| Land as a place of life and a source of information for life,with the contradictions between people and the prominent,it's role,characteristics and problems are more and more people concerned,land landscape changes,the destruction of land resources,land quality decline are all the land problem,correctly handle the contradiction between man and land,to achieve the reasonable allocation of land resources and to achieve the sustainable use of land,to optimize and upgrade of the land use landscape are urgent problems in today's society to solve.This is to strengthen the healthy development of the economy,the protection of the ecological environment has important practical significance.This study choose Banan District which is the typical mountainous and hilly areas,as the research object,having geometric correction,radiometric calibration,atmospheric correction,image enhancement and other steps of pretreatment on the remote sensing images of the study area in 1995,2002,2009 and 2015,and then through the supervision of classification and unsupervised classification,extracting of different land use types of the region of interest to be interpreted,completed the land use maps,the land use type is divided into six categories,construction land,farmland,forest land,grassland,water and unused land,analyzing the land use landscape pattern from dimension and scale.From the landscape type level and landscape level,selecting indexes include PD,MSI,PLAND,AI,COHESION and NP,SPLIT,LSI,SHDI CONTAG.On the dimension,the elevation and slope information of the Banan area are extracted according to the DEM data,using the Arcgis space overlay function,the elevation and slope levels are superimposed on the land use profiles of each year,to analyze the characteristics of landscape indexes change at different elevation and slope levels,and construct terrain index,to study the distribution of landscape indices in terrain index.On the scale,the study size is divided into 15 scales,different types of landscape was calculated on each scale distribution index.According to the minimum cumulative resistance model,to construct the index system of source resistance evaluation,finally,based on the resistance difference surface,combined with the existing research results in Banan District,to optimize the landscape pattern of Banan District,and put forward different development suggestions for different ecological zones.The results are as follows:(1)The main landscape type is forest landscape,the speed of construction land growing faster.The proportion of forest land in the land use landscape of Banan District is the largest,and the proportion of farm land accounts for more than 80% of the total area.The proportion of construction land increased from 6.48% in 1995 to 11.92% in 2015,which is the fastest growth rate.The degree of fragmentation of the farm land is declining,the plowing of the farm land is more and more fragmented,and the degree of aggregation is reduced,the degree of connectivity between the landscape is decreasing,the landscape towards the diversification trend of development.(2)landscape pattern terrain gradient difference is obvious.In the elevation,the low elevation area of Banan District is dominated by water landscape,and the area with high elevation is dominated by forest landscape and farm landscape.The degree of landscape fragmentation below 200 m is decreasing and the degree of gathering of the landscape is increasing,200 m to 400 m landscape fragmentation degree and the degree of aggregation are reduced,the degree of landscape fragmentation is increasing,the degree of aggregation is reduced in the area of more than 400 m.On the slope,the main land use landscape with slope of 6 ° and below is cultivated land,the degree of landscape fragmentation is decreasing and the degree of gathering of the landscape is improved.6 ° above mainly is the forest land,landscape fragmentation is increasing,in the degree of aggregation of the landscape,6 °-15 ° area in the increase,more than 15 ° area in the lower.In the terrain,the farm land,the forest land and the grassland are mainly distributed in the high terrain area with high elevation and high slope.The construction land,the water land and the unused land are mainly distributed in the low terrain area with low elevation and low slope.Conform to the objective distribution of land landscape.(3)The landscape pattern has obvious difference,and the trend of change is similar.In the percentage of landscape index,except for grassland,the land use type of the curve of each year have significant changes,the percentage of the landscape of the six kinds of land shows the first wave after the change,the trend of each year has similarity.The MSI index of land use landscape is consistent with the particle size of 30m-120 m,and the change trend of AI index in 60m-450 m particle size research unit is relatively consistent.With the increase of the range of study scale,the number of landscape patches decreased,the shape tends to be regularized,the degree of fragmentation decreased,the appropriate particle size for the study of the landscape level index in this area should be 30m-60 m.(4)Division of landscape ecological function.The optimal model of landscape ecological resistance in Banan area was constructed by using the minimum cumulative resistance model,try to introduce the landscape index and composite index of land use,from the terrain,land cover,socio-economic and comprehensive index and other aspects to establish the ecological source resistance rating system,to evaluate resistance influence factors more comprehensive,also for the final landscape pattern of ecological area to lay a good foundation.Through the calculation of the landscape pattern ecological resistance model,the Banan area is divided into three ecological functional areas.The western ecological maintenance area is the most important urban development area of Banan District and the important economic growth pole in the south of Chongqing.It should be based on maintaining the existing ecological environment,realizing the intensive and economical use of land,optimizing the land use structure,to protect the Yangtze River environment,relying on urban green space,mountain forest land for urban construction land to provide a good ecological environment.The central ecological control area undertakes the responsibility of providing production protection,living guarantee and ecological security,taking the ecological control as the mainstay,strengthening the ecological environment regulation and rational planning and development land,and establishing the ecological compensation mechanism,to avoid the original ecological environment damage and ecological system confusion due to the land collection for the purpose of promoting development.The eastern ecological protection zone has a natural ecological barrier,ecological protection should be the main direction of the implementation of key development,to maintain the stability of the ecosystem,to ensure that agricultural production,comprehensive protection of ecological development strategy,strict control of construction land,optimize the layout of villages and towns to achieve the ecological environment of health and stability. |
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