Publications

Yao, R; Cao, J; Wang, LC; Zhang, WW; Wu, XJ (2019). Urbanization effects on vegetation cover in major African cities during 2001-2017. INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION, 75, 44-53.

Abstract
Urbanization effects on vegetation cover (VC) have been analyzed in many regions. However, little attention has been paid to Africa, which has undergone rapid urbanization in recent decades. In this study, MODIS land cover and enhanced vegetation index (EVI) data were used to examine urbanization efects on VC in 59 large cities in Africa during 2001-2017. The AEVI (urban EVI minus rural Delta EVI) was used to represent urbanization effects on VC. Major findings include: (1) for 59 cities averaged, annual Delta EVI averaged from 2015 to 2017 was -0.116. Negative annual Delta EVI (i.e. urban EVI lower than rural) were observed in 56 of 59 cities. (2) For 59 cities averaged, urban area increased 17.9% from 2001 (262.8 km(2)) to 2016 (309.8 km(2)). (3) Annual Delta EVI decreased significantly (p < 0.05) in 44 of 59 cities for the period 2001-2017, and annual average area of urbanization effects on VC increased significantly in 40 of 59 cities. For 59 cities averaged, the percentage of urban area with significant decreasing trends of annual Delta EVI was 60.0%. Spatially, cities near the Gulf of Guinea showed more significant decreasing Delta EVI than cities in other regions. In addition, the trends and spatial distributions of urbanization effects on VC differed little by seasons. These results suggested that urbanization and its effects on VC in Africa should arouse more attentions.

DOI:
10.1016/j.jag.2018.10.011

ISSN:
0303-2434