POTENTIAL CLIMATIC IMPACTS OF VEGETATION CHANGE - A REGIONAL MODELINGSTUDY

The human species has been modifying the landscape long before the dev elopment of modern agrarian techniques. Much of the land area of the c onterminous United States is currently used for agricultural productio n. In certain regions this change in vegetative cover from its natural state may have led to local climatic change. A regional climate versi on of the Colorado State University Regional Atmospheric Modeling Syst em was used to assess the impact of a natural versus current vegetatio n distribution on the weather and climate of July 1989. The results in dicate that coherent regions of substantial changes, of both positive and negative sign, in screen height temperature, humidity, wind speed, and precipitation are a possible consequence of land use change throu ghout the United States. The simulated changes in the screen height qu antities were closely related to changes in the vegetation parameters of albedo, roughness length, leaf area index, and fractional coverage.