CHAPTER ONE: INTRODUCTION

Computerized techniques for mapping and analyzing geographic information have greatly expanded the realm of possibilities in landscape planning. Whereas manual techniques once limited planning efforts to nonquantitative analyses of the landscape, the enhanced capabilities offered by computers provide landscape planners the opportunity to create data that is much richer, more precise, and less subjective. For example, the landscape planner can now apply sophisticated methods of quantitative analysis that use mathematical formulas to describe the spatial patterns and composition of regions. The data created from these formulas can be used as indices that describe areas within the landscape along an interval scale in relation to the whole region being studied.

Considering that the ability to describe and analyze landscape patterns is one of core skills of landscape planners, these methods should be have a home in every landscape planners "tool box." The usefulness of these tools is further magnified by the need for landscape planners to have quantitative data to support their decisions. A wide variety of these techniques have been created and applied by disciplines such as geography and ecology, providing a base upon which landscape planners can build. One example is the group of measurements used by ecologists to describe diversity, both in communities of species and in landscapes

Diversity has long been one of the central themes of ecology. Today, the topic is more relevant than ever as increasing demands placed on Earth's resources by human society threaten the continued existence of many species, biotic communities, and ecosystems. As preserving biodiversity becomes a higher priority in the planning and management of the landscape, all environmental planners must become more conversant with the methods used to measure diversity in this context. Furthermore, since diversity measures are, in essence, tools for identifying and interpreting patterns, they could be used to analyze non-ecological aspects of the landscape as well.

This study is an exploration of the information diversity indices offer the planning process and a demonstration of how these measures can be calculated using computerized techniques. It is intended to inform landscape architects about the variety of methods available for measuring diversity, discuss some of the ways they have been applied to analyze the landscape, and demonstrate how they can be implemented. Chapter Two describes methods commonly used by ecologists to quantify both species diversity and landscape diversity. These methods are classified by the aspect of diversity they measure and the process of calculating each is described. Chapter Three is a demonstration of how diversity within the landscape can be quantified by some of the measures discussed in chapter two, describing how they can be calculated using computerized mapping and analysis tools. Data describing tree canopy density in the City of Seattle, created by the Remote Sensing Applications Laboratory at the University of Washington is used as the basis for this demonstration. Chapter Four presents the results of the demonstration and Chapter Five interprets the results and discusses possible uses of these indices. Finally, the thesis concludes with a summary discussion and some ideas for further research and application of diversity indices in landscape planning.