Map of the website
The contents of the site have been divided into two parts
PART 1
Part
1
is
made
of
several
tabs
and
sub-tabs.
Each
of
them
is
dedicated
to
a
specific
theme
related
to
the
building
of the GIS and the ecosystem of the Inner Delta of the Niger river, in the Republic of Mali.
INTRODUCTION
The authors (p.30)
The history of the project (p.31)
VEGETATION
Methodology used for ground studies and data processing (p.32)
The structure of the GIS (part 1): spatial data (p.33)
The structure of the GIS (part 2): thematic data( (p.34)
Vegetal associations (p.35)
Flora (p.36)
ECOLOGY
Ecological data (p.37)
Soils (p.38)
The relationship between the flood and vegetal associations (p.39)
FLOODING
The internal waterway network within the inner Delta (p.40)
Floodable areas (p.41)
The 3-D model for flooded areas (p.42)
Analysis of the model for a 6.60m flood (p.43)
Analysis of the model for a 6.21m flood (p.44)
Analysis of the model for a 5.97m flood (p.45)
Analysis of the model for a 5.10m flood (p.46)
Analysis of the model for a 4.40m flood (p.47)
Vegetal landscapes and hydrological basins (p.48)
Conclusion (p.49)
TOWARDS A DIGITAL ELEVATION MODEL?
Methodological suggestions (p.50)
Each
theme
includes
a
scientific
summary
and
maps.
The
original
data
and
the
layers
of
spatial
information provided by the ARC GIS 9.3 software are available for downloading
PART 2
This
second
part
has
been
approached
differently
from
the
first
one;
each
tab
is
dedicated
to
one
theme
and
shows
a
detailed
plan.
The
full
contents
for
each
theme
can
be
downloaded
as
a
pdf
document
(text
and
maps)
and
an ARC GIS geodatabase (GIS Files)
Populations and their territories (p.51)
Flooded rice cultures (1952, 1975, 1989, 2015) in relation with soil and flooding (p.52)
Pastoral infrastructures and main routes : Leyde (territories), cattle tracks and shelters. (p. 53)
Fodder production in relation to animal feeding (p.54)
Conclusion (p.55)
The
DELMASIG
GIS
uses
a
WGS
84
UTM
zone
30
North.
Distances
are
measured
in
metres
and
areas
in
hectares.
As
the
original
photo-interpretation
was
based
on
uncorrected
photo-coverage,
local
distorsions of up to 500m may be found when the maps are superimposed with satellite images.
Use
of
the
data
is
free,
provided
reference
is
duly
made
to
the
website
https:/www.delmasig.com
and
/or
to
the
specific
documents
used
and
their
authors.
We
recommend
that
users
of
the
databases
report
their projects to the following address:
info@delmasig.com
and
marie.jerome2@wanadoo.fr
Jérôme MARIE & Pierre HIERNAUX
The
Inner
Niger
Delta,
with
nearly
20,000
km
2
of
land
susceptible
to
flooding,
is
the
3rd
largest
wetland
on
the
planet
after
the
Pantanal
on
the
Amazon
(100,000
km
2
)
and
the
Sudd
on
the
White
Nile
(57,000
km
2
).
In
West
Africa,
the
Inner
Delta
is
at
the
same
time
the
1st
inland
fishing
area
(50,000
t/year),
the
cradle
of
flooded
rice
cultivation
and
the
area
that
offers
the
most
productive
pastures
in
West
Africa,
which
are
frequented
each
year
by
about
1.5
million
cattle.
It
is
also
home
to
a
resident
population
of
560,000
inhabitants
(Rec.
2009)
within
the
limits
of
the
annual
flood
and
nearly
800,000
inhabitants
within
the
51
communes that crisscross the Delta and its margins.
The
Inner
Delta,
as
named
by
Elisée
Reclus,
extends
from
Ké
Macina
on
the
Niger
and
from
Beneny
Kegni
on
the
Bani
to
Lake
Debo
in
the
north.
Beyond
the
Debo,
begins
the
region
of
lakes
irregularly
filled
by
the
Niger,
which
extends
from
Akka
to
Lake
Faguibine.
To
equate
the
lake
region
with
the
Inner
Delta
-
called
the
Central
Delta
by
some
authors
who
assign
it
an
area
of
60,000
km
2
-
is
a
misinterpretation
that
amounts
to
adding
more
than
30,000
km2
of
Sahelian
and
Sahelo-Saharan
dry
land
to
the wetland proper.
What
we
propose
here
is
a
model
of
the
Inner
Delta,
starting
with
its
vegetation,
as
we
publish
here
the
only
study
carried
out
on
this
subject.
The
fieldwork,
dating
from
the
1980s,
was
updated
during
a
long
tour
in
2014.
The
article
"
The
resilience
of
wetland
vegetation
to
recurrent
drought
in
the
Inner
Niger
Delta
from
1982
to
2014"
-
(P.
Hiernaux,
M.D.
Turner,
M.
Eggen,
J.
Marie,
M.
Haywood),
published
in
Wetland
Ecology
and
Management
in
2021,
shows
that
the
data
from
the
eighties
are
still
valid.
The
study
presented
here
deals
with
plant
formations
and
their
relationship
with
flooding,
from
which
a
model
of
flood
areas
and
a
digital
terrain
model
are
deduced.
The
study
also
addresses
the
human
geography
of
the
Delta:
the
evolution
of
its
population,
that
of
rice
cultivation
from
1952
to
2015,
the
pastoral
system
with
its
territories
and
its
network
of
pastoral
tracks,
as well as the productivity of the pastures.
The
system
was
initially
developed
on
Arc
Info
and
then
translated
on
Arc
Gis.
The
original
data
included
in
the
GIS
is
freely downloadable.