Case Study: Land subsistence in the American Southwest

Using the links provided as well as your own research, answer the following questions in full sentences. 

a) Describe the causes of land subsistence in the American Southwest and explain why it is getting worse over the past few years. (4 marks)

The common causes of land subsidence from human activity are pumping water, oil, and gas from underground reservoirs, collapse of underground mines and drainage of organic soils.

Over drafting of aquifers is the bigger cause of subsidence in the southwestern United States. As ground water pumping continues the land subsidence will also increase. In many areas ground water is pumped from open spaces that are between sand and gravel. If an aquifer has clay the more water that is pumped from that area the lower the clay will fall. The lowering of land surface elevation can be permanent. 


b) Describe the potential impacts of land subsistence. (4 marks) 

Land subsidizing can cause damages to bridges, roads and railroads. It can cause damages to buildings and forces fine grain materials to enter the aquifer systems. The damage it also costs is changing the elevation state of streams canals and drains. 

c) Outline ways to prevent further land subsistence. (This will require you to think on your own) (4 marks)

When planting trees people should be carful and select their area for planting properly. After they planted the trees they should manage the well being of them to reduce the risk of subsiding.

Trees are a common cause of subsidence because they absorb waster from the soil causing clay particles to dry and shrink.

Having proper maintance of gutters and drains prevent leaks and ensure water is safely diverted away from your house and land. 
Educating town’s people about the effects land subsidence has can be an eye opener for the public. It will make them want to learn how to help lower down and prevent land subsidence. They will be more open to trying new ideas to help save their community.

                                                

-