[Music] >>[Amber] Among the organizations actively working to address
these concerns are the World Bank Group’s Global Gas Flaring Reduction and the Planet
Earth Institute.>>[Charles] To assist their efforts, the Angola Energy Team applied NASA Earth observations
to calculate potential energy from flared natural gas, derive deforestation measurements
from various vegetation indices, and ascertain biomass energy equivalent, and map suitable
site locations for infrastructure needed to transfer petroleum associated natural gas>>[Emmanuel] To estimate flare volumes, a sensor aboard the Suomi NPP known as the Visible
Infrard Imaging Radiometer Suite, or VIIRS, was utilized. During nightime overflight,
VIIRS can detect light emissive sources on Earth from which variables such as temperature
and radiant heat can be derived, which, can distinguish combustion sources from gas flares.
VIIRS daily data files were acquired from the NOAA NGDC Nightfire System and aggregated
into monthly and yearly flare detections from which volumetric flow rates for the methane
reactanct were calculated.>>[Shikher] For suitability studies, Shuttle Radar Topography Mission data were used to
define terrain of the study area. An Analytical Hierarchy Process, or AHP, included ancillary
datasets such as population, roads, canopy cover, railroads, and prohibited areas.
In accordance with AHP, these and other variables were then ranked using a pairwise comparison
table that assigned weighted scores to each.>>[Chris] The higher the score, shown in black, the more relative importance is placed
on that variable. From population data, pipeline destination points were selected and using
weighted and unweighted accumulated cost grids, routes were extended along a least cost path
to selected source points. The least cost path takes into account each
variable to avoid populous locations, prohibited areas, areas of dense vegetation, railroad
crossings, and terrain such as mountains, hills, and plateaus.>>[Kenny] In order to estimate domestic energy use supplied from biomass, the Moderate Resolution
Imaging Spectroradiometer, or MODIS, onboard NASA’s Terra and Aqua satellites was used.
A regression analysis was performed using MODIS leaf area and normalized vegetation
indices in comparison with known woody biomass estimation from the Woods Hole Research Center.
MODIS reflectance bands 1-7 were used in an unsupervised classification to estimate forest
area. From these, biomass energy equivalence was estimated annually from 2002 to 2014.>>[Charles] Total estimated live woody biomass has reduced by approximately 996 million metric
tonenes. The areas of most concern are along the coastlines, particularly in the North
and Central areas of Angola. The trend line shows the biomass present is
decreasing on average by 833 million MJ per year.
The forest change map confirms the areas of concern in biomass lost along the coastline.>>[Emmanuel] An AHP derived cost grid makes a considerable amount of difference in LCP
analysis by giving due consideration to relative importance of parameters. It does however,
come at the cost of route length. A no parameter path is much shorter than a weighted and unweighted
paramter path.>>[Amber] This study showed approximately 109 million cubic meters of natural gas was
flared in Angola over the period of one year. Adjusting for the higher consumption efficiency
of natural gas compared to biomass, this equates to 20 billion MJ of energy equivalent and
a value of 17.5 million USD that could meet the energy needs of approximately 10% of the
Angola population [Music over credits]