Zoning Optimization And Ecological Environmental Effects Based On The Zuli River Basin,which Are Simulated By Multi-Scenario Simulation

The Zuli River Basin,as one of the typical areas of ecological fragile areas in the upper reaches of the Yellow River Basin,is faced with both the pressure of ensuring rapid economic growth and the challenge of safeguarding the ecological security in the upper reaches of the Yellow River and the ecological security barrier in the west.Multi-scenario simulation prediction and comparison can not only provide theoretical basis for ecological restoration,but also provide decision-making basis for building ecological spatial security pattern.However,no studies have been carried out on land use prediction,eco-environmental effect and zoning optimization aiming at this problem.Therefore,this paper takes Zuli River Basin as the research area,analyzes the characteristics of land use change and the driving forces of various types of land expansion from 1980 to 2020,and combines the grey prediction model with the PLUS model as the new model.To identify the ecologically vulnerable areas and reveal the law of land use evolution by simulating and predicting the trend of land use change in 2030 and 2040,so as to provide reference for local ecological restoration.Based on the simulation results,the spatial pattern distribution and change trend of ecological quality in the current and future periods were analyzed to provide decision-making aid for balancing ecological security and economic development in the local area.Selective qualitative analysis,the values of production,living and ecological functions were calculated according to the functional attributes of various land uses.Based on the relevant research results and the principle of zoning based on the local land use characteristics,the Zuli River basin zoning is optimized,and the zoning is carried out based on the changing trend of the relationship between the"three and ecological"functions.The corresponding development suggestions are provided according to the characteristics of each region,so as to promote the high-quality development of the local area.The results show that:(1)The distribution characteristics of land use in the Zuli River Basin are as follows:the low coverage grassland is mainly concentrated in the area east of the Zuli River Basin;The construction land is mainly concentrated in Fengxiang Town and Huining County,and the rest scattered on both sides of Zuli River;Forest land is mainly distributed in the upper and middle reaches of the basin.High coverage grassland and medium coverage grassland were mainly distributed in the west of Zuhe River,and the former was located in the high and medium altitude areas.The land of lake beach and reservoir pit is close to the construction land on both sides of the Zuli River.The main land types were cultivated land and low coverage grassland,whose maximum area was 4223.347 km~2(2000)and 4242.327 km~2(1980).The expansion of productive land and ecological land was the main contradiction of local land use.In recent 40 years,low coverage grassland had the largest shrinking area of173.075 km~2.The characteristics of local land use change were as follows:cultivated land was mainly converted into construction land,grassland with medium coverage and grassland with low coverage.Construction land is mainly converted into cultivated land;Medium coverage grassland is mainly transformed into construction land and high coverage grassland.(2)According to the three life functions of various types of land,taking the functional comprehensive index,the functional coupling coordination index and the land use degree index as indicators,using the natural discontinuous point grading method to divide each index into grade intervals,making rules and dividing the watershed into six types of areas.The result of the first partition is:The production-ecological quality coordination zone and the production-ecological general coordination zone are the main zoning types in the area.The high-quality coordination zone is mainly concentrated in the downstream area of the basin,the general coordination zone is mainly concentrated in the mainstream and tributaries of the Zuli River,and the mildly and moderately unbalanced production-ecological zone is concentrated in the upstream area of the basin and the ecological advantage area.The corresponding development suggestions are provided according to the characteristics of each district.(3)GM-PLUS has a good fitting effect on land use simulation of the Zuli River Basin.Compared with the commonly used coupling model,Markov chain-PLUS,the simulation results are more accurate and reliable.The distance between cultivated land,forest land,low coverage grassland,construction land and bare land is the main reason for the expansion,while the environmental climate is the main reason for the expansion of high coverage grassland,medium coverage grassland,lake beach and reservoir pit.The forecast results show that:The change trend of cultivated land area in the late development stage of each scenario is downward.The expansion degree of construction land is the largest in the ecological protection scenario,the ecological land area in the natural development scenario shrinks seriously,and the ecological and living land area in the ecological protection scenario increases at the same time.The area change trend of different types of land area is similar in the material optimization and cultivated land protection scenario.It shows that timely measures should be taken to cope with the trend of arable land shrinkage in the future,land use and management cannot be separated from the restrictions and guidance of policies,and ecological protection and economic development are not completely opposite.(4)Through the analysis of the regional eco-environmental quality index and the ecological contribution rate of land use transformation of the results of material optimization,ecological protection and cultivated land protection scenarios,it was found that the eco-environmental quality of the Zuli River Basin could keep the trend of improvement degree higher than deterioration only under the ecological protection scenario,and in the ecological environmental protection scenario,Local regional eco-environmental quality index in 2030 is much higher than other scenarios;In all scenarios,the index of 2040 in the study area is very similar,but the value is still the highest in the ecological environment protection scenario.The conversion of low coverage grassland to forest land has been the main reason for improvement.Compared with other scenarios,the local area should adhere to the ecological conservation development route.(5)The Zuli River Basin land use prediction results in 2030 and 2040 in the ecological protection scenario were divided according to the rules.Then,through the superposition analysis,the Zuli River Basin was divided into four land consolidation areas and corresponding land management suggestions were given according to the change trend of the"three and ecological"functions and the coupling and coordination between functions:Areas not suitable for renovation:the areas with the trend of"high-quality coordination"or"production-ecological high-quality coordination"and the areas with the state of"high-quality coordination"or"production-ecological high-quality coordination"are classified into this category.Such areas should maintain the local ecological policy to continue to develop,and make appropriate policy adjustments in the details.We will accelerate the construction of a high-quality development belt in the Zuli River Basin.Selection of remediation areas:the areas with the trend of"general coordination"and"production-ecological general coordination"and the areas with the state of"general coordination"and"production-ecological general coordination"are classified into this category.All regions should take into account the local terrain,climate,light,soil quality and water resources and other conditions to carry out land consolidation work.Protection and improvement areas:The areas that have the tendency to change into"ecological advantage"and the areas that maintain the state of"ecological advantage"are classified into this category.Such areas need to be regulated according to the actual local conditions.We should adhere to the principle of"ecology first,production second,and ecology feeding production".Key regulation areas:the areas with the trend of"serious imbalance"and"production-ecological light-moderate imbalance"and the areas with the state of"serious imbalance"and"production-ecological light-moderate imbalance"are classified as such.This kind of area is the focus of attention in the process of regulation.As a densely populated urban area,the expansion of construction land should be slightly limited in the future,and the proportion of park and green space should be increased to balance the functional balance of"production-life-ecological".Aiming at land planning and management,this paper puts forward a new research idea and coupling model,and puts forward more forward-looking development suggestions for land use.The results can provide reference for decision making to improve environmental quality and optimize living environment.It will help build a beautiful China and implement the strategy of harmonious development between man and nature.