城市用地紧凑变化对河岸带生境的影响 ——以汉江小流域武汉段为例

流域尺度上的城市扩张会对河岸带生境产生显著的 负面影响，目前还不清楚何种用地模式能更有效地支持河岸带 生物多样性。以汉江小流域武汉段为研究对象，从用地强度、 形态和布局3个维度构建了城市用地紧凑度评价指标体系。根 据河岸带生境结构及其联系构建城市河岸带生境质量评价体 系。运用Spearman相关性分析和RDA分析探究子流域水平 上的城市用地紧凑变化对河岸带生境的影响。结果表明：随用 地紧凑度提升，河岸带综合生境质量显著降低；开发利用强 度、居住用地占比及土地利用混合度是致使河岸带生境变差的 主导因子；用地形态与布局的紧凑变化对河岸带生境质量的影 响不显著，且分形维度指数与河岸带生境质量呈正相关关系。 研究证明了在同等开发强度下，提升城市用地形态与布局紧凑 度是协同城市化与河岸带生物多样性提升的有效策略。

Influence of Urban Land Use Compact Change on Riparian Habitat: A Case Study of Wuhan Section of Hanjiang River Small Watershed

The urban expansion on watershed scale will have a significant negative impact on riparian habitat. It is unclear which land-use model can effectively support the biodiversity of riparian zone. Taking Wuhan section of Hanjiang River small watershed as the research area, this paper set up the evaluation system of urban land use compactness from three dimensions of land use intensity, form and layout. The evaluation system of urban riparian habitat quality was established according to the riparian habitat structure and its connection. Spearman correlation and RDA analysis were used to explore the impact of urban land compact change on riparian habitat at small watershed scale. The results show that: with the improvement of land use compact, riparian habitat quality decreases significantly; the intensity of land development, the proportion of residential land and the land use mix degree are the main factors leading to the deterioration of riparian habitat; the impact of land use form and layout compact change on riparian habitat quality is not significant, and the fractal dimension index was positively correlated with the habitat quality. It proves that under the same development intensity, improving the compactness of urban land use form and layout is an effective strategy for collaborative urbanization and riparian biodiversity improvement.