Table 1:
Characteristics of the 18 publications included
| Reference | Location | Study period | Case | Resolution |
|---|---|---|---|---|
| Tian, Liang et al. 2018(11) | Beijing | 2010–2012 | 114777 | Monthly |
| Chen, Sun et al. 2015(12) | Suzhou | 2012–2013 | 1730 | Monthly |
| Feng, Duan et al. 2014(13) | Zhengzhou | 2008–2012 | 2932 | Monthly |
| Gou, Liu et al. 2017(14) | Gansu | 2010 | 12428 | Monthly |
| Huang, Deng et al. 2013(15) | Guangzhou | 2008–2011 | 100875 | Weekly |
| Jiang, Yang et al. 2016 (17) | Qingdao | 2007–2014 | 78641 | Weekly |
| Li, Qiu et al. 2018(19) | Shandong | 2008 | 6439 | Weekly |
| Wu, Hu et al. 2017(22) | Hunan | 2009–2015 | 895429 | Monthly |
| Xu, Yu et al. 2015(26) | Beijing | 2010–2012 | 14152 | Daily |
| Zhao, Wang et al. 2017(39) | Huainan | 2009–2014 | 113475 | Weekly |
| Zheng, Cao et al. 2014(25) | Shenzhen | 2008–2010 | 39046 | Monthly |
| Li, Zhang et al. 2019(18) | Ningxia | 2009–2013 | 917285 | Monthly |
| Liu, Bao et al. 2019(21) | Jiangsu | 2009–2016 | 13 928 | Monthly |
| Hong, Hao et al. 2018(40) | Inner Mongolia Autonomous Region | 2016 | 114777 | Monthly |
| Liu, Chen et al. 2018(20) | Nanjing | 2010–2015 | 1105117 | Weekly |
| Xu, Hu et al. 2019(27) | Guangdong | 2010–2013 | 357238 | Daily |
| Yan, Wei et al. 2019(23) | Shenzhen | 2009–2017 | 4873 | Daily |
| Huang, Ning et al. 2019(16) | Ningbo | 2012–2016 | 59809 | Daily |