A Hydrological Classification of International Wetlands of Iran

Human activities have increased the vulnerability of wetlands, most of them relate to water extraction and water course alteration. There are various ecological, hydrological, geological and climatologic methods of wetland classification. To protect and assess the environmental impacts on wetlands efficiently, an awareness of the hydrological condition of the wetlands is necessary. We have reviewed a schema of wetland classification based on Gilver and McIness method in this paper which can be used to assess the hydrological vulnerability of wetlands. The schema has been applied to Iranian wetlands of international importance. As there are other categories of wetlands in Iran not covered by the original method, we have amended the schema to suit Iran's condition. We have identified 16 Rheotrophic, 1 Minerotrophic, 3 Omnitrophic, 2 Marine, and 4 Marine-Rheotrophic, and 3 Rheotrophic-Marine classes of wetlands for Iran of which the last three are introduced for the first time in this paper. Ombrotrophic wetlands are less vulnerable, while Rheotrophic wetlands are vulnerable to most of the threats with the exception of the underground water extraction. Minerotrophic wetlands are most vulnerable to acid rain, land use conversion, water extraction, and river course alteration and mining. Omnitrophic wetlands are vulnerable to all sources of threats.