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CENTURY模型在内蒙古草地生态系统的适用性评价 被引量:19
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作者 陈辰 王靖 +2 位作者 潘学标 魏玉蓉 冯利平 《草地学报》 CAS CSCD 北大核心 2012年第6期1011-1019,共9页
基于草地生态系统模型评估气候变化对草地的影响及其适应对于草地的可持续利用和草地荒漠化的防治具有重要意义。本研究选择内蒙古草甸草原、典型草原、荒漠草原及草原化荒漠4种主要草地类型的代表性站点-额尔古纳右旗、镶黄旗、乌审旗... 基于草地生态系统模型评估气候变化对草地的影响及其适应对于草地的可持续利用和草地荒漠化的防治具有重要意义。本研究选择内蒙古草甸草原、典型草原、荒漠草原及草原化荒漠4种主要草地类型的代表性站点-额尔古纳右旗、镶黄旗、乌审旗和苏尼特左旗,基于牧业气象试验站的长期围封草地生物量观测资料,对草地生态系统模型(CENTURY)进行了校正和验证。结果表明:CENTURY模型模拟的草甸草原、典型草原、荒漠草原和草原化荒漠生长季地上部分生物量的模拟值与实测值变化趋势比较一致,决定系数(R2)分别为0.60,0.60,0.65和0.59,均方根误差(RMSE)分别为29.65,31.45,25.51和7.90g C.m-2,CENTURY模型能够模拟草地地上部分生物量对气候因子的响应,适用于气候变化对内蒙古草地生态系统的影响研究。模型参数敏感性分析表明:草地地上部分生物量敏感的生理参数是草地生长最适温度、最高温度及潜在生产力系数。对过去50年草地地上部分生物量的变化模拟显示:额尔古纳右旗与乌审旗的草地年累积地上部分生物量在近50年间呈现波动增加,镶黄旗与苏尼特左旗呈现波动减少,但统计上均不显著。 展开更多
关键词 草地生态系统模型 气候变化 适应性 验证
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A Preliminary Application of the Differential Evolution Algorithm to Calculate the CNOP 被引量:4
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作者 SUN Guo-Dong MU Mu 《Atmospheric and Oceanic Science Letters》 2009年第6期381-385,共5页
A projected skill is adopted by use of the differential evolution (DE) algorithm to calculate a conditional nonlinear optimal perturbation (CNOP). The CNOP is the maximal value of a constrained optimization problem wi... A projected skill is adopted by use of the differential evolution (DE) algorithm to calculate a conditional nonlinear optimal perturbation (CNOP). The CNOP is the maximal value of a constrained optimization problem with a constraint condition, such as a ball constraint. The success of the DE algorithm lies in its ability to handle a non-differentiable and nonlinear cost function. In this study, the DE algorithm and the traditional optimization algorithms used to obtain the CNOPs are compared by analyzing a theoretical grassland ecosystem model and a dynamic global vegetation model. This study shows that the CNOPs generated by the DE algorithm are similar to those by the sequential quadratic programming (SQP) algorithm and the spectral projected gradients (SPG2) algorithm. If the cost function is non-differentiable, the CNOPs could also be caught with the DE algorithm. The numerical results suggest the DE algorithm can be employed to calculate the CNOP, especially when the cost function is non-differentiable. 展开更多
关键词 differential evolution algorithm conditional nonlinear optimal perturbation non-differentiable
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