Study On The Landscape Pattern Evolution And Ecological Security Of Urban-rural Intersection Belt In Siping City

This study takes Siping City as an example,and on the basis of field investigation and data collection,the gravity model is used to determine the range of urban and rural intersection zone in Siping City.Based on Landsat TM/ETM 30m resolution remote sensing interpretation data and CA-Markov model prediction,the current situation and driving forces of landscape pattern change in the research area from 1990 to 2030 were analyzed,and the main driving factors of the research area were identified.On this basis,using the theory of ecological security evaluation,together with the present situation of ecological environment in the study area and main driving factors,selecting representative Siping area evaluation factor,adopting"pressure-state-response"model,from the state of natural resources,environment,ecological response of stress,nature and constructing ecological safety evaluation factors,weight is calculated by fuzzy evaluation method.The ArcGIS 10.1 software was used to carry out the single factor and multi-factor comprehensive evaluation of the ecological security pattern and reveal the spatial differentiation law of landscape pattern change,natural resource status,environmental and ecological pressure,natural and environmental response and ecological security pattern.Finally,based on the above results,the paper puts forward some Suggestions on rational development and protection of the region from the perspectives of economic development,population growth,resource exploitation and utilization and the construction of ecological security supervision system.The main research conclusions are as follows:(1)Combine the gravitation model in physics with population,landscape,land and other factors,and the primary and secondary change rates of the gravity value are used to determine that the inner boundary of the urban and rural intersection zone in Siping City is within 2.1?30.2km from the city center.The population density,the proportion of agricultural land and the proportion of construction land showed a trend from high to low,and the landscape diversity index gradually increased.(2)In the past 30 years,the landscape fragmentation degree in Siping City has increased,the landscape shape tends to be single,the landscape connectivity and diversity are uniform,and the evenness decreases.The urban landscape and woodland landscape area increased,and the proportion of cultivated land landscape area decreased.On the whole,the urban landscape and farmland landscape show the trend of fragmentation.From the perspective of land use transfer,farmland is transformed into woodland.With the acceleration of urbanization,the landscape of forest and grass is gradually transformed into the landscape of town.It shows that with the aggravation of urbanization,the population of Siping City has a greater demand for food and land,and the cultivated land and urban land are gradually increasing,gradually encroachment of forest and grass land and unused land,ecological land loss and ecological balance destruction.(3)Logistic regression model was used to analyze the driving forces of landscape pattern change.Grassland,woodland,town and water area all showed that the main driving factors were all natural factors.The main driving forces in the two stages of 1990?2010 and 2010?2018 were roughly the same,with grass coverage rate,soil organic matter,distance from rivers and precipitation as the main driving forces.On this basis,the CA-Markov module in IDRISI software is used to predict the land type and landscape pattern distribution in the research area in 2030.The results show that from2018 to 2030,the cultivated land and the urban area of Siping City show an overall trend of increase,while the area of forest land,grassland and water area all show a trend of decrease.The trend of the overall degradation of the ecological environment in the natural state requires further ecological protection measures to ensure the ecological security of Siping City.(4)Using"PSR"model to evaluate ecological security pattern,the results show that the ecological security of the urban-rural ecotone in Siping City is mainly based on the security level,with an area of 3419.74 km~2,accounting for 73.28%of the total area of the urban-rural ecotone,which is concentrated in the whole range of the urban-rural ecotone.Due to the impact of land use development and population growth,the ecological security level of Siping district is relatively low.It is suggested to strengthen land use management and protect the ecological red line in the region.