Under normal conditions, at least in the past,
people derived their most life-giving benefits from rivers. It was along
waterways that communities settled and grew. The rivers provided one of the
most important necessity for life: water, for drinking and irrigating of the
crops which were the prime food source.
Annually, spring floods brought nutrient-laden
material from up-river areas to restore the capability of fields to produce
crops and water to nourish the seedlings that would mature into those crops.
Occasionally, larger volumes of water during flood stages would cause damage to
communities and temporary dislocation of residents and animal stock.
If drought hit the region, water flows would have been reduced, severely
affecting the agricultural areas. As more people crowded into the farming
regions, mostly from urban expansion, the pressure to control floods grew. It
is still ongoing as illustrated by what has happened in the Mississippi River
valley over many decades.
Hurricane Katrina
and Louisiana, USA
One of the most negative results of human influence in control water
flow is the devastation that can happen when normal river processes are not
allowed to happen. In efforts to control Mother Nature, humans have created
whole new categories of disasters with the basic elements of natural phenomena
magnified. In the case of Hurricane Katrina and its aftermath in
Louisiana, in 2005, the destruction of parts of the City of New Orleans was
made worse by long-term changes to the hydrology and ecology of wetlands in the
region as well as by the design of flood protection infrastructure.
 |
New Orleans, Louisiana in the
aftermath of Hurricane Katrina, showing Interstate 10 at West End Boulevard (retrieved
29 October 2019 from https://en.wikipedia.org/wiki/File:KatrinaNewOrleansFlooded_edit2.jpg
)
People can also change the natural equilibrium through their
exploitation of minerals and material used in construction. I wrote about the
situation in Hallsands, Devon, England, in the 1890s (Shepheard, 2018). The
village had been protected by a broad sand and shingle beach fronting Start
Bay. The low incline of the beach and offshore area insured that potentially
destructive waves did not encroach on the lands where the community had been
built.
Dredging of the beach and offshore area commenced in 1897. The material
was needed to build up the port area of Devonport. Millions of tons of rock and
sand were removed with the effect that the beach level fell, and the offshore
areas became deeper and with more severe slope. By 1900 waves were breaking on
the sea wall and foundations of buildings nearest the shoreline. In subsequent
years, infrastructure and roads suffered failure, collapsing into the sea.
Destruction culminated on 26 January 1917 when a major storm hit the
region. With high tide combined with gale-force winds, waves broke over almost
all the buildings in the village. The end result was that, because of human
interference, an industry based on fishing was decimated, 54 families were
rendered homeless and an entire community was abandoned.
 |
Map of Hallsands area from 1904 report
by H. R. worth
The result of such catastrophic events as Katrina and Hallsands is the
same, of course: widespread suffering of people, more so that would normally
have been the case in past decades or centuries.
The lesson is, “Don’t mess with Mother Nature!”
References
Jodal, Morten.
(2019). New Orleans and hurricane Katrina – the real story. Watts Up With That
blog post, 2 August 2019. https://wattsupwiththat.com/2019/08/02/new-orleans-and-hurricane-katrina-the-correct-story/
Shepheard,
Wayne. (2018). Surviving
Mother Nature’s Tests: The
effects climate change and other natural phenomena have had on the lives of our
ancestors (with examples from the British Isles). St. Agnes, South
Australia: Unlock the Past.
Worth,
R. Handsford. (1904). Hallsands and Start
Bay. Report and Transaction of the Devonshire Association for the
Advancement of Science, Literature and Art, 36, pp. 302-346.
