OBJECTIVES 
The overall objective is to develop techniques for producing regional 
resource maps for the coastal area of Western Saudi Arabia, using 
Landsat. The maps should reveal synoptic data on geomorphology, soils, 
vegetation and land use as a first step towards an integrated resource 
map. These maps should then provide information on land capability, 
soil erodability, hazard assesment, e.g. salt, flood, etc. 
The study has concentrated on the utility of Landsat imagery in regard 
to integrated resource survey and mapping because it offers timely, 
repetitive and accessible data and has been used successfully else 
where. However because many of the signatures for resource management 
are dependent on vegetation characteristics the application of Landsat 
data may prove difficult and will have to be revalidated in the xeric 
conditions of Saudi Arabia. 
The study therefore initially involved analysing the value of different 
levels of Landsat data use from: 
1. Simple visual interpretation of unenhanced Landsat imagery. 
2. Visual interpretation Landsat imagery digitally enhanced to 
improve interpretability 
and 
3. Machine processing and classification of Landsat data. 
Initially these various Landsat data were to be evaluated for ease of 
interpretability and thematic information content with respect to 
detailed ground surveys in a pilot area before being applied to a 
comprehensive mapping program. The results presented here relate to 
this initial phase of the project. The aim of this first phase is 
twofold viz: 
(i) to evaluate visual interpretation of various types of Landsat 
imagery against aerial photography as a tool for integrated 
survey. 
(ii) the compilation of detailed thematic maps for geomorphology, 
soils, vegetation and land use. In the absence of collateral 
information these maps will provide control for assessing 
advanced Landsat image categorisations techniques in the later 
phase of the project. 
PILOT SURVEY AREA 
A 5,000 km 2 area (21°30' to 22°00'N, 39°00' to 40°00'E) north of Jeddah 
was selected as a pilot study area. The area straddles the coastal 
plain or Tihama, bounded by the Red Sea and the hills fringing the 
scarp edge of the Arabian Shield. 
The area contains many of the geological geomorphological, edaphic and 
vegetative features of the Red Sea coast and is a zone of urban and 
industrial development. The area is coincident with a single rectified 
aerial photomosaic at 1:100,000, which provides a convenient base for