喀斯特山区贫困乡村土地利用的地形梯度特征

为厘清喀斯特地区小尺度土地利用在地形梯度的特征。基于0.5 m分辨率的Pleiades遥感影像和DEM数据,在ArcGIS技术支持下,采用人工目视解译方法,进行土地利用分类和地形位指数计算,并利用Fragstats 4.2软件,从景观生态学视角,分析4种不同喀斯特地貌的典型乡镇土地利用的地形梯度特征。研究发现:4个不同地貌乡镇的斑块数量(NP)和斑块形状指数(LSI)变化在地形位梯度上存在相似性,而与斑块所占景观面积(PLAND)变化规律有明显不同。斑块水平上各指标变化在4个地貌乡镇之间存在一定差异。随着地形位指数增加,4个乡镇的聚集度(AI)和蔓延度(CONTAG)整体上呈增加趋势,而4个地貌乡镇的香浓多样性指数(SHDI)和连接度(COHENSION)变化存在差异。不同地貌的土地利用结构的差异是形成不同喀斯特地貌贫困乡村土地利用梯度特征的重要因素。

Topography gradients of land use in poverty-stricken rural area in Karst mountainous

In order to clarify the characteristics of small-scale land use in the topographic gradient in Karst area, the land use types were classified and topographic position index were calculated by using artificial visual interpretation method with the support of ArcGIS based on the 0.5 m resolution Pleiades remote sensing image and DEM data. The characteristics of land use in terrain niche gradients in four typical towns with different karst landforms was analyzed from the perspective of landscape ecology by using Fragstats 4.2 software. The results showed that the changes of number patch and patch shape of each landscape type in the four towns with different landforms were similar in terrain niche gradients, but which were obviously different from the changes of percentage landscape patch area. There were differences in the changes of each index at the patch level in four towns with different Karst landforms. With the increase of terrain niche index, AI and CONTAG presented an increasing trend. The changes of SDHI and COHENSION among the four towns were different in terrain niche gradients. The difference of land use structure in different landforms is an important factor to form the gradient characteristics of land use in Karst poor rural area with different landforms.