基于流域的山区景观格局分析和分区研究--以山东省栖霞市为例

Catchment-based landscape patterns and divisions in mountain areas: A case study of Qixia City in Shandong Province

  • 摘要: 本文以位于胶东半岛中部山区的栖霞市为例, 在对整个研究区进行流域提取的基础上, 分别统计各流域内的景观指数, 并通过聚类分析对整个栖霞市的山区景观进行分区。首先解译2010年Thematic Mapper(TM)遥感影像数据, 获得栖霞市景观格局图, 以1︰25 000地形图为基础数据源, 建立DEM模型, 利用ArcGIS水文分析模块将研究区划分为300个子流域。然后根据常用景观格局指数所反映的生态学意义和景观特征信息, 并结合研究区内的具体景观结构, 选择边缘密度(ED)、多样性指数(SDI)、斑块大小变异系数(PSCOV)、面积加权平均分维数(AWMPFD)和核心区密度(CAD)5个景观指数, 并结合各流域的平均高程与空间分布对每一个子流域进行景观格局分析, 探讨各子流域景观格局的空间差异, 揭示人类活动、自然干扰等各种景观生态机制对区域景观生态的影响。研究结果为: ED值和CAD值随着海拔的增加而逐渐变大, 垂直分异特征明显; SDI值呈现出由低海拔向高海拔逐步减少的趋势; PSCOV值随海拔的增加呈现出类似倒"U"形曲线; AWMPFD值不具有明显的垂直分异特征。最后将这5个指数进行聚类分析, 同时利用流域主体景观类型对栖霞市进行景观格局分区, 各土地利用类型被划分为3个景观生态类型区。研究结果为: 一类区面积最小(10.14%), 该区域是农作物种植的稳定农业区, 景观结构和规模都很稳定, 需要继续保护; 二类区面积最大(50.93%), 各种景观类型呈现空间交错分布, 斑块形状复杂, 属于自然景观和人文景观的过渡区域, 需要加强该区域的土地规划和产业合理布局; 三类区面积较大(35.92%), 主要集中在中高海拔区域, 林地和草坡地居多, 开垦难度较大。分区结果能够较好地反映研究区景观生态结构的显著特征与空间分异状况, 对栖霞市的土地管理和规划具有一定的指导意义。

     

    Abstract: This paper used Qixia City (which lies in the center of Jiaodong Peninsula) as a case study of typical mountain areas to investigate catchment-based landscape pattern divisions with cluster analysis of landscape indices generated from digital elevation model (DEM). Firstly, Landsat TM image (2010) covering the whole study area was interpreted and geo-referenced to generate the landscape patterns in Qixia City and the corresponding relief map (1︰25 000) vectorized to build DEM model. Then 300 catchments were divided using hydrology extension support in ArcGIS. Taking into account ecological significance and features of common landscape indices as well as local ground truth, five indices were selected for the analysis. The indices included edge density (ED), Shannon's diversity index (SDI), coefficient of variance of patch size (PSCOV), area-weighted mean patch fractal dimension (AWMPFD) and core area density (CAD). Based on average elevation and spatial distributions, landscape patterns in each catchment were analyzed. The effects of human activity and natural disturbance on regional landscape ecology were also discussed in the paper. All the indices analyzed in each catchment were synthesized using cluster analysis and combined with dominant landscape type in the catchment to build zoning maps of landscape. The results suggested that ED and CAD values increased as altitude gradually increased and significant vertical differentiation characteristics were noted. The SDI values gradually grew smaller with increasing altitude. Then PSCOV values showed inverted U-shaped trend with increasing altitude. The AWMPFD values did not show significant vertical differentiation characteristics. Three landscape ecology classes were regionalized in Qixia City. ClassⅠhad the smallest land area (10.14%) and stable agricultural zones. This implied that the landscape structure and scale were very stable and needed protection. Class Ⅱ had the biggest land area (50.93%). Here, a variety of landscape types had spatially cross distributions with complex patchy shapes. This area belonged to the transition zone of natural landscape and cultural landscape which needed strengthened land use planning and rational distribution of industry. Class Ⅲ had the bigger land area (35.92%) and was mainly concentrated in high altitude areas with main land use types of woodland and grassland. Thus larger reclamation of land in this class was a very difficult task in terms of development and utilization. The study argued that the use of landscape metrics in landscape zoning better reflected prominent landscape features and spatial variation patterns of landscape ecological structure. To a certain extent therefore, the study provided a significant guidance on planning and utilization of land in Qixia City.

     

/

返回文章
返回