Assessment of Normalized Difference Vegetation Index (NDVI) of Port Harcourt Metropolis and Environs, from 1986 to 2018: Implication to Urban Greening and Management

In the past 33 years, population and urbanization in Port Harcourt metropolis and environs has resulted to rapid vegetal removal and alteration of its urban green surface. This paper examines Normalized Difference Vegetation Index (NDVI) of Port Harcourt metropolis and environs from 1986 to 2018 using algorithm of the Google Earth Engine (GEE) from Geographic Information Systems (GIS). The results show that in 1986, with population of 757,022 persons, NDVI recorded lowest value of -0.08 and highest value of 0.43 ranging 0.5; NDVI was observed to be thickly visible at the east, north and western segments of the city showing dense vegetal cover at Rumuekini and Oyigbo segments. In 2003, with population of 1,143,103 persons, NDVI was between 0.53 and -0.10 ranging0.63 with high density at the north-eastern section (Rumuekeni) north-western section (Oyigbo), east and south-eastern sections (Okirika). Also, in 2018, NDVI was between 0.043 and -0.06 with a range of 0.49, shifted its concentration to the north-eastern section (Oyigbo) and south-eastern segment (Okirika) with population of 3,095,342 persons having the highest loss of the city greening. Thus, it is established that there is rapid and intense decline of vegetal cover on the city green surface areas. It is therefore recommended that policy makers and development practitioners implement tree planting and urban greening in Port Harcourt metropolis and environs to intervene the thermal discomfort and hazards possible in the city.

Keywords: NDVI, Urbanization, GIS, Urban Greening, Biophysical Component, Evapotranspiration, Temperature, Land Use Land Cover.