nologie untersucht ,um die Chancen wiederholter Beobachtungen zu erhöhen,
Die erhaltenen Ergebnisse sollen einen Beitrag leisten für Ent-
scheidungen zur Durchführung von Umweltüberwachungsprogrammen und Umweltpoliti-
ken in tropischen Zonen der am wenigsten entwickelten Länder.
10 Km
x x
lo
Lo 1. Prerequisites,equipment,material bases and techniques of Remote Sensing in
developing countries.
Periodic ecological monitoring by remote sensing in tropical zones involves
equipment,material bases and techniques which have to be appropriate to the re-
search capacity of a developing country.
While only a small part of the developing countries,mostly the oil producing
countries are capable to finance larger remote sensing projects the poor majori-
ty is not touched by these activities,although the necessity is much more pres-
ni sing.Therefore large parts of these countries are lying in the shadow of remote
sensing researches as long as sophisticated methods are applied.
m Basic researches for remote sensing observations are possible to carry out even
with limited amounts and costs of technology,such as simple designs of an all
Ee band radiometer for both ground and airborne observations,camera arrangements
for photographic and photogrammetric operations,existing air photos,maps and
= machine processed scenes of satellite imagery.
Computer support by pocket or desk computers is often in the realm of the fi-
nancial capacity of an institution in a developing country.
The experiments and approvals of methods reported here habe been carried out
with image processed LANDSAT-scenes from the DFVLR,DIBIAS-System/Oberpfaffen-
hofen,West-Germany with the aid of simple and low cost technology.
Fi
0
4
2. Environmental factors characterizing tropical zones
Among many particular factors characterizing an environment of a tropical re-
gion several main ones are valid for all zones:
1. The river basin and its characteristics
scale number n
T 2. The vegetation coverage and geomorphology
2 3. Rainfall,runoff and evaporation
3 4. Antropogene influences
5 Their detection and determination by remote sensing datas is partly difficult
S to achieve with modest prerequisites in inaccessible regions.
$ li Limiting their validity a priori to 80% probability as experiments have shown,
3 the determination of these factors can be accepted for practical applications
in forecasting and planning.
5
3. River basin analysis(Fig. 1,2,3,4)
Drainage density Dc
5x10
Geomorphology of river basin is the basic structure of a region. Water runoff
and storage is determined strongly by the basin characteristics like stream
order number,stream frequency,drainage density,bifurcation ratio,longitudinal
and cross section geometry and hypsometry.
| On each rectified LANDSAT-scene of southern Tanzania in different scales a ri-
NC ver basin was delineated several times independently to minimize misinterpreta-
sy alle tions of catchment borders.
According to the laws of Horton and Strahler a statistic was carried out,deter-
mining the parameters mentioned above.
These were correlated with runoff datas from terrestrial measurements and hy-
drograph analysis.Relationships between them were highly correlated.
The empiric equations are different to those of Horton and Strahler due to the
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