| River Basin is an important foundation and support for human production.The inter basinwater transfer project realizes the optimum configuration of water resources,improves economic benefits and improves people’s well-being.It will inevitably have an impact on ecological protection,reduce ecological risks under the background of inter basin water transfer project,enhance the connectivity between patches and maintain the dynamic balance of ecosystem.Taking the Yangtze River to Huaihe River Diversion Project(Anhui Section)as an example,the impact of land change is analyzed by landscape pattern index,the core area is identified through morphological spatial pattern analysis(MSPA),the patches in the core area with large area are screened,and the source is identified based on the patch importance index.The basic resistance surface is constructed according to the resistance factor,and the basic resistance surface is corrected with the landscape connectivity index.The ecological corridor is constructed by integrating the minimum cumulative resistance model(MCR)and Circuit model.To explore the method of building a scientific and reasonable ecological network path.Provide detailed optimization paths from the aspects of ecological source,ecological corridor and ecological nodes.Finally,build the ecological network of the completed river diversion to Huaihe River Project(Anhui Section).The main conclusions of the study are as follows:(1)Based on each index,the impact on the environment before and after the completion of the Yangtze river diversion to Huaihe River Project(Anhui Section)was analyzed.From the patch type index analysis,it could be seen that the project of diverting the Yangtze River to the Huaihe River had exacerbated the fragmentation of habitat and changed the living space of organisms,but its impact on the construction land was limited.According to the analysis of landscape type index,the overall fragmentation degree of the study area had increased,the overall connectivity had decreased,and the landscape heterogeneity and type diversity had improved.(2)The ecological source area of the river diversion to Huaihe River Project(Anhui Section)was 9659 km~2,and the core area identified by MSPA was 11779 km~2,accounting for 83.5%of the prospective area.The ecological source was mainly distributed in the south of the Jianghuai watershed and near the Huaihe River,mainly in forest land,water area and grassland patches.There were few patches in the north of the Jianghuai watershed,and there were few large areas of forest land and grassland except rivers.The distribution density of ecological corridors is generally high in the southeast and low in the northeast.As a large area of cultivated land in the north was connected with the construction land,and the ecological corridor was mainly distributed along the urban green belt and farmland,there was a certain degree of ecological barrier.(3)Compared and analyzed MCR model and Circuit model.Based on MCR model,the current ecological network of the Yangtze Huaihe River Diversion Project(Anhui Section)was a"point line surface"structure composed of 82 ecological sources,38 potential corridors and 23 ecological nodes.The ecological network constructed based on the Circuit model was composed of 82 ecological sources,165 ecological corridors and 76 ecological nodes.Compared with the MCR model,the ecological network constructed by the Circuit model had better connectivity.(4)After the completion of the Yangtze River to Huaihe River Project(Anhui Section),83 ecological sources were determined,and 214 ecological corridors and 116 ecological nodes were constructed by integrating the two models.On the whole,the ecological corridor presents a distribution pattern of"more in the South and less in the north".From the perspective of landscape connectivity,the river diversion to Huaihe River project helps to increase the connectivity of rivers and lakes,but it had a certain barrier effect on the connectivity of the overall ecological network.(5)Add 14 ecological sources,add 10 ecological corridors and 5 ecological nodes,and enhanced the connectivity and stability of the ecological network north of the Huaihe River.In addition,35%of the ecological node blind areas and 153 ecological fracture points were identified,which targeted the key points of the protection and restoration research area to provide support for the high-quality development of the habitat.Protection and construction strategies were proposed from"source corridor node"to optimize the ecological network.Based on the ecological network,an ecological spatial structure of"three corridors,two belts,four areas,one core,two lakes and six areas"would be formed. |
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