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LOW COST MONITORING OF LAND USE AND SOIL EROSION IN THE 
HUMID TROPICS : AN APPLICATION OF AERIAL PHOTOGRAPHY 
Dr Peter Collier Dept of Geography 
Prostsmouth Polytechnic 
Dr W. Gordon Collins Dept of Civil Engineering 
University of Aston Birmingham UK 
Abstract 
One serious threat to the future of world food supplies is the problem of soil 
erosion; which is far more severe in tropical developing countries than it is 
in temperate developed ones. 
Tropical developing countries often lack the technical and financial require- 
ments necessary to undertake surveys or monitoring of their land resources 
and soil erosion. 
Using a test area in Jamaica a suitable methodology was developed to provide a 
low cost system for monitoring land use and soil erosion. 
The test area had a wide range of land uses, slopes and soils, but a fairly 
homogenous rainfall pattern. ; 
The soils, slopes, land uses and extent of soil erosion, were all mapped at a 
scale of 1:12 500. The land uses and extent of soil erosion were obtained from 
interpretation of 1:25 000 scale black and white aerial photographs. 
It was necessary to develop a classification of land use that was both relevant 
to the data source, (1:25 OOO scale aerial photography), and at the same. time 
accurately reflected the true nature of the land uses. 
A further requirement was that both the "Classification"and the "guidelines for 
interpretation" should be suitable for semi-skilled interpreters to use. 
Similar consideration prevailed in the development of the methodology for 
mapping eroded land. 
The data obtained from the interpretation were then composited with soils and 
' slope data derived from the original soil survey field sheets. 
Some of the results of this analysis are outlined, and recommendations are made 
on the extension of the methodology to other tropical environments. 
  
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