Wednesday, January 5, 2011

Natural wetlands and Human population

From Wetlands International an useful book about wetlands and the world that twist around them. This  provides a baseline understanding of how people and wetlands are connected, why these linkages are vital and how they can be better managed.

Wetlands and Water, Sanitation and Hygiene (WASH) 
Understanding the linkages

From Chapter 1 - Introduction:

" People’s health and well being are influenced by water supply, sanitation and hygiene WASH).  Interventions to improve these have long been an important aspect of the development agenda. Such interventions are normally based on a community’s needs and local conditions, but in the past they have generally not taken into account linkages with and effects upon the surrounding natural environment and its water sources. Yet WASH interventions interact with natural water sources, such as wetlands in a number of ways:
1. water resources, of a certain quality, are tapped as a source of water inflow;
2. waste flows, usually in the form of lower quality water, are produced and discharged;
3.  the natural system receiving the discharge is often either the same as, or connected upstream or downsteam, to the original water resource.

from Box 4.1 The capacity of wetlands to treat waste water
"When a critically high load of pollutants enters a wetland it changes the balance between the various naturally occurring processes. If its treatment capacity is rapidly exceeded, the ecology of the wetland system can exhibit a sudden, drastic change often involving a shift in species dominance and species composition.  If there is a steady overloading of the system, this can result in a gradual shift in species composition that will slowly compromise the ability of the wetland to provide water treatment and degrade the important provisioning services of the wetland, such as fish production".

Wetlands International, 2010. Wetlands & Water, Sanitation and Hygiene (WASH) - understanding the linkages. 
Wetlands International, Ede, The Netherlands. 
Published by Wetlands International

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