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CHAPTER 9. DROUGHT <br />9-6 <br />9.2.4 Severity <br />The severity of a drought depends on the degree of moisture deficiency, the duration, and the size and <br />location of the affected area. The longer the duration of the drought and the larger the area impacted, the <br />more severe the potential impacts. Droughts are not usually associated with direct impacts on people or <br />property, but they can have significant impacts on agriculture, which can impact people indirectly. When <br />measuring the severity of droughts, analysts typically look at economic impacts on a planning area. <br />9.2.5 Warning Time <br />Droughts are climatic patterns that occur over long periods of time. Only generalized warning can take <br />place due to the numerous variables that scientists have not pieced together well enough to make accurate <br />and precise predictions. <br />9.3. SECONDARY HAZARDS <br />The secondary hazard most commonly associated with drought is wildfire. A prolonged lack of precipitation <br />dries out vegetation, which becomes increasingly susceptible to ignition as the duration of the drought <br />extends. <br />9.4. CLIMATE CHANGE IMPACTS <br />Research conducted by the Climate Impacts Group at the University of Washington indicates that the <br />temperature of Eastern Washington is increasing. As temperatures increase there will be less water stored <br />as ice and snow. This reduction may not result in a net change in annual precipitation, but it will result in <br />lower late spring and summer river flows. Accordingly there will be increased competition between power, <br />sport fishing and environmentalists, and farmers dependent on irritation. <br />Global water resources are already experiencing the following stresses without climate change: <br />• Growing populations <br />• Increased competition for available water <br />• Poor water quality <br />• Environmental claims <br />• Uncertain reserved water rights <br />• Groundwater overdraft <br />• Aging urban water infrastructure <br />With a warmer climate, droughts could become more frequent, more severe, and longer-lasting. From 1987 <br />to 1989, losses from drought in the U.S. totaled $39 billion (OTA, 1993). More frequent extreme events <br />such as droughts could end up being more cause for concern than the long-term change in temperature and <br />precipitation averages. <br />Dalton et. al. found that reduced water supply combined with increased water demands in the summer could <br />lead to water shortages, reducing the proportion of irrigable cropland and the value of agricultural <br />production. A case study in the Yakima River Basin projects the more frequent occurrence of conditions in <br />which senior water right holders experience shortage. Water shortages could impact the proportion of <br />cropland able to be irrigated during the growing season and lead to substantially reduced value of <br />agricultural production; however, certain producer strategies may mitigate the shortage. Some evidence