Study On Landscape Ecological Evolution And Ecological Network Identify In Hebei Province

In recent years,the rapid development of urbanization has intensified the conflict between human activities and ecological environment,which has caused a certain pressure on the ecological system.With the continuous promotion of ecological civilization construction,the ecological environment is constantly affected by natural factors and human factors,which leads to the dynamic change of landscape ecological pattern.The limitation of natural resources determines the scarcity of resources,the rapid pace of urbanization has exacerbated land pressure,further leads to ecological fragmentation,landscape connectivity decline and other ecological security problems.Nowadays,ecological construction has become the cornerstone of social and economic development.Exploring landscape ecological evolution has important practical significance for ecological security.The construction of regional ecological network can effectively alleviate the contradiction between urbanization development and ecological protection,and coordinate the sustainable development relationship between social economy and landscape ecological pattern.In this study,we used the Globe Land30 data of 2000,2010 and 2020 to explore the land use change and the spatial-temporal evolution of landscape pattern in Hebei Province in the past 20 years.Based on Globe Land30 data,MSPA model was used to select potential ecological sources and patch importance index was used to extract ecological sources.The resistance factors were selected based on land classification data,DEM data,MOD13Q1 data,ecological reserve data,river data and traffic road data,and the weights of the selected resistance factors were set and the resistance surface was constructed by AHP.The MCR model was used to identify the ecological network of Hebei province,and the ecological corridors and ecological nodes were extracted.At the same time,according to the ecological status of Hebei province and the above analysis,it puts forward scientific suggestions and optimization countermeasures for the ecological safety protection of Hebei province.The main research results are as follows:(1)The land use types are divided into cultivated land,grassland,forest land,construction land,water area,wetland,shrub land and unused land.Using the method of transfer matrix of land use type and landscape index changes analysis of landscape pattern changes from 2000 to 2020 in hebei province were analyzed.The results showed that the land use types of Hebei Province from 2000 to 2020 were mainly cultivated land,grassland,forest land and construction land.The proportion of cultivated land area was the largest and concentrated in the southern part of Hebei Province,but the total area of cultivated land showed a downward trend.Construction land is expanding rapidly,and its main source of growth is cultivated land.The area of grassland and forest land did not change greatly,but the structure layout of land use type changed.Other land use types have relatively smaller areas and less fluctuating changes.(2)According to the calculation results of landscape index in Hebei Province from 2000 to 2020,the fragmentation degree of landscape ecological patches increased,and the fragmentation index of grassland,forest land and construction land was higher.The maximum patch index of cultivated land was the highest,indicating that cultivated land was the main dominant landscape type in Hebei Province,and the aggregation index of cultivated land was the highest,indicating that cultivated land distribution was concentrated.Both Shannon diversity index and Shannon evenness index showed an increasing trend,indicating that landscape pattern complexity became higher and landscape types tended to be uniform in spatial and quantitative distribution.(3)The 52 patches with the largest patch importance index were extracted as ecological sources,including 17 in Zhangjiakou,15 in Chengde,5 in Qinhuangdao,and less than 5 in other cities.Ecological source area belongs to the region with high local ecological value,and its landscape type is usually forest land,grassland,water and other ecological land,which plays an important role in maintaining regional ecological security and sustainable development.Therefore,we should strengthen the protection of the local ecological source.(4)The comprehensive resistance surface was obtained by constructing resistance index evaluation system.The greater resistance in Zhangjiakou is related to the elevation,land use type and vegetation coverage.The average elevation of the Bashang Plateau in Zhangjiakou is more than 1400 m,while the average elevation in the south of Zhangjiakou is more than 500 m.The land type is mainly grassland and cultivated land,so the vegetation coverage is also lower,which leads to the greater resistance in this region.In the southern part of Hebei Province,cultivated land and construction land are the main areas with traffic roads.Human activities also have a certain hindrance to the migration of biological species,so the resistance is relatively large.(5)Using MCR model to identify ecological network in Hebei Province.A total of 114 ecological corridors and 28 ecological nodes were extracted by Arc GIS spatial analysis.In terms of spatial distribution,the corridors in the province are densely distributed in the north and sparsely distributed in the south.The distribution of corridors is uneven,and the number of ecological sources in Handan,Xingtai,Hengshui,Cangzhou and Langfang is relatively small,resulting in a small number of ecological corridors.Ecological nodes can enhance the overall ecological connectivity of the region.The nodes are located on the ecological corridor,and the distribution of the corridor also determines the distribution of the nodes.In view of the current ecological environment,the number of corridors and nodes should be increased to increase the stability of the ecosystem.Based on the above studies,the evolution trend of landscape pattern in Hebei Province in recent years can be understood.The landscape index can be used to understand the degree of landscape fragmentation in more detail,and provide realistic data basis for the identify of ecological network in Hebei Province.The distribution of ecological corridors and nodes in Hebei Province can provide data support for ecological protection in Hebei Province,further strengthen the ecological stability of the province,and improve the ecological security index of Hebei Province.