Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/3/1996
Publication Date: N/A
Technical Abstract: The effect of increased radioactive trace gasses and associated climatic changes on hydrology, crop yield and erosion need to be investigated on watersheds with various vegetation type, climate, management and soil conditions for future watershed planning and water resources management. A modeling approach is being utilized to investigate the impact of increasing gatmospheric CO**2 and temperature on water balance, plant growth, and soil erosion of watersheds in the U.S. and Austria. The evapotranspiration (ET) and plant growth of the USDA-Water Erosion Prediction Project (WEPP) computer model was modified and improved to reflect the effect of the atmoshperic CO**2 changes on plant transpiration and plant growth. The new model, WEPP-CO**2 was evaluated using hydrometeorlogical data from five watersheds in the U.S. and two watersheds in Austria. The scenario used was that the average daily temperature increased 3 C over the present temperature and CO**2 will increase by 160ppm over the present 330ppm by year 2046. The results indicated that the water balance, crop yield, and soil erosion response to the increase of temperature and CO**2 depends on plant water use efficiency, type of soil land present climate situation. In general, and under the given scenario and sites tested, the increase of CO**2 coupled by temperature increase resulted in increased crop yield, leaf area index, ET, and reduced storm runoff and soil erosion.