| The exploitation of mineral resources brings not only the national economic promotion,but also a series of environmental problems,the first of which is the destruction of land resources.In the vicinity of open-pit mining area,the original land is constantly occupied by mining and industrial land,at the same time,waste disposal site and tailings where the exploitation duties already completed constantly reclaimed by new vegetation lands,which makes the open-pit mining sites as the area with the most frequent land use change and the most unstable ecological environment.If we don't monitor and assess this unstable change of land elements in time,it will bring irreversible damage to the ecosystem of the whole region.With the development of spatial information technology and the deepening understanding of landscape ecology theory,combining remote sensing and GIS technology with the landscape ecology theories,we can deeply explore the spatial arrangement and internal driving mechanism of this land element,and the result can provide data support for mining units to formulate follow-up work plans.In this study,one large-scale state-owned open-pit phosphorus mine located in Jinning District,Kunming City,Yunnan Province was taken as the main research area.With the help of statistical yearbook and other written materials,as well as the support of the theories and techniques of GIS,landscape ecology and statistics,,we extracted the main land use in study area and the spatial distribution maps of landscape pattern index in the relevant years were obtained based on CBERS-02B image in 2007,ZY-3 image in 2013 and GF-2 image in 2017.This paper discussed the change of land use information and landscape pattern characteristics in the study area from 2007 to 2017,and analyzed the main reasons for the change of landscape pattern in the study area from natural and human factors.The main research contents and conclusions are as follows:(1)The land use information of open-pit mining area in the past 10 years was monitored by remote sensing.According to the spectral and texture features of typical surface features in open pit mining area,a set of classification features is constructed,and the main types of surface features are extracted by using object-oriented classification method.Accuracy verification results show that this method can effectively eliminate the "salt and pepper" noise and greatly improve the classification accuracy.The land use dynamic degree and transfer matrix can clearly display the change range and flow of land use types.The analysis results show that the land structure of Jinning open-pit mining area changed significantly from 2007 to 2013,and tended to be stable after 2013.The main reasons for these changes are the transfer of mining lands,grass lands and forest lands.(2)The temporal and spatial variation characteristics of landscape pattern in Jinning mining area was analyzed intuitively from two levels of landscape type and landscape level.Combining the landscape pattern index in time series with the moving window analysis method,we can realize spatial visualization of landscape pattern index.The results show that in the past 10 years,the maximum vale of fragmentation and diversity landscape index has spread from the edges to the center,and gradually formed the landscape pattern of patch aggreging distribution in the mining land and mountain woodland,and discreting distribution on the urban margin.(3)The influence of different natural and human driving factors on landscape pattern change was analyzed.We found that the environmental factors such as vegetation coverage and elevation affects the formation of landscape pattern by promoting the ecological process in low vegetation coverage areas and preventing the further complexity of landscape pattern in areas with smaller impact.The human being factors can be described into three aspects:the development of phosphate mineral industry,the policy regulation and urban construction,which all have great impact on the shaping of landscape environment in different times and spaces. |
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