厦漳泉新兴都市区生态质量遥感评价

Remote sensing-based study on the urban ecological quality of the emerging Xiamen-Zhangzhou-Quanzhou metropolitan area

城市生态系统和地表生物物理组分之间存在复杂的潜在非线性关系,这使得城市聚集的都市区生态质量客观评估遇到了技术挑战。针对性选取干度、路网密度、土地利用程度综合指数、植被覆盖率、生态连接度、湿度、热度、生态系统服务价值指数8个城市生态重要影响因子,利用主成分分析进行指标集成建立城市生态评价遥感指数UEQ,并分析不同等级UEQ与地表景观格局指标的定量关系,评价区域一体化背景下厦漳泉新兴都市区生态状况。结果表明,受8个指标综合作用,厦漳泉都市区UEQ均值为0.558,生态指数等级为中等。对比UEQ指数的8个指标分量,对生态质量起正向作用的生态系统服务价值指标值较低,对生态质量起负向作用的干度、土地利用程度综合指数和热度指标值较高,其它4个指标贡献度较低。从空间分布来看,厦漳泉都市区生态质量总体呈“西高东低”的空间格局。东部核心区高不透水面覆盖地区,生态用地的生态效益较低,其生态质量比都市区整体平均值低0.212;西部绿色山地保育带,完整连续的生态用地发挥的生态效益也更高,其平均生态质量比总体平均值高0.104。不透水面斑块小、斑块内部连通度低且斑块聚集度低的区域,其生态质量好于不透水面斑块大、斑块内部高度连通且斑块高度聚集的区域。

Owing to the complex,potentially nonlinear relationship between urban ecological systems and biophysical surface components in metropolitan areas,selecting suitable quantitative models to evaluate their urban ecological quality is not always clear.The Xiamen-Zhangzhou-Quanzhou metropolitan area was taken as an example.Eight ecological indicators,including NDBSI,RD,La,NDVI,ECI,W,LST,and V,were integrated into a new model named the Urban Remote Sensing Ecological Quality Index(UEQ)using Principal Component Analysis.The UEQ was used to quantitatively evaluate the ecological quality of the emerging Xiamen-Zhangzhou-Quanzhou metropolitan area.The quantitative relationship between UEQ at different levels and landscape indices was analyzed.Results showed that the Xiamen-Zhangzhou-Quanzhou metropolitan area had a mean ecological quality value of 0.558.Comparing the eight indices within the UEQ,the NDVI,ECI,W,and V indices positively affected the ecology,while the NDBSI,RD,La,and LST indices had a negative effect.It had high NDBSI,La,and LST values and low V values.The other four indicators had a low contribution to UEQ results.According to the spatial distribution of the UEQ,the ecological quality value in the western region of the Xiamen-Zhangzhou-Quanzhou metropolitan area was generally higher than that in the east region.The eastern urban center,covered by a high ratio of impervious surfaces and a low ratio of vegetation,had low ecological connectivity between the ecological land patches,resulting in a lower ecological quality value of 0.212 than that of the whole study area.The western mountain conservation belt had high NDVI and ECI values,which helped reach a higher ecological quality value of 0.104 than the whole study area.The ecological quality of the region with small and dispersive impervious surface patches and low intra-patch connectivity was better than that with large and aggregate impervious surface patches.