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<br />Changnon, S. A., R. T. Shealy, and R. W. Scott, 1991: Precipitation changes in fall, winter, and spring caused
<br />by St. Louis. Journal of Applied Meteorology, 30:126-134.
<br />
<br />Analysis of precipitation events in the St. Louis area, based on pre-event low-level wind flow, was
<br />pursued to ascertain the presence of urban effects on fall, winter, and spring precipitation. Data from a
<br />circular, dense raingauge network were used to defme quadrant (NW, NE, SE, SW) average
<br />precipitation. Winds before each event (443 events in 1971-75) were used to define the urban plume
<br />and identify which quadrant was "downwind" of the city. Results for fall revealed a 17% increase in
<br />precipitation downwind of St Louis and a 13% increase in events with their peak rainfall occurring
<br />downwind; both outcomes were statistically significant at the 1 % level. The downwind enhancement
<br />was greatest when pre-event winds were from the SE, and when average precipitation in the quadrant
<br />with the maximum value was either light (<5.1 mm) or quite heavy (>17.9 mm). The fall results agree
<br />well with earlier findings for summer rainfall that revealed a 25% increase due to enhancement in
<br />isolated airmass showers and during heavier, well-organized convective systems. Winter precipitation
<br />indicated little precipitation change downwind of St Louis. However, when SW pre-event winds
<br />existed (a flow often associated with convection), there was a statistically significant downwind increase
<br />in winter precipitation; but when pre-event winds were from SE or NW (flows frequently associated
<br />with stratifonn precipitation), downwind decreases occurred. The number of spring precipitation
<br />conditions that maximized downwind of St Louis was significantly greater than expected by chance
<br />particularly in light (<5.1 mm) events, but the total spring rainfall downwind increased only 4%. There
<br />was no suggestion of decreased precipitation in spring or fall. The urban influences to enhance
<br />precipitation appeared to be related to precipitation conditions with convective processes, and urban
<br />influences in more stratifonn precipitation situations were negligible.
<br />
<br />Changnon, S. A., 1990: Great Lakes waters: Too little or too much? In: Supplying Water and Saving the
<br />Environmentfor Six Billion People, EE Division/ASCE. American Society of Civil Engineers,
<br />New York, 41-49.
<br />
<br />Water supplies in the Great Lakes Basin, the world's largest fresh water supply, are more than adequate
<br />to meet current and projected needs. However, supplies could become a problem if the climate changes
<br />or water quality seriously degrades. The principal water quantity problem of the Great Lakes is the
<br />fluctuations in lake levels, providing too much or too little water. Society around the lakes has become
<br />extremely sensitive to these aberrations around average levels, one of the major lessons learned in recert
<br />years. Recent basin-wide problems like water quality, fluctuating levels, and acid rain reveal a need for
<br />new policies and institutional approaches to the management of the Great Lakes. Lake-level forecasts
<br />are not sufficiently accurate or long-term to allow for wise management decisions. Continuing
<br />degradation of water quality or a major climatic change during the next few decades could seriously
<br />reduce net basin supplies and create serious water supply problems.
<br />
<br />Changnon, S. A., 1990: Impacts and some lessons taught by the 1988 drought Planning for water shortages.
<br />Proceedings, Irrigation and Drainage Division, 1989 Meeting of the ASCE, St. Louis, MO,
<br />October 15-16, 1990. American Society of Civil Engineers, New York, 263-270.
<br />
<br />No abstract
<br />
<br />Changnon, S. A., R. R. Czys, S. E. Hollinger, F. A. Huff, M. S. Petersen, R. W. Scott, and N. E. Westcott,
<br />1990: Analysis and planning for Precipitation Augmentation for Crops Experiment Final Report,
<br />NOAA Cooperative Agreement NA89RAH0986. Illinois State Water Survey, Champaign, IL, 110 pp.
<br />(available from National Technical Information Service, 5285 Port Royal Rd., Springfield, V A 22161).
<br />
<br />No abstract.
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