Normalized Difference Vegetation Index (NDVI) Assessment of Vegetation Around Oben Gas Flow Station, Edo State, Nigeria

Abstract

The burning of associated gas from crude oil is known as gas flaring
and it is a frequent practice in Nigeria. One of the main reasons for
its continued usage is the lack of an effective regulatory framework,
which may be due to a lack of environmental knowledge of its
consequences. This study seeks to determine the effects of gas flaring
on vegetation using Oben gas flow station as a case study. The study
assessed vegetation health with the use of GIS at marked distances
of analyzed years. Several studies have been undertaken to highlight
the environmental impact of gas flaring, but none have yet been
undertaken to quantify the long-term cumulative effect on vegetation.
In addition, little attempt has been made in Nigeria to assess the
impact of gas flaring using GIS. This study employed the use a GISbased change detection methodology (Normalized Difference
Vegetation Index) to analyze vegetation changes over time in the
study area. Three separate time series of satellite imagery of
research area (Landsat 4 TM and Landsat 7 ETM 1987, 2002, 2019)
were gathered to achieve this. The findings indicate that gas flaring
is a substantial contributor to the study areas change in natural
vegetation, where in the year 1987 vegetation was normal, the
average mean was 0.62; In 2002 vegetation was very poor and
affected, average mean decreased to 0.18 but slightly increased in
2019 to an average of 0.26. This study recommends that government
should provide adequate funding for scientific research on gas
flaring, to fully assess its impact on vegetation, biodiversity and the
entire ecosystem, and develop ways of mitigation.