Spatial and temporal patterns of erosion and deposition in the lower Yellow River reaches and their controlling factors
This study used the cross-section topographic data of the river channel of the lower Yellow River reaches to systematically calculate the inter-annual and seasonal erosion-deposition volume of the main river channel from 1992 to 2011.The major results were presented as follows.From 1992 to 1999,the river channel of the lower Yellow River reaches silted continuously,with a cumulative silt-ation volume of 1.090 km3.After 2000,the channel shifted from siltation to erosion with a total vol-ume of 1.597 km3 by 2011.On seasonal scale,two-stage pattern of channel evolution was presented.During the flood season from 1992 to 1999,the lower reaches of the Yellow River accumulated 1.471 km3,about 1.4 times of the annual siltation volume.Erosion dominated dùring dry seasons with a total of 0.473 km3,accounting for 32％of the siltation volume during the flood season.During the flood season from 2000 to 2011,the channel shifted from siltation to erosion with an accumulated volume of 1.148 km3,accounting for 75％of the annual erosion of the lower Yellow River.The erosion flux dur-ing dry seasons in 2000-2011 gradually decreased,and the cumulative erosion during the period was 0.381 km3,only 25％of the annual amount.Changes in water and sediment conditions as well as river channel features played critical roles in the evolution process of the river channel in the lower Yellow river reaches.After the implementation of the Xiaolangdi reservoir,the coefficient of sediment incom-ing decreased significantly,resulting that the river channel turned from siltation to erosion.The river regime coefficient of the lower river channel had dropped overall,and the lower river channel had be-come more stable.
the lower Yellow River reacheserosion-deposition processtemporal-spatial patternsec-tion methoderosion-deposition intensity
NETL
NSTL
万方数据
