The formulation of the safety base-line for atmospheric environmental quality is not only basic needs of mankind maintaining the quality of survival environment but also concrete measures of red line system for nation...The formulation of the safety base-line for atmospheric environmental quality is not only basic needs of mankind maintaining the quality of survival environment but also concrete measures of red line system for national ecological protection. It is urgent to solve the problem in current environmental management how to draft the safety basa-line of atmospheric environmental quality. To solve this problem, the connotation of safety base-line for atmospheric environmental quality is defined firstly, and then the indexes for atmospheric importance, sensitivity and vulnerability are generalized. Moreover, formulation methods for red, yellow and green lines of the safety base-line for atmospheric environmental quality are put forward ,and corresponding division principle and management principle are put forward finally.展开更多
A new explanation on drift of base line (BL) value in geomagnetic observation was presented by means of detailed analysis on BL value of H variometer at Tianshui Observatory from 1991 to 1995, in association with so...A new explanation on drift of base line (BL) value in geomagnetic observation was presented by means of detailed analysis on BL value of H variometer at Tianshui Observatory from 1991 to 1995, in association with some numerical simulation. It was confirmed that drift does not always exist. For variometers running normally for many years, drift appears to be zero. The temperature dependence of BL value is reversible below a certain temperature but irreversible above it. This irreversibility is the main reason that causes the BL value to show a monotonous declination with time, which has been mistaken for the drift in the past. As to the H variometer at Tianshui Observatory, no drift exists in BL value in these years. A new method was introduced to study the BL value variation with temperature by separating it into three parts.展开更多
[目的]输电线覆冰是电力系统中常见的极端气象风险之一。为提高输电线路的安全运行水平,文章针对输电线路覆冰预测与监测的关键技术问题展开研究。[方法]构建了一种融合数值天气预报模型(Weather Research Forecasting,WRF)与Makkonen...[目的]输电线覆冰是电力系统中常见的极端气象风险之一。为提高输电线路的安全运行水平,文章针对输电线路覆冰预测与监测的关键技术问题展开研究。[方法]构建了一种融合数值天气预报模型(Weather Research Forecasting,WRF)与Makkonen物理覆冰模型的覆冰厚度预测方法。同时创新性地引入机器视觉图像识别技术,提出一种基于像素宽度测量的非接触式覆冰厚度实测方法,实现对模型结果的精确验证。[结果]以2025年1月24日一次宝鸡市翻越秦岭区域输电线路覆冰事件为例,研究表明:高低空环流形势配合下逆温层形成、暖湿气流输送与地形抬升作用的协同机制是造成此次输电线覆冰主要天气学背景;利用机器视觉图像识别技术的覆冰厚度识别算法误差≤3.08%,已达到实际输电线路监测预警精度要求,展现出良好的现场应用潜力;WRF模式能够较好地模拟出此次覆冰过程中的关键气象要素,其模拟值与观测值的相关系数高达0.9,具有较高的可靠性;基于WRF模式驱动的Makkonen模型模拟的覆冰厚度与基于机器视觉的实测值吻合良好,平均绝对误差仅为0.632 mm,能准确反映覆冰的动态增长趋势。[结论]基于WRF模式和Makkonen模型的覆冰厚度预测方法,结合机器视觉图像识别技术,能够有效预测和监测输电线路覆冰厚度,为提高输电线路安全运行水平提供新的技术手段。展开更多
文摘The formulation of the safety base-line for atmospheric environmental quality is not only basic needs of mankind maintaining the quality of survival environment but also concrete measures of red line system for national ecological protection. It is urgent to solve the problem in current environmental management how to draft the safety basa-line of atmospheric environmental quality. To solve this problem, the connotation of safety base-line for atmospheric environmental quality is defined firstly, and then the indexes for atmospheric importance, sensitivity and vulnerability are generalized. Moreover, formulation methods for red, yellow and green lines of the safety base-line for atmospheric environmental quality are put forward ,and corresponding division principle and management principle are put forward finally.
文摘A new explanation on drift of base line (BL) value in geomagnetic observation was presented by means of detailed analysis on BL value of H variometer at Tianshui Observatory from 1991 to 1995, in association with some numerical simulation. It was confirmed that drift does not always exist. For variometers running normally for many years, drift appears to be zero. The temperature dependence of BL value is reversible below a certain temperature but irreversible above it. This irreversibility is the main reason that causes the BL value to show a monotonous declination with time, which has been mistaken for the drift in the past. As to the H variometer at Tianshui Observatory, no drift exists in BL value in these years. A new method was introduced to study the BL value variation with temperature by separating it into three parts.
基金国网陕西省电力有限公司科技项目“110~330 k V穿越秦岭线路覆冰、覆雪气象灾害预报与告警技术研究”(SGTYHT/23-JS-0033)。
文摘[目的]输电线覆冰是电力系统中常见的极端气象风险之一。为提高输电线路的安全运行水平,文章针对输电线路覆冰预测与监测的关键技术问题展开研究。[方法]构建了一种融合数值天气预报模型(Weather Research Forecasting,WRF)与Makkonen物理覆冰模型的覆冰厚度预测方法。同时创新性地引入机器视觉图像识别技术,提出一种基于像素宽度测量的非接触式覆冰厚度实测方法,实现对模型结果的精确验证。[结果]以2025年1月24日一次宝鸡市翻越秦岭区域输电线路覆冰事件为例,研究表明:高低空环流形势配合下逆温层形成、暖湿气流输送与地形抬升作用的协同机制是造成此次输电线覆冰主要天气学背景;利用机器视觉图像识别技术的覆冰厚度识别算法误差≤3.08%,已达到实际输电线路监测预警精度要求,展现出良好的现场应用潜力;WRF模式能够较好地模拟出此次覆冰过程中的关键气象要素,其模拟值与观测值的相关系数高达0.9,具有较高的可靠性;基于WRF模式驱动的Makkonen模型模拟的覆冰厚度与基于机器视觉的实测值吻合良好,平均绝对误差仅为0.632 mm,能准确反映覆冰的动态增长趋势。[结论]基于WRF模式和Makkonen模型的覆冰厚度预测方法,结合机器视觉图像识别技术,能够有效预测和监测输电线路覆冰厚度,为提高输电线路安全运行水平提供新的技术手段。
