Applying remote sensing, GIS and emissions techniques to air quality and carbon dioxide emissions measurements and monitoring in the Niger Delta

Fagbeja, Mofoluso

Abstract

Due to economic, accessibility and security constraints, the majority of developing countries within the low-latitudes lack the capacity to establish networks of ground-based air pollution monitoring stations. As a result, there is a lack of systematic and consistent measurements and monitoring of the concentrations of air pollutants in most of these countries. In addition, there is the lack of verifiable inventories of sources of atmospheric emissions. In order to mitigate these constraints, this research presents an investigation into the relevance of currently available satellite sensors to estimate concentrations of air pollutants (carbon monoxide, nitrogen dioxide and tropospheric ozone) and carbon dioxide over the Niger Delta, a developing region in southern part of Nigeria. It further presents a methodological framework designed to interpolate column concentrations from satellite sensors over the entire study area using ordinary kriging interpolation techniques in ArcGIS Geostatistical Analyst. The study also carries out an assessment of the reliability and resolution of the interpolated surfaces based on a subjective categorisation of the number of column measurements available from satellites sensors and the mean of the Euclidean distances between the column measurements. The results indicate varying degrees of reliability and resolution depending on the climatic seasons in the Niger Delta. The results further show that measurements from satellite sensors are reliable means of measuring and monitoring total and tropospheric column concentrations of air pollutants over the Niger Delta. However, ground-based measurements are required to infer ground-level concentration of pollutants from satellite sensor measurements. Seasonal variations observed in the concentrations of air pollutants indicate higher concentrations during the dry season than during the wet season.

In addition to the satellite sensor-based assessment of concentrations of air pollutants and CO2, this research designed and constructed a GIS-based Niger Delta Emission Inventory (NDEI) infrastructure for criteria air pollutants (carbon monoxide, particulate matter, nitrogen oxides and sulphur dioxide), methane, non-methane volatile organic compounds and carbon dioxide. The NDEI has point-source, line-source and area-source components. The construction of the inventory infrastructure effectively relied on the interoperability of GIS and spreadsheet. Due to the lack of access to data, the infrastructure is populated with data generated based on a series of assumptions. This produced estimates with varying degree of uncertainties. Despite these uncertainties, the methods applied in generating data are transferrable to other developing regions where there is limited access to data required for estimating emissions. In addition, the process successfully validates the functionality of the infrastructure to produce accurate emission estimates as and when data that are more accurate are available. Although the estimates of emissions generated from the inventory have limited accuracy, the spatial distributions of the emissions have varying degree of accuracy. The most reliable estimates and spatial distribution of estimates are generated from the area-source (residential) component of the inventory due to the available data and the assumptions applied. The spatial distribution of emissions generated from the inventory are accurate to the extent of the available input spatial data.

The thesis concludes by recommending further research work to explore opportunities to infer ground level concentrations of pollutants from satellite sensor measurements. In addition, the thesis recommends the implementation of a site survey to collect site-specific information in order to refine the input data into the NDEI to produce accurate estimates of emissions. The recommendations made from this study aim towards enhancing the development of relatively inexpensive means of measuring and assessing air quality for developing regions within the low latitudes.

Citation

Fagbeja, M. Applying remote sensing, GIS and emissions techniques to air quality and carbon dioxide emissions measurements and monitoring in the Niger Delta. (Thesis). University of the West of England. Retrieved from https://uwe-repository.worktribe.com/output/946155

• Thesis Type: Thesis
• Keywords: air quality, air pollution, carbon dioxide, satellite, remote sensing, GIS, emission, emission estimation, emission inventory, Niger Delta, Nigeria, oil and gas, SCIAMACHY, GOME, OMI,
• Public URL: https://uwe-repository.worktribe.com/output/946155
• Award Date: Jun 20, 2012