Author
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Zhang, Xunchang |
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Nearing, Mark |
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Submitted to: Catena
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/1/2004 Publication Date: 3/1/2005 Citation: Zhang, X.J., Nearing, M.A. 2005. Impact of climate change on soil erosion, runoff, and wheat productivity in central Oklahoma. Catena. 61:185-195. Interpretive Summary: Knowledge of the potential impacts of climate changes on soil erosion is critical to natural resources conservation planning. The objective of this work was to evaluate the potential impacts of possible climate changes on soil erosion, surface runoff, and wheat productivity in central Oklahoma. Monthly projections for the period of 2070-2099 from the Hadley Centre's general circulation model (HadCM3) under the scenarios representing high, low, and intermediate emissions were used. The Water Erosion Prediction Project (WEPP) model was run for each scenario under three tillage systems (conventional tillage, conservation tillage, and no-till). The projected mean annual precipitation during 2070-99 at El Reno, OK decreased by 14, 7, and 6% for high, low, and intermediate; and mean annual temperature increased by 5.7, 4.0, and 4.7 degree Celsius, respectively. Predicted average annual soil loss in systems excluding no-till during 2070-99, compared with the present climates, increased by 18-30% for high, remained similar for low, and increased by 67-82% for intermediate. Predicted soil loss in no-till did not increase in the three scenarios. Predicted mean annual runoff in the three tillage systems increased by 16 to 25% for high, remained similar for low, and increased by 6 to 19% for intermediate. Small changes in wheat yield, ranging from a 5% decrease in low to a 5% increase in intermediate, were predicted. The overall results indicate that conservation tillage and no-till systems should be effective in controlling soil erosion under projected climate changes in central Oklahoma. This work provided useful information to soil and natural resources conservationists for adjusting conservation practices in response to possible climate changes. Technical Abstract: The potential for global climate changes to increase risk of soil erosion is clear, but quantitative analysis of this risk is limited. The objective of this study was to evaluate the potential impacts of three climate change scenarios on soil erosion, surface runoff, and wheat productivity in central Oklahoma. Monthly projections for the period of 2070-2099 from the Hadley Centre's general circulation model (HadCM3) under three greenhouse gas emissions scenarios (A2a, B2a, and GGa1; representing high, low, and intermediate emissions, respectively) were downloaded and downscaled to daily series using, a stochastic weather generator (CLIGEN). The Water Erosion Prediction Project (WEPP) model was run for each scenario under three tillage systems (conventional tillage, conservation tillage, and no-till). Average annual precipitation during 2070-99 at El Reno, OK decreased by 14, 7, and 6% for A2a, B2a, and GGa1; and mean annual temperature increased by 5.7, 4.0, and 4.7 degree Celsius, respectively. Predicted average annual soil loss in systems excluding no-till, compared with the present climates, increased by 18-30% for A2a, remained similar for B2a, and increased by 67-82% for GGa1. Predicted soil loss in no-till did not increase in the three scenarios. Predicted mean annual runoff in three tillage systems increased by 16 to 25% for A2a, remained similar for B2a, and increased by 6 to 19% for GGa1. The greater increases in soil loss and runoff under GGa1 were caused by greater variability in monthly precipitation. Small changes in wheat yield, ranginging from a 5% decrease in B2a to a 5% increase in GGa1, resulted from the offsetting effects of the rising temperature and carbon dioxide concentration. The results indicate that conservation tillage and no-till systems should be effective in combating soil erosion under the projected climates in central Oklahoma. |
