• 长江源区1980—2020 年水沙变化规律

    Subjects: Geosciences >> Geography submitted time 2023-05-30 Cooperative journals: 《干旱区研究》

    Abstract: 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.