Arid Zone Research ›› 2023, Vol. 40 ›› Issue (5): 726-736.doi: 10.13866/j.azr.2023.05.05

• Land and Water Resources • Previous Articles     Next Articles

Variation of runoff and sediment in the headwaters of the Yangtze River from 1980 to 2020

YAO Chunyan1,2,3(),LIU Honghu1,2,4(),LIU Jing1,2,3   

  1. 1. The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling 712100, Shaanxi, China
    2. Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China
    3. University of Chinese Academy of Sciences, Beijing 100049, China
    4. Changjiang River Scientific Research Institute, Changjiang Water Resource Commission, Wuhan 430010, Hubei, China
  • Received:2022-08-18 Revised:2022-10-06 Online:2023-05-15 Published:2023-05-30

Abstract:

The changes in soil loss, runoff, and sediment load in the headwaters of the Yangtze River and their correlation were studied based on the data of daily precipitation at 12 stations, and annual runoff and sediment at Zhimenda station in the headwaters of this river from 1980 to 2020. (1) The annual soil erosion modulus in the source area showed a significantly increasing trend (P<0.05), and the average annual soil erosion modulus was 4.71 t·hm-2·a-1. The erosion intensity and higher grades of erosion were mainly distributed in the southeast of the headwaters of the Yangtze River. (2) The runoff increased significantly (P<0.05), however, there was an abrupt change in 2004 when the suspended sediment concentrate and sediment load showed no significant change. (3) Precipitation had a significant positive effect on runoff and soil loss at 70% and 52.9%, respectively. Both runoff and soil loss showed direct positive effects on the sediment load. Precipitation, runoff, and soil loss explained 72.5% of the variation in sediment load. During this period, changes in precipitation had significant effects on soil loss and sediment in the headwaters of the Yangtze River. The results can provide a scientific basis for the research and evaluation of the effects of implementing ecological engineering in the headwaters of the Yangtze River.

Key words: Chinese soil loss equation, structural equation model, climate change, soil loss