Drought is defined as a period of time when a region experiences deficiency in its water supply. This happens in every region from time to time, and is actually a normal climate function. However, extended periods of drought point to an imbalance in the eco-system which can have disastrous long-term effects including desertification, loss off wildlife, food shortages, and loss of human life. So, what causes droughts?
The amount of precipitation an area receives is equal to the amount of water vapor in its atmosphere. Through the process of transpiration, trees and other plants release water vapor from their leaves. So basically, trees help to make rain. They also store large amounts of water in their roots systems; releasing it over time. This being the case, it is easy to see how deforestation contributes to drought.
In the past 40 years, 20% of the Amazonian Rainforest has been cut down. Researchers from Duke University, Durham, N.C. have found that this has caused a significant reduction in rainfall as far away as Mexico and Texas.
This year alone (2011)–due to drought–Texas has experienced over 8,000 wildfires which have scorched more than 1.5 million acres of its landscape. Hundreds of people have lost their homes, their belongings, and some have even lost their lives. So what measures can be taken to prevent such disasters from occurring in the future?
Keyline Design is a permaculture technique which offers a simple, low-cost method for harvesting water and preventing drought. It involves contour plowing and the implementation of ridges, valleys, earth damns, strip forests, and special cultivation methods which infiltrate water into the soil and keep it on the land as long as possible.
This technique was developed in Australia in the 1950’s by P.A. Yeoman. It is tried and true, and has the potential to reverse the desertification process which is occurring throughout the world. If you would like to learn more about Keyline Design, visit: http://www.keyline.com.au/