| Soil erosion has become a serious ecological problem worldwide and has caused land degradation,which continues to affect natural ecosystems.The United Nations has proposed 17 Sustainable Development Goals in order to protect soil and achieve sustainable development.The 20th National Congress of the Communist Party of China also proposed to promote green development,issue relevant documents to improve soil conservation capacity,and build a sound interactive feedback process between natural ecosystems and human development systems to achieve harmonious coexistence between man and nature.From the perspective of land use landscape pattern,this study explores the impact mechanism of soil erosion and the potential spatial spillover effect,and the optimization path,and finally seeks the sustainable development.Firstly,the study selects 7 indicators from the three dimensions of area,edge-shape,and convergence to build a measurement framework of landscape pattern,and analyzes the spatial and temporal changes of land use transfer and the dynamic evolution characteristics of landscape pattern during from 2005 to 2020;Secondly,by extracting physical geographic data such as precipitation,terrain and soil,and ecological environment data such as vegetation coverage and soil conservation measures,based on the RUSLE model,the actual soil erosion modulus of the four periods from 2005 to 2020in the Jianghan Plain was evaluated.Then,based on Root,Meng Qinghua and others put forward the SCS theoretical framework to analyze the impact mechanism of land use landscape pattern on soil erosion,and confirmed this significant effect at the small watershed scale with the characteristic scale of landscape pattern in Jianghan Plain as the threshold.At the same time,the possible spatial spillover effects were further explored,the original model was optimized by adding spatial variables to build a more robust spatial error model,and the local impact mechanism of soil erosion was explored.Finally,according to the relevant impact analysis,the research constructs the landscape disturbance index and the human disturbance index,and constructs the optimal partition of the landscape pattern for reducing soil erosion in the Jianghan Plain according to the MCR model,and proposes a targeted optimization path.Research Conclusions:(1)The land use type of the Jianghan Plain is mainly cultivated land.From 2005 to 2020,land use types have undergone changes to varying degrees,showing a gradual expansion from the center of the county,accompanied by infrastructure and the characteristics of the zonal distribution of key items.In terms of landscape pattern,the Jianghan Plain presents a fragmented development,and the landscape patches are continuously split into fine patches.At the same time,cultivated land,woodland and grassland are affected by human modification and their shapes are constantly becoming regular,while other landscape types tend to develop disorderly.Overall,the diversity and heterogeneity of landscape patches are in a stable state.(2)The degree of soil erosion in the Jianghan Plain has continued to deepen,and the average soil erosion modulus has grown as high as 80.97%in 15 years.On the whole,the actual soil erosion modulus of the Jianghan Plain showed a trend of high in the west,low in the east,and high in the north and low in the south,and the spatial layout remained relatively stable from 2005 to 2020,without strong spatial shift.In the hinterland of the Jianghan Plain,there are scattered special land uses and natural features,forming micro-soil erosion areas of different sizes.(3)NP and ED have a positive driving effect on the actual total soil erosion,while PD and POP have a negative impact on the actual total soil erosion.At the same time,significant positive spatial autocorrelation was detected for the actual total amount of soil erosion in the 4 periods.After adding spatial variables,R~2increased significantly compared with the original model,and the regression results were more significant and robust.(4)According to the empirical results,a comprehensive resistance surface based on landscape disturbance and human disturbance index is constructed.The minimum cumulative resistance surface for slowing soil erosion can be divided into four categories:control area,buffer area,sensitive area,and monitoring area through the natural breakpoint method.It accounts for 32.70%,27.09%,24.48%and15.73%of the Jianghan Plain,respectively.According to the research results,from the perspectives of landscape type optimization,comprehensive management of small watersheds,ecological management and control,and soil erosion monitoring,this paper proposes the corresponding optimal path for reducing soil erosion intensity in the Jianghan Plain.The study believes that it is necessary to fortify areas with severe erosion step by step,give full play to the natural restoration of the ecosystem,focus on strengthening the control of"soil erosion sources",and establish a"forest-water integrated ecological protection area"to protect the protection source landscape with a good ecological foundation,and finally effectively slow down soil erosion and strengthen ecological protection and restoration.The research results help to clarify the impact mechanism of land use landscape pattern on soil erosion,and understand the coupling relationship between soil erosion,landscape disturbance and human disturbance.They provide references for the formulation of relevant policies to achieve green development and regional sustainable collaborative governance in which man and nature coexist harmoniously. |
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