where 28 people were killed (Tines 1974^) and. houses were devastated in a 
wide area near the plant (Times 1974a). 
If these industries have some detrimental effect when active (more 
commonly in spoiling the environment), then they certainly cause more 
damage when derelict. Apart from the retention of a disfigured landscape, 
dereliction also brings danger to safety through unattended works, pits, 
etc., and socio-economic losses through unemployment. These factors, when 
considered with the fact that the derelict landscape is an unutilized 
landscape and as such a wasted resource, indicate that remedial action in 
the form of reclamation and redevelopment is necessary. To achieve this 
goal, however, one needs to know the distribution, amount and type of 
dereliction that is to be reclaimed. The situation that existed before 
the current survey in Glamorgan, a county shown (Municipal Year Book, 
1972 ) to have a population density of 64 I persons/sq. km, was one as 
outlined above, i.e., a highly urbanized county with competing land uses 
but with an unutilized derelict landscape of unknown proportions and 
nature, and an urgent need for reclamation. It is in this context that 
the present survey was evolved and conducted as described below. 
Bata Sources. 
As described in the INTRODUCTION, aerial photography seemed to be a 
potentially useful data source, and photographs, black and white at a 
scale of 1:5000 taken 197^ - 72 were borrowed from the County Planning 
Department. Several other data sources, however, were found to contribute 
valuable information. Geological maps at a scale of 1:10,5^0, for 
example, indicated the mineral or rock extracted, while Ordnance Survey 
maps at the same scale gave, via place and street names, the likely 
cause of many derelict sites. Land use maps prepared by the County 
Planning Department in 19^9» gave the rough location of large sites, while 
telephone directories were used to confirm possible air—photo 
interpretations of other sites. 
Survey Procedure. 
Using the data sources outlined above the spoiled landscape was 
surveyed in the following stages. 
1. Air-photo interpretation using Wild ST4 stereoscopes fitted with 
3X and 8X binoculars. This was done in conjunction with all 
other sources of information except geological maps to which no 
immediate access could be obtained. 
2. Mapping survey data on 1:10,560 Ordnance Survey base maps by 
visual methods. 
3. Checking of interpretation and mapping by another research worker 
4. Use of geological map to interpret the geology of areas where 
mining and other extractive industries were or had been operating 
5. Pinal checking of map.