Wetlands
are of the most important natural resources on earth. It ensures a
balance in our bio-diversity and offers water, food and breeding
habitat for a large variety of living organisms.
One
of the direct benefits of wetlands, specifically for humans, is the
fact that wetlands can drastically reduce the risk of damage as a
result of natural disasters.
The
frequency of disasters worldwide has more than doubled in just 35
years, driven by climate- and weather related hazards like flooding,
tropical cyclones and droughts. UN Water estimates that 90% of all
natural hazards are water-related. And the Intergovernmental Panel on
Climate Change (IPCC) predicts even more extreme events
going
forward.
Statistics
about these disasters are shocking: 1.35 million people died as a
result of disasters between 1996 and 2015. In material terms, weather
related disasters caused US$3.3 trillion in damage between 1980 and
2014.
Defined
as flat land areas that are flooded with water, either seasonally or
permanently, wetlands are a natural buffer against disasters.
The
amount of water on planet earth cannot increase, but it also cannot
decrease. The two factors that affect the availability of water are
the population growth, and the management of water sources. Wetlands
play a critical role in the management of water sources.
It
functions like a huge sponge that slows down the flow of water
through an area and at the same time clear the water from impurities.
In a way it is similar to the human kidneys: it absorbs and slows
down the flow of water, filters impurities, and prevents major floods
further downstream.
When
an extreme event hits, healthy wetlands can absorb some of the shock,
cushioning the damage in local communities. In Hikkaduwa, Sri Lanka
where offshore coral reefs are protected through a marine park, the
damage from the 2004 tsunami extended just 50m inland. In nearby
Peraliya, where coral mining had degraded the reefs, the damage
extended 1.5 km inland.
Wetlands
can also speed up the recovery and help to “build back better”
after a disaster, acting as natural water filters and nutrient
restorers. After a 1999 cyclone that hit Odisha in eastern India,
rice paddies that were protected by mangroves recovered their food
production much more quickly than croplands without the buffer.
Wetland
types that help us cope with extreme weather events, include the
following:
1.
Mangroves
Mangroves
are salt-water tolerant shrubs and trees that grow in shallow,
tropical coastal waters. Their roots bind the shoreline and reduce
the impact of cyclones/hurricanes and tsunamis. A good example of a
mangrove wetland is at the St Lucia lake in KwaZulu-Natal.
2.
Coral Reefs
Coral
reefs are solid structures found in shallow, tropical waters and are
built by living colonies of tiny coral polyps. In addition to being a
habitat for several marine species, coral reefs also act as offshore
wave barriers. The Coral Reefs of Tongaland on the northern coast of
KwaZulu-Natal is one of South Africa’s Ramsar wetlands.
3.
Rivers and flood plains
During
sudden floods, flood plains act as a giant reservoir which can spread
and store flood water over a wide area, reducing damage downstream.
4.
Inland deltas
When
rivers flow into a wide, flat inland lake without draining into the
ocean, an inland delta is formed. The best example is the Okavango
Delta in Botswana which provides a habitat for a large number of
animals, birds and plants in an otherwise dry, arid area.
5.
Peatlands
Peatlands
are water-saturated lands containing decomposed plant material up to
30 meters deep that has accumulated over time. They cover 3% of the
earth’s land surface and store more than twice as much carbon as
all of the world’s forests combined. It play an important role in
mitigating some effects of climate change.
Several
activities occur world wide to celebrate World Wetlands Day. Most of
these are organised by the institutions responsible for the Ramsar
wetlands of that country. I am aware of events in South Africa at St
Lucia, Edendale near Pietermaritzburg, and Colbyn near Pretoria. The
Department of Environment Affairs plans an official event for 17
February at Esselen Park Pans, Thembisa in the Ekurhuleni
Metropolitan Municipality.
If
you are close to a wetland, contact them to find out what happens
there and how you can get involved.