Abstract:
Although wildland fire occurs on a large scale in Sudan, there is limited
knowledge on its extent, seasonality and frequency.
Consequently its
impacts on the environment are not well understood. The overarching
objective of this study is to contribute in finding and recommending
measures leading to minimize the adverse impacts of wildland fire on the
environment in Sudan. This objective is investigated in the Albaja region of
Sudan, which is chosen as a demonstration area representative of Sudan’s
marginal grassland. To address the objective in Albaja, the study integrates
both biophysical and social survey data collected in the field with remote
sensing
data
from
the
MODIS
(MOderate
Resolution
Imaging
Spectroradiometer) sensor. MODIS remote sensing data is analysed for the
2000-2005 period to discover Albaja’s fire regime (extent, seasonality and
frequency of burn). This new, satellite-derived information on burning in
Albaja is then used to assess the effectiveness of the local fire management
system that is currently applied to control wildland fires. The impacts of
wildland fire frequency on trees, shrubs and grasses is then investigated by
analyzing the satellite-derived fire data in conjunction with data collected in
a vegetation cover survey carried out in Albaja in 2005. The study also
combines MODIS vegetation index data with field measurements of
herbaceous biomass in order to produce a spatially explicit map of end-of-
wet-season biomass across the study area. Finally, a questionnaire survey
with local farmers and nomads is used to investigate the different causes of
wildland fire. The investigation reveals that on average 40% of the Albaja
study area burns every year. It also reveals that the currently applied fire
management activities do not control wildland fires and makes
VII
recommendations to make these activities more effective. The study also
concludes that the repeated wildland fires are negatively affecting the
existence of the most valuable trees, shrubs and grasses, which subsequently
reduces the range carrying capacity of Albaja and hence increase the poverty
of the local people and the nomads. The study also finds that the spatial
configuration and quantity of biomass become predictable at the end of the
wet season by correlating field measurement of aboveground dry biomass
with time-integrated vegetation index values obtained from MODIS
vegetation indices product. Field-calibrated remote sensing data therefore
provides a new, practical basis to prioritize the construction of fire lines to
begin in areas with high biomass that are at most risk of fire spreading out of
control. The social survey finds that the main causes of fire are Careless
cooking, Charcoal production and Poachers. The combined results highlight
the importance of fire as a process that affects not only the biophysical
environment but also exerts direct control on people’s livelihoods.
