380 
Figure 7. Malekote settlement with coral for cattle. 
Banana and maize crop along inner bend of the river. 
from those of the neighbouring communities i.e. the 
Pokomo. the Orma or the Somali. The latter group is 
present in this zone in the dry season only, staying 
in crude loose leaf shelters or manyattas surrounding 
the separate night enclosures for their sheep and 
goats, camels and cattle. 
Malekote and Wanyoyaya have no specialization. Shif 
ting agriculture is the mainstay but also some animal 
husbandry, spear fishing and honey collection is 
practised. The Somali in this zone are nomadic pasto- 
ralists. 
Shambas (agricultural fields) are abandoned after 
signs of exhaustion of the soils or other negative 
trends appear to set in. Most shambas are located on 
the levee lands. The alluvial floodplain of the river 
basin land is narrow and the few cut-off meanders are 
highly sought after as arable land. 
By far the most remarkable and distinctive method by 
the Malekote and Wasanya that does not appear in any 
downstream zones of the river is the reclamation of 
river basin land by cutting a straight channel for 
the river through the narrow land separating two 
succesive meanders. 
The reclamation of this meander is with the technolo 
gy of these groups quite an effort. Explanations for 
these great efforts can be found in the fact that: 
- there is a general shortage of agricultural land 
- the alluvial floodplain is only slightly developed, 
the general state of physiography and soils (ferti 
lity limit the viability of arable and flood depen 
dent agriculture as practised downstream. 
Reduction in flooding frequency and sediment load in 
the river will both adversely affect the carrying 
capacity of the described land utilization. Village 
irrigation may h e promoted as a remedy. Reduction in 
flooding frequency will also accelerate degradation 
of riverine forests and floodplain morphology and 
therefore reduce the carrying capacity for grazing 
being a refuge for Somali herds. 
4. Discussion and conclusions 
4.1 Methods 
In the previous sections the use of a microlight 
aircraft in the survey has been illustrated with 
photographs. However, the value of the use of the 
aircraft cannot be illustrated with photographs. 
One of the land use specialists in the study also 
flew the aircraft for a great deal of the time. These 
flights were for the pilot similar to a photo inter 
pretation and yielded the specialist a very clear 
insight in land use patterns and its relation with 
the flooding regime and related aspects, which were 
of crucial importance in the survey. 
Also the production capability of the whole system 
has not been mentioned yet. When the pilot got more 
experienced in a period of 13 days 40 hours of flight 
were made, during which 1100 vertical B&W 
panchromatic photographs were produced, of which 900 
had a good to reasonable quality and 300 oblique 
colour photographs were made. The vertical photog 
raphs usually had a scale of 1 : 6,000 and were taken 
from an altitude of 1,000 ft., which could even in 
turbulent conditions be maintained reasonably well. 
The vertical photography was produced with overlap 
for stereoscopic analysis of preselected areas, or 
strips which were selected during the flight, the 
longest of which had a length of 10 km and a width of 
350 m. Also photoblocks were photographed of areas to 
300 ha. with reasonable sidelap and overlap. 
The study was set up to identify different land 
utilization types, without quantifying these land 
utilization types. Upon completion of the surveys it 
was however realized that it would have been techni 
cally feasible to perform an inventory as well in a 
quantitative way, given the production capacity of 
the system. 
With respect to the aircraft type it is concluded 
that the Eagle is indeed not a very stable platform 
for aerial photography given its rather large wing 
surface and low speed. Other modern "third genera 
tion" microlights will have a much better performance 
in this respect. 
4.2 Environmental impact analysis 
The results of the inventory of land utilization 
types are combined with the result of modelcalcula- 
tions on the morphology of the river in the future. 
The combination of these two types of results lead to 
a number of statements on impacts per land utiliza 
tion type and recommendations for remedial measures 
and further study, which go beyond the scope of this 
article. 
In summary the impact of changes in the river regime 
as a result of structures planned include: 
- reducing for a large area the flooding to virtually 
nil and thereby preventing a great deal of the 
present small scale cultivation and interfering 
with the livestock grazing now practiced on the 
annually temporary inundated land 
- changes in the sedimentation pattern that may lead 
to a meandering system whereby irrigation schemes 
are being cut off from their water supply 
- permanent inundation of parts of the floodplain, 
creating whole new ecosystems 
It is concluded that the concept of land utilization 
types can be used in combination with results of 
model calculations in river morphology, when land 
utilization types are well defined in terms of the 
relation with the dynamics of the river. 
Alan S 
Cranfiel 
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England 
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