Laserfiche WebLink
<br />003404 <br /> <br />The Weather Modification Advisory Board (1978:125) states that cloud <br />seeding is not designed nor expected to eliminate drought. Sonka (1979:48) <br />also writes that weather modification is not expected to eliminate <br />drought. He expresses the opinion, however, that the "value of even <br />relatively small increments of moisture for agricultural production and <br />water supplies may be substantial during such periods." Yevjevich <br />(1978:168) states that "when weather modification is most needed, the <br />potential of air masses to respond .. is the lowest." He concludes that <br />"it is very important to study the number of storms in dry years and <br />the average yield per storm." <br /> <br />Howell and Grant (1972) present evidence that suggests that seeding <br />opportunity may exist during dry' periods. They emphasize that a seeding <br />program should involve cooperation on legal, economic, legislative ar1d <br />social levels, as well as at the level of water-systems operations. <br /> <br />DROUGHT IN roLORAOO <br /> <br />Drought is a recurrent phenomenon in the western and central United <br />States. Colorado is particularly susceptible to drought because its <br />growing population places increasing demands upon its supplies of water. <br /> <br />In the winter of 1976-77, Colorado experienced its first period of <br />extreme water shortage since the early 1950s. By the end of January 1977 <br />snowfall was at record low levels in many mountain areas. Runoff from <br />melting mountain snows, which under normal conditions provides <br />approximately 70 percent of the state I s water, was minimal. Record lows <br />were recorded at two-thirds of the checkpoints on major Colorado rivers <br />(Gray, 1979:1).. Although rains returned in the summer, reservoir storage <br />levels fell dramatically and soil moisture levels remained low in many <br />areas. It was feared that if the following winter were as dry, Colorado <br />would suffer disastrous consequences. <br /> <br />5 <br />