| The Chushandian reservoir is one of the 172 major water conservancy projects determined by the State Council.It is the only large I type reservoir in the upper reaches of the Huigan River.After the operation of the reservoir,the flood control standard in the upper reaches of the Huaihe river can be raised from once in less than 10 years to once in 20 years,the peak flood flow can be reduced by 4,197m~3/s,and 1.7 million people and 2.2 million mu of farmland in the lower reaches can be protected;it can supply more than 8,000×10~4 m~3 of water to the Xinyang River,irrigate more than 500,000 mu of cultivated land on both sides of the river,and generate more than 750×10~4 KW·h of electricity annually.Soil and water loss and ecological environment are two problems that need to be studied and solved in the construction and operation of the reservoir,taking soil and water conservation and landscape ecology as the cut-in point and elastic landscape function as the core goal,the study on the elastic landscape function of soil and water conservation in Chushandian Reservoir provides theoretical support for regional ecological protection and ecological benefit of reservoir.Based on the theory of soil and water conservation and the theory of Landscape Ecology,the concept of elastic landscape is introduced in this study,which makes full use of the detailed and accurate basic data of the construction of Chushandian Reservoir,the achievements of soil and water conservation and ecological environment,etc.,the basic theory of soil and water conservation elastic landscape was established through Literature Research;Based on 3S technology,DEM and other basic data information and on-site investigation,division of Soil and water conservation elastic landscape unit,interpretation of landscape elements data information;Based on the analysis of land use landscape dynamic evolution,ecological vulnerability assessment,calculation of soil and water conservation ecosystem service function,calculation and analysis of basic landscape characteristics of soil and water conservation landscape elements,the elastic function index system is constructed,based on the theory of landscape ecology and the principle of neutral model,the elastic landscape function model of soil and water conservation was established,and the elastic landscape function of soil and water conservation in Chushandian reservoir was calculated,it lays a foundation for the prevention and control of water and soil loss and the protection of ecological environment.The conclusion of this study is as follows:(1)The concept of soil and water conservation elastic landscape was put forward and the elements of soil and water conservation elastic landscape were mainly composed of farmland,woodland,grassland and water area;The elastic landscape function of soil and water conservation is defined,The elastic landscape function of soil and water conservation is defined,which is composed of soil and water conservation function,ecological protection function and ecological production function;The basic theory of elastic landscape function of soil and water conservation is put forward.When disturbed,the function of soil and water conservation landscape reaches its maximum elastic threshold;When the disturbance is over,the elastic landscape of soil and water conservation can be restored to the minimum elastic threshold.(2)Based on 3S technology and DEM,it is divided into 33 elastic landscape units;Based on the basic landscape elements of cultivated land,woodland,grassland,construction land,water area and unused land,a total of 16886 map spots were interpreted and the total area of map spots was 95809.41hm~2.(3)The dynamic evolution of land use landscape in the study area of Chushandian reservoir from 2000 to 2018 was analyzed by constructing Markov Transfer Matrix,single dynamic attitude model and comprehensive dynamic attitude model:From 2000 to 2015,the total area of each land use type changed little;Between 2015 and 2018,the water area and construction land R1 are relatively large;Between 2000 and 2005 the conversion of land types was very small;From 2005 to 2015,arable land,woodland,grassland and construction land were transferred into and out of the more obvious,the spatial dynamic attitude is more intense;From 2015 to 2018,the spatial dynamics of land use types were quite violent;LC values from 2000 to 2005 were minimal;Between 2005 and 2010 LC was 3.5788%,between2010 and 2015 LC was 3.7099%,between 2015 and 2018 LC was 6.5755%.(4)The EVI is divided into five grades according to the calculation and analysis of ecological vulnerability index with 17 indexes and 6 principal components from three levels of ecological sensitivity,ecological resilience and ecological stress,The ecological frangibility is divided into five grades:Slight Frangibility,light frangibility,medium frangibility,heavy frangibility and extreme frangibility,The spatial distribution characteristics of ecological frangibility in Chushandian Reservoir region as a whole show the pattern of high ecological frangibility in northwest and low ecological frangibility in southeast.(5)The total value of forest,grassland,cultivated land and water ecosystem services is28151.56million yuan,with an average value of 0.355 millionyuan/hm~2,The values of woodland,grassland,farmland and water area are 18749.26,545.4,3174.8,5682.05million yuan respectively,the average values are0.54,0.308,0.082,1.31millionyuan/hm~2 respectively.(6)The density of Landscape Patch was 17/km~2 in 33 landscape units,the density of cultivated land patch was the smallest and the water area was the largest.The average patch area is 5.74km~2/individual,the average cultivated land area is the largest and the water area is the smallest.The patch shape index of cultivated land,woodland,grassland,water area,construction land and unused land were 106.14,81.73,37.78,59.18,75.10,34.29 respectively,the fractal dimensions of patches are 1.60,1.58,1.59,1.57,1.62 and 1.59 respectively,which are all larger than 1.The patch shape of landscape elements is more complex.The diversity index,the diversity index and the evenness index were 0.12,0.05 and 0.03 respectively.The diversity and evenness of landscape elements were low.The landscape elements dominance of cultivated land,forest land,grassland,water area,construction land and unused land were15.08,9.32,2.99,1.09,1.04 and 0.31,respectively,unused Land Min.0.31.(7)Soil and water conservation elastic landscape function(E)Model Threshold 0?5,and the bigger?E is,the less soil erosion,the better ecological environment and the bigger ecological production function;The function of soil and water conservation was characterized by negative soil erosion modulus,the larger the soil erosion Modulus,the more serious the soil erosion,and the smaller the function of soil and water conservation;There was a positive correlation between e value and ecological protection function,ecological production function,and a negative correlation between e value and soil erosion modulus.The maximum and minimum values of e are 4.162 and 2.505 respectively,the present value is 3.994,and the average value of e is 2.5,it shows that soil and water loss is relatively slight,ecological environment is good and ecological production function is large in the study area of Chushandian Reservoir,and the current landscape function of soil and water conservation has not yet reached its maximum value,it shows that there is still room for ecological protection and soil erosion control.The maximum value and the minimum value of the 33 soil and water conservation elastic landscape units are 4.094 and 3.321 respectively,which are unit 28 and unit 22.The maximum value is 23.28%higher than the minimum value The maximum value in the minimum value of e is 2.320 and the minimum value is 1.126,which are unit 22 and unit 13 respectively.The maximum value is 106.04%higher than the minimum value;The maximum value of e was 4.094,the minimum value was 1.126,the maximum value was263.59%,the minimum value was less than the average value of e threshold was 2.5,the results show that there are serious soil and water loss and bad ecological environment in the study area,and more efforts should be made to prevent soil and water loss and protect ecology.In this paper,the soil and water conservation function SW,ecological protection function EP,ecological production function NPP were calculated by means of?E model and subsidiary Equation Group,selecting the indexes that are easy to be quantified,that have sources of calculation data,that are highly representative and that are easy to operate in calculation methods,According to the analysis results of dynamic evolution of land use landscape,the functional constraints of soil and water conservation elastic landscape are determined,and the maximum and minimum values are obtained by Matlab program,which is an idealized state,however,soil erosion,ecological production and ecological protection are complex systems,which are affected by many factors.Therefore,there is more research space to construct?E model and index system to calculate and analyze the elastic landscape function of water and land conservation.. |
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