基于改进熵权物元模型的河网尺度物理生境评价——以太湖流域为例

Physical Habitat Evaluation on River Network Scale Based on Improved Entropy Weight and Matter Element Model: A Case study of the Taihu Basin

平原河网地区社会经济快速发展过程中,河网水系受人类活动干扰强烈,生境退化现象突出。以太湖流域为研究区域,选取盒维数(D)、区域河流坡降(P)、河网复杂度(CR)、河网实际结合度(γ)、区域河网加权曲度(S_R)、骨干河网密度(R)等6个物理生境指标,基于改进熵权物元模型,构建了河网尺度的物理生境评价体系。研究结果显示,太湖流域物理生境质量多处于"较好"~"差"等级;生境因子的质量:盒维数(D)>河网复杂度(CR)>区域河网加权曲度(S_R)>河网实际结合度(γ)=骨干河网密度(R)>区域河流坡降(P);太湖流域物理生境空间分异现象明显,西部丘陵地区物理生境质量优于城镇化程度高的东部平原地区。河网尺度的物理生境评价体系较为直观的反映了流域物理生境现状,有效的完善了平原河网地区生境评价结果。

With the rapid socio-economic development in the plain river network area,river networks are strongly influenced by human activities,which degrades the physical habitat evidently.The Taihu Basin was taking as a case study.Six physical habitat indicators were selected to establish the evaluation system,including the weighted curvature,box dimension,actual integration of river network,regional river slope,river network density and river network complexity.Moreover,the Improved Entropy Weight and Matter Element Model was adopted to quantify the physical habitat of different catchments.The results show that:The quality levels of physical habitat vary mostly between"relatively good"to"bad".The ranking order of habitat factors is:Box dimension>River network complexity>Regional river network weighted curvature>Actual integration of river network=River network density>Regional river network slope.The spatial variation of physical habitat in the Taihu Basin is obvious,while the quality of physical habitat of the western hilly area is better than that of the highly urbanized eastern plain area.Physical habitat evaluation on the river network scale is capable of representing the status quo of the basin directly,and effectively improves the performance of plain river network evaluation.