Analysis On Spatial Gradient Of Land Use Landscape Pattern In Jiayuguan City

To study the gradient of land use pattern in different human disturbance is very important for drawing up the land use planning rationally.At present,there are many researches on the spatial gradient effect from the perspective of geography,and the study of the spatial gradient effect from the view of human activity intensity is less.In this paper,with the support of GIS and the theory of landscape ecology,gradient effect of land use pattern in different disturbance in Jiayuguan city were studied using the influence of terrain factor,residential area and road.The results showed that:(1)The study area is an oasis city in arid area,and its land use structure is dominated by unused land,land use landscape pattern have changed obviously during 20 years.With the urbanization process accelerating,the construction land area increased significantly,the area of cultivated land and forest land increases slightly,and the area of grassland decreased first and then increased,and the area of water and unused land continued decreased.The conversion between land use types is mainly converted to other land by occupying unused land.(2)The cultivated land and forest land in the study area are mainly distributed in the range of low human activity intensity.With the increase of human activity intensity,the distribution index of these two types of land use is decreasing.The dominance of grassland is mainly located in the low intensity range of human activity,the distribution index of grassland in 2015 increased with the increase of human grassland,and began to distributed to high human activity gradient area.The distribution range of water area was mainly concentrated in the low intensity range of human activity,the distribution index of construction land is positively correlated with the intensity index of human activity,and the distribution of the gradient of the unused land is quite different.(3)With the increase of human activity intensity,plaque level index and landscape level index showed obvious spatial gradient difference.At the plaque level,the landscape index increases first and then decreases.Plaque area in the second ladder is the largest.The proportion and shape index of land types affected by human activities is larger in medium human activities,the other types of land use are larger under lower disturbance.The aggregation degree of the land use type is declining except the water area.At the level of landscape,the diversity index and the uniformity index decrease with the increase of human activity intensity,while the index of expansiveness is increasing.(4)With the increase of the intensity of human activities,the land use comprehensive index of the three periods showed a trend of rising and then decreasing,and the land use degree was higher under the intensity of medium human activities.The study area can be divided into three land use control areas,including the core area,the buffer zone and the edge area.