相关实验视频
Updated: Jul 23, 2025

16:14
Trajectory Data Analyses for Pedestrian Space-time Activity Study
Published on: February 25, 2013
13.6K
在城市范围内使用卫星和地面数据在COVID-19爆发前后跟踪空气质量趋势和车辆交通动态
D De Santis1, S Amici2, C Milesi3
1Department of Civil Engineering and Computer Science Engineering, "Tor Vergata" University of Rome, Rome, Italy.
The Science of the total environment
|July 16, 2023
概括
由于COVID-19的封锁,撒丁岛卡利亚里的二氧化 (NO2) 空气污染显著降低,与交通减少有关. 在限制放松后,空气质量恢复到封锁前的水平.
科学领域:
- 环境科学 环境科学
- 大气化学 大气化学
- 城市研究 城市研究
背景情况:
- 随着COVID-19的流行,全球都开始实施封锁,影响了城市空气质量.
- 之前的研究分析了锁定期间在大城市和地区的空气质量变化.
- 撒丁岛的卡利亚里提供了一个案例研究,作为一个具有工业定居点的代表性沿海城市.
研究的目的:
- 评估COVID-19限制对卡利亚里空气质量和交通动态的影响.
- 在封锁期间之前,期间和之后调查二氧化 (NO2) 水平.
- 为了将空气污染数据与城市沿海环境中的交通模式相关联.
主要方法:
- 利用来自Sentinel-5P/TROPOMI的卫星数据进行二氧化 (NO2) 测量.
- 综合现场地面测量以进行全面的空气质量分析.
- 采用统计分析,包括皮尔森的相关性,以比较卫星和地面数据,以及交通动态.
主要成果:
- 在COVID-19封锁期间,氧化物 (NO2) 水平在卡利亚里城市地区的封锁前和后期间相比,显著降低.
- 炼油厂附近的NO2水平没有显示与封锁相关的显著变化.
- 在卫星检测到的NO2和地面NO2之间观察到强烈的相关性 (皮尔森系数≈0.78),特别是在市中心附近.
- 减少的车辆流量与下降的每周平均热层NO2值直接相关.
结论:
- 通过减少NO2污染,COVID-19封锁措施有效地改善了卡利亚里的空气质量.
- 交通量是卡利亚里等城市地区NO2度的主要驱动因素.
- 卫星和地面监测是评估环境政策和事件对空气质量影响的宝贵工具.
相关概念视频
Effects of Air-entrainment in Concrete
112
Air entrainment in concrete significantly enhances the material's durability, especially in environments subjected to freeze-thaw cycles. Introducing small air bubbles into the concrete mix acts as internal voids that accommodate the expansion of water when it freezes, thereby alleviating internal stress and preventing structural cracks. This function is crucial in climates with significant freezing and thawing, as it protects the concrete from repeated stresses that could lead to premature...
112
Variation of Atmospheric Pressure
2.2K
Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the decreasing gravitational force per unit area as we move away from the surface of the earth.
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
2.2K
Factors Affecting Pulmonary Ventilation
1.5K
Besides the pressure difference between the external environment and the lungs, the airflow rate and ease of pulmonary ventilation are also influenced by three other factors: surface tension of the fluid in the alveoli, compliance of the lungs, and airway resistance.
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
1.5K
Residuals and Least-Squares Property
7.4K
The vertical distance between the actual value of y and the estimated value of y. In other words, it measures the vertical distance between the actual data point and the predicted point on the line
If the observed data point lies above the line, the residual is positive, and the line underestimates the actual data value for y. If the observed data point lies below the line, the residual is negative, and the line overestimates the actual data value for y.
The process of fitting the best-fit...
If the observed data point lies above the line, the residual is positive, and the line underestimates the actual data value for y. If the observed data point lies below the line, the residual is negative, and the line overestimates the actual data value for y.
The process of fitting the best-fit...
7.4K
Steps in Outbreak Investigation
153
In the ever-evolving field of public health, statistical analysis serves as a cornerstone for understanding and managing disease outbreaks. By leveraging various statistical tools, health professionals can predict potential outbreaks, analyze ongoing situations, and devise effective responses to mitigate impact. For that to happen, there are a few possible stages of the analysis:
153
Applications of GIS: Disaster Management and Emergency Response
113
Geographic Information System (GIS) technology is essential for risk identification, action prioritization, and resource optimization in critical situations like flooding and earthquakes. By integrating spatial and demographic data, GIS provides a comprehensive framework for emergency response.GIS integrates data layers, like rainfall intensity, topography, elevation profiles, and river levels, to model high-risk flood zones. These layers assess areas susceptible to flooding based on their...
113

