Wetland

而世界各國約有50種定義來解釋「濕地」一詞，這其中最被大家所熟知及通用的，是各國於1971年在伊朗拉姆薩所共同決議通過的「國際重要水鳥棲地保育公約」(Convention on Wetland of International Importance Especially as Waterfowl Habitat)，簡稱「濕地公約」(Wetland Convention) 或「拉姆薩公約」(Ramsar Convention) ，其定義如下：「無論天然或人為、永久或暫時、靜止或流水、淡水或鹹水、或二者混合者，由沼澤、泥沼、泥煤地或水域所構成的區域，包括水深在低潮時不超過六公尺之沿海區域。」。
Source:
http://www.wetland.org.tw/newweb/wetland/WhatIsWetland.htm
他國的定義
Many definitions for wetlands have been proposed and utilized over the years--see FW definitions. Among the most widely accepted definitions is that of Cowardin et al. (1979), which was adopted by the U.S. Fish and Wildlife Service.
Land where an excess of water is the dominent factor determining the nature of soil development and the types of animals and plant communities living at the soil surface. It spans a continuum of environments where terrestrial and aquatic systems intergrade.

溼地的分類系統，最高等級可分為五類(Schot 1999)
1.marine海洋 2.estuarine河口 3.riverine河流 4.lacustrine湖沼>8ha 5.palustrine非潮汐<8ha
Source:
http://academic.emporia.edu/aberjame/wetland/define/define.htm