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Water Resources of North Dakota |
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On the basis of three sediment-based chronologies, Fritz and others (1994) concluded that during the "Little Ice Age" (from about 1500 to 1850), the Devils Lake Basin generally had less effective moisture (precipitation minus evaporation) and warmer temperatures than at present. In this comment, we argue that historic data indicate runoff and effective moisture were greater than at present. The largest 19th century floods (1826, 1852, and 1861) were significantly greater than the 20th century floods, and flooding in the Red River of the North Basin occurred more frequently from 1800 to 1870 than since 1870. Between 1776 and 1870, the ratio of wet to dry years was about 2 to 1. Mean temperatures in all seasons were cooler for 1850-70 than for 1931-60. Lake levels of Devils Lake during the first half of the 19th century were higher than they are today, and, even when Devils Lake was almost dry, the salinity was less than the " diatom-inferred" salinity values that Fritz and others (1994) estimated for 1800 through about 1850. We acknowledge the importance of high-resolution paleoclimatic records, but interpretation of these records must be consistent with historic information.
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