作 者 ：李志,刘文兆,张勋昌,郑粉莉
期 刊 ：生态学报 2010年 30卷 19期 页码：5306~5315
Keywords:climate change, the Loess Plateau, soil loss, GCMs, WEPP,
摘 要 ：已经确认的极端降水事件增多等气候变化趋势，可能对黄土高原的土壤侵蚀造成重要影响。使用一种简单有效的转换函数法和天气发生器CLIGEN (CLImate GENerator)，解集4种GCMs (General Circulation Models)在3种排放情景下的时空尺度建立气候变化情景，结合WEPP (Water Erosion Prediction Project)模型评估2010-2039年气候变化对黄土高塬沟壑区长武农田土壤侵蚀的潜在影响。结果表明，较1957-2005年，长武2010-2039年的年均降水量可能变化-2.6%-17.4％，年均降水方差是当前的0.984-1.389倍，降水量增多且暴雨次数增加的概率较大；最高和最低温度分别升高0.6-2.6 ℃和0.6-1.7 ℃，方差分别是当前值的0.748-1.155和0.736-1.387倍，方差增大的概率较大。受气候变化影响，2010-2039年径流普遍增长10%-130%，土壤侵蚀变化-5%-195%，侵蚀加剧的可能性极大；但保护性耕作可有效减少径流和侵蚀，是农田生态系统适应未来气候变化的有效措施。
Abstract:The confirmed climate change trends, such as the increase of extreme rainfall events, may have great impacts on soil erosion through altering driving forces of soil erosion and influencing the growth condition of plants. The Loess Plateau of China is one of the most erodible areas in the world, the potential response of soil erosion to future climate change need to be assessed specifically for this information is very useful for decision-making. The objective of this study was to assess the site-specific impacts of climate change during 2010-2039 on soil erosion in Changwu County in the tableland-gully region of the Loess Plateau. A new simple transfer function method and weather generator CLIGEN (CLImate GENerator) were used to downscale the spatial-temporal scales of four General Circulation Models (CCSR/NIES, CGCM2, CSIRO-Mk2 and HadCM3) under three emission scenarios (A2, B2 and GGa). The WEPP (Water and Erosion Prediction Project) model was employed to simulate the responses of agro-ecosystems. Two tillage systems, i.e. conventional tillage and conservation tillage, were used to discuss the adaptive measures to climate change. Results showed that climate would change significantly during 2010-2039 compared with 1957-2005. The annual mean precipitation would change -2.6% to 17.4%, the variance of annual precipitation would be 0.984 to 1.389 times of the present, and it is very likely that the precipitation amount and storm frequency would increase. Annual mean maximum and minimum temperature would increase 0.6 to 2.6 ℃ and 0.6 to 1.7 ℃, and the variance ratios of 2001-2039 to 1957-2005 for maximum and minimum temperature were 0.748-1.155 and 0.736-1.387, respectively. The probability of variance increase was great. The predicted climate changes would cause great changes in runoff and soil loss in slope field of the Loess Plateau. Under conventional tillage, WEPP predicted a change of 10% to 130% for runoff, -5% to 195% for soil loss during 2010-2039. However, WEPP predicted a change of -34.2% to 71% for runoff, -76.5% to -25.8% for soil loss during 2010-2039 under conservation tillage. The changed magnitudes of runoff and soil loss under conservation tillage were far less than those under conventional tillage. The results indicated that adoption of conservation tillage had great potential to reduce the adverse effects of climate changes on runoff and soil loss and thus protect agro-ecosystems. The new spatial downscaling method, emphasizing on matching the probability distributions, can be widely used in climate scenarios development based on GCMs as it relaxed the demands upon the existence of strong correlationships between station-measured and GCM-projected monthly precipitation and temperature.
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