黔中城市群景观生态风险时空动态研究

Space-time dynamic analysis of landscape ecological risk of urban agglomeration in central Guizhou

以遥感影像数据为来源,通过ENVI5.2对其进行预处理,提取土地利用信息,在FRAGSTATS4.2中基于土地利用分类图选取景观尺度和景观类型两个尺度的景观指数指标,旨在分析黔中城市群的景观破碎度程度、分离程度,从而得出人们对土地利用景观系统的干扰程度,而后同反映土地利用类型本身承受干扰能力的脆弱度指数和土地利用景观生态功能和生态过程方面的损失度一起构建土地利用景观的生态风险指数,利用ARCGIS10.2制作黔中城市群景观生态风险等级空间分布图,从时间和空间尺度研究黔中城市群的景观生态风险特征,为制定减少发展的景观生态风险、降低高风险区的规划和政策提供一些科学的理论依据。从景观风险评价来看:土地利用类型景观水体类型的风险指数最小,风险指数最大的是草地和耕地,城镇用地的风险指数一直持续增长。贵州是依靠农业带动经济发展的省份,其工业化发展程度低,随着城市化的快速推进,对土地利用类型明显增加需求和加大利用程度的是草地和耕地,也就是说,城镇化的过程中,城镇用地扩张很大程度上是靠占用草地和耕地两种土地利用类型。从景观生态风险空间分布看:黔中城市群的低生态风险区和较低生态风险区主要分布在黔中城市群西以及西南部发达程度不高的地区,中生态风险区主要分布在北部,东部地区。较高和高生态风险区主要分布在黔中城市群中部,北部和东部经济水平、城镇化水平高的城市。说明人们对土地需求和利用程度的增加加剧了对城市土地利用景观生态系统的干扰破坏程度,加剧了城市发展的景观生态风险。

In this study,we preprocessed the remote sensing image data with ENVI5.2,extracted the land use information,and selected the indexes of landscape scale and landscape type based on land use classification map in FRAGSTATS4.2.Then the landscape fragmentation degree and separation degree of the urban agglomeration in central Guizhou were analyzed to obtain the degree of people′s interference with the landscape system.Then the landscape ecological risk index was constructed combining the vulnerability index and the loss degree of ecological function and ecological process of landscape.The spatial distribution map of landscape ecological risk level of central Guizhou urban agglomeration was produced by ARCGIS 10.2,and the features of the landscape ecological risk was studied from the aspects of time and space.The conclusions of the study were as follows:the risk index of water bodies was the smallest,the risk index of grassland and cultivated land was the biggest,and the risk index of urban land had been increasing continuously.With the rapid development of urbanization,the demand and utilization of grassland and cultivated land was obviously increasing.The areas with low ecological risk were mainly distributed in the west and southwest of the urban agglomeration,and the areas with middle ecological risk were mainly distributed in the north and east.The areas with high ecological risk were mainly distributed in the well-developed cities in the center,the north and the east.The results indicated that the increase demand and utilization of land intensified the disturbance and destruction of urban landscape ecosystem,and increased the landscape ecological risk of urban development.