flooded areas 
flooded areas 
Western highway 
(marks at each £ mile between mile 8 to 15) 
highway. 
-t—h- Western highway 
flood flow direction 
'channel' routes of deepest water in relation to the 
Western highway. 
3.2. Metric Camera investigations 
Metric Camera imagery of the lower floodplain was 
obtained from scene 0901 with a nominal ground resol 
ution of about 20m. (Schroeder I985). The stereoscopic 
possibilities of this information source were not sui 
table for an area of such low relief (Dowman 1985) but 
enlargements at 1:250,000 and 1:50,000 scale provided 
durable prints despite some degradation of the image. 
Distortional effects of the enlargements were present 
and the relationship of the image to map scales were 
identified as being in the average form: 
Map scale = 1.0706 - 7.56 x Image scale 
The interest of this imagery is not only to identify 
its ability in presenting the features of the flood- 
plain but also the extent to which these features may 
be presented without the advantage of a flood event 
occurring. The Metric Camera imagery was found to give 
an accurate identification of vegetation distribution 
as an adjunct to LANDSAT data, where the spectral 
signatures of different, mixed land cover types may 
confuse such identification. 
From the observation of Metric Camera imagery at and 
around the area miles 9£ 60 12^ on the Western highway 
the-locations of relatively high and low land were seen 
Differences in vegetation density, the presence of 
human activity (consistantly confined to the 'pine 
ridge' higher ground in this region), tracks and other 
associated features provided indicators. Features less 
than 10 metres in width were seen by contrast with their 
surroundings. 
The disposition of higher features indicated a conce 
ntration of floodwater around the Almond Hill and the 
Straight lagoon sections of the highway as can be seen 
ih figure 5. 
3*3. Ground survey investigations 
The survey (Richards and Dumbleton 1981) was under 
taken to identify the location of most severe flooding 
on the Western highway and propose remedial measures. 
It provides precise elevations between miles 0 to 15 
on the highway but was less concerned with the internal 
drainage of the floodplain. The opinion of the report 
was that "..this section of the road (miles 9is 60 12^) 
is believed to be affected by the backwater from the 
Sibun river., and overflow from the Belize river" 
(Richards and Dumbleton 1981:84). 
The elevations of the flood levels are not strictly 
defined by the report and are taken from anecdotal 
sources and estimated as being 2metres over this part 
of the highway (Richards and Dumbleton 1961:85). 
The consideration of channel-full capacities of the 
Belize river led the authors of the report to draw the 
following conclusions: 
1. That overspill from the Belize river around Davis 
Bank would be relatively small. 
2. Upstream of Davis Bank, the attenuation of the 
flood peak by the channel was probably more important 
than loss to the floodplain, though overspill was not 
ruled out. 
3. No correlation could be found between the three 
possible sources of floodwater. 
4. Flooding appeared to be closely linked to high 
levels in the Sibun. 
Figure 6 illustrates the survey's levelling of the 
flood prone part of the highway and may be used in