基于叶面积指数的乌鲁木齐市绿色空间格局分析

Analysis of Greenspace Pattern in Urumqi Based on Leaf Area Index

叶面积指数(Leaf Area Index, LAI)作为植被结构和生长状况的重要指标和生态参数,能够较好地反映植被的生长状况与分布情况,本文基于LAI反映城市绿色空间的分布状况,以乌鲁木齐市作为研究区,使用2016~2022年的Sentinel-2系列遥感数据反演了乌鲁木齐市夏季LAI时间序列数据。引入景观指数分析乌鲁木齐市2016~2022年不同等级绿色空间的组分与结构变化特征;使用结合Sen斜率估计的M-K趋势检验分析了乌鲁木齐市夏季LAI的变化趋势;并通过地理探测器分析了不同驱动因子对LAI的驱动作用。结果表明:(1)建成区内部多为低密度植被区域覆盖,高密度植被覆盖区域集中于城市边缘;(2)乌鲁木齐市的绿色空间面积主要呈减少趋势。(3)影响乌鲁木齐市绿色空间的驱动因子主要为土地利用类型和降水量;(4)交互探测表明驱动因子交互作用影响力强于单个驱动因子。

As an important indicator and ecological parameter of vegetation structure and growth status,Leaf Area Index(LAI)can better reflect the growth and distribution of vegetation,so LAI reflects the distribution of urban greenspace.In this paper,using Urumqi as the research area,the Sentinel-2 series of remote sensing data from 2016~2022 was used to invert the summer LAI time series data in Urumqi.The landscape index was introduced to analyze the composition and structural changes of different grades of green space in Urumqi from 2016 to 2022.The M-K trend test combined with Sen slope estimation was used to analyze the changing trend of summer LAI in Urumqi.The driving effect of different drivers on LAI was analyzed by the geographic detector.The results show that:①the interior of the built-up area is mostly covered by low-density vegetation areas,and the high-density vegetation coverage area is concentrated in the urban edge;②The area of green space in Urumqi is mainly decreasing.③The main drivers affecting green space in Urumqi are land use type and precipitation;④Interaction detection shows that the influence of driver interaction is stronger than that of individual drivers.