Investigation of Spatial Distributions and Temporal Trends of Triclosan in Canadian Surface Waters

2018 ◽  
Vol 76 (2) ◽  
pp. 231-245 ◽  
Author(s):  
Benoit Lalonde ◽  
Christine Garron ◽  
Alice Dove ◽  
John Struger ◽  
Kristina Farmer ◽  
...  
Keyword(s):  
Surface Waters ◽  
Temporal Trends ◽  
Spatial Distributions

scholarly journals Getis-Ord Gi* statistics for hydrocarbons content analysis in the Tromjegan river basin

2020 ◽  
Vol 26 (2) ◽  
pp. 151-160
Author(s):  
Valentina Dobryakova ◽  
Natalya Moskvina ◽  
Andrey Dobryakov ◽  
Lilia Zhegalina ◽  
Ildar Idrisov
Keyword(s):  
Environmental Monitoring ◽  
River Basin ◽  
Surface Waters ◽  
Temporal Dynamics ◽  
Hot Spot ◽  
Temporal Trends ◽  
Environmental Research ◽  
Analysis Tool ◽  
Hydrocarbon Pollution ◽  
Average Maximum

The information content and effectiveness of ecological research of the territory can be improved using the methods of multivariate analysis and mapping of the results. The article presents the analysis and mapping results of spatial and temporal trends of hydrocarbon pollution in the Tromjegan river basin for the period 2006–2018 using the tools of ArcGIS Pro. The informational and basic research is the data of local environmental monitoring of licensed blocks of the Khanty-Mansiysk Autonomous Okrug — Ugra. Pollution analysis was carried out on the basis of a detailed study of the geography of the source data using statistical calculations (minimum, average, maximum distances between sampling points, Getis-Ord Gi* index). Thematic maps were constructed using data averaged over the year. The spatial and temporal dynamics of hydrocarbons concentration in surface waters for 2006–2018 is analyzed using the “Hot Spot Analysis” tool. A temporary cluster section of hydrocarbons average annual concentration according to the Getis-Ord Gi* indicator allowed us to identify trends in the dynamics of indicators. Maps of hydrocarbons average annual concentration were compiled and the results of a spatial-temporal analysis of hydrocarbons average annual concentration in surface waters were presented. The identification of patterns in large arrays of long-term data and the consideration of the spatial component are necessary elements of modern environmental research. Analysis of the time series of average annual concentrations in the Tromjegan river basin showed a clear trend in the dynamics of hydrocarbon pollution. The findings can be the basis for making managerial decisions in the environmental monitoring of licensed blocks of the Khanty-Mansiysk Autonomous Okrug — Ugra.

Spatial Distributions and Temporal Trends in Sediment Contamination in Lake St. Clair

2007 ◽  
Vol 33 (3) ◽  
pp. 668 ◽  
Author(s):  
Sarah B. Gewurtz ◽  
Paul A. Helm ◽  
Jasmine Waltho ◽  
Gary A. Stern ◽  
Eric J. Reiner ◽  
...  
Keyword(s):  
Temporal Trends ◽  
Sediment Contamination ◽  
Spatial Distributions

scholarly journals Intercomparison in spatial distributions and temporal trends derived from multi-source satellite aerosol products

2019 ◽  
Vol 19 (10) ◽  
pp. 7183-7207 ◽  
Author(s):  
Jing Wei ◽  
Yiran Peng ◽  
Rashed Mahmood ◽  
Lin Sun ◽  
Jianping Guo
Keyword(s):  
Large Scale ◽  
Missing Values ◽  
Spatial Scales ◽  
Temporal Trends ◽  
European Space Agency ◽  
Temporal Variations ◽  
Wide Field ◽  
Spatial Distributions ◽  
Spatial Coverage ◽  
The World

