| The evolution of regional landscape pattern and its driving mechanism are of great significance to regional ecological environment protection and regional sustainable development.Hongshui basin,which located in the southwest karst mountain,is a unique geographical unit of Guangxi Province owing to it seconomic development,abundant resources and ecological environment.The basin is abundant in mining,biology and tourism resources whereas weak in ecological environment,lag behind in the economic development and with a nervous relationship between land use and human beings.By analyzing the landscape pattern evolution of the basin and driving mechanism,to provide scientific basics for the ecological landscape construction and sustainable development of the study area.Based on the remote sensing imagery with a spatial revolution of 30 m,the landscape in the study area was divided into 8 classes: forestland,Sparse bushes,grassland,paddyfield,dryland construction land,water body and others.Combined with Arc GIS and Fragstats software,we analyzed the dynamic characteristics of Landscape Pattern Evolution of Guangxi Hongshui River Basin and studied the driving mechanism of landscape pattern evolution within the aspects of natural and cultural conditions.Finally,the optimizational strategy of landscape pattern is suggested based on the problems revealed in the evolutional process,and the results and conclusions proposed here might provide the scientific fundamental of ecological environmental control and reasonable development.The results show that:1)The landscape and spatial pattern shows significant discrepancy of Hongshui basin in 2015.The largest area of sparse bushes is 1934226.54,which is the dominant landscape in the landscape.The dry land,which influenced by human activities significantly,has the biggest average dimension,but with an FRAC_MN of only 1.0212.The grassland,which has the PD(plague density)of 3.5294,is the biggest in landscape fragmentation.Hydrophobic shrub landscape has the biggest ED of 68.7054,with the most complicated boundary and the most irregular boundary shape.And other,water and construction land landscape boundary is relatively simple,boundary shape rule.Water landscape is biggest in IJI of 88.3215,with the highest adjacent probability to other landscape types.On the contrary,forestland has the lowest adjacent probability to other landscape types.Hydrophobic shrub landscape is always the biggest area in all upstream,midstream and downstream.Forestland is mainly distributed in upstream while construction land,water body,paddy land and arid land primarily in downstream area.2)The spatial pattern of landscape in Hongshui basin has been a comparatively large change from 2000 to 2015.The patch numbers and densities of the whole landscape decreased to 764978 and 14.9333 respectively,so as the fragmentation,the boundary density ED also declined from 108.47 to 104.6132.The landscape boundary tended to be simple with a more regular shape.The landscape was transformed from nonuniform to uniform with an increased landscape concentration as the SHDI,AI of the landscape increased from 1.508 to 1.5728,51.1056 to 52.8446 respectively.The fragmentation of forestland,grassland and arid land landscape is decreasing and the landscape is tending to be more complete.The patch density of hydrophobic shrub,paddy land,construction land and water landscape is increasing,as well as the landscape fragmentation degree.The spread of the construction land and the IJI value of the juxtaposed index are decreasing,and the adjacent probability of other patch types is decreasing.The construction land,arid land interfered by human activities has the smallest average dimension.The main transformation between the landscape types is: forestland to hydrophobic shrub,hydrophobic shrub to forestland,paddy and arid land to hydrophobic shrub,paddy land to construction land.3)The driving force analysis of landscape evolution shows that the evolution of landscape spatial pattern mainly includes the natural condition driving factor and the human condition driving factor.The different physiognomy type,elevation,slope and hypsography included in natural conditions has different influence on landscape types,whereas the temperature,precipitation and relative humidity fluctuations always cause natural disasters,and finally influenced the landscape area.While the driving forces in cultural conditions such as the developement of society,economics and technology,the implementation and change of policy,the human activities changed by human minds has an obvious effects on landscape spatial pattern.4)In the evolutional process of Hongshui basin from 2000 to 2015,forestland landscape and the matrix of landscape increased and gathered sharply by occupying other landscape space,resulted in the simpler landscape boundary,and hindered the material circulation and energy flow between various types of landscape,decreased the ecological landscape diversity and ecological safety ability.The landscape distribution of construction land is scattered,without reasonable planning.For the purpose of solving these problems,some reasonable and helpful suggestions were given here.Firstly,the relevant departments continue to strengthen the standardized management of forestland landscape and planting and protect the diversity of landscape.Secondly,the land of scientific planning and construction should attach equal importance to ecological aesthetics and sustainable development.Thirdly,the relevant departments continue to control the area of farmland from declining and guarantee the basic farmland area.Finally,accelerate construction of the ecological corridors between the various types of landscape,to improve the landscape ecological pattern.And establish the green corridor in rocky desertification area to protect the sensitive rocky desertification landscape. |
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