eastern drainage (ED). In the terms of percent area of desert in drainages, it can be sequenced as WD > MD > ND > ED > PD. For percent area of shifting dunes in deserts, WD > PD > MD > ED > ND. Considering the classification of aeolian dunes, transverse dune dominates in all drainages, and its proportion can be sorted as PD > ED > MD > WD > ND. There is a significant difference in their morphological parameters between interior and exterior watersheds. In exterior watersheds, desert area, shifting dune or transverse dune areas are not significantly associated with drainage area respectively, but interior watersheds have good correlations between them. And in three rivers of Tarim Basin, along with increasing distance from the river bank, the types of aeolian dune (complexity) increased step-wisely, implying that sand dune extends along the river terrace. Those data and preliminary findings confirm that the rivers are indispensable to the development and evolution of deserts, performing as channels (‘arteries’) and platforms (‘skeletons’) in providing sand sources and spaces.