基于最佳分析粒度的大辽河流域湿地景观格局分析

湿地景观格局分析是湿地生态和全球变化研究领域的热点,最佳分析粒度是景观格局分析准确性的关键指标.定性与定量相结合,综合利用景观指数粒度效应分析和信息损失评价,确定了大辽河流域湿地景观格局的最佳分析粒度为60m.在该粒度下,选取反映空间组成和空间构型的指数,进行湿地景观格局分析.结果表明:①大辽河流域湿地景观主体为水田、...

Landscape pattern analysis of wetlands in the Daliaohe Watershed,based on optimal grain size

Wetland landscape pattern analysis is a hot issue in wetland ecology and global change research fields. Landscape pattern depends on the scales of observation or analysis, while the optimal grain (grain size) is the key factor to calculate landscape indices and improve the accuracy of landscape pattern analysis. To solve this problem, the optimal grain selection method was developed in this paper, which integrates two methods, the grain effect analysis of landscape index and data loss assessment. Using this method, the optimal grain in Daliaohe watershed was determined before landscape pattern analysis. Grain effect analysis of landscape index showed that 40m~60m and 110m~200m were the appropriate grain ranges by analyzing these grain inflexions comprehensively. Data loss assessment showed that 40m~60m was the appropriate grain extent. In addition, time-consuming factor was considered. As a result, 60m was selected as the optimal grain for wetland landscape pattern analysis. Based on the optimal grain, indices about composing and structure were chosen to describe the pattern of the study area. The analysis about landscape patterns revealed that: (1) The landscapes of study region were dominated by paddy, river and swamp, among which artificial wetlands were the most. Wetland landscape types with small average patch size were prevalent, implying that wetland landscape was significantly affected by human activities. (2) Shape of river and reservoir were complex, while paddy field and lake were relatively regular. Aggregation degree of Reservoir and paddy field were higher, while pond and beach were lower. The whole wetland landscape shape was complex, aggregation degree was not high, and the degree of fragmentation was high.