Table 1 Quality evaluation of included literature
First author | Published year | Sample size | Study area | Research type | Quality score |
|---|---|---|---|---|---|
Xin Meng [24] | 2015 | 1493 | Jilin province | provincial | 6 |
Tao Li [14] | 2013 | 162 | Akesu city,Xinjiang province | municipal | 6 |
Xiaofei Wu [13] | 2013 | 300 | Kashi city, Xinjiang province | municipal | 4 |
Qian Zhou [6] | 2015 | 1500 | Inner Mongolia province | provincial | 8 |
Chunxia Liu [7] | 2015 | 303 | Haigang district, Qinghuangdao city | district | 6 |
Chunxia Liu [8] | 2015 | 300 | Haigang district, Qinghuangdao city | district | 6 |
Hua Li [9] | 2015 | 2378 | Hebei province | provincial | 5 |
Lei Qiao [16] | 2010 | 440 | a district, Beijing | district | 8 |
Xiuyun Sun [15] | 2011 | 801 | Chongwen district, Beijing city | district | 4 |
Xiaoqin Feng [31] | 2015 | 1990 | Lvliang city,Shanxi province | municipal | 5 |
Lixia Ma [19] | 2014 | 610 | Ningxia province | provincial | 6 |
Yine Zhang [12] | 2016 | 610 | Xingqing district and Zhongning county,Ningxia province | district | 6 |
Yaru Qin [11] | 2015 | 303 | Zhongning county, Ningxia province | district | 5 |
Can Liu [10] | 2016 | 304 | Baohe district, Hefei city | district | 6 |
Ying Deng [22] | 2015 | 2373 | Sichuan province | provincial | 5 |
Yajun Meng [32] | 2014 | 301 | Huangshigang district, Huangshi city | district | 4 |
Chuanhua Yu [17] | 2016 | 1800 | Hubei province | provincial | 5 |
Tianjing He [18] | 2016 | 1724 | Hubei province | provincial | 5 |
Donghui Jin [21] | 2015 | 2088 | Hunan province | provincial | 6 |
Xiaohong Zhou [45] | 2015 | 303 | Xiacheng district, Hangzhou city | district | 6 |
Kaixu Xie [46] | 2014 | 1800 | Tongxiang city, Zhejiang province | municipal | 7 |
Yan Xu [20] | 2015 | 1495 | Jiangxi province | provincial | 6 |
Ling Chen [47] | 2015 | 302 | Haicheng district, Beihai city | district | 6 |