scholarly journals Pollutant Concentration Patterns of In-Stream Urban Stormwater Runoff

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2534
Author(s):  
Laurel Christian ◽  
Thomas Epps ◽  
Ghada Diab ◽  
Jon Hathaway
Keyword(s):  
Temporal Distribution ◽  
Pollutant Transport ◽  
Transport Processes ◽  
Urban Watersheds ◽  
First Flush ◽  
Urban Stormwater ◽  
Initial Portion ◽  
Explanatory Variables ◽  
Transport Dynamics ◽  
First Flush Effect

Although a number of studies have investigated pollutant transport patterns in urban watersheds, these studies have focused primarily on the upland landscape as the point of interest (i.e., prior to stormwater entering an open stream channel). However, it is likely that in-stream processes will influence pollutant transport when the system is viewed at a larger scale. One initial investigation that can be performed to characterize transport dynamics in urban runoff is determining a pollutant’s temporal distribution. By borrowing from urban stormwater literature, the propensity of a pollutant within a system to be more heavily transported in the initial portion of the storm can be quantified (i.e., the “first flush”). Although uncommon for use in stream science, this methodology allows direct comparison of results to previous studies on smaller urban upland catchments. Multiple methods have been proposed to investigate the first flush effect, two of which are applied in this study to two streams in Knoxville, TN, USA. The strength of the first flush was generally corroborated by the two unique methods, a new finding that allows a more robust determination of first flush presence for a given pollutant. Further, an “end flush” was observed and quantified for nutrients and microbes in one stream, a novel outcome that shows how the newer methodology that was employed can provide greater insight into transport processes and pollutant sources. Explanatory variables for changes in each pollutant’s inter-event first flush strength differed, but notable relationships included the influence of flow rate on microbes and influence of rainfall on Cu2+. The results appear to support the hypothesis that in-stream processes, such as resuspension, may influence pollutant transport in urban watersheds, pointing toward the need to consider in-stream processes in models developed to predict urban watershed pollutant export.

A traditional first flush assessment of E. coli in urban stormwater runoff

2009 ◽  
Vol 60 (11) ◽  
pp. 2749-2757 ◽  
Author(s):  
D. T. McCarthy
Keyword(s):  
First Flush ◽  
Regression Analyses ◽  
Urban Stormwater ◽  
Explanatory Variables ◽  
E Coli ◽  
Statistical Inferences ◽  
Treatment Technologies ◽  
Urban Catchments ◽  
Urban Stormwater Runoff ◽  
Crucial Part

The behaviour of microorganisms in urban stormwater should be thoroughly investigated and understood to (a) design treatment technologies that can reduce the human health risks of utilising stormwater and (b) develop models which can accurately predict the levels of microorganisms in urban stormwater to aid in health risk assessments. A crucial part of understanding the behaviour of pollutants in urban stormwater is to determine whether the pollutant experiences higher levels in certain portions of the event (e.g. does the pollutant experience a first flush?). The aim of this paper is twofold: (a) determine if the first flush phenomenon exists for a commonly used microbial indicator, Escherichia coli, and (b) determine whether the presence of a first flush is dependent on antecedent climatic and/or hydrologic characteristics. E. coli data collected from the wet weather flows of four urban catchments in Melbourne was used in the paper. Cumulative mass versus volume curves were used in conjunction with standard statistical inferences to determine that the first flush phenomenon was not consistently present, and that the presence and magnitude of a first flush varied considerably between each site. Regression analyses were used to determine that this variation was probably not caused by the same governing processes for all four sites, with different explanatory variables significantly explaining the first flush at each site.

