Potential of Precipitation Modification in Moderate to Severe Droughts

Abstract

Assuming that successful precipitation modification could be achieved under atmospheric conditions favorable for the development of natural precipitation, a three-phase study was made to acquire information on the potential for alleviation of moderate to severe droughts in Illinois. The first phase involved time-space analyses of monthly precipitation characteristics in previous major droughts of 12- to 24-month duration. In the second phase, detailed analyses were made of various storm properties during the 1953?54 drought, one of the worst on record in Illinois. The third phase involved use of a one-dimensional cloud model to investigate cloud seeding potential in the 1953?54 drought. Overall, results indicated that atmospheric conditions are favorable for natural precipitation development frequently enough in most droughts that successful cloud seeding operations could contribute occasionally to temporary alleviation of water shortages over portions of an extensive drought region, particularly with respect to agricultural needs.