为改善建筑群风环境,通过数值模拟技术研究了原始建筑群的风环境情况,并通过分层优化方法改善建筑群的风环境。结果表明,利用分层优化方法对原始建筑群风环境进行优化,使整个研究区域1.5 m高度处平均风速获得提升效果,风速低于1 m ·...为改善建筑群风环境,通过数值模拟技术研究了原始建筑群的风环境情况,并通过分层优化方法改善建筑群的风环境。结果表明,利用分层优化方法对原始建筑群风环境进行优化,使整个研究区域1.5 m高度处平均风速获得提升效果,风速低于1 m ·s^-1 和高于5 m ·s^-1 的区域面积缩小。可见,分层优化方法有效地改善了建筑群的风环境状况,使行人高度处的风速达到满足人体舒适度的合理阈值。展开更多
We design a weather-based indemnity index for the insurance against freeze damage to citrus orchards so as to provide technological support for the development of policy-based agriculture. The indices are prepared by ...We design a weather-based indemnity index for the insurance against freeze damage to citrus orchards so as to provide technological support for the development of policy-based agriculture. The indices are prepared by separating a relative meteorological yield from the yield that is dependent on tree age, high-yield and low-yield years, and environmental factors, and then using a risk assessment scheme to determine the percentage yield reduction due to the meteorological hazard. We thus develop a set of indices associated with cold temperature damage with which to construct more severe weather indices in conjunction with the yield percentage decrease. We then combine the insured regional citrus yield index with the insured meteorological counterpart to obtain a weather-based indemnity index for the varying degree of freeze damage to crops. When the freeze damage index （FDI） is greater than -7.0℃ for the coastal belt of Zhejiang Province, China, or greater than -9.0℃ for other regions of Zhejiang, weather-based indemnity index （WBII） is zero, meaning there is no compensation; when the FDI is from -7.0 to -7.9℃ for the coastal belt or from -9.0 to -9.9℃ for other regions, the WBII is 1 with 50% compensation; when the FDI is from -8.0 to -8.9℃ for the coastal belt or from -10.0 to -10.9℃ for other regions, the WBII is 2 with 70% compensation; and when the FDI is less than -9.0℃ for the coastal belt or less than -11.0℃ for other regions, the WBII is 3 with 90% compensation. The weather indemnity indices of insured orchards are developed in the interest of owners, thereby eliminating adverse selection and moral hazard issues and providing timely recompense from the insurer, and resolving the problem of high indemnity cost in agricultural insurance.展开更多
文摘为改善建筑群风环境,通过数值模拟技术研究了原始建筑群的风环境情况,并通过分层优化方法改善建筑群的风环境。结果表明,利用分层优化方法对原始建筑群风环境进行优化,使整个研究区域1.5 m高度处平均风速获得提升效果,风速低于1 m ·s^-1 和高于5 m ·s^-1 的区域面积缩小。可见,分层优化方法有效地改善了建筑群的风环境状况,使行人高度处的风速达到满足人体舒适度的合理阈值。
基金supported by the National Natural Science Foundation of China (30370914)the major projects of Zhejiang Province Weather Bureau,China(2006zd005)
文摘We design a weather-based indemnity index for the insurance against freeze damage to citrus orchards so as to provide technological support for the development of policy-based agriculture. The indices are prepared by separating a relative meteorological yield from the yield that is dependent on tree age, high-yield and low-yield years, and environmental factors, and then using a risk assessment scheme to determine the percentage yield reduction due to the meteorological hazard. We thus develop a set of indices associated with cold temperature damage with which to construct more severe weather indices in conjunction with the yield percentage decrease. We then combine the insured regional citrus yield index with the insured meteorological counterpart to obtain a weather-based indemnity index for the varying degree of freeze damage to crops. When the freeze damage index （FDI） is greater than -7.0℃ for the coastal belt of Zhejiang Province, China, or greater than -9.0℃ for other regions of Zhejiang, weather-based indemnity index （WBII） is zero, meaning there is no compensation; when the FDI is from -7.0 to -7.9℃ for the coastal belt or from -9.0 to -9.9℃ for other regions, the WBII is 1 with 50% compensation; when the FDI is from -8.0 to -8.9℃ for the coastal belt or from -10.0 to -10.9℃ for other regions, the WBII is 2 with 70% compensation; and when the FDI is less than -9.0℃ for the coastal belt or less than -11.0℃ for other regions, the WBII is 3 with 90% compensation. The weather indemnity indices of insured orchards are developed in the interest of owners, thereby eliminating adverse selection and moral hazard issues and providing timely recompense from the insurer, and resolving the problem of high indemnity cost in agricultural insurance.
