基于微地形的南方沟-塘湿地系统景观异质性研究--以风岭流域为例

Study of the South Ditch-Pond Wetland Landscape Heterogeneity Based on Micro-Topography——A Case Study of Fengling Watershed

本文以Quickbird遥感影像和DEM为基础,利用GIS技术和实地调查相结合,并通过SPSS数据分析软件,对仪征市风岭流域的地形、沟-塘湿地系统网络结构及其空间异质性进行研究.结果表明:1流域以微地形为主要特征,但在平均坡度、平均坡面曲率、平均高程变异系数上依然存在明显的差异性.据此划分的3个地形特征区域A、B、C的地形复杂度依次降低.2不同地形特征区域内水塘与沟渠的景观结构特征存在着差异.3个地形特征区域的水塘在单位面积水塘面积指标上差异不显著,在单位面积水塘库容、密度、聚合度、聚集度指标上差异显著,总体地形特征越简单的区域,其水塘结构特征越复杂;3个地形特征区域的沟渠在环度、连通度指标上差异不显著,在单位面积沟渠数、单位面积沟渠节点数、密度和线点率指标上差异显著,总体地形特征越复杂的区域,其沟渠结构特征越复杂.3不同地形特征区域内沟-塘湿地系统景观结构特征存在着差异.3个地形特征区域沟-塘湿地系统在连接率指标上差异不显著,在线面率、可达性总成本指标上差异显著,总体地形特征越复杂的区域,其结构特征越复杂.通过分析研究区域的地形、沟-塘湿地系统景观结构及其异质性,能够更好地优化设计不同地形特征区域的沟-塘湿地系统,合理分配水资源.

Based on Quickbird remote sensing image and DEM, using GIS technology and combined with field survey, through the SPSS data analysis software to research on the topography, ditch-pond wetland system network structure and spatial heterogeneity of the Fengling watershed in Yizheng are studied. The results show that ： （1）The main feature of the watershed is micro-topography, but in the average degree of slope, the average profile curvature, the variation coefficient of average elevation still exist obvious differences. On the basis of three characteristics of A, B, C, the terrain complexity is decreased in turn. （2）In different feature areas, the landscape structure characteristics of ponds and ditches are different. Among the three regions, the index of the area of ponds in the unit area has no significant difference, but the indexes of capacity in the unit area, density, aggregation, cohesion have significant difference, overall, the region which topographic features are simpler, the network features of ponds are more complex ; Ditches in the indexes of degree of ring, connected have no significant difference, but the indexes of number in the unit area, node number in the unit area, density and line rate have significant difference, overall, the region which topographic features are more complex, the network features of ditches are more complex. （3）In different feature areas, the landscape structure characteristics of the ditchpond wetland system are different. Among the three regions, the index of connection rate has no significant difference but the indexes of line and plane rate, up to total cost have significant difference, overall, the region which topographic features are more complex, the network features are more complex. Through the analysis of the topography, the ditchpond wetland system landscape structure and its heterogeneity, it can be better to design the ditch-pond wetland system in different areas, and distribute the water resources efficiently.