延安市土地景观格局变化与特征

Characteristics and changes of landscape pattern in Yan'an region

根据延安市2000、2005、2010年的土地覆被数据,借助Arc GIS和景观格局分析软件Fragstats,统计和分析不同时期的景观格局特征及各景观类型之间的转化,定量揭示延安市潜在的景观秩序。结果表明:延安市的景观格局以草地、林地和耕地为主。景观形状指数和聚散性呈持续下降趋势,草地和林地的形状指数值逐年降低,形状结构相对比较规则和简单,景观类型内部连通性较好。耕地的形状特征相对破碎和不规则,耕地斑块数量增加但总面积持续减小。景观格局破碎化程度和异质性增加,局部景观格局变得更复杂。相对分布均匀的斑块类型、提升较大的景观多样性、景观类型的演替与更新更加明显是延安市景观特征的变化趋势。

According to the land cover data in 2000, 2005 and2010, using the Arc GIS and the landscape pattern analysis software Fragstats, the paper counted and analyzed the landscape pattern characteristics in different period and the transformation of various types of landscape, and quantitatively revealed the potential landscape order in Yanan region. The result shows that the landscape pattern includes mainly grassland, woodland and the cropland. The landscape index and the agglomeration have declined, and the shape index of grassland and woodland decreases year by year. The shape structure is relatively regular and simple, and the internal of the landscape type has a good connectedness. The shape feature of the cropland is relatively cracked and irregular, and the number of cropland patches increases but the total areas continue to decrease. The degree of landscape fragmentation pattern and the heterogeneity increases, and the local landscape patterns become more complex. The variation trend of the landscape characteristics in Yan＇an region is the patch type which has relatively uniform distribution, promoting the larger landscape diversity and the more significant landscape type.