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analysis of environmental impacts of development projects,
and supported the elaboration of irrigation and climate change
adaptation scenarios (see case study).
The importance of monitoring dry forests
ESA has been an accredited observer organization of the
United Nations Framework Convention on Climate Change
(UNFCCC) since 2001, providing EO solutions for systematic
observations of the environment, long time series of essential
climate variables and monitoring of forests to support climate
mitigation activities like REDD+.
Reducing emissions from deforestation, forest degrada-
tion, conservation and enhancement of forest carbon stocks
and sustainable management of forests (REDD+) has mainly
concerned humid tropical forests due to their high carbon content,
putting aside dry forests and woodlands despite their importance
as carbon sinks. Recently more emphasis has been put on dry
forests to develop dedicated forest monitoring, reporting and
verification approaches relevant to REDD+. In Africa dry forests
occur predominantly in sub-Saharan regions where they cover 2.4
million km
2
. Population pressure for agricultural land, fuel wood
and timber extraction leads to some of the highest deforestation
rates, with negative impacts on biodiversity, soil fertility and water
availability, as well as on the livelihoods of local people.
An ESA-funded project on dry forests developed a methodol-
ogy to efficiently map dry forests in Southern Africa based on a
Case study: Erosion risk indicator for the
Maradi region, Niger
The predominance of crop and
livestock farming and poor
diversification make Niger’s
economy very vulnerable to
climate and market changes.
An erosion risk indicator
was produced for the
Maradi region, based on
a combination of digital
elevation model, land use/
land cover maps and
meteorological data.
The risk of erosion
increases from north
to south, due to fewer
precipitations with less
intensity in the north. Areas
with high slopes increase the
risk of erosion, as detected in
several small Wadis.
Source: GAF AG, ESA and IFAD
From bottom: slope, slope
aspect, drainage system,
land use/land cover map and
erosion risk indicator
L
iving
L
and
Case study: Bush encroachment in Namibia
The phenomenon of bush encroachment is a major threat for the
livelihood of many people. Once densely established, bush species
block grass growth and prevent the cattle from grazing. The image
shows the major areas affected by bush encroachment in Namibia.
The ESA Diversity II project evidenced some gradients of increasing
vegetation greenness during the dry seasons for the years 2002 to 2012
that matches well the areas known to be subject of bush encroachment.
The Dry Season fAPAR trends, together with land cover changes and
rainfall trends, constitute a wealth of information for assessing bush
encroachment in the region.
Source: ESA Diversity II project/GeoVille
Areas affected by bush encroachment in Namibia (left); Trends (2002-2013) of Dry Season fAPAR (right)
Image (left): Bester, F.V. (1998),
Major Problem — Bush species and densities in Namibia
. Ministry of Agriculture, Water and Rural Development, Namibia
3
Acacia mellifera (2,000/ha)
4
Colophospermum mopane (4,000/ha)
7
Dichrostachys cinerea (10,000/ha)
2
Acacia reficiens (3,000/ha)
1
Colophospermum mopane (2,500/ha)
8
Acacia mellifera (5,000/ha)
9
Terminall cericea (8,000/ha)
6
Acacia mellifera (4,000/ha)
5
Acacia mellifera (8,000/ha)
10
Rhigozum trichotomum (2,000/ha)