Land degradation is a term that refers to a human-induced or natural process that results in a decline in the overall quality of soil, water or vegetation.
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National Brownfield Association
The NBA is a non-profit, member-based organization operating within the United States and Canada, promoting the sustainable development of brownfields, encouraging green design and construction practices. Its organizational structure, chapters, and membership policies are defined, and its educational and training events are scheduled. - National Brownfield Association
http://www.brownfieldassociation.org/