410 
- collection of detailed ground data related to 
forestry at sites, whose selection was guided 
interpretation of the LANDSAT image. 
- identification of ground condition classes, which 
are significantly different from the standpoint 
of forestry, using data collected from the field 
sites. 
- define the relationships which exist between 
forestry related ground conditions and their 
appearances on the LANDSAT and aerial photos. 
and 
- use the appropriate imagery type as an implement 
to extrapolate the limited ground data to the 
area of interest. 
3.2 The area to be mapped in order to determine 
forest surface area 
The study area for which forested area was to be 
determined is shown in Figure 1. This zone was 
defined in consultation with NFS planning personnel, 
and in consideration of several aspects. This zone is 
basically the arable portion of Niger, and as such, 
has the highest capability for forestry production, 
management related return, and potential degradation 
from competing land uses. It is also the zone for 
which several forms of base data are available, 
including complete coverage by LANDSAT satellite 
imagery and aerial photography. 
Also shown in Figure 1 is the area where initial 
test applications of the mapping procedure has been 
completed. This area, indicated by cross-hatching 
includes the two arrondissements of Mirria and 
Matameye, and covers a total surface area of 12,000 
square kilometers. 
3.3 Products to be generated through the 
development and application of the mapping procedure 
The primary product requested by the NFS is a 
series of maps, which show, for each arrondissement 
in the study zone, where forest lands are located 
and what is their extent. There are two basic 
elements to these maps: 1) their format, and 2) the 
information presented either by the map alone or in 
association with a report. The format selected is a 
line drawing map drawn on paper with a series of 
codes to represent ground conditions. The map is to 
have an associated report which explains the meaning 
of each map code. The maps are to be completed at a 
scale of 1/200,000 which will permit direct 
comparison with the topographic map series available 
for the area. 
The second element is the identification of the 
information to be presented by the maps and 
associated reports. Forestry decisions rely very 
heavily on physical conditions present at a specific 
site as well as what vegetation does, or could, 
occupy the site. These physical conditions include 
the general land form and specific configuration of 
terrain present at the site, and the soils 
characteristics. These conditions were selected, 
along with vegetation species composition and cover 
percentage as the primary information themes of the 
maps, and they were designated soil/vegetation/land 
form (S/V/LF) base maps. 
An additional product, of equal importance from 
the standpoint of regional applicability, is the 
photo interpretation key. This key was developed to 
standardize the interpretation of the aerial 
photography in the process of extrapolating the 
site-specific ground data to the entire study area. 
3.4 Data sources used in the mapping procedure 
The primary data sources used in the mapping 
procedure included: 1) LANDSAT MSS data in false 
color infrared format (bands 4, 5 and 7) at a 
reproduced scale of 1/200,000, 2) medium scale 
aerial photography acquired at 1/60,000 and 1/70,000 
in 23cm x 23cm, black and white, format, 3) the 
1/200,000 topographic maps, and 4) ground data. 
Figure 1. A map of the Republic of Niger showing the portion for which basic terrain elements are being mapped 
and forest surface area determined. Also shown is the area in which applications testing has been completed. 
In this zone, comprised of two arrondissements, Mirria and Matameye, the entire procedure was applied; from 
initial stratification using the LANDSAT images to the production of the soil/vegetation/land form (S/V/LF) 
base map and calculation of the forest type surface area.