Temporal characterization of minute-level PM2.5 variation within a local monitoring network using DWT-DTW

2021 ◽  
pp. 108221
Author(s):  
Yuli Fan ◽  
Qingming Zhan ◽  
Lujia Tang ◽  
Huimin Liu ◽  
Sihang Gao
Keyword(s):  
Monitoring Network ◽  
Local Monitoring

scholarly journals Characterization of COVID-19’s Impact on Mobility and Short-Term Prediction of Public Transport Demand in a Mid-Size City in Spain

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6574
Author(s):  
Ana Belén Rodríguez González ◽  
Mark R. Wilby ◽  
Juan José Vinagre Díaz ◽  
Rubén Fernández Pozo
Keyword(s):  
Public Transport ◽  
High Performance ◽  
Monitoring Network ◽  
Traffic Monitoring ◽  
Health Economy ◽  
Accurate Information ◽  
Short Term ◽  
Public And Private ◽  
The Impact

COVID-19 has dramatically struck each section of our society: health, economy, employment, and mobility. This work presents a data-driven characterization of the impact of COVID-19 pandemic on public and private mobility in a mid-size city in Spain (Fuenlabrada). Our analysis used real data collected from the public transport smart card system and a Bluetooth traffic monitoring network, from February to September 2020, thus covering relevant phases of the pandemic. Our results show that, at the peak of the pandemic, public and private mobility dramatically decreased to 95% and 86% of their pre-COVID-19 values, after which the latter experienced a faster recovery. In addition, our analysis of daily patterns evidenced a clear change in the behavior of users towards mobility during the different phases of the pandemic. Based on these findings, we developed short-term predictors of future public transport demand to provide operators and mobility managers with accurate information to optimize their service and avoid crowded areas. Our prediction model achieved a high performance for pre- and post-state-of-alarm phases. Consequently, this work contributes to enlarging the knowledge about the impact of pandemic on mobility, providing a deep analysis about how it affected each transport mode in a mid-size city.

CHARACTERIZATION OF VIBRATIONS MEASURED IN THE GRONINGEN BUILDING MONITORING NETWORK

2020 ◽  
Author(s):  
Chris Geurts ◽  
Okke Bronkhorst ◽  
Davide Moretti ◽  
Jitse Pruiksma ◽  
Ron Snijders
Keyword(s):  
Monitoring Network ◽  
Building Monitoring

The fundamental role of environmental isotopes in the characterization of landfill impact on groundwater

2021 ◽  
Author(s):  
Elisabetta Preziosi ◽  
Eleonora Frollini ◽  
Daniele Parrone ◽  
Pasquale Manara ◽  
Stefano Ghergo
Keyword(s):  
Organic Compounds ◽  
Organic Contaminants ◽  
Groundwater Monitoring ◽  
Inorganic Compounds ◽  
Landfill Gas ◽  
Central Italy ◽  
Environmental Isotopes ◽  
Monitoring Network ◽  
Natural Conditions

<p>Modern urban landfills are useful instruments for the safe disposal of everyday waste, especially when associated to a correct separate waste collection and circular economy best practices. Nevertheless, environmental pollution in the surrounding of the disposal area is always a major threat. The leachate and gas produced during the waste maturation must be carefully collected and conveyed to appropriate treatments or uses e.g. for energy production, in order to avoid harmful pollutants from migrating to groundwater or other natural matrices.</p><p>Appropriate monitoring practices are required to intervene promptly at the first sign of inefficiency of the protective barriers or leachate and gas collection systems. As regards groundwater, the monitoring network must include at least 3 observation points. The parameters to be analyzed, required by the legislation, aim at detecting the passage of specific contaminants or indicators of pollution, including inorganic elements and organic contaminants.</p><p>Very often, reducing conditions are observed in the groundwater underlying landfills, which trigger the reductive dissolution of iron and manganese (hydro)oxides. Reasons for this include: natural conditions of the aquifer, leachate pollution, the interaction of groundwater with landfill gas migrating from the plant.</p><p>Groundwater monitoring campaigns have been conducted for several years for the characterization of landfill impact on groundwater in central Italy and several case studies have been analyzed. Natural background levels have been applied, when possible, to distinguish the presence in groundwater of metals due to natural conditions from exceedances related to anthropogenic impact. Traditional groundwater monitoring has been complemented with the analysis of environmental isotopes including tritium and 13-carbon . Tritium is an excellent tracer of landfill pollution because its concentration is particularly high in both leachate and landfill gas.</p><p>The aim of this communication is to present some successful examples of isotope application to resolve doubts about the origin of high levels of inorganic compounds in groundwater, as well as traces of organic compounds, which are of concern as a possible sign of failure of the protective barriers of the plant.</p><p>In particular, we compare the results of the monitoring activities at two landfills, one currently active and one that has been operating in the past and is now completely dismissed. Field parameters (T, EC, pH, DO, ORP) were measured with probes in a flow-through cell. Ammonia, nitrite, sulfur and cyanide were measured in the field (UV-VIS). Quality control includes blind samples, field blanks and equipment blanks. Lab analysis were performed for major and trace elements, environmental isotopes (δ<sup>18</sup>O, δ<sup>2</sup>H, Tritium, δ<sup>13</sup>C), DOC, VOC with standard procedures.</p><p>The hydrochemical, hydrogeological and isotope data indicate a slow and modest groundwater contamination that is taking place in the old plant. The traces of organic compounds observed there were ascribed to the leachate, which is still produced and collected, which possibly infiltrates the groundwater. In the active plant no indication of pollution was found and some anomalous data regarding sulfur and chloride were provisionally ascribed to a geogenic origin.</p>

scholarly journals Assessment of PM2.5 Exposure during Cycle Trips in The Netherlands Using Low-Cost Sensors

2021 ◽  
Vol 18 (11) ◽  
pp. 6007
Author(s):  
Joost Wesseling ◽  
Wouter Hendricx ◽  
Henri de Ruiter ◽  
Sjoerd van Ratingen ◽  
Derko Drukker ◽  
...  
Keyword(s):  
Air Pollution ◽  
The Netherlands ◽  
Low Cost ◽  
Fine Particulate Matter ◽  
Monitoring Network ◽  
Personal Exposure ◽  
Sensor Data ◽  
Background Concentrations ◽  
Fine Particulate

Air pollution, especially fine particulate matter (PM2.5), is a major environmental risk factor for human health in Europe. Monitoring of air quality takes place using expensive reference stations. Low-cost sensors are a promising addition to this official monitoring network as they add spatial and temporal resolution at low cost. Moreover, low-cost sensors might allow for better characterization of personal exposure to PM2.5. In this study, we use 500 dust (PM2.5) sensors mounted on bicycles to estimate typical PM2.5 levels to which cyclists are exposed in the province of Utrecht, the Netherlands, in the year 2020. We use co-located sensors at reference stations to calibrate and validate the mobile sensor data. We estimate that the average exposure to traffic related PM2.5, on top of background concentrations, is approximately 2 μg/m3. Our results suggest that cyclists close to major roads have a small, but consistently higher exposure to PM2.5 compared to routes with less traffic. The results allow for a detailed spatial representation of PM2.5 concentrations and show that choosing a different cycle route might lead to a lower exposure to PM2.5. Finally, we conclude that the use of mobile, low-cost sensors is a promising method to estimate exposure to air pollution.

A Comparison of the 1981, 1982, 1986 and 1987–1988 Microearthquake Swarms At Moodus, Connecticut

1989 ◽  
Vol 60 (4) ◽  
pp. 177-184 ◽  
Author(s):  
John E. Ebel
Keyword(s):  
Main Shock ◽  
Monitoring Network ◽  
Primary Source ◽  
B Value ◽  
Active Period ◽  
Local Monitoring ◽  
Time Histories ◽  
Small Primary

Abstract Four extensive microearthquake swarms, in 1981, 1982, 1986 and 1987–1988, have occurred near Moodus, Connecticut since the installation of a dense local monitoring network in 1979. All of the swarms have been accompanied by at least one event of M≥2.0, have had depths of less than 2.4 km, and have originated from one small primary source volume. A few of the events from 1981 and 1982 were located about 1.5 km west to southwest of this primary source locality. The time histories and energy releases have varied from swarm to swarm, with the 1981 and 1982 swarms having some foreshocks, a main shock, and a decaying aftershock pattern. The 1986 and 1987–1988 swarms were more distributed in time and totaled fewer events than the earlier swarms. The b-value for the 1987–1988 swarm is closer to that of the foreshocks from 1981 and 1982 than that of the aftershocks from those swarms. The 1980’s have been an unusually active period at Moodus, but the geologic and seismological evidence are ambiguous as to the cause the Moodus earthquakes and how large an event can take place at this locality.

scholarly journals Microseismicity of the Tehran region based on the data recorded in a local monitoring network: 2004-2010

Episodes ◽  
2014 ◽  
Vol 37 (3) ◽  
pp. 206-217 ◽  
Author(s):  
Jamileh Vasheghani Farahani ◽  
Mehdi Zaré ◽  
Artur Cichowicz
Keyword(s):  
Monitoring Network ◽  
Local Monitoring ◽  
Tehran Region

scholarly journals Seasonal characterization of submicron aerosol chemical composition and organic aerosol sources in the southeastern United States: Atlanta, Georgia and Look Rock, Tennessee

2015 ◽  
Vol 15 (16) ◽  
pp. 22379-22417 ◽  
Author(s):  
S. H. Budisulistiorini ◽  
K. Baumann ◽  
E. S. Edgerton ◽  
S. T. Bairai ◽  
S. Mueller ◽  
...  
Keyword(s):  
Monitoring Network ◽  
Organic Aerosol ◽  
Rural Site ◽  
Urban Site ◽  
Mass Spectral ◽  
Submicron Aerosol ◽  
Southeastern Us ◽  
One Year ◽  
The One

Abstract. A yearlong near-real-time characterization of non-refractory submicron aerosol (NR-PM1) was conducted at an urban (Atlanta, Georgia) and rural (Look Rock, Tennessee) site in the southeastern US using the Aerodyne aerosol chemical speciation monitor (ACSM) collocated with established air-monitoring network measurements. Seasonal variations in organic aerosol (OA) and inorganic aerosol species are attributed to meteorological conditions as well as anthropogenic and biogenic emissions in this region. The highest concentrations of NR-PM1 were observed during winter and fall seasons at the urban site and during spring and summer at the rural site. Across all seasons and at both sites, NR-PM1 was composed largely of OA (50–76 %) and inorganic sulfate (12–31 %). Six distinct OA sources were resolved by positive matrix factorization applied to the ACSM organic mass spectral data collected from the two sites over the one year of near-continuous measurements at each site: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), semi-volatile oxygenated OA (SV-OOA), low-volatility oxygenated OA (OOA), isoprene-derived epoxydiol (IEPOX) OA (IEPOX-OA), and 91Fac OA (a factor dominated by a distinct ion at m/z 91 fragment ion previously observed in biogenic influenced areas). LV-OOA was observed throughout the year at both sites and contributed 30–66 % of total OA mass. HOA was also observed during the entire year only at the urban site (15–24 % of OA mass). BBOA (15–33 % of OA mass) was observed during winter and fall, likely dominated by local residential wood burning emission. Although SV-OOA contributes quite significantly (∼ 27 %), it was observed only at the urban site during colder seasons. IEPOX-OA was a major component (27–41 %) of OA at both sites, particularly in spring and summer. An ion fragment at m/z 75 is proposed as an additional marker for IEPOX-OA, as it is shown to correlate well with the m/z 82 ion shown to be associated with the aerosol mass spectrum of IEPOX-derived secondary organic aerosol (SOA). The contribution of 91Fac to the total OA mass was quite low at the urban site (∼ 9 %), but was significant (21–23 %) at the rural site during warmer months. Comparison of 91Fac OA time series with SOA tracers measured from filter samples collected at Look Rock suggests that isoprene oxidation through a pathway other than IEPOX SOA chemistry may contribute to its formation. Other biogenic sources could also contribute to 91Fac, but there remains a need to resolve the exact source of this factor based on its significant contribution to rural OA mass.

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