Wetlands are nature's system of flood control and water cleaning. They store excess water from a river flood or during a storm and allow it to flow slowly back to the river as a storm abates. Wetlands filter out excess nutrients and pollutants and provide habitats for a wide variety of wildlife. In nature, wetlands can be swamps, bogs and marshes along a coastline, such as the Florida Everglades, or an inland system, such as the Okavango Delta in Botswana. The past two decades have witnessed extensive wetland nature reserve restoration and construction. Newly constructed wetland nature reserves provide wastewater treatment facilities as well as wildlife habitats
Wetlands in the form of swamps are breeding grounds for mosquitoes and other diseases. Mosquito populations may be controlled partly in constructed wetlands.
Constructed wetlands are land-intensive undertakings. In the past, many countries had policies of draining and filling in natural wetlands to permit urban development. Levees, heightened river banks and sea walls provided flood defenses. Hurricane Katrina demonstrated the folly of such policies.
Methane has 10 times the atmospheric warming capacity of carbon dioxide and is the most effective greenhouse gas for global warming. Wetlands produce about one quarter of the Earth's atmospheric methane through the anaerobic decomposition of organic matter.
Constructed wetlands are unable to treat highly toxic modern wastewater. Such waste needs to be pretreated in special installations, which could impact on the visual beauty of a nature reserve. Residual pollutants may have a negative effect on the reserve's wildlife.
- Photo Credit Jupiterimages/Comstock/Getty Images
The Advantages and Disadvantages of Flood Defenses
Flooding can result in significant damage to the economy, environment, infrastructure and property. Flooding can be caused by small watercourses, direct surface...
Advantages and Disadvantages of Natural Environments
Natural environments sustain the animal and plant life dependent on the current weather patterns and overall conditions of Earth. Humans greatly impact...
Advantages and Disadvantages of Natural Lighting
Natural light has both advantages and disadvantages based upon how it is used. Natural light is obviously a free source but it's...
Negative Effects of Fossil Fuel
Negative Effects of Fossil Fuel. Fossil fuels have been formed from the organic remains of long-dead plants and animals. They contain a...
Risks in Building Your Own Home
Risks in Building Your Own Home. Many people who start out to build their own homes have never built anything before. This...