Abstract. Satellite-derived aerosol products provide long-term and large-scale observations for analysing aerosol distributions and variations, climate-scale aerosol simulations, and aerosol–climate interactions. Therefore, a better understanding of the consistencies and differences among multiple aerosol products is important. The objective of this study is to compare 11 global monthly aerosol optical depth (AOD) products, which are the European Space Agency Climate Change Initiative (ESA-CCI) Advanced Along-Track Scanning Radiometer (AATSR), Advanced Very High Resolution Radiometer (AVHRR), Multi-angle Imaging SpectroRadiometer (MISR), Moderate Resolution Imaging Spectroradiometer (MODIS), Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Visible Infrared Imaging Radiometer (VIIRS), and POLarization and Directionality of the Earth's Reflectance (POLDER) products. AErosol RObotic NEtwork (AERONET) Version 3 Level 2.0 monthly measurements at 308 sites around the world are selected for comparison. Our results illustrate that the spatial distributions and temporal variations of most aerosol products are highly consistent globally but exhibit certain differences on regional and site scales. In general, the AATSR Dual View (ADV) and SeaWiFS products show the lowest spatial coverage with numerous missing values, while the MODIS products can cover most areas (average of 87 %) of the world. The best performance is observed in September–October–November (SON) and the worst is in June–July–August (JJA). All the products perform unsatisfactorily over northern Africa and Middle East, southern and eastern Asia, and their coastal areas due to the influence from surface brightness and human activities. In general, the MODIS products show the best agreement with the AERONET-based AOD values on different spatial scales among all the products. Furthermore, all aerosol products can capture the correct aerosol trends at most cases, especially in areas where aerosols change significantly. The MODIS products perform best in capturing the global temporal variations in aerosols. These results provide a reference for users to select appropriate aerosol products for their particular studies.

scholarly journals Spatial and Temporal Evaluation of Ecological Footprint Intensity of Jiangsu Province at the County-Level Scale

2020 ◽  
Vol 17 (21) ◽  
pp. 7833
Author(s):  
Decun Wu ◽  
Jinping Liu
Keyword(s):  
Spatial Data ◽  
Ecological Footprint ◽  
Temporal Trends ◽  
Spatial Association ◽  
Jiangsu Province ◽  
Control Measures ◽  
Spatial Data Analysis ◽  
Spatial Distributions ◽  
County Level ◽  
Over Time

Due to the high ecological pressure that exists in the process of rapid economic development in Jiangsu Province, it is necessary to evaluate its ecological footprint intensity (EFI). This article focuses on ecological footprint intensity analysis at the county scale. We used county-level data to evaluate the spatial distributions and temporal trends of the ecological footprint intensity in Jiangsu’s counties from 1995 to 2015. The temporal trends of counties are divided into five types: linear declining type, N-shape type, inverted-N type, U-shape type and inverted-U shape type. It was discovered that the proportions of the carbon footprint intensity were maintained or increased in most counties. Exploratory spatial data analysis shows that there was a certain regularity of the EFI spatial distributions, i.e., a gradient decrease from north to south, and there was a decline in the spatial heterogeneity of EFI in Jiangsu’s counties over time. The global Moran’s index (Moran’s I) and local spatial association index (LISA) are used to analyze both the global and local spatial correlation of EFIs among counties of Jiangsu Province. The high-high and low-low agglomeration effects were the most common, and there were assimilation impacts of counties with strong agglomeration on adjacent units over time. The results implied the utility of differentiated EFI reduction control measures and promotion of low-low agglomeration and suppression of high-high agglomeration in EFI-related ecology policy.

scholarly journals Spatial Distribution and Temporal Trend of Tropospheric NO2 over the Wanjiang City Belt of China

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yu Xie ◽  
Wei Wang ◽  
Qinglong Wang
Keyword(s):  
Temporal Trends ◽  
Temporal Variations ◽  
Spatial Distributions ◽  
Ozone Monitoring Instrument ◽  
Hysplit Model ◽  
Transport Pathways ◽  
Transfer Policy ◽  
Industrial Transfer ◽  
Air Masses ◽  
Comparison Results

We utilize the tropospheric NO2 columns derived from the observations of Ozone Monitoring Instrument (OMI) onboard AURA to analyze the spatial distributions and temporal trends of NO2 in Wanjiang City Belt (WCB) of China from 2005 to 2016. The aim of this study is to assess the effect of industrial transfer policy on the air quality in WCB. Firstly, we used the surface in situ NO2 concentrations to compare with the OMI-retrieved tropospheric NO2 columns in order to verify the accuracy of the satellite data over the WCB area. Although it is difficult to compare the two datasets directly, the comparison results prove the accuracy of the OMI-retrieved tropospheric NO2 columns in cities of WCB. Then, the spatial distributions of the annual averaged tropospheric NO2 total columns over Anhui Province show that NO2 columns were considerably higher in WCB than those in other areas of Anhui. Also, we compared the spatial distributions of the total NO2 columns in 2005 through 2010 and in 2011 through 2016 and found that the total NO2 columns in WCB increased by 19.9%, while the corresponding value increased only 13.9% in other Anhui areas except the WCB area. Furthermore, the temporal variations of NO2 columns show that although the NO2 columns over WCB and Anhui increased significantly from 2005 to 2011, they decreased sharply from 2011 to 2016 due to the strict emission reduction measures in China. Finally, the HYSPLIT model was used to analyze the origins of NO2 and transport pathways of air masses in a typical city, Ma’anshan city.

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