典型喀斯特地区土地利用转型的时空特征及其景观格局演变——以仁怀市为例

Temporal and Spatial Characteristics of Land Use Transformation and Its the Evolution of Landscape Patterns in Typical Karst Regions:a Case Study of Renhuai City

探究仁怀市土地利用转型及其景观格局演变对地区土地利用管理和生态保护具有重要意义。以2010、2015、2018年Landsat TM影像为数据源,并结合实地调研对解译数据进行对比验证,通过对土地利用动态指数,核密度和景观格局指数的计算来揭示仁怀市土地利用动态的幅度、速度以及时空转型特征及其景观格局的演变规律。结果表明:①仁怀市土地利用主要以灌木林地、有林地、旱地、水田为主,其次是农村居民用地、草地和城镇用地;2010—2018年,仁怀市土地利用转型幅度最大的是有林地、城镇用地、农村居民用地和旱地,其转型幅度阶段:2015—2018年>2010—2015年;转型速度最大的是城镇用地、道路,转型速度阶段:2010—2015年>2015—2018年;②2010—2018年,仁怀市土地利用类型转换面积较大的是有林地、草地、城镇用地、农村居民用地、旱地、水田;从空间上,2010—2015年,土地利用转换主要集中于仁怀市中部主城区,其土地利用转换向北部迁移;2015—2018年,仁怀市地区土地利用类型转变现象不明显;③随着时间发展,仁怀市的景观斑块密度(PD)、景观形状指数(LSI)、蔓延度指数(CONTAG)、聚集度指数(AI)都呈现出增加态势,景观斑块类型逐渐增多,斑块破碎化大,空间集聚程度集中,空间异质性强,景观斑块呈现多样化,逐渐趋于均匀分布态势,斑块融合较强;④仁怀市土地利用演变模式主要为城区扩张型、道路指向型、区位型和斑块多样型,驱动土地利用转型及其景观格局演变的影响因素是自然因素、人口因素、社会经济因素和政策因素相互作用的结果。

It is of great significance to explore land use transformation and its landscape pattern in Renhuai,which can help regional land use management and ecological protection.This study was based on Landsat TM high-resolution images of 2010,2015 and 2018.Those data source was combined with field survey to verify the images.Moreover,by the analysis of the land use dynamic correlation index,kernel density estimation and landscape pattern index,the dynamic amplitude,speed spatial and temporal transformation characteristics of and evolution laws of landscape pattern in Renhuai were revealed.The results show that the land use is mainly composed of shrub land,forest land,dry land and paddy fields,followed by rural land,grassland and urban land.During period of 2010 to 2018,the land use transformation in Renhuai mainly includes in woodland,urban land,rural residential land and dry land,and the transformation amplitude during 2015 to 2018 is greater than that during 2010 to 2015.The quickest speed of transformation is urban land and roads,and the speed of 2010 to 2015 is greater than that of 2015 to 2018.During period of 2010 to 2018,the land use conversion area of Renhuai is significantly changed as woodland,grassland,urban land,rural residential land,dry land and paddy land.In terms of space,during period of 2010 to 2015,land use conversion is mainly concentrated in the central urban area of Renhuai and shifting to the north.However,in 2015 to 2018,the phenomenon of land use type change in Renhuai is not obvious.With the development of time,indexes of PD,LSI,CONTAG and AI in Renhuai show an increasing trend.The landscape patches are gradually increasing,the plaques is fragmented,the spatial concentration is concentrated,the spatial heterogeneity is strong,and the landscape patches are diversified.The gradual tendency is evenly distributed,and the plaques are strongly integrated.The evolution modes of land use in Renhuai are mainly of urban sprawl,road orientation,location,and patch diversity.It is the interaction of natural factors,population factors,socio-economic factors and policy factors driving the transformation of land use and the evolution of landscape pattern.