Construction Of Regional Ecological Security Pattern Around Chaohu Lake And Repair Path Study

This thesis takes the circum-Chaohu region as the research object,analyzes the changes of land use and landscape pattern,calculates the value of each ecosystem type and the ecosystem service function in each district and county based on the assessment of ecosystem service function value,constructs the ecological security pattern of circum-Chaohu region with the help of the circuit theory model,and proposes ecological restoration paths from the macro,meso and micro perspectives.The main conclusions are as follows:(1)The change of land use type is significant in Chaohu Lake region.Agricultural land and construction land were the main types of land use in the study area.In recent 30 years,the area of agricultural land and forest land decreased by 1200.76km~2and 403.88km~2,water body decreased by 210.53km~2,construction land increased by 1815.17km~2,and the area of land type changed significantly.(2)Landscape pattern and Morphological space(MSPA)analysis revealed the regional evolution.The edge density showed a decreasing trend,the landscape shape index also declined,and the degree of aggregation index also decreased slightly.The fragmentation degree of landscape patches in the study area was enhanced and their shapes tended to be consistent.MSPA analysis further verified the separation and fragmentation of landscape structure in the study area.(3)Ecosystem service function value assessment highlights the regional value distribution.The ecological value of all land types declined,and the service value provided by water body was the highest,followed by woodland and cultivated land.The distribution of value in space presents the characteristics of"low around,high in the middle".Among the individual ecosystem service values,food production and raw material production are the most important value types.From the perspective of total value,the regulating service function>supporting service function>supplying service function>cultural service function.In space,the functional values have strong correlation and high degree of aggregation.(4)Build a regional ecological security pattern.The ecological source areas were concentrated in the central and southeastern regions with small areas and fragmented distribution.Most of the districts and counties were in areas with high resistance value.The number of identified key ecological corridors was up to 116,with a total length of1222.7km,and 19 potential ecological corridors with a total length of 409.51km.There were 466 ecological pinch points with a total area of 65.52km~2,368 ecological barrier points with an area of 367km~2,and 447 ecological break points.(5)Explore the ecological restoration path around Chaohu Lake.At the macro level,realize the linkage between the lake and the city inside and outside,and incorporate it into the overall urban planning;At the meso-level,the restoration methods under different districts and counties were developed based on the ecosystem service value zones.Microcosmic protection of ecological source,consolidation of ecological corridor,restoration of ecological nodes.