scholarly journals Spatial and temporal distributions of total and methyl mercury in precipitation in core urban areas, Chongqing, China

2012 ◽  
Vol 12 (20) ◽  
pp. 9417-9426 ◽  
Author(s):  
Y. M. Wang ◽  
D. Y. Wang ◽  
B. Meng ◽  
Y. L. Peng ◽  
L. Zhao ◽  
...  
Keyword(s):  
Urban Areas ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Mean Value ◽  
Motor Vehicles ◽  
Volume Weight ◽  
Spatial And Temporal Distributions ◽  
The City

Abstract. The spatial and temporal distribution patterns of mercury (Hg) in precipitation were investigated in the core urban areas of Chongqing, China. During the period from July 2010 to June 2011, total mercury (THg) and methyl mercury (MeHg) concentrations in precipitation were analysed from three sampling sites. Our results suggested that the volume-weight mean THg and MeHg concentrations in precipitation were 30.67 ng l−1 and 0.31 ng l−1, respectively. The proportion of MeHg in THg ranged from 0.1% to 7.6% with a mean value of 1.3%. THg and MeHg concentrations showed seasonal variations, while the highest THg value was measured in winter. Contrarily, the highest MeHg concentration was observed in autumn. Additionally, a geographically gradual decline of THg concentration in precipitation was observed from the downtown to the suburb, then to the controlled site in the city. 5 mm rainfall might be a threshold for the full wash-out capability. Rainfall above 5 mm may have a diluting effect for the concentrations of THg. Moreover, the current research implies that the coal combustion and motor vehicles could be the dominant sources for Hg in the precipitation.

scholarly journals Spatial and temporal distributions of total and methyl mercury in precipitation in core urban areas, Chongqing, China

2012 ◽  
Vol 12 (4) ◽  
pp. 10243-10272
Author(s):  
Y. M. Wang ◽  
D. Y. Wang ◽  
B. Meng ◽  
Y. L. Peng ◽  
L. Zhao ◽  
...  
Keyword(s):  
Urban Areas ◽  
Methyl Mercury ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Mean Value ◽  
Motor Vehicles ◽  
City Center ◽  
Volume Weight ◽  
Spatial And Temporal Distributions ◽  
The City

Abstract. The spatial and temporal distribution patterns of mercury (Hg) in precipitation were investigated in the core urban areas of Chongqing, China. During the period form July 2010 to June 2011, total mercury (THg) and methyl mercury (MeHg) concentrations in precipitation were analyzed from three sampling sites. Our results suggest that the volume-weight mean THg and MeHg concentrations in precipitation were 30.67 ng l−1 and 0.31 ng l−1, respectively. The proportion of MeHg in THg ranged from 0.1% to 7.6% with a mean value of 1.3%. THg and MeHg concentrations showed seasonal variations, while the highest THg value was measured in winter. Contrarily, the highest MeHg concentration was observed in autumn. Additionally, a geographically gradual decline of THg concentration in precipitation was observed from the city center to the suburb, then to the exurb. 5 mm rainfall might be a threshold for the full wash-out capability. Rainfall above 5 mm may have a diluting effect for the concentrations of Hg. Moreover, the current research implies that the coal combustion and motor vehicles could be the dominant sources for Hg in the precipitation.

Simulation of the Cooking Organic Aerosol Concentration Variability in an Urban Area

2021 ◽  
Author(s):  
Evangelia Siouti ◽  
Ksakousti Skyllakou ◽  
Ioannis Kioutsioukis ◽  
Giancarlo Ciarelli ◽  
Spyros N. Pandis
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Temporal Distribution ◽  
Late Summer ◽  
Field Studies ◽  
Organic Aerosol ◽  
Basis Set ◽  
Cooking Times ◽  
The City ◽  
Lunch Time

<p>Cooking operations can be an important fine PM source for urban areas. Cooking emissions are a source of pollution that has been often ignored and are not included or are seriously underestimated in urban emission inventories. However, several field studies in cities all over Europe suggest that cooking organic aerosol (COA) can be an important component of the total organic PM. In this study we propose and evaluate a methodology for the simulation of the COA concentration and its variability in space and time in an urban area. The city of Patras, the third biggest in Greece is used for this first application for a typical late summer period. The spatial distribution of COA emissions is based on the exact location of restaurants and grills, while the emissions on the meat consumption in Greece. We estimated COA emissions of 150 kg d<sup>-1</sup> that corresponds to 0.6 g d<sup>-1</sup> per person. The temporal distribution of COA was based on the known cooking times and the results of the past field studies in the area. Half of the daily COA is emitted during dinner time (21:00-0:00 LT), while approximately 25% during lunch time (13:00-16:00 LT). The COA is simulated using the Volatility Basis Set with a volatility distribution measured in the laboratory and is treated as semivolatile and reactive. The maximum average COA concentration during the simulation period is predicted to be 1.3 μg m<sup>-3</sup> in a mainly pedestrian area with a high density of restaurants. Peak hourly COA concentrations in this area exceed 10 μg m<sup>-3</sup> during several nights. The local production of secondary COA is predicted to be slow and it represents just a few percent of the total COA.</p><p> </p>

scholarly journals Mengevaluasi Efektivitas Pelaksanaan Program Kota Tanpa Kumuh (Studi Kasus pada Wilayah Kota Langsa)

2021 ◽  
Vol 12 (2) ◽  
pp. 200-213
Author(s):  
Safrizal Safrizal ◽  
Safuridar Safuridar ◽  
Muhammad Fuad
Keyword(s):  
Urban Areas ◽  
Mean Value ◽  
Primary Data ◽  
Community Members ◽  
Government Programs ◽  
City Community ◽  
The Mean ◽  
The Government ◽  
The City ◽  
Slum Areas

Population growth and development can lead to excesses for the emergence of slum areas, which are often seen as a potential problem in urban areas. To reduce the problems of housing and slum areas, one of the government programs is the City Without Slum (in Indonesia called KOTAKU) program. This study aims to analyze the effectiveness of the program in Langsa City and identify the inhibiting factors of this program. 166 respondents were all village chiefs in Langsa City, community members who were directly or indirectly involved in the program, as well as other stakeholders. Primary data were collected through a questionnaire. The effectiveness evaluation is calculated using the mean value as a percentage of each indicator. The results found that the KOTAKU program was considered effective as an effort to reduce slum settlements in Langsa City. However, several factors were identified that were the main obstacles in the implementation of the program.

scholarly journals The ectomycorrhizal community of urban linden trees in Gdańsk, Poland

2020 ◽  
Author(s):  
Jacek Olchowik ◽  
Marzena Suchocka ◽  
Paweł Jankowski ◽  
Tadeusz Malewski ◽  
Dorota Hilszczańska
Keyword(s):  
Urban Areas ◽  
Classification Tree ◽  
Principal Component ◽  
Distribution Patterns ◽  
Fungal Species ◽  
Urban Environments ◽  
Cenococcum Geophilum ◽  
Tree Damage ◽  
Ectomycorrhizal Communities ◽  
The City

The linden tree ( Tilia  spp.) is a popular tree for landscaping and urban environments in central and northwest European countries, and it is one of the most popular in cities in Poland. Ectomycorrhizal fungi form a symbiosis with many urban tree species and protect the host plant from heavy metals and against salinity. The aim of this study was to characterize the ECM fungal community of urban linden trees along the tree damage gradient. The study was performed on two homogeneous sites located in the centre of the city of Gdańsk, in northern Poland. The vitality assessment of urban linden trees was made according to Roloff’s classification. Tree damage classes were related to soil characteristics using principal component analysis. The five ectomycorrhizal fungal species were shared among all four tree damage classes, and  Cenococcum geophilum  was found to be the most abundant and frequent ectomycorrhizal fungal species in each class. Park soil had significantly lower pH and Na, Cl and Pb content than street soils. Our knowledge of ectomycorrhizal communities in urban areas is still limited, and these findings provide new insights into ectomycorrhizal distribution patterns in urban areas.

scholarly journals Spatial distribution change of groundwater quality in deep aquifer of Semarang alluvial plains area in past five years

2021 ◽  
Vol 896 (1) ◽  
pp. 012057
Author(s):  
Susanto ◽  
Syafrudin ◽  
T T Putranto
Keyword(s):  
Groundwater Quality ◽  
Urban Areas ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Unconfined Aquifer ◽  
Quality Parameters ◽  
Coastal Areas ◽  
Chloride Ions ◽  
Time Range ◽  
Deep Aquifer

Abstract Over time, excessive groundwater usage in urban areas can affect groundwater conditions both in quantity & quality. In some regions, groundwater in the unconfined aquifer has been heavily involved, but for confined aquifers that are deep & tend to be protected, they are not involved too much. The extensive effect, especially groundwater quality, is very significant, especially in coastal areas where seawater intrusion is common & changes in water salinity occur within a specific time range. Regarding these conditions, research was carried out related to changes in spatial & temporal distribution patterns of groundwater quality, exceedingly physical & chemical parameters related to salinity in confined aquifer conditions in coastal areas. By taking a case study in the alluvial plains of Semarang City, this study aims to determine whether there are significant changes in the five years, starting from 2016 to 2020. By using data sourced from groundwater quality tests taken in the reference year, the results gained from the data processing explained that the groundwater quality parameters such as electrical conductivity, total dissolved solids (TDS), acidity (pH), & chloride ions (Cl-) are changing respectively, both spatially & temporally.

scholarly journals Measures of Spatial and Demographic Disparities in Access to Urban Green Space in Harbin, China

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Qian Xie ◽  
Ming Lu
Keyword(s):  
Urban Areas ◽  
Green Space ◽  
Distribution Patterns ◽  
Urban Green Space ◽  
Spatial Accessibility ◽  
Walking Distance ◽  
Urban Green ◽  
Bivariate Correlation ◽  
Spatial Equity ◽  
The City

Access to urban green space (UGS) is associated with the enhancement of health and disparities in access generate issues of spatial equity and socioenvironmental justice. The aim of this study is to measure spatial accessibility and investigate access disparities to UGSs in urban areas of Harbin, China. A Gaussian-based two-step floating catchment area method and spatial autocorrelation analysis were used to measure the accessibility and evaluate its distribution patterns in residential tracts. Bivariate correlation was employed to examine the statistical relations between demographic characteristics of residential tracts and green space access. The results show that most residential tracts have minimal green space access within walking distance, while a few have limited access within cycling distance. Additionally, spatial disparities were found with low-accessibility tracts clustering in the center of the city, while high-accessibility tracts were located in northern and southern suburbs. Demographic disparities were also identified in the study: females have less access to UGS than males, areas with a high birth rate generally have more access, and population density is negatively associated with UGS access. The findings not only indicate that Harbin has an uneven distribution and disproportionate provision of UGS for urban residents but also identify which areas and population groups within the city are disadvantaged in access to UGS and thus provide suggestions for future construction and provision of UGS.

scholarly journals Ground Deformation and Its Causes in Abbottabad City, Pakistan from Sentinel-1A Data and MT-InSAR

2020 ◽  
Vol 12 (20) ◽  
pp. 3442
Author(s):  
Naeem Shahzad ◽  
Xiaoli Ding ◽  
Songbo Wu ◽  
Hongyu Liang
Keyword(s):  
Land Subsidence ◽  
Vertical Velocity ◽  
Urban Areas ◽  
Ground Deformation ◽  
Anthropogenic Activities ◽  
Soil Layer ◽  
Temporal Distribution ◽  
Precipitation Data ◽  
Water Pumping ◽  
The City

Land subsidence, as one of the engineering geological problems in the world, is generally caused by compression of unconsolidated strata due to natural or anthropogenic activities. We employed interferometric point target analysis (IPTA) as a multi-temporal interferometric synthetic aperture radar (MT-InSAR) technique on ascending and descending Sentinel-1A the terrain observation with progressive scans SAR (TOPSAR) images acquired between January 2015 and December 2018 to analyze the spatio-temporal distribution and cause of subsidence in Abbottabad City of Pakistan. The line of sight (LOS) average deformation velocities along ascending and descending orbits were decomposed into vertical velocity fields and compared with geological data, ground water pumping schemes, and precipitation data. The decomposed and averaged vertical velocity results showed significant subsidence in most of the urban areas in the city. The most severe subsidence was observed close to old Karakorum highway, where the subsidence rate varied up to −6.5 cm/year. The subsidence bowl profiles along W–E and S–N transects showed a relationship with the locations of some water pumping stations. The monitored LOS time series histories along an ascending orbit showed a close correlation with the rainfall during the investigation period. Comparative analysis of this uneven prominent subsidence with geological and precipitation data reflected that the subsidence in the Abbottabad city was mainly related to anthropogenic activities, overexploitation of water, and consolidation of soil layer. The study represents the first ever evidence of land subsidence and its causes in the region that will support the local government as well as decision and policy makers for better planning to overcome problems of overflowing drains, sewage system, littered roads/streets, and sinking land in the city.

