For the first two action-packed days following our return from the R&R of Spring Break, the focus of our in-class discussion in APES was Water Resource Issues. In nearly ninety minutes of never-dull, thoroughly engaging lecture and discussion, we covered, in brief, what our freshwater resources are, why our society experiences freshwater shortages, what solutions we put in place to combat these shortages, the environmental impact of how we combat these shortages, and how we can conserve our water resources.
First, we went over some basic facts about our planet’s freshwater supply. Though there’s a tremendous amount of water on Earth, only about 3% of Earth’s water is freshwater. And of this freshwater, roughly 3/4 of it is frozen (see below), and roughly 1/4 of it is below ground. In fact, only about 1% of Earth’s freshwater exists as surface freshwater.
A glacier, one example of frozen freshwater (Source: http://www.iceagenow.com/HubbardGlacier.jpg)
This background information led us to our next two topics: why our society experiences freshwater shortages and what solutions we put in place to combat these solutions. To know why our society experiences freshwater shortages, one needs only to remember the four D’s: dry climate, drought, desiccation (dry soil), and demand. Each of these conditions has the potential to be responsible for a society’s having an either insufficient or unsustainable supply of water. As for the solutions to these problems, they can
also be remembered by recalling four five D’s. The five solution D’s are dams (see below), diversion, drilling, desalination, and demand reduction. With these “solutions,” we, as a society, are able to combat the freshwater shortages brought on by the other D’s.
The colossal Hoover Dam (Source: http://www.visitingdc.com/images/hoover-dam-directions.jpg)
These “solutions,” however, aren’t entirely perfect. Though each of them combats freshwater shortages, each them–with the exception of demand reduction–comes with adverse environmental impacts. Building dams or water transfer apparati (diversion) involves habitat destruction, which, in turn, leads to a loss of biodiversity. As for drilling for groundwater, it has the potential to cause a host of environmental issues, including water table lowering, depletion from overdrafting, subsidence (which can lead to sinkholes), saltwater intrusion, and chemical contamination (a graph detailing such contamination of groundwater can be seen below).
Groundwater Contamination (Source: http://groundwater.org/gi/images/contamination_diagram.jpg)
Finally, we discussed strategies for reducing water demand/conserving freshwater resources. Since so much of our freshwater–70 % of it on a global scale–is used for agriculture, one strategy that figured prominently in our discussion was efficient irrigation. With new technologies like drip irrigation and LEPA sprinklers (see below) farmers can now irrigate their fields with greater than 90% efficiency. We also discussed water-saving technologies like better-designed shower heads, toilets, and other household appliances. Furthermore, we examined the benefits of improved water management techniques like tiered water prices and the use of gray water by municipalities.
A LEPA Sprinkler (Source: http://www.senninger.com/wordpress/wp-content/uploads/2010/04/LEPA-QuadSpray-Circle-sm.jpg)
In short, Monday and Tuesday were two very scholarly, very productive days in APES. For all of those of you who were in class, I hope you had as much fun as I did. Hopefully, you’ll find this summary of the day’s activities to be helpful. Peace.