用地紧凑变化对武汉市绿色空间生境质量的影响

Impact of land use compactness change on the habitat quality of green space in Wuhan City

城市化以及人类活动所造成的土地利用变化严重影响了城市绿色空间生境质量,从而引起了一系列生态环境危机。如何科学合理协调用地建设与绿色空间生境质量的关系是城市可持续发展的重要内容。尽管当前不少学者探究了建设用地扩张强度、景观格局变化、土地利用类型变化等因素对自然生境的影响,但用地紧凑视角下用地规模、形态、强度等方面如何影响生境质量仍少有研究。以武汉市三个建设时期(2005、2013、2018年)为例,首先从生境适宜度与生境承载力视角出发构建生境质量综合评价体系,围绕土地利用强度以及土地功能布局,构建用地紧凑度评价指标体系;其次依据三个时期生境质量的热点分布情况将样本网格划分为生境冷点区、生境热点区以及生境变化区;最后通过相关性与空间自相关分析,探究生境质量与用地紧凑度的相关性及其在空间上的关联格局。结果表明:(1)武汉市用地紧凑变化对生境质量有消极影响,2005年至2018年生境质量由0.624下降到0.578,其时空分异特征明显,在三个时期内均呈现中心低、边缘高的分布特征,总体上退化速度加快,城市生境质量的提升工作效果不显著,城市发展边界是生境质量退化的重点区域。(2)不同区间生境质量受用地紧凑度影响的程度呈现出明显的差异性,生境冷点区受用地紧凑度影响最为显著,生境变化区内其与建设用地密度、居住用地密度、路网密度、土地聚集度、土地利用多样性、公交站点密度等存在较强的相关性。(3)用地紧凑因子均会对周边区域生境质量产生潜在影响,建设用地密度、土地聚集度、土地利用多样性、用地混合度、路网密度五项指标不仅对所处地块生境质量造成影响,还与周围地块生境质量退化有着密切联系,对生境影响范围较广,用地整合度对生境质量影响较小。研究结果对优化用地格局、维持生境高质量、实现用地高效配置、完善绿色空间生态系统具有重要参考意义。

Changes of land use caused by urbanization and human activities have seriously affected quality habitat of urban green space,resulting in a series of environmental crises.How to strategically coordinate the relationship between land use construction and green space habitat quality is an important part of urban sustainable development.Although many scholars have explored the impact of many factors on natural habitats,from intense expansion of land construction,landscape pattern change,to land use type change and more,there is still little research on how land use scale,shape,intensity and other aspects affect habitat quality from the perspective of compact land use.Take the three construction periods in Wuhan(2005,2013 and 2018)for an example.This paper firstly constructs a comprehensive evaluation system of habitat quality from the perspective of habitat aptness and carrying capacity,and a land use compactness evaluation system is built based on land use intensity and land function layout.Secondly,the paper divides the study sample into cold spot area,hot spot area and habitat change area according to the hot spot distribution of habitat quality in the three periods.Finally,through correlation and spatial autocorrelation analysis,the paper explores the relationship between habitat quality and land use compactness in addition to its spatial correlation pattern.The results show that:(1)The compact change of land use in Wuhan has a negative impact on local habitat quality.From 2005 to 2018,the habitat quality decreased from 0.624 to 0.578,and its spatial and temporal differentiation characteristics were obvious,showing a low quality in center area and high quality in periphery across the three periods.The overall degradation of habitat quality is accelerated,and the improvement of urban habitat quality is not significant.The urban development boundary is the key area of habitat quality degradation;(2)The degree to which the habitat quality is affected by the compactness of land use in different areas shows obvious differences.The cold spot area of habitat is most significantly affected by the compactness of land use.The affect in habitat change area has strong correlations with the density of construction land,residential land,road network,land aggregation,diversity of land use,and density of bus stops;(3)The compactness of land use,as a factor,will have a potential impact on the habitat quality of the surrounding area.The five indicators of construction land density,land aggregation,land use diversity,land mix,and road network density not only affect the habitat quality of the land parcel,but also have a close relationship with the degradation of the habitat quality of the surrounding land parcel.They have a wide range of impacts on the habitat,and the integration of land use has a small impact on the habitat quality.The research results have significant references for optimizing land use pattern,maintaining high quality of habitat,realizing efficient land allocation and improving green space ecosystem.