干旱内陆河流湿地景观破碎化模型构建与尺度分析——以黑河中游湿地为例

尺度的选择一直是地理学及景观生态学的研究重点和热点。在遥感和GIS的支持下,以黑河中游湿地为例,利用移动窗口技术和空间形态学准则构建湿地类型变化追踪模型;利用面积频率统计法、卡方分布归一化尺度方差、分维数距平和多样性指数探讨干旱内陆河流湿地类型变化追踪模型的适宜和最佳窗口尺度。结果表明：1）类型变化追踪模型能实现基于像元的湿地景观空间格局分析,弥补传统湿地景观破碎化研究主要基于景观和斑块类型水平尺度,难以深入解析湿地空间演变过程的不足;2）黑河中游湿地类型变化追踪模型的适宜窗口尺度为150 m×150 m~450 m×450 m,最佳窗口尺度为250 m×250 m。该结果是进一步研究黑河中游湿地空间破碎化特征的基础,同时对于丰富干旱内陆河流湿地景观破碎化研究尺度选择有一定积极作用。

Landscape Fragmentation Model Construction and Scale Analysis for Wetland in Arid Region: A Case Study of the Middle Reaches of the Heihe River,China

Riparian wetland in the arid region is particularly important to the oasis ecosystems. The health of wetland in the middle reaches of Heihe River is important for the biodiversity conservation and oasis development in Hexi Corridor. It is significant to improve the understanding of wetland fragmentation process between different wetland fragmentation types. Selecting a suitable scale for study object has become the focus of geography and ecology, and was important to a credible wetland fragmentation analysis. Based on remote sensing and GIS, the type change tracker model is constructed with sliding window technique and spatially morphological rule in this study. The suitable scale and optimum scale of the fragmentation model of wetland landscape in the middle reaches of Heihe River is determined by area frequency statistics method, Chi-square distribution normalized scale variance, fractal dimension and diversity index. The results showed that: 1) the type change tracker model, analyzing the spatial pattern of wetland fragmentation on the pixel level, is better than the traditional wetland fragmentation analysis on the landscape and patch level. 2) The suitable scale for the wetland fragmentation is between 150 m × 150 m to 450 m × 450 m and the optimum scale is 250 m × 250 m in the middle reaches of Heihe River. This study would theoretically support the deeply study of the spatial distribution of wetland fragmentation. Simultaneously, the study will supply a case of scale selection for the wetland fragmentation study in arid region.