378 
Figure 3a. Eagle 215B in flight, microlight aircraft 
used in this study. 
Figure 3b. Camera mounting and Hasselblad camera 
mounted for vertical photography. 
tal line which is important in photographic flights 
with a vertical camera. 
Table 1 
types f 
Zone 
Designation 
River charac 
teristics 
Land use type 
and economics 
Methods and 
technology 
omplementary 
ctivities 
t . 
Figure 3c and d. Flying instruments, with wrist alti-. 
meter, camera interval timer (left), compass, cylin 
der head temperature gauge, variometer, airspeed 
indicator and camera control light (right). 
rison to other microlights it has a low cruise speed, 
low stall speed and good glide ratio in power-off 
situations. The aircraft is equipped with a 
parachute. 
Due to its large wing surface, low weight and speed, 
it is rather sensitive for turbulence, which makes it 
difficult to keep the aircraft on a straight horizon- 
As a camera the Hasselblad 500 EL/M with 3,5/100 mm 
Planar and 50 mm Distagon lenses were used. The 
camera is placed in an especially manufactured moun 
ting attached to the airframe, in a position where it 
does hardly interfere with the airstream along the 
aircraft, see also Figure 3b. Camera operation can be 
done either manually or automatically. Both 70 expo 
sure cassettes and 12 exposure cassettes were used. 
In many cases the intervalsetting of the camera could 
be programmed for normal stereoscopic overlap (60- 
65%). 
Oblique aerial photography was produced from a hand 
held camera held by the pilot. 
The flying instruments consist of a wrist-altimeter, 
variometer, airspeed indicator, compass and cylinder 
head temperature gauge.The instrument panel also 
informs the pilot on satisfactory camera operation. 
3. Results 
3.1 Contents of land utilization types 
A generalisation of land utilization types has been 
made into four classes each having a great variety of 
land uses within the unit, but rather homogenous with 
regard to the relation of land use and the hydraulic 
regime. In Figure 4 the delineation of these four 
zones is presented. 
The description of land utilization types is a result 
of the analysis of existing information, interviews 
in the field and of crucial importance, of the re 
sults of the microlight aerial surveys. In the des- 
Figure 
mango i 
dug th: 
criptii 
emphas 
bearin; 
the fl 
cribed 
are: 
design 
charac 
social 
thereo 
gy, co 
tions 
survey 
remedi 
The re 
of thi 
In the 
of th 
types. 
3.2 
3.2.1 
In ge 
the ri 
preser