黄河"几字弯"水沙变化与系统治理OA

Among the numerous challenges in the management of the Yellow River,sediment control stands as the foremost.The key to addressing this lies in reconciling the disparate sources of water and sediment through eco-engineering measures,thereby driving the coordinated evolution of the river channel and the basin.To explore the erosion and deposition evolution of the river channel in the Yellow River's Ordos Loop and the future direction of water and sediment discharge regulation,this study quantified the changes in water and sediment discharge evolu-tion,river channel erosion and deposition,and spatial sources of sediment discharge in the Ningxia-Inner Mongolia reach over the past 70 years using hydrological sequence analysis and sediment balance methods.It also analyzed the impacts of these changes and proposed regional management countermeasures.The results show that:(1)Water con-sumption in the Ningxia-Inner Mongolia reach is significant,with an annual average water consumption of 8.672 bil-lion m³,of which the Ningxia section and the Inner Mongolia section account for 28%and 72%of the annual average water consumption respectively;the Ningxia-Inner Mongolia reach has an annual average siltation of 13.5 million tons,among which the Ningxia section is generally eroded while the Inner Mongolia section is continuously silted.(2)The dominant factors influencing sediment discharge fluctuations in the Ningxia section are sediment from tribu-taries and sediment carried by water diversion in irrigation areas,whereas for the Inner Mongolia section,they are sediment from the Ten Kongdui Tributaries and cumulative siltation in the river channel.From 1951 to 1985,the sediment variability in the Ningxia-Inner Mongolia reach was dominated by riverbed erosion and deposition,whereas from 1986 to 2020,it was jointly driven by sediment from tributaries and sediment from water diversion.(3)The water-sediment imbalance pattern of"decreasing water,increasing sediment,less erosion,and more siltation"in the Ningxia-Inner Mongolia reach has triggered chain impacts on the ecology,flood control,and industrial development of the Ordos Loop.In the future,it is necessary to systematically restore the sediment transport capacity of the river channel,reduce sediment sources from tributaries and wind-blown sand entering the Yellow River through the entire chain,maintain water-sediment matching efficiency from multiple dimensions,and ensure the long-term effective-ness of governance through institutional guarantees.This will enable systematic sediment control,precise sediment regulation,and coordinated sediment adjustment in the Ningxia-Inner Mongolia reach,ensuring that water-sediment management shifts from"intensive campaigns"to"sustained governance"and providing enduring guarantees for the ecological protection and high-quality development of the Ordos Loop.