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close this bookConducting Environmental Impact Assessment in Developing Countries (United Nations University, 1999, 375 p.)
close this folder4. EIA methods
close this folder4.3 Matrix
View the document(introduction...)
View the document4.3.1 Descriptive matrix
View the document4.3.2 Symbolized matrix
Open this folder and view contents4.3.3 Numeric and scaled matrices
View the document4.3.4 The component interaction matrix
View the document4.3.5 Advantages of the matrix approach
View the document4.3.6 Limitations of the matrix approach


Matrices relate activities to environmental components so that the box at each intersection can be used to indicate a possible impact. The term "matrix'' does not have any mathematical implication, but is merely a style of presentation.

The matrix can be used to identify impacts by systematically checking each development activity against each environmental component. If it was thought that a particular development activity was to affect an environmental component, a mark is placed in the cell at the intersection of the activity and the environmental component. A matrix analysis can systematically identify potentially important effects demanding more careful attention or analysis or focus attention on important possible effects that might otherwise be overlooked. Matrix is thus an extension of the basic checklist.

There are three types of commonly used matrices:

• descriptive matrices;
• symbolic and presentation matrices;
• scaled/weighted or numeric matrices.