CHAPTER 11 PROACTIVE OR RISK MANAGEMENT CASES 11.1 DROUGHT IN THE U.S. GREAT PLAINS

There is good evidence that droughts have been a recurrent feature of the climate of the Great Plains for as far back. at least. as man has inhabited the region. Much of the evidence is based on chronologies of tree rings. Specimens of red cedar and western yellow pine found in western Nebraska were studied by Weakly (1965). In the time span extending back to 1220 A.D, he found many short periods of drought. Droughts frequently lasted for more than five years. and one such period lasted 38 years. Will (1946) found a similar pattern in central North Dakota extending back to 1539 A.D. More recently. Stockton. Mitchell and Meko (1981) have prepared time series of drought indices based on tree rings since 1700 A.D. for several Great Plains sites