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The Largest Act of Environmental Warfare in History. Steven I. Dutch Natural and Applied Sciences University of Wisconsin-Green Bay Green Bay, WI 54311-7001. Something New?. Topography of China. Loess in China. Huang He Diversions 400 BC - Present. Scale of Huang He Diversions. 1890.
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The Largest Act of Environmental Warfare in History Steven I. Dutch Natural and Applied Sciences University of Wisconsin-Green Bay Green Bay, WI 54311-7001
Military Effects of the Breach • Minor losses of Japanese troops and materiel • Few troops caught on the wrong side escaped • Chinese gain time for withdrawal and relocation of capital • Flood also protects Japanese flank • Little additional fighting in Central China • Japanese capture of Wuhan (Hankow) delayed by only a couple of months • No central authority in much of Central China • Communists gain support
Flood Fatality Estimation • Graham, W.J., 1999, DSO-99-06, A Procedure for Estimating Loss of Life Caused by Dam Failure • Assuming poor understanding of risk downstream • Fatality rate in parentheses is recommended prediction value
Casualty Model Applied to 1938 • Population of Henan, Anhui and Jiangsu flooded counties = 13.2 million (Lary, 2001) • Medium severity, no warning (15%) 2 million fatalities • Medium severity, > 1 hour warning (3%) 400,000 fatalities • 844,000 fatalities = 6.4%
Lessons From Banqiao, 1975 • > 1 m rain in 24 hours from typhoon • 1000 year dam but 2000 year floods • After nine days, a million people were still stranded • 26,000 died in the flooding, 145,000 from disease and famine • More violent event than 1938, but happened in peacetime with intact infrastructure
Moral Large at-risk population + Flat terrain + Lack of Mobility or Communications = Huge Death Toll • Bangladesh 1971: 300,000 • Bangladesh 1991: 140,000 • Myanmar 2008: 200,000
What We’d Still Like to Know • Survivor Accounts: Need to Act Quickly • Exact chronology and extent of flooding • Effects of normal Huang He floods later • Specific Causes of Mortality • Drowning by flood? • Exposure of stranded victims? • Dehydration? • Water-borne disease? • Loss of Crops?