National-Wide Environmental Unit Classification using Remote Sensing and GIS -A Case Study in Zambia
Ryota Nagasawa, Kazushi Endo, Yoshinori, Takahashi Yukiko Kojima
PASCO Internatlonal Inc.
3-7-8 Kammiuma, Setagaya-ku
Tokyo, 154, Japan
Tel : 81-3-34 13-9321 Fax : 81-3-34 13-9805
E-mail :34153274@people.or.jp
Abstract
For the purpose of structurally understanding the regional ecosystems, natural environmental factors, consist of geomorphology, geology, land cover, elevation, annual precipitation and evapotranspiration , were data based and combined so as to divide the national area into environmental units or zone. Quantification theory III is applied in multivariate analysis, in which qualitative data (categorical data) relating to each environmental factor, because it was proved to be effective in graphically expressing and categorizing the samples based on the patterns of reaction of sample data categories. Mesh (grid) data, which are used for multivariate analysis, on a size of 1 km (totally numbers 7,522) were prepared through vector / raster conversion of the established database. As a result of analysis, the study area, the Republic of Zambia, can be divided into 10 environmental units reflecting the mutual interrelations between 6 environmental factors. The result almost totally matches with existing ecological viewpoints and can be said with great confidence to be proper and correct.
1. Introduction
It wasn't until the late 1980s that the world sat up and started to show concern towards global environmental issues. Problems such as global warming, destruction of the ozone layer, the depletion of forests and desertification caused by
Acid rain each differ in their effects, ranges and features, however, the solution to these problems can be said to be largely dependent on the actions of every individual human being and the degree of environmental management on the local and regional levels. When people come to plan and implement regional development projects in the future, they will have to pay attention to the global environment and give ample consideration to environmental plans aimed at the preservation and revitalization of regional ecosystems.
Regional environments are composed of single ecosystem that is formed from the delicate relationship of a variety of environmental factors such as topography, geology, soil, climate and flora and fauna. This means that it is necessary to spatially unify environmental factors in order to be able to understand the regional ecosystem. This report aims to give an introduction to methods for obtaining a structural understanding of regional ecosystems, seen from the regional environmental viewpoint, through the use of remote sensing and GIS technology.
2. Study: Area
The whole of the Republic of Zambia, located in south-central Africa and covering an area of 752, 612 m' , is the area of study. Most of the national land area of this country is situated on geographically the Zambezi River and its tributaries, there are steep fault
escarpments and tectonic valleys that result form the tectonic structure of the rift valley.
Zambia is located within the tropical zone, however, the high altitude ensures that the climate is comparatively cool throughout the year. The vegetation land cover in Zambia is broadly classified as savanna, but within this classification, some district differences are identified due to the type of soil, gradient, altitude and climate.
3. Methodology
The methodology used here consists mainly of regional area division methods that utilize multivariate analysis. As statistical means form the basis, an overlay-like spatial analysis model enables, not only elimination of the arbitrariness (subjectiveness) that often occurs in the stage of environmental factor unification, it also allows a quantitative understanding of factor cause and effect interrelationships to be gained in those cases where numerous environmental factors exist. In this study, natural environmental factors (topography, geology, land cover information, etc.) were combined to divide the study area into environmental units or zones, and an attempt was made to gain a structural understanding of the mutual cause and effect relationships of environmental factors. Quantification III theory is
utilized in multivariate analysis, in which qualitative data {categorical data) relating to Geomorphology, geology and land utilization, etc. is used.
Quantification III methodology involves the quantification of both samples and categories based on the patterns of reaction of sample data categories, and it is intended to graphically express and categorize those samples and categories. This method was originally proposed by Dr. Hayashi in 1983 and proves useful in classifying and finding out about samples and categories. In this study, the six types of map data {qualitative data) of elevation, geomorphology, geology, land cover, annual precipitation and evapotranspiration were used in carrying out regional area division in terms of environment, in order to gain an understanding of environmental units. Fig.-1 illustrates the analysis flow formed by this qualitative data.
Fig.1 Analysis Flow Chart