scholarly journals EMMISION OF POLLUTANTS ORIGINATING FROM MOBILE SOURCES ON THE EXAMPLE OF THE CITY OF KRAGUJEVAC

2019 ◽  
pp. 115
Author(s):  
Zoran Marjanović ◽  
Miomir Raos ◽  
Milena Jovanovic ◽  
Jovana Randjelović
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Motor Vehicles ◽  
Traffic Density ◽  
Human Environment ◽  
Local Climate ◽  
Climate Conditions ◽  
Exhaust Gases ◽  
Mobile Sources ◽  
The City

Traffic jam makes cities less pleasant for living and it also decreases traffic efficiency whereas travel time, fuel consumption and drivers’ stress are increased. A special problem is its influence on people’s health caused by emission of exhaust gases. Emission of pollutants originating from mobile sources is primarily conditioned by a level of technologies applied to the vehicle, vehicle’s technical state, traffic intensity, traffic density, local climate conditions, etc. Air pollution due to use of motor vehicles is becoming one of the major problems in urban areas across the world. With the increase of the number of motor vehicles and traffic intensification, the influence of exhaust gases on human environment also has increased. Considering the average age of the vehicles participating in traffic in the city of Kragujevac and the traffic capacity of traffic arteries, most frequently not designed for such a large number of vehicles concentrated at the core of the city, it is to be expected that the air pollution coming from mobile sources will become a problem that requires detailed analysis. For that purpose, a detailed statistical analysis of the vehicle fleet of the city of Kragujevac is conducted. An estimation of the influence of the vehicles on the air pollution in the city of Kragujevac, has been given in the paper.

scholarly journals The ectomycorrhizal community of urban linden trees in Gdańsk, Poland

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0237551
Author(s):  
Jacek Olchowik ◽  
Marzena Suchocka ◽  
Paweł Jankowski ◽  
Tadeusz Malewski ◽  
Dorota Hilszczańska
Keyword(s):  
Urban Areas ◽  
Classification Tree ◽  
Principal Component ◽  
Distribution Patterns ◽  
Fungal Species ◽  
Urban Environments ◽  
Cenococcum Geophilum ◽  
Tree Damage ◽  
Ectomycorrhizal Communities ◽  
The City

The linden tree (Tilia spp.) is a popular tree for landscaping and urban environments in central and northwest European countries, and it is one of the most popular in cities in Poland. Ectomycorrhizal fungi form a symbiosis with many urban tree species and protect the host plant from heavy metals and against salinity. The aim of this study was to characterise the ECM fungal community of urban linden trees along the tree damage gradient. The study was performed on two sites located in the centre of the city of Gdańsk, in northern Poland. The vitality assessment of urban linden trees was made according to Roloff’s classification. Tree damage classes were related to soil characteristics using principal component analysis. The five ectomycorrhizal fungal species were shared among all four tree damage classes, and Cenococcum geophilum was found to be the most abundant and frequent ectomycorrhizal fungal species in each class. Soil samples collected in the vicinity of trees belonging to the R0 class had significantly lower pH Na, Cl and Pb content than other soils. Our knowledge of ectomycorrhizal communities in urban areas is still limited, and these findings provide new insights into ectomycorrhizal distribution patterns in urban areas.

scholarly journals Method of Land Cover Change and Number of Vehicles Increasing on Land Surface Temperature: Case Research of Surabaya City, East Java Province, Indonesia

2020 ◽  
Vol 9 (3S) ◽  
pp. 177-181
Keyword(s):  
Land Cover ◽  
Surface Temperature ◽  
Land Cover Change ◽  
Land Surface ◽  
Urban Areas ◽  
Motor Vehicles ◽  
Landsat 8 ◽  
Multi Temporal ◽  
Urban Heat ◽  
The City

Urban Heat island phenomenon that occurs in some major cities to Indonesia can be caused by several factors like a construction of high building, land cover change and air pollution by motor vehicles. The phenomenon of small climate change in urban areas such as the city of Surabaya, the province of Jawa Timur can cause rising surface temperatures that can impact the decline in health and environmental degradation. This research was conducted to know the dynamics of land cover change, and dynamics of the vehicle to surface temperature in Surabaya city. Methods that are in use are a spatial analysis of multi-temporal imagery and analysis by using statistical data. The data used in surface temperature analysis and land cover analysis in the form of vegetation is Landsat-8 (OLI/TIRS) during the recording period from 2014 to 2019 and vehicle dynamics data. The results showed a change of land cover with an estimated area of 2989,8 ha, a rise in surface temperature with an estimate of 3.95 0C, and with the increase in a several of vehicles by 929.225 units from 2013 until 2018. Large surface temperature shows the areas with crowded activities such as settlements area, industrial zone, and government zone.

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