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<br />3. Scientific analysis and evaluation. - A number of physical studies haye been conducted <br />as part of Programme Al Ghait. Some of these have concentrated on understanding seeding <br />opportunities in ~[orocco. Physical studies with measurements taken inside precipitating <br />storms of the Hilrh A~las indicate that conditions which are favorable to seeding occur <br />- ~ <br />frequently and extend oyer large areas. Analyses of supercooled clouds obsen-ed in 1985 by <br />the Cniversity of ~orth Dakota cloud physics aircraft indicated that supercooled liquid water <br />occurred often. with concentrations ran!!in!! from 0.2 to 0.7 21m3 in the absence of natural ice <br />- __ _I <br />at tempe:-atures of -5 to -12 =c. These conditions are considered fayorable for cloud seeding <br />and. to some degree. m0re so than those found in the Sierra ~eYada of California. where ice <br />occurred more frequently. Cloud physics data collected after 1987 with the instrumented King <br />Air haye cor.firmed the earlier estimates of frequency and areal extent of regions of <br />opportunity for seeding. Radar. satellite. and numerical modeling studies are being conducted <br />to better define tr.e frequency of fayorable opportunities and the areal extent of seedable <br />conditions detected in the cloud physics analyses, <br /> <br />Statistical analysis of historical target and control streamt10w data indicated that at least <br />6 years with cloud treatment are necessary to proyide a 50-percent probability of detecting a <br />lO-percent increase in streamtlo\\-. Howeyer. only 1.5 years of seeded results are available for <br />evaluation. as a result of the elimination for analysis purposes of the first 2,5 seasons of <br />seecing riue to the low initial cloud seeding efficiency (less than 15 percent) and unavailability <br />of control streamt10w for the 1988-89 season, With only a 1.5-year treated sample available. <br />which represents about one-fourth of the required data. it was decided not to analyze any <br />seeded results because they could be misleading, Even when the 1988-89 results become <br />available, at least -t more years of efficient cloud seeding are required for the statistical <br />evaluation. <br /> <br />.-. Increased awareness of weather modification as a water resources management option. - <br />Hydrologic and economic studies were designed to assess the economic feasibility of cloud <br />seeding programs in ~Iorocco. These studies were conducted by ~Ioroccan water resources <br />agencies working \....ith Reclamation hydrologic and economic experts and D~I~ scientists to <br />de\'elop objectiye methods for the evaluation of hydrologic impacts on the ~loroccan economy. <br />Through close cooperation and collaboration. the water resources management institutions in <br />~-Iorocco eyentually became aware of Programme AI Ghait and its potential for impacts on <br />their operations. American experts presented special seminars and workshops to the <br />Moroccan water resources experts and Programme i~J Ghait staff. Such meetings increased <br />interest in weather modification as an additional tool in water resources management. <br />Preliminary results of conducted studies pro\'ided additional credence to its feasibility for that <br />purpose. <br /> <br />Hydrologic studies produced some interesting results. !'umerical river simulation models <br />that included the hydroelectric generating characteristics of powerplants and irrigation and <br />domestic water diversions within the Oued Oum Er Rbia basin were used to simulate the <br />effects of additional water from Kovember to July of the period 19-t0 to 1985. The additional <br />water represented the effects of 5- and lO-percent increases in monthly streamt10w due to <br />seeding. The Administration de Hydraulique (Hydraulique) ri\'er model that was employed <br />ga\'e results indicating significant increases of 46 and 89 gigawatt hours (GWh) above the <br />normal annual average hydroelectric power generation for the 5-and lO-percent streamt10w <br />increases, respectively. The ~ational Electrical Organization (O~E) rh'er model produced <br /> <br />viii <br />