917 
Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986 
Evaluation of regional land resources using geographic 
information systems based on linear quadtrees 
James Hogg, Mark Gahegan & Neil Stuart 
School of Geography, University of Leeds, UK 
ABSTRACT: Evaluation of regional land resources involves the integration and analysis of 
geographic data which comes from a variety of different sources and in many different 
forms. This paper describes results of a pilot study using a computerised geographic 
informations system (GIS) based on linear quadtrees to integrate and analyse geographic 
data for evaluation of regional land resources near Matlock in the Peak District of 
Derbyshire, England. Results are presented which show the response to queries involving 
set logic operations on binary raster images and are discussed in relation to methods of 
regional land resources evaluation. The paper concludes that GIS based on linear quadtrees 
provide a flexible, powerful analytical tool for geographical research involving 
integration of geographic data from various sources, including remote sensing. 
RESUME: L' evaluation des ressources regionales d'i terrain comprend l'intégration et 
l'analyse de données géographiques provenant de différentes sources et se présentant sous 
des formes differentes. Cette recherche décrit les résultats d'une étude-pilote utilisant 
un système d'information géographique sur ordinateur, de façon a établir une évaluation 
des resources régionales d'un terrain situé près de Matlock, dans le Peak District du 
Derbyshire, en Angleterre. La recherche conclut que le Système d'informations 
Géographiques est bases sur des "quadtrees" linéaires, et fournit un outil d'analyse 
flexible et efficace pour la recherche géographique concernant l'intégration de données 
géographiques provenant de sources diverses, y compris les images satellites. 
INTRODUCTION 
Evaluation of land resources involves the 
study of geographic data from many 
different sources and in many different 
forms. Geographic data can be efficiently 
integrated and analysed using computerised 
geographic information systems (GIS). 
These are data base management systems 
which allow users to store, retrieve, 
manipulate, analyse and display geographic 
data at their request. The concept of GIS 
has evolved over the past two decades 
(Tomlinson 1984). Its origin lies in the 
computerised data banks which were created 
to store locational data such as the 
coordinates of points for specific 
applications in surveying and mapping. It 
has now broadened and expanded rapidly to 
embrace sophisticated computerised systems 
for modelling and decision-making in land 
management (Dangermond, 1984; Estes et. 
al. 1985). 
The purpose of this paper is to describe 
the characteristics of a pilot GIS that we 
are developing and to demonstrate its use 
for land resources evaluation in an area 
near Matlock in the Peak District National 
Park, Derbyshire. Results are presented 
and discussed in relation to traditional 
methods of land resources evaluation and 
the need to integrate geographic data from 
different sources, with various levels of 
resolution and accuracies. 
In order to place the current work in 
context, we begin by outlining recent 
changes in the approach to land resources 
evaluation and trends in the development 
of integrated GIS. Then we describe a 
quadtree data model for encoding images 
and present and discuss results. 
LAND RESOURCES EVALUATION 
Land resources evaluation is concerned 
with making assessments about man's 
potential use of land for purposes such as 
agriculture, forestry, recreation, urban 
planning or engineering (Christian and 
Stewart, 1968). It involves analysis of 
the capabilities and constraints imposed 
by the physical characteristics of a 
region and is usually conducted in support 
of some decision-making process in land 
management. It is carried out by 
scientists from many different fields of 
study but, in many cases, they adopt a 
similar approach, though of course the 
level of detail and specific requirements 
and methods usually differ (Mitchell, 
1973). Moreover they draw typically upon a 
common core of information about the land. 
The extent of this common core is usually 
substantial - all require basic 
information about topography, geology, 
soils, climate and land use. While there 
are usually minor differences in specific 
requirements, the major difference often 
lies in the level of detail required. 
In conducting land resources evaluations, 
land is usually characterised by a 
distinctive assemblage of attributes and 
interlinking processes in space and time 
(Townshend, 1983). The attributes include 
topography, soils, water, climate, 
vegetation, and fauna as well as the