Author(s): Yuchong He; Zhiwei Li

Linked Author(s): Zhiwei Li

Keywords: Braided river; Climate change; Morphodynamic processes; Water and sediment change; Remote sensing imagery

Abstract: With the rising air temperature and precipitation, water and sediment flux in the Source Region of the Yangtze River (SRYR) on the Qinghai-Tibet Plateau has increased significantly since 2000. Nonetheless, the response of braided river morphology to climate-driven water and sediment flux change is still unknown. Water bodies of 9 large braided rivers from 1990 to 2020 were extracted based on Google Earth Engine platform, and impacts of climate change on morphological indices and morphodynamic processes were quantified. The warming and wetting trend led to vegetation cover increase. With the increase of water flux, the water area of each braided reach has increased in both flood and non-flood season. The 3-5 year mean annual erosion and accretion intensity (newly proposed in this study) of the channel shows three different trends of increasing, weakening, and unchanged over time. These three trends can be classified into three patterns in response to climate-change driven water and sediment flux change in the SRYR as follows: sediment increase constrained pattern (weakening or unchanged), sediment increase dominated pattern (increasing), and water increase dominated pattern (increasing or unchanged). This study is of great significance on highlighting the impact mechanism of climate-driven water and sediment flux change on morphological characteristics and activation of pristine braided rivers on the High Mountain Asia.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P1727-cd

Year: 2025