Department of Remote Sensing and GIS, Faculty of Geography, University of Tehran, Tehran, Iran.
Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
J Environ Manage. 2021 May 15;286:112236. doi: 10.1016/j.jenvman.2021.112236. Epub 2021 Feb 23.
The COVID-19 pandemic has caused unprecedent negative impacts on our society, however, evidences show a reduction of anthropogenic pressures on the environment. Due to the high importance of environmental conditions on human life quality, it is crucial to model the impact of COVID-19 lockdown on environmental conditions. Consequently, the objective of this study was to model the impact of COVID-19 lockdown on the urban surface ecological status (USES). To this end, the Landsat-8 images of Milan for three pre-lockdown dates (Feb 13, 2018 (MD1), April 18, 2018 (MD2) and Feb 3, 2020 (MD3)) and one date over the lockdown (April 14, 2020 (MD4)), and Wuhan for three pre-lockdown dates (Dec 17, 2017 (WD1), March 23, 2018 (WD2) and Dec 7, 2019 (WD3)) and one lockdown date (Feb 9, 2020 (WD4)) were used. First, pressure-state-response (PSR) framework parameters including index-based built-up index (IBI), vegetation cover (VC), vegetation health index (VHI), land surface temperature (LST) and Wetness were calculated. Second, by combining the PSR framework parameters based on comprehensive ecological evaluation index (CEEI), the USES were modeled on different dates. Thirdly, the USES during the COVID-19 lockdown was compared with the USES for pre-lockdown. The mean (standard deviation) of CEEI for Milan on MD1, MD2, MD3 and MD4 were 0.52 (0.12), 0.60 (0.19), 0.57 (0.13) and 0.45 (0.16), respectively. Also, these values for Wuhan on WD1, WD2, WD3 and WD4 were 0.63 (0.14), 0.67 (0.15), 0.60 (0.13) and 0.57 (0.13), respectively. Due to the lockdowns, the mean CEEI of built-up, bare soil and green spaces for Milan and Wuhan decreased by [0.18, 0.02, 0.08], [0.13, 0.06, 0.05], respectively. During the lockdown period, the USES improved substantially due to the reduction of anthropogenic activities in the urban environment.
新型冠状病毒肺炎疫情对我们的社会造成了前所未有的负面影响，但有证据表明，环境所受的人为压力有所减轻。鉴于环境条件对人类生活质量至关重要，因此，对新型冠状病毒肺炎疫情封控对环境条件的影响进行建模至关重要。因此，本研究的目的是对新型冠状病毒肺炎疫情封控对城市表面生态状况（USES）的影响进行建模。为此，使用了米兰的 Landsat-8 图像，这些图像有四个日期：2018 年 2 月 13 日（MD1）、2018 年 4 月 18 日（MD2）、2020 年 2 月 3 日（MD3）和 2020 年 4 月 14 日（MD4），以及武汉的三张封控前的图像（2017 年 12 月 17 日（WD1）、2018 年 3 月 23 日（WD2）和 2019 年 12 月 7 日（WD3））和一张封控期间的图像（2020 年 2 月 9 日（WD4））。首先，计算了压力-状态-响应（PSR）框架参数，包括基于指数的建成区指数（IBI）、植被覆盖（VC）、植被健康指数（VHI）、地表温度（LST）和湿度。其次，根据综合生态评价指数（CEEI），结合 PSR 框架参数，对不同日期的 USES 进行建模。然后，将新型冠状病毒肺炎疫情封控期间的 USES 与封控前的 USES 进行了比较。米兰的 CEEI 的平均值（标准差）为 MD1、MD2、MD3 和 MD4 分别为 0.52（0.12）、0.60（0.19）、0.57（0.13）和 0.45（0.16）。武汉的 CEEI 的平均值（标准差）分别为 WD1、WD2、WD3 和 WD4 为 0.63（0.14）、0.67（0.15）、0.60（0.13）和 0.57（0.13）。由于封控措施，米兰和武汉的建成区、裸土和绿地的平均 CEEI 分别下降了[0.18、0.02、0.08]、[0.13、0.06、0.05]。在封控期间，由于城市环境中人为活动的减少，USES 得到了显著改善。
