Ecological Evaluation And Restoration Planning Of The Middle And Lower Liaohe River Based On Changes In Water And Sediment

As the mother river of the Liaoning people,the Liaohe River has always been a major problem in the Liaohe River Basin.For a long time,the Liaohe River has suffered from over-exploitation,severe resource damage,lack of ecological water,and deterioration of the ecological environment.As early as 2006,it was listed as the “three rivers and three lakes” of national key governance(three rivers refers to the Huaihe,Liaohe,and Haihe,three Lake refers to one of Taihu Lake,Chaohu Lake and Dianchi Lake.In recent years,during the spring plowing season(March-April),sand and dust weather has frequently occurred in many places in Liaoning Province,which seriously affects the daily life of the people.For example,on March 31,2007,the whole province of Liaoning encountered a large-scale and long-term blowing sand and dust weather,which lasted for nearly 23 hours,and the total amount of dustfall reached 253,200 tons.The amount of dustfall in the Chaoyang area exceeded 50,000 tons,and the minimum visibility was only 500 m.This is very inconsistent with the overall layout of my country’s "ecological civilization construction" and the green development concept of "green water and green mountains are golden mountains and silver mountains".In this context,it is very necessary to conduct ecological evaluation and ecological restoration planning research on the middle and lower reaches of the Liaohe River.Aiming at the ecological problems in the middle and lower reaches of the Liaohe River,this study analyzes the characteristics of water and sand,land use structure,and vegetation coverage in the study area,and obtains relevant data to construct an evaluation index system for the ecological status of the middle and lower reaches of the Liaohe River.The fuzzy comprehensive evaluation method is used to study the The ecological status of the district is evaluated.Get the following conclusions:The monthly average maximum discharges of Fudedian Station,Tongjiangkou Station,and Tieling Station in the study area were 755 m3/s,1050 m3/s and 829 m3/s respectively in August 1998;the average annual sediment discharge of the three stations They are 1.0467 million tons,1.3619 million tons,and 1.2407 million tons,respectively,and the corresponding inter-annual coefficients of variation are 2.10,1.67,and 1.94,respectively;the runoff and sediment transport rate of the three stations are all significantly positively correlated,and the relative difference between April and September Among them,Fudedian and Tongjiangkou had the strongest water-sediment correlation in July and April,respectively,and the Pearson simple correlation coefficients reached 0.943 and 0.939,respectively;the significant positive correlation between Tieling station was not as strong as the other two stations,which was different from the original The problem of data has a certain relationship,and the period from December tof March is relatively weak.(1)The monthly average maximum discharges of Fudedian Station,Tongjiangkou Station,and Tieling Station in the study area were 755 m3/s,1050 m3/s and 829 m3/s respectively in August 1998;the average annual sediment discharge of the three stations They are 1.0467 million tons,1.3619 million tons,and 1.2407 million tons,respectively,and the corresponding inter-annual coefficients of variation are 2.10,1.67,and 1.94,respectively;the runoff and sediment transport rate of the three stations are all significantly positively correlated,with a relative comparison between April and September.Among them,Fudedian and Tongjiangkou had the strongest water-sediment correlation in July and April,respectively,and the Pearson simple correlation coefficients reached 0.943 and 0.939,respectively;the significant positive correlation between Tieling station was not as strong as the other two stations,which was different from the original The problem of data has a certain relationship,and the period from December to March is relatively weak.(2)The land use in the study area is cultivated land and bare land,which both account for 50% of the total.The area of bare land decreased in 2018,and the corresponding unused land area increased sharply.This increase is in line with the delimitation of natural enclosure and returning farmland(forest)to rivers The measures are closely related.(3)The vegetation coverage in the study area is above 40%,and there has been a decrease and recovery between 2005 and 18,but the overall change is not significant.(4)The fuzzy comprehensive evaluation calculates the characteristic value of the ecological status quo level of 0.405,and its corresponding evaluation level is "general",which indicates that there is still a certain gap between the level of sediment control and ecological status in the study area and the goal of Liaoning Province’s ecological province construction,and corresponding measures need to be formulated Improve the ecological status of the Liaohe River Basin.(5)Propose corresponding ecological restoration plans for ecological problems.Formulate five major measures for sediment control: "Blocking,discharging,releasing,regulating,and digging";from the perspective of key ecological factors,the ecological restoration plan for the construction of the Liaohe River Wetland Park and the ecological water storage wetland is proposed,which is an ecological corridor in the Liaohe River Basin The construction of the Liaohe River Basin will provide the foundation to ensure the development of the Liaohe River Basin in a good direction.