Drought mitigation strategies have a great advantage in comparison to many other disaster minimizing strategies in that severe droughts develop over long periods of time. Because of this slow onset the effects of drought can be lessened through mitigation and preparedness.
In areas where yearly rainfall and the resulting accumulated snow pack provide water for local use, and especially in those areas where rainfall fluctuates widely, it is vital to prepare in case there are dry years. If the area is also agricultural and/or supports large herds of livestock it is even more critical to prepare for periods of drought.
While most citizens may sigh as they watch their lawns turn brown or see the level of water in their pool drop from evaporation during drought years, the highest danger is from crop loss and the loss of livestock.
Most drought mitigation strategies depend on preparedness as a first line of defense. The ability to use climate studies to predict the possibility of a drought relies on data from many sources. Snow packs are measured, as is the amount of stored water. Data is collected from these ground based sources as well as satellite observations to form numerical models to predict whether or not drought conditions are developing.
Local use is monitored to determine how much impact drought would have on this use. Land use, determining the effects of short and long term drought, population density, agricultural yields, public health are some of the factors assessed.
Drought mitigation involves changing practices that can worsen the effect of drought as well as using water that is available most efficiently. The main areas for attention are conservation of the soil and water and managing herds.
It is important to carefully manage livestock during times of drought. Not only do these animals require water directly, their food sources may be affected as well. Herd reduction can be effective, either selling part of the herd or moving some to fields that are less affected. Calves can be weaned earlier than usual giving a vulnerable cow a better chance in dry conditions. Herds can be divided into classes so that animals with similar needs can be shifted to meet these needs. Pregnancy testing allows the farmer to target these animals for special treatment for their continued health.
In addition, these animals must be monitored for parasites more strenuously and much more attention must be paid to water supplies to be sure they are not contaminated. Drought stressed animals are more prone to illness and death from these threats and water supplies are more likely to excess saltiness as well as excesses of other compounds.
Salt and other supplements can cause problems in times of drought. Sufficient water must be given to prevent this. Forage and cut hay may have higher levels of certain elements and must be monitored so livestock does not suffer and more care must be taken to prevent the consumption of toxic plants in forage poor fields.
Agriculture must also be addressed, especially soil and water conservation. Practices designed to protect the health of the fields and the crops include such things as crop rotation and terracing, changing tillage practices to retain moisture and prevent erosion, constructing windbreaks to prevent evaporation and reclaiming salt-affected soil.
While different methods may ultimately be used depending on the exact slope of the land and soil type as well as the amount and intensity of rainfall all of these methods are designed to conserve water, prevent erosion and promote healthy plants that are more likely to resist pests and disease.
In addition to these strategies it is critical to plan water use by collecting rainwater and utilizing natural run-off to water plants further down slope. Evaporation can also be minimized, directing water to the plants and not into spreading pools prone to evaporative loss.
A combination of these practices, monitoring and predicting as well as direct mitigation can greatly reduce the devastating effects of long-term drought. These practices can be tailored more specifically depending on local conditions but with care, the people, animals and crops in these areas can survive and even thrive.
http://threeissues.sdsu.edu/three_issues_droughtfacts04.html
http://kyclim.wku.edu/BRADD/drought/mitigation.html
http://cwcb.state.co.us/Conservation/DroughtPlanning/DroughtMitigationPlanning/