Spatial and Temporal Distribution of Heavy Metals Concentration in Urban Stormwater Runoff

2013 ◽  
Vol 726-731 ◽  
pp. 1801-1804 ◽  
Author(s):  
Shu Min Wang ◽  
Hui Yu
Keyword(s):  
Heavy Metal ◽  
Stormwater Runoff ◽  
Temporal Distribution ◽  
Urban Region ◽  
Spatial And Temporal Distribution ◽  
Urban Stormwater ◽  
Metal Concentrations ◽  
Heavy Metal Concentrations ◽  
Urban Stormwater Runoff ◽  
Cu And Zn

In order to know the characteristic of spatial and temporal distribution of heavy metal concentrations in urban stormwater runoff, rainfall runoff from impervious underlying surfaces in urban region was observed during rain events. Results showed that during the precipitation process, heavy metal concentrations decreased gradually temporally (except Cd); concentrations of Fe, Cu and Zn meet Class III standard of Environmental Quality Standards for Surface Water in terminal runoff, but concentrations of Cd and Pb go beyond this standard far. Heavy metal concentrations in runoff from different types of landuses were significantly different. The arithmetic average concentrations of Fe, Cd, Cu and Zn in stormwater runoff from roof (e.g.,34.4mg/L, 0.15mg/L, 1.25mg/L and 1.23mg/L, respectively) were obviously higher than that in stormwater runoff from road (e.g., 11.8mg/L, 0.05mg/L, 0.13mg/L and 0.69mg/L, respectively).

A WebGIS-Based System for Urban Stormwater Risk Analysis Using a Cloud Matter-Element Model

2020 ◽  
Vol 16 (3) ◽  
pp. 80-99
Author(s):  
Junfei Chen ◽  
Cong Yu
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Temporal Distribution ◽  
Element Model ◽  
Economic Loss ◽  
Risk Level ◽  
Urban Stormwater ◽  
Intelligence System ◽  
Prototype Development ◽  
Matter Element Model

The interaction of human activity, climate change, and urbanization gives rise to more frequent urban stormwater disasters, which causes great economic loss in cities. This article presents a prototype of an interactive WebGIS system for urban stormwater risk analysis. The system has a Browse/Server(B/S) structure and uses WebGIS techniques for prototype development. It is based on the theory of disaster system and Cloud matter-element model for risk assessment. The risk results are immediately generated and visualized interactively by rendering risk maps. Finally, two urban stormwater events in Nanjing in 2015 and 2016 were selected to verify the accuracy of the risk assessment. The results show that the intelligence system can effectively assess the risk level and identify the spatial-temporal distribution of urban stormwater risk in Nanjing, China.

A new modeling approach for estimating first flush metal mass loading

2005 ◽  
Vol 51 (3-4) ◽  
pp. 159-167 ◽  
Author(s):  
L.-H. Kim ◽  
M. Kayhanian ◽  
S.-L. Lau ◽  
M.K. Stenstrom
Keyword(s):  
First Flush ◽  
Runoff Coefficient ◽  
Mass Loading ◽  
Storm Events ◽  
Metal Contaminants ◽  
Rain Intensity ◽  
Dry Period ◽  
Variable Parameters ◽  
Total Runoff ◽  
First Flush Effect

The purpose of this study was to investigate pollutant mass loading from major highways in Southern California, with emphasis on interpretation of event mean concentrations and first flush effects. The results of monitoring eight sites during the 1999–2002 storm seasons found that metal contaminants had higher concentrations at the early stages of storm events compared with other stages of rain storms. A new washoff model was developed to predict the event mean concentrations of metal contaminants taking first flush effect into account. Model variable parameters included average daily traffic, antecedent dry period, rain intensity, total runoff volume, and runoff coefficient. The results obtained using the washoff model were compared with measured values and found to fit well for heavy metals with R2 ranging from 0.8 to 0.95.

Runoff pollution characterization and first flush effect of urban roof catchment

2018 ◽  
Vol 119 ◽  
pp. 262-266 ◽  
Author(s):  
Wei Zhang ◽  
Xiaoyue Zhang ◽  
Jingli Fan ◽  
Zhennan Shi ◽  
Yuhua Zhao ◽  
...  
Keyword(s):  
First Flush ◽  
First Flush Effect ◽  
Runoff Pollution

scholarly journals Tuning molecular motor transport through cytoskeletal filament network organization

2018 ◽  
Author(s):  
Monika Scholz ◽  
Kimberly L. Weirich ◽  
Margaret L. Gardel ◽  
Aaron R. Dinner
Keyword(s):  
Motor Proteins ◽  
Molecular Motor ◽  
Myosin Ii ◽  
Transport Processes ◽  
Force Generation ◽  
Transport Dynamics ