济南地区南部为山区,北部为平原,南北海拔跨度较大,地形条件复杂.为了探究天气研究与预报模型(Weather Research and Forecasting,WRF)的模拟结果对不同陆面资料的敏感性,本研究使用中分辨率成像光谱仪(Moderate Resolution Imaging Spe...济南地区南部为山区,北部为平原,南北海拔跨度较大,地形条件复杂.为了探究天气研究与预报模型(Weather Research and Forecasting,WRF)的模拟结果对不同陆面资料的敏感性,本研究使用中分辨率成像光谱仪(Moderate Resolution Imaging Spectroradiometer,MODIS)土地利用和植被覆盖两类陆面资料替换模式中默认的陆面资料,分别进行了4组敏感性试验,模拟了济南地区2020年7月气温和降水.结果表明:模拟的温度误差和降水误差普遍为南部山区偏大,北部平原偏小;只改变土地利用资料使北部平原地区的温度模拟误差显著减小(均方根误差、平均误差分别减小了0.2~1.0℃和0.2~0.8℃);只改变植被覆盖资料使得南部山区的温度和降水的模拟误差明显减小,模拟的温度均方根误差减小了0.2~1.2℃,模拟的日降水量均方根误差减小了0.2~1.2 mm/d;同时改变土地利用和植被覆盖资料模拟的温度和降水的效果最好,全市大部分站点的模拟误差有明显减小.降水对植被覆盖资料的敏感性比气温更高.展开更多
Agroforestry ecosystems are constructed by simulating natural ecosystems, applying the principles of symbiosis in nature, and organizing multiple plant populations to coexist, while conducting targeted cultivation and...Agroforestry ecosystems are constructed by simulating natural ecosystems, applying the principles of symbiosis in nature, and organizing multiple plant populations to coexist, while conducting targeted cultivation and structural control scientifically. Rubber agroforestry complex ecosystems aim for sustainable development in terms of industry, ecology, resource utilization, and the livelihoods of producers. Rubber agroforestry complex ecosystems create a complex production structure system that integrates biology, society, and the economy through species combinations. Rubber trees and associated biological components coordinate with each other, mutually promote growth, and yield a variety of products for producers. Cultivation techniques and patterns of rubber agroforestry are essential components of these ecosystems. This study analyzes the production practices of rubber agroforestry complex cultivation, with a focus on the development and characteristics (complexity, systematicity, intensity, and hierarchy) of rubber agroforestry systems using a literature analysis and a survey approach. It explores the types and scales of complex planting, specifications and forms, and major effects of complex cultivation. This study identifies successful rubber agroforestry cultivation patterns and practical techniques, as well as the potential benefits of developing rubber agroforestry cultivation. It also points out the shortcomings in the development of complex planting, including an emphasis on production practices but insufficient theoretical research, a focus on production but inadequate attention to the market, and an emphasis on yield while overlooking the improvement of standards, brands, and added value. There are various complex patterns for young rubber plantations, but relatively fewer for mature plantations. Based on this analysis, this study suggests that future efforts should focus on in-depth research on interspecies and environmental interactions in rubber agroforestry ecosystems, clearly define key roles, accelerate the innovation of development patterns, and strengthen the foundation for development. It recommends promoting and demonstrating successful rubber agroforestry complex patterns and providing technical training, developing product branding for rubber agroforestry patterns, enhancing product value, expanding the application functions of rubber-forest mixed crop products, and establishing a stable and sustainable industry chain. This study provide practical experience and theoretical insights in rubber agroforestry complex systems from China the potential to enrich the knowledge of rubber agroforestry composite systems, provide practical experience to improve the operating income of smallholders, and even promote the sustainable development of rubber plantations.展开更多
为识别复杂地形影响下香港国际机场(HKIA,Hong Kong International Airport)低空风切变的易发空域,采用大涡模拟方法(LES,large eddy simulation)对机场及其周边地形进行了风场精细化数值模拟。结合风速云图比较东、东南、南、西南风背...为识别复杂地形影响下香港国际机场(HKIA,Hong Kong International Airport)低空风切变的易发空域,采用大涡模拟方法(LES,large eddy simulation)对机场及其周边地形进行了风场精细化数值模拟。结合风速云图比较东、东南、南、西南风背景下3条跑道起降航道上的风速变化,分析得出了地形与风场分布间的因果关系。通过与无地形情况下的对照试验结果对比,采用F因子(识别逆风)和7节标准(识别侧风)识别机场跑道低空风切变易发区间。结果表明,东风易造成飞机进离场的逆风风速发生时空变化;西南风影响跑道东侧着陆路径上的逆风风速,但几乎不影响跑道西侧离场路径的风速;在东南风和南风背景下,3条跑道起降航道低空段的侧风均受地形影响显著。根据3条跑道进离场航道上的低空风切变易发空域,得到了地形因素对香港国际机场低空风切变的影响范围,研究结果可为机场风切变风险防控提供主动规避措施和建议。展开更多
文摘济南地区南部为山区,北部为平原,南北海拔跨度较大,地形条件复杂.为了探究天气研究与预报模型(Weather Research and Forecasting,WRF)的模拟结果对不同陆面资料的敏感性,本研究使用中分辨率成像光谱仪(Moderate Resolution Imaging Spectroradiometer,MODIS)土地利用和植被覆盖两类陆面资料替换模式中默认的陆面资料,分别进行了4组敏感性试验,模拟了济南地区2020年7月气温和降水.结果表明:模拟的温度误差和降水误差普遍为南部山区偏大,北部平原偏小;只改变土地利用资料使北部平原地区的温度模拟误差显著减小(均方根误差、平均误差分别减小了0.2~1.0℃和0.2~0.8℃);只改变植被覆盖资料使得南部山区的温度和降水的模拟误差明显减小,模拟的温度均方根误差减小了0.2~1.2℃,模拟的日降水量均方根误差减小了0.2~1.2 mm/d;同时改变土地利用和植被覆盖资料模拟的温度和降水的效果最好,全市大部分站点的模拟误差有明显减小.降水对植被覆盖资料的敏感性比气温更高.
文摘Agroforestry ecosystems are constructed by simulating natural ecosystems, applying the principles of symbiosis in nature, and organizing multiple plant populations to coexist, while conducting targeted cultivation and structural control scientifically. Rubber agroforestry complex ecosystems aim for sustainable development in terms of industry, ecology, resource utilization, and the livelihoods of producers. Rubber agroforestry complex ecosystems create a complex production structure system that integrates biology, society, and the economy through species combinations. Rubber trees and associated biological components coordinate with each other, mutually promote growth, and yield a variety of products for producers. Cultivation techniques and patterns of rubber agroforestry are essential components of these ecosystems. This study analyzes the production practices of rubber agroforestry complex cultivation, with a focus on the development and characteristics (complexity, systematicity, intensity, and hierarchy) of rubber agroforestry systems using a literature analysis and a survey approach. It explores the types and scales of complex planting, specifications and forms, and major effects of complex cultivation. This study identifies successful rubber agroforestry cultivation patterns and practical techniques, as well as the potential benefits of developing rubber agroforestry cultivation. It also points out the shortcomings in the development of complex planting, including an emphasis on production practices but insufficient theoretical research, a focus on production but inadequate attention to the market, and an emphasis on yield while overlooking the improvement of standards, brands, and added value. There are various complex patterns for young rubber plantations, but relatively fewer for mature plantations. Based on this analysis, this study suggests that future efforts should focus on in-depth research on interspecies and environmental interactions in rubber agroforestry ecosystems, clearly define key roles, accelerate the innovation of development patterns, and strengthen the foundation for development. It recommends promoting and demonstrating successful rubber agroforestry complex patterns and providing technical training, developing product branding for rubber agroforestry patterns, enhancing product value, expanding the application functions of rubber-forest mixed crop products, and establishing a stable and sustainable industry chain. This study provide practical experience and theoretical insights in rubber agroforestry complex systems from China the potential to enrich the knowledge of rubber agroforestry composite systems, provide practical experience to improve the operating income of smallholders, and even promote the sustainable development of rubber plantations.
文摘为识别复杂地形影响下香港国际机场(HKIA,Hong Kong International Airport)低空风切变的易发空域,采用大涡模拟方法(LES,large eddy simulation)对机场及其周边地形进行了风场精细化数值模拟。结合风速云图比较东、东南、南、西南风背景下3条跑道起降航道上的风速变化,分析得出了地形与风场分布间的因果关系。通过与无地形情况下的对照试验结果对比,采用F因子(识别逆风)和7节标准(识别侧风)识别机场跑道低空风切变易发区间。结果表明,东风易造成飞机进离场的逆风风速发生时空变化;西南风影响跑道东侧着陆路径上的逆风风速,但几乎不影响跑道西侧离场路径的风速;在东南风和南风背景下,3条跑道起降航道低空段的侧风均受地形影响显著。根据3条跑道进离场航道上的低空风切变易发空域,得到了地形因素对香港国际机场低空风切变的影响范围,研究结果可为机场风切变风险防控提供主动规避措施和建议。
