Environmental impacts of development on wetlands in arid and semi-arid lands

Abstract Wetlands, as defined by the Ramsar Convention, are productive ecosystems providing goods and services for people. Negative effects of “development” on wetlands are exemplified through adverse climatic effects (Aral Sea, USSR), inadvertent environmental changes (Canadian Prairie Potholes), non-sustainable alternative uses (South Chad Irrigation Scheme, Nigeria), exacerbation of problems (Garaet El Haouaria, Tunisia), detri-mental effects on rare species (Mikri Prespa, Greece), social disruption (Kissingin Fadama, Nigeria), international obligations (Ichkeul, Tunisia), and sub-optimal management (Weija-Panbros, Ghana). The functions and values of wetlands, following the Adamus approach, are described and exemplified for the Hadejia-Nguru wetlands (Nigeria) and Lake Hula (Israel). Threats to wetlands from agricultural intensification, pollution, engineering schemes and urban development are discussed. Since the societies and institutions that degrade wetlands are themselves complex systems, an under...