Drought I

2006 Drought, Union County, New Mexico

© EOP

Today the Los Angeles Times stated "California's drought may be over, but no one's rushing to lift restrictions."  Meanwhile, in a story posted on Huffington Post.com  the former BBC reporter and current Oxfam representative Caroline Gluck wrote "Millions face severe hunger in Niger." Both the southwestern quadrant of the United States and the Sahel region of Africa have been through prolonged dry spells, drought that put severe strains on water supplies. In Southern California that means a little less water for the garden and restrictions on using water to wash cars and sidewalks. In Niger it may well mean mass hunger or even famine. The el Niño conditions of the past autumn and winter brought rainfall to the southwestern region of the US, and for the first time in several years runoff and stream flow have allowed reservoirs to be filled and discussion of lifting restrictions on water use. No such relief is in sight for the Sahel, and while food is available in the markets of towns and cities, subsistence farmers face starvation because they lack the means to purchase food and their fields are unproductive.

Drought is one of the most difficult of natural conditions to predict and even to define. Most climates are characterized by annual dry spells. Mediterranean climates like that of California have dry summers with most of the precipitation falling in the cooler months of autumn and winter. Monsoonal climates, the climate of south Asia, are characterized by a dry cool season and heavy rain during the summer months. Adaptation to annual variation is not too difficult if there is adequate precipitation in the rainy season. In a drought wet season precipitation is inadequate to meet dry season demands. If that absence of precipitation should extend over a number of years, the drought is considered severe.

The most famous drought in the United States was that of the 1930s when "dust bowl" conditions prevailed over a large swath of land extending south from the Dakotas to Texas on the High Plains, the western margins of the Great Plains. The Seattle writer Tim Egan tells the story of the drought in the region where Colorado, Kansas, New Mexico, Oklahoma, and Texas adjoin (including Union County, NM pictured above) in his harrowing The Worst Hard Time. While dust storms and similar conditions have not returned, that same region has been under severe water stress over the past 5 years, a drought that has cut agricultural production and led to some economic dislocations. Only widespread use of ground water from the Oglalla aquifer has allowed field crops to thrive in the region.

In future postings we shall examine both drought and groundwater resources in more detail.