403
Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986
A remote sensing aided inventory of fuelwood volumes in the Sahel
region of west Africa: A case study of five urban zones in the
Republic of Niger
Steven J.Daus & Mamane Guero
Resources Inventory and Monitoring section, Forestry and Land Use Planning project, Niamey, Niger
Lawally Ada
Department of Agronomy, University of Niamey, Niger
Abstract: An inventory of fuelwood volume has been conducted in five urban zones, totaling approximately
150,000 square kilometers, in the Republic of Niger using an approach aided by the interpretation of LANDSAT
satellite images and medium scale aerial photography. The purpose was to provide planning level information to
assist the government of Niger (GON) in making a general assessment of fuelwood supplies available in
important regions of the country. Using a soil/vegetation/land form base map (at a scale of 1/200,000),
produced with the aid of the LANDSAT imagery and the aerial photography, 349 field sites were identified for
the collection of field data. The sites were selected using a multi-level list sample with a bias toward known
forestry types. Linear transect data was collected at each site and fuelwood volume estimates were generated
using cover percentage and height data in a multiple regression procedure.
Resume: Une inventaire du volume du bois de chauffage a était fait dans cinq zones urbans de la Republique du
Niger aide par 1'interpretation des images satellites LANDSAT et photos aeriennes a echelle moyenne. Le but
d'inventaire était de donner au governement les renseignements au niveau de la plannification concernant
l'offre du bois de chauffage disponible a la population dans les cinq zones importants, une superficie total
de environs 150.000 kilometres carre. Un total de 349 sites de terrain a était reparti a l'aid d'une carte
sol/vegetation/forme de terrain realise des efforts comprenee de 1'interpretation des images satellites et les
photos aeriennes. Les sites a etaitent choisi par rapport d'une méthode d'échantillonage par liste
multi-niveau, et le choix était pondéré vers les terrains forestiers. Les données quantitatives etaitent
collecte par rapport d'un système des transects et le volume du bois de chauffage, en steres par kilometer
carre, était calcule utlisent une equation de regression multiple.
1.0 INTRODUCTION
The results presented in this paper are from work
completed at the Resource Inventory and Monitoring
(RIM) section of the Forestry and Land Use Planning
(FLUP) project. This project is funded under the
cooperative agreement #683-0230, between the United
States Agency for International Development (USAID)
and the government of the Republic of Niger (GON).
The primary aim of this bilateral project is to
established within the National Forest Service (NFS)
of the GON a unit, the Office of Technical
Assistance (OTA), capable of furnishing technical
information regarding natural resources, for the
purposes of planning.
The RIM section was established within the
structure of the FLUP project in order to: 1)
develop and implement resource inventory methods
appropriate to the various information needs of the
GON, and, 2) train GON forestry personnel in the
planning and conduct of such inventories. It is
intended that the developed capability of the RIM
section, both the procedures instituted and the
personnel trained, will become an integral part of
the OTA.
An essential element of a training program,
especially in the field of inventory science, is to
identify actual information requirements and use
them as practical examples. During the design phase
of the FLUP project several basic information needs
were identified regarding forestry resources in
Niger. One major information lack at the present
time is the volume of wood presently available for
use by the population for cooking and heating
purposes. Without this figure it is very difficult
to develop appropriate and coordinated plans for
proper management and/or exploitation of the
resource. The provision of this information was
identified as one of the practical objectives to be
addressed by the RIM section.
2.0 IDENTIFICATION OF THE APPROACH USED TO
ESTIMATE FUELWOOD VOLUMES IN SELECTED URBAN ZONES
2.1 Context and consideration regarding the
approach
The approach to the production of fuelwood volume
estimates was identified through consideration of:
1) the GON's expressed need to know what volume of
fuelwood exists, and where, 2) constraints to the
level of effort, 3) the types and amounts of source,
or base, data available, 4) previous work completed,
and 5) capabilities of the RIM section personnel.
The approach designed included the following major
elements. An inventory with two phases, the first
with the objective of producing a suitable base map
showing the distribution of fuelwood related ground
conditions, and a second phase to estimate the
volume of fuelwood. Both phases rely heavily
on the interpretation of remotely sensed data, and
statistical sampling and data analysis procedures
will be employed. This approach will maximize the
efficiency of the mapping and volume estimation
procedures, as necessitated by the constraints faced
by the RIM section, and will produce valid and
comparable volume estimates due to the application
of the statistical procedures.
2.2 Selection of the zones to be inventoried
Fuelwood volumes were estimated for the five zones
shown in Figure 1. These zones are circles, with a
radius of 100 kilometers, and have a major urban
center at the foci. The 100 kilometer radius was
selected for two primary reasons. Within the limits
of these zones lives a large majority of the
population of Niger. This is where the greatest
pressure exists on the fuelwood resource, and where
accurate and precise information is essential for
