REPRESENTATION OF FORESTED REGIONS AT SMALL SCALES, DERIVED
FROM LARGE SCALE MAPPING
S. Perikleous, W.A. Mackaness, O. Chaudhry
william.mackaness@ed.ac.uk
The extent
of forested parcels of land is captured at fine detail typically from mapping
at 1:1 250 or
The
methodology of the generalization algorithm is loosely based on an idea from
Muller and Wang but with significant differences.
Input came
from Ordnance Survey’s MasterMap(1:1250/1:10,000) Forestry layer which is a
vector-based topography layer. Example output compared favourably with hand
drawn maps at equivalent scale. The algorithm has removed regions of ‘forestry
inconsequence’ and given additional emphasis and regionality to broader
forested areas. The output obtained was evaluated by comparing with OS Strategi
dataset (1:250,000) and results were also evaluated by a Ordnance Survey
cartographers. Though favourable results were achieved the research pointed to
additional work that could usefully be undertaken.
The research is part of the long term research
in pursuit of systems capable of generating multi scaled maps from a single
detailed database with nominal human intercession in the map compilation
process. The algorithm was implemented in Java and Eclipse. Java Topology Suite (JTS) and
Jump libraries were used. The algorithm is available via the Ordnance Survey map
generalisation webpage.