Abstract

The application of Satellite Earth Observation (EO) data provides the possibility of large scale mapping for the assessment of the effects of environmental factors on vegetation cover at the flaring sites. Twenty oneLandsat 7 Enhanced Thematic Mapper Plus (ETM+) data, and four Landsat 8 Operational Land Imager and Thermal Infrared Sensor (OLI-TIRS) data dated from 21/04/2000 to 05/02/2022 with < 3 % cloud cover were employed to study 11 gas flaring sites in Rivers State, Nigeria. MATLAB code was developed for data processing and analysis. Normalized Differential Vegetation Index (NDVI) was computed from the atmospherically corrected multispectral bands (1-4) for Landsat 7, and bands (2-5) for Landsat 8. Change in NDVI was computed as(δNDVI450-60)min the N, E, S and W directions which is the difference between NDVI at 450 m and 60 m distance from the flare stack. The available environmental factors (Facility size, flare stack height and time i.e. year, month and day) were applied to the (δNDVI450-60m) in the 4 cardinal directions. Pairwise linear and multiple regression statistical analyses were adopted to investigate the relationships between each of the (δNDVI450-60)mN, (δNDVI450-60)mE, (δNDVI450-60)mS and (δNDVI450-60)mW and facility size, stack height and time. The results show that only 12 % of the variance in (δNDVI450-60)mN is explained by the available data. Therefore, it can be concluded that the combination of the facility size, flare stack height and time accounted for only 12 % of the results.

Key words: Environmental factors, vegetation cover, remote sensing, Landsat 7, Landsat 8, Niger Delta