Grade 8: Settlements and the Environment

The Environmental Factors involved in Settlements

climate- the average weather of an area over a long period of time

physical process- any naturally occurring change on or in Earth, such as an Earthquake

climate change- changes in long-term weather patterns caused by natural events and human activity

Severe drought occurred in the Amazon basin in the year 2005.  This happened again 5 years later.  The loss of tree canopy and trees led to trees not growing back in some areas.  The effects include the following: stranded boats, failed crops, extended pipelines to irrigate crops, and a migration away from farmlands.  These factors affect settlements.

volcanic activity- the Ring of Fire outlines where the Pacific plate meets with plates from Asia to Australia and from North to South America

Why do people settle near volcanoes? There are mineral deposits such as gold, silver, and copper in these areas. Therefore, mining communities exist.  The volcanic ash too is ideal for farming.  Mount Pinatubo in the Philippines has ideal soil for growing crops such as papaya.  Most importantly, these areas are known for geothermal energy.  Countries, such as Iceland, can harness this energy.  Above all, active volcanic areas become tourist destinations such Ecuador.

Which is more catastrophic, an earthquake or a tsunami?

In 2011, a tsunami hit northeastern Japan and cased the evacuation of 1/3 of a million people and the deaths of nearly 20 000 people.  An earthquake in Haiti the year before led to the deaths of approximately 300 000 people.  The seismic waves released from the epicenter of an earthquake, where two plates meet and release great levels of energy.  The energy is transmitted through the water and the wave is amplified once it hits the continental shelf and spills deep into the interior of the mainland.  Earthquakes send shock waves that lift, shake or liquefy soil.  After shocks, falling debris, and survival in a modern society that has seized to exist usually results in a tremendous loss of life.  For both, the level of population density determines the number of causalities.  Nations that can afford to rebuild attempt to build more flexible structures while other nations rely on assistance.  In many cases, segments of the population are permanently displaced.

desertification- the unplanned process of turning arable land into a desert because of factors such as reduced rainfall and poorly-thought-out agricultural policies; lands become deserts

drylands- are areas with a long growing season with very light precipitation levels, such as semi-desert scrub and grasslands

Nearly 2/5^th of the Earth surface is too dry to grow substantial crops

China has attempted to build a ‘Great Green Wall’ by planting shrubs, grasses and trees along the Taklmakan and Gobi deserts to attempt to curtail desertification.  Dust storms or seasons when dust storms are common reduce visibility and damage equipment and buildings. Mineral deposits or fine nutrients can be carried by winds from the Sahara Desert in North Africa to the rainforests of Central America.  This is perhaps the only benefit.

Landslides can be causes by heavy rains, melting snow, and earthquakes.  Deforestation or logging too many trees can kill roots and leave the barren mountainside vulnerable to erosion and future landslides.  Mining operations too can trigger landslides as well as earthquakes.  Ideally, settlements should be built far from possible landslides and planting trees, shrubs and grasses can help reduce soil erosion and even mudslides.  In 2014, over 150 deaths were attributed to a landslide in Nepal.

Warming Temperatures

There are pros and cons to the Earth’s temperature rising:

There are some pros: there will likely be extended growing seasons in areas that are 30 to 60 degrees’ latitude; new settlements may occur farther north in Canada, Europe and Russia; transportation may increase once ice melts; and new employment opportunities may develop.

There are definitely cons: invasive species may migrate; desertification will increase; jobs may disappear if new job opportunities move elsewhere; coastal regions become submerged underwater; animals will have difficulty adapting and the number of species will continue to decrease if the change is not gradual. Even industries, such as skiing, may have to diversify to other recreational activities or simply go out-of-business.

Changing Precipitation Patterns

This too is double edged sword.  Less precipitation leads to drought and crop devastation.  More precipitation may help other regions, but too much may result in floods, increased soil erosion, and crop failure.  Too much rain increases the water content of fruits, such as grapes.  Therefore, wine regions could be affected in terms of quality of wines and job opportunities may diminish.

Extreme Storms

After Hurricane Katrina in 2005, New Orleans was destroyed in many parts. Its flood plain is located beneath sea level; many homes had to rebuilt once the levees broke.  The strongest hurricane, Typhoon Haiyan hit the Philippines in 2013 with winds over 300 km/h.  Hurricane prevention such as increasing the size of mangrove forests to act as buffer zones is one option. Rather than claiming more land for  settlements, homes must be relocated or built on stilts to prevent future loss of properties.  Early warning systems must be improved.  Extreme storms may simply make certain coastal region uninhabitable or sustainable in the future.

Rising Sea Levels

Global sea levels have continued to rise since 1994 at over 3 mm each year.  Ocean ice and glaciers continue to melt, including the ice cap in Antarctica.  This leads to increased flooding of port lands, business districts and residential areas.  Nearly 1 billion people live along coastlines at that are merely 10 meters above sea level.  Islands in the South Pacific will eventually disappear if rising levels continue. 

Land reclamation efforts create new land in coastal areas.  Nearly ¼ of Hong Kong’s population lives on reclaimed land.  An airport off the coast, which is continually sinking as it settles since the land was not compacted, was built by levelling the tops of a mountain range.  These areas, especially the Netherlands, are at high risk.  Property will become worthless and massive tides of population will need to be re-located.  These people will become the environmental refugees of the 21^st century.

Coastal erosion occurs when there is a gradual or rapid wearing away of the coastline from wind, water and time.  Engineers have created sea walls to slow down the process of erosion but the cost is quite great. 

Coastal flooding often deposit pollutants, such as salt, which make the soil infertile.  Flooding from rivers deposit natural nutrients found in silt along the river banks, but the levees prevent this natural process in order to protect settlements.  The soil is not replenished and artificial fertilizers are used to add more nitrogen to the soil.  The soil depletes in its depth and eventually it becomes infertile.  Coastal flooding may encourage the planting of salt-resistant strains of rice.  Fields may be flooded again to replenish sediments.  Some farmers have begun to farm catfish, shrimp, and crabs.   In efforts to adapt, areas such have Bangladesh, have introduced floating homes, hospitals, and libraries.  These efforts are ingenious but temporary adaptations to a changing environment.