Landscape Pattern Dynamic Analysis And Prediction Research Of Woodland And Grassland On Qinhuangdao

In recent years,due to the deterioration of urban ecological environment,urban ecological construction has attracted much attention.woodland and grassland,as important carriers of urban ecological system,have important ecological functions.It is of great significance to clarify the dynamic change of urban woodland and grassland for urban ecological construction.Taking the woodland and grassland of Qinhuangdao city as the research objects,this paper uses ArcGIS 10.2 technology and landscape index to analyze the dynamic change rule and corresponding driving force in 2005,2010 and 2015,and through the CA-Markov model,the change trend in 2020 is simulated.The conclusions are as follows:1.The area of woodland and grassland accounts for nearly half of the total area of Qinhuangdao.Among the woodland types,the area with forest land is the largest,followed by shrub land.Judging from the change rate of the whole stage from 2005 to2015,the forest land shows an increasing trend.Among them,the annual change rate of open forest land is 5.81%,grassland shows a decreasing trend,and the annual change rate is-1.14%.In terms of stages,the change of woodland and grassland between 2005 and 2010 is obviously higher than that between 2010 and 2015.2.At the level of type,from the LPI,the forest land and grassland patch index are larger,which shows that forest land and grassland are the dominant ecological types.According to the LSI,the grassland shape index is the largest,followed by shrubs land,forest land,open forest land and other forest land.PD has increased from2005 to 2015,indicating that the degree of fragmentation of woodland and grassland has been increasing.With regard to AI,there has been a downward trend for forest land,shrub land,other forest land and grassland,while only open forest land had been rising,indicating that the intensity of artificial forestation is increasing.3.On the landscape level,the patch density of the landscape shows an overall upward trend in the past ten years,indicating that the landscape fragmentation degree further increased.Perimeter-area fractal dimension is decreasing,i.e.patchboundaries appear more regular and simple.On the contrary,the degree of separation shows a downward trend,indicating that the distance between woodland and grassland types in Qinhuangdao city is decreasing.Simpson's diversity and evenness index increases slightly on the whole,which shows that the ecological diversity and evenness are relatively good and stable.4.Through the analysis of the driving forces of natural factors,social factors and economic factors,the optimized suggestions are obtained.5.The Markov cellular automaton model of Qinhuangdao city is established to predict the change of woodland and grassland in Qinhuangdao city in 2020.The predicted results show that only shrub forest will continue to reduce from 2015 to2020,while forest land,sparse forest land,other forest land and grassland will all increase.The grassland area will increase the most,followed by forest land.The increasing area is slightly lower than that of grassland,much higher than other types.