Detection of potentially gas flaring related pollution on vegetation cover and its health using remotely sensed data in the Niger delta, Nigeria

Abstract

Detection of potentially gas flaring-related pollution on vegetation cover using remotely sensed data at 11 flaring sites in Rivers State, Nigeria is the emphasis of this research. 21 Landsat 7 Enhanced Thematic Mapper Plus (ETM ), and 4 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 used. Normalized Differential Vegetation Index (NDVI) was retrieved from corrected Landsat 7 bands (1-4), and Landsat 8 bands (2-5). Corrected thermal band was used for the computation of Land Surface Temperature (LST). Change in NDVI (δNDVI450-60)m and LST ( δLST60-450m) were computed. NDVI values at 60 m from the stack show that as the year increases, NDVI values around the stack reduces to almost zero. Linear regression analysis was considered for (δ NDVI450-60)mN against ( δNDVI450-60)mE, (δNDVI450-60)mN against (δNDVI450-60)mS, and (δNDVI450-60)mN against (δNDVI450-60)mW. Only (δNDVI450-60)mN against (δNDVI450-60)mW give statistically significant results at 99 % confidence level (p-value 0.0016). (δNDVI450-60)mN,E,S,W against (δLST60-450)mN,E,S,W were considered and results show positive correlation but statistically insignificant. Based on the results of this research, it can be concluded that flaring-related pollution can be detected on vegetation cover using Landsat 7 and Landsat 8 data in the Niger Delta.

Assessments of the impacts of environmental factors on vegetation cover at gas flaring sites in the Niger Delta, Nigeria

“…There are significant results with (𝛿NDVI450-60)mN and (𝛿NDVI450-60)mE when the predictive variables were applied with (𝛿NDVI450-60)mN, (𝛿NDVI450-60)mE, (𝛿NDVI450-60)mS and (𝛿NDVI450-60)mW with 𝛼 = 0.01.The results also present the impacts of the South prevailing wind direction in the Niger Delta [8,9,13]. However, the available data could only explained 12 % of the variance in (𝛿NDVI450-60)mN suggesting that other factors such as rate and volume of the burning gas and vegetation speciation etc.…”

“…The flaring activity is an indivisible part of the oil, gas, and petrochemical industries to provide safe and dependable operating conditions. Flaring gas at oil production facilities is grouped into three categories: (i) Routine flaring; (ii) Safety flaring; and (iii) Non-routine flaring [1].The environmental harm generated by the oil production activities in Nigeria is enormous and continuous [2,3]. For example, the recent oil spillage that occurred in Rivers State was reported by one of the Nigerian Media Company named ARISE (Arise News) on 12 th July, 2022 [4].…”

“…Vegetation covers that are predominantly found near flaring locations in the Niger Delta are cassava and oil palm [7]. Flaring affects vegetation and its growth; agricultural activities and productivity of several plant species in the Niger Delta [8][9][10][11][12][13][14]. For example, Lawanson, et al [15] reported that flaring is responsible for decrease in cassava's length and weight; and increase in its amino acid and sugar contents.…”

“…Advent of technology has transformed the mapping of flares and its emissions; therefore, remote sensing methods and technologies have been widely acknowledged as vital tools for the study of flares and its effects in the environment [2,3]. Previous studies on flaring and its activities have been centred on detection [8,21] monitoring [22] volume estimation [23] environmental effects [8,9,13]. But, there is no flare analysis that assessed the…”

Quantification of Gas Flaring from Satellite Imagery: A Comparison of Two Methods for SLSTR and BIROS Imagery

“…Flaring of natural gas is a polluting process harmful for the natural environment (e.g., [ 2 , 3 , 4 ]) as well as human health (e.g., [ 5 , 6 , 7 ]), with up to 360 premature deaths estimated in the US [ 8 ]. Flaring also contributes to global greenhouse gas (GHG) emissions (e.g., [ 9 ]).…”