5 research outputs found
Can remote sensing be used to support sustainable forestry in Malawi?
Sustainable forest management is a key issue in Malawi. Malawi is a
relatively small, resource poor, densely populated country, which in some
areas is close to exceeding the energy capacity of the environment to
support it. Despite the importance of forestry in Malawi, there is a severe
lack of knowledge about the current state of Malawi’s forest resources.
Remote sensing has the potential to provide current and historical
insights into forest cover change. However, Malawi faces a number of key
challenges with regards to in-country remote sensing. These include
technical capacity for obtaining accurate and consistent forest area and
biomass estimates, with errors at acceptable levels, as well as the
necessary supporting capacity development for individuals and
institutions.
This thesis examines how remote sensing can be used to support
sustainable forestry in Malawi, by assessing the use of both optical and
Synthetic Aperture Radar (SAR) data for mapping forest cover, forest
cover change and aboveground biomass (AGB). L-band SAR data was
used to try and establish a relationship between radar backscatter and
biomass, which has been achieved many times in other areas. However,
no correlations between any field-based forest metric and backscatter
explained enough of the variability in the datasets to be used to develop
empirical relationships between the variables. There were also
differences between my field measured AGB and AGB values predicted by
a published backscatter-biomass relationship for African dry forests. The
speckle inherent in SAR imagery, the heterogeneity of Malawi’s dominant
miombo savanna, and Malawi’s variable topography are likely to have
played a significant role in this.
Two different MODIS products were investigated for their potential for
mapping forest cover change, with regards to potential REDD+ schemes.
As part of this, a published equation was used to calculate the break-even
point for REDD+ schemes in Malawi, using estimates of forest area and
deforestation for the United Nations Forest Resources Assessment 2010.
The results of this equation show that measurement error is the most
important factor in determining whether or not Malawi can make REDD+
economically viable, particularly at lower levels of deforestation. While
neither of the MODIS products were able to produce a verifiable forest
cover change map, they do confirm that Malawi is experiencing some
level of forest loss, and help to narrow down the range of possible forest
loss rates Malawi is experiencing to between 1-3% net forest loss per
year.
Finally, this thesis examines global trends in the engagement of
developing country researchers with global academic remote sensing
research, to investigate differences in in-country capacity for monitoring
forests using remote sensing. The results of this found that while a
significant proportion of Earth observation research (44%) has developing
countries as their object of research, less than 3% of publications have
authors working, or affiliated to, a developing country (excluding China,
India and Brazil, which are not only countries in transition, but have well
established EO capacity). These patterns appear consistent over the past
20 years, despite the increasing awareness of the importance of capacity
development over this period.
Despite inconclusive results from the approaches examined here, remote
sensing can play a role in improving understanding about the dynamics
of Malawi’s forest resources. There is a need for nationwide accurate,
validated forest maps that can be repeated at least on a yearly basis, and
remote sensing could produced these without the resources needed to
conduct full national ground inventories each year. If remote sensing is to
be useful as a forest mapping tool in Malawi, it needs to provide
consistent, verifiable and updatable estimates of forest cover and biomass
change. This ideally needs to be achieved using free or low cost data, and
by using open source or open access software, as this will better enable incountry
researchers to conduct on-going forest mapping activities
DDI Economic Development Opportunities: The Lothians
This study aims to identify key areas where Data Driven Innovation (DDI) could drive socio-economic growth across the three Lothian Councils (East Lothian, Midlothian, West Lothian) as part of the Edinburgh and South East Scotland City Region Deal (ESES-CRD), against the background of recent development of a Regional Prosperity Framework (RPF) and Scotland’s National Strategy for Economic Transformation (NSET). This study is the first step in enhancing regional collaborative approaches to realise the potential these DDI opportunities represent, and achieve the regional prosperity and inclusive growth objectives by increasing the wider economic and social resilience across the Lothians
Quantifying small-scale deforestation and forest degradation in African woodlands using radar imagery
Carbon emissions from tropical land-use change are a major uncertainty in the global carbon cycle. In African woodlands, small-scale farming and the need for fuel are thought to be reducing vegetation carbon stocks, but quantification of these processes is hindered by the limitations of optical remote sensing and a lack of ground data. Here, we present a method for mapping vegetation carbon stocks and their changes over a 3-year period in a > 1000 km2 region in central Mozambique at 0.06 ha resolution. L-band synthetic aperture radar imagery and an inventory of 96 plots are combined using regression and bootstrapping to generate biomass maps with known uncertainties. The resultant maps have sufficient accuracy to be capable of detecting changes in forest carbon stocks of as little as 12 MgC ha-1 over 3 years with 95% confidence. This allows characterization of biomass loss from deforestation and forest degradation at a new level of detail. Total aboveground biomass in the study area was reduced by 6.9 +/- 4.6% over 3 years: from 2.13 +/- 0.12 TgC in 2007 to 1.98 +/- 0.11 TgC in 2010, a loss of 0.15 +/- 0.10 TgC. Degradation probably contributed 67% (96.9 +/- 91.0 GgC) of the net loss of biomass, but is associated with high uncertainty. The detailed mapping of carbon stock changes quantifies the nature of small-scale farming. New clearances were on average small (median 0.2 ha) and were often additions to already cleared land. Deforestation events reduced biomass from 33.5 to 11.9 MgC ha-1 on average. Contrary to expectations, we did not find evidence that clearances were targeted towards areas of high biomass. Our method is scalable and suitable for monitoring land cover change and vegetation carbon stocks in woodland ecosystems, and can support policy approaches towards reducing emissions from deforestation and degradation (REDD).</p
Quantifying small-scale deforestation and forest degradation in African woodlands using radar imagery
Carbon emissions from tropical land-use change are a major uncertainty in the global carbon cycle. In African woodlands, small-scale farming and the need for fuel are thought to be reducing vegetation carbon stocks, but quantification of these processes is hindered by the limitations of optical remote sensing and a lack of ground data. Here, we present a method for mapping vegetation carbon stocks and their changes over a 3-year period in a > 1000 km2 region in central Mozambique at 0.06 ha resolution. L-band synthetic aperture radar imagery and an inventory of 96 plots are combined using regression and bootstrapping to generate biomass maps with known uncertainties. The resultant maps have sufficient accuracy to be capable of detecting changes in forest carbon stocks of as little as 12 MgC ha-1 over 3 years with 95% confidence. This allows characterization of biomass loss from deforestation and forest degradation at a new level of detail. Total aboveground biomass in the study area was reduced by 6.9 +/- 4.6% over 3 years: from 2.13 +/- 0.12 TgC in 2007 to 1.98 +/- 0.11 TgC in 2010, a loss of 0.15 +/- 0.10 TgC. Degradation probably contributed 67% (96.9 +/- 91.0 GgC) of the net loss of biomass, but is associated with high uncertainty. The detailed mapping of carbon stock changes quantifies the nature of small-scale farming. New clearances were on average small (median 0.2 ha) and were often additions to already cleared land. Deforestation events reduced biomass from 33.5 to 11.9 MgC ha-1 on average. Contrary to expectations, we did not find evidence that clearances were targeted towards areas of high biomass. Our method is scalable and suitable for monitoring land cover change and vegetation carbon stocks in woodland ecosystems, and can support policy approaches towards reducing emissions from deforestation and degradation (REDD).</p