Study On Dynamics Of Land Use Landscape Pattern And Spatial Extent Effect In Tianshui

The study of the scale effect in the landscape pattern is to identified the characteristic scale.At present,the research of scale effect mostly focused on the particle grain effect.And it was also focused on land use landscape pattern.The study on extent effect of land use landscape pattern was reflected the spatial distribution and change regulation of land use pattern.Therefore,this paper based on the current situation of land use in Tianshui in 2009 and 2015,to study the dynamic evolution of land use landscape patterns in Tianshui and the spatial characteristics,the change rules,and distribution patterns of land use landscape patterns under different extent.It is necessary to understand the spatial patterns and distribution of land use patterns,and to provide reference for land planning and management and rational land use control measures.The results showed:(1)From 2009 to 2015,the degree of landscape fragmentation and diversity of land use landscape pattern in Tianshui were showed an increasing trend.The number of patches,patch density,landscape shape index and Shannon diversity index were increased,but the landscape aggregation index was decreased,which means that the landscape fragmentation was increased,and the landscape diversity was more abundant.(2)The landscape pattern index of land use pattern in Tianshui was showed a significant extent dependence on patch level and landscape level.The extent effect of different landscape elements were different.The extent effect of different landscape pattern indexes were also different.In the range of 5-25 km,the patch level indexes and landscape level indexes of each landscape element were greatly affected(0.18%-96.08%)by the extent change,which indicated that the sensitivity of the landscape indexes to the extent variation was quite different in the range of the extent;Within the range of 25-85 km,the extent affected the change of landscape pattern indexes and landscape level indexes of landscape elements.The patch level indexes and landscape level indexes were different in this extent range,but the difference was relatively small(0.03%-56.75%),which indicated that the sensitivity of the landscape index were decreased;beyond 85 km,the patch level indexes and the landscape level indexes of the landscape elements did not change.So the 25 km and 85 km is the Optimum range of the extent effect of the land use pattern.(3)In 2015,the landscape pattern index of land use pattern in Tianshui was showed an agglomeration and distribution trend in space,and all landscape elements were also clustered and distributed in space.There were differences in the degree of spatial distribution and aggregation of different landscape elements.The more complex the landscape shape,the more the distribution of the landscape in the spatial distribution.The higher of the degree of landscape diversity,the higher of the spatial distribution of landscape elements in the landscape gathers.In future land use planning,it is necessary to strengthen the scientific and detailed management of land use,to optimize the land use structure,and to rationally develop and use land.