WORKING GROUP 9 
CHIN FUNG KEE 
493 
Soil Characteristics 
Land use and natural vegetation are indicators to the engineer of soil types, 
and hence of foundation and drainage problems. Rice fields, readily distin 
guishable in aerial photographs by their quaint system of ridges or “batas”, in 
form the engineer that the soil is heavy organic alluvium. Rubber plantations 
are generally associated with lateritie soils and well-drained ground. 
The new rubber is clearly distinguished by the contour trenches and terraces 
- a pattern which remains perceptible long after the crown growth has com 
pletely overcast the ground. Tin tailings and old tin mines are easily identified 
from photographs by the comparatively bare and treeless surface, the bunds 
and pools. They forewarn the engineer of possible subsurface pinnacles of 
limestone and great variations in soil and foundation characteristics. In an 
industrial site in Petaling Jaya, the depth of the soil to bedrock was found to 
vary from 10 to about 100 feet between two points less than 10 feet apart. In 
another factory site, timber piles penetrated with ease some 60 feet into the 
ground but just across the road the piles could barely be driven 20 feet. 
Site investigations and borings made in the states of Kedah, Perlis and Johore 
in connection with the construction of schools under the Second Rural Devel 
opment Plan, confirm the soil deductions made from aerial photographs. The 
soil type was deduced from the methods of land management. 
Siting of the Coastal Bund, Kubang Pasu Irrigation Scheme 
Aerial photographic techniques contributed much valuable information to 
the siting and location of the coastal bund in the Kubang Pasu Irrigation 
Scheme. The coastal belt, which extends for nearly 10 miles from Kuala Kedah 
to Kuala Jerlun, was periodically inundated by sea water. To prevent the 
ingress of the sea, the early settler at the coast bunded his own plot of land. 
Internal drainage was usually provided by a drain which discharged to the 
sea or through a simple tidal control outlet. 
As the belt of cultivation increased in depth from the coast, these drains were 
extended inland until they became too small to cope with the increasing dis 
charge. This usually resulted in the undermining and destruction of these 
indigenous structures and the scouring of the drains which rapidly enlarged 
into channels through which the tidal water penetrated deep inland, with dir^ 
effect on the padi crop. As a result, most of this area of otherwise rich rice padi 
land was abandoned. 
In 1954, it was proposed to construct a coastal bund to protect this area 
from the ingress of the sea, with suitably designed control gates to regulate the 
discharge to the sea. The location of this bund depended on whether the coast 
showed accretion or erosion. In certain parts of Malaya it was found necessary 
to site such coastal bunds some 600 feet from the shore. A location so far from 
the shore would in this part of the coast have deprived the landowners of a 
considerable portion of their holdings. The site examination carried out in 1954