From WLockeretz@infonet.tufts.eduFri May 24 16:42:22 1996 Date: Fri, 24 May 96 14:12:12 EDT From: WLockeretz@infonet.tufts.edu To: SANET-MG@amani.ces.ncsu.edu Subject: Of droughts and dust bowls Julie Elfving's recent posting on the current drought in the Plains is right on the mark in differntiating drought, a natural phenomenon, from dust storms, a (largely) man-made phenomenon. There have been many serious droughts on the Plains before; in fact, in every odd-numbered decade has had one at least since settlement by whites in the 1870s, leading to a "feast or famine" pattern of settlement (and de-settlement). The seriousness of the resulting soil erosion depends greatly on how the land has been treated. The "dirty thirties" reflected severe abuse of the land, arising from the great plow-up prompted by World War I, overspecialization in cash crops, mainly wheat, because of extreme economic pressures during the agricultural depression of the 1920s and the Great Depression of the 1930s, indiscriminate tilling of highly erodible grasslands when gasoline tractors became available (1920s), and other human factors. Around the time of the severe 1970s drought (and its attendant soil erosion, which was bad but not as bad as in the 1930s), I ended an article on the subject this way: "That there will be another drought we can predict quite confidently, since drought is a physical phenomenon entirely outside our control. But how much damage it will do is very much within our control and therefore much harder to predict" ("The Lessons of the Dust Bowl," American Scientist 66(5):560-569 [1978]). Unfortunately, it seems we are about to learn (once more). William Lockeretz Tufts University