Leopold matrix

Environmental impact assessment method
The Leopold matrix is a qualitative environmental impact assessment method developed in 1971 by Luna Leopold and collaborators for the USGS. It is used to identify and assign numerical weightings to potential environmental impacts of proposed projects on the environment. The magnitude (from 10 to +10) is inserted on the top left diagonal and the importance (from 1 to 10) is inserted on the bottom right diagonal. Additionally, the grid format allows for a visual display of results that can be easily understood by policymakers and the public. The matrix is also capable of expanding and contracting based on the scope and environmental context of any given undertaking, rendering it functional for both large and small scale projects.

One of the fundamental downfalls of the method is the lack of criteria or standard methods for assigning magnitude and significance values which may lead to subjective judgements. In the same vein, the method has also been identified as lacking the ability to facilitate any degree of public involvement, primarily due to the subjective value judgements of the user. Another potential pitfall is the sheer size of the matrix with a total of 17 600 items of information potentially being analyzed. The size of the matrix has also been criticized as being too detailed for some projects while simultaneously being too imprecise for others. In terms of direct content, the chance of double counting certain impacts is also present. The matrix has further been identified as being highly biased toward biophysical impacts making the social impacts of a given project difficult to assess. Of the impacts that are covered, the matrix is seldom capable of taking into consideration secondary or cumulative impacts which are often significant considerations in environmental impact assessment. Another area that the method can be deficient in is having a mechanism capable of distinguishing between long term impacts and short term impacts. Due to the presentation of completed matrices, the method has also been identified as treating interactions as though they are certain to occur, with no consideration of probability. Vojvodina ecological network; an assessment of the influences of anthropogenic factors on an ecological network (salt steppes, marshes, etc.). Karbala water projects; a study on seven drinking water treatment facilities based on physio chemical properties. Binh Thuan desertification; an assessment of the potential desertification effects and subsequent impacts on socio economic conditions and water availability.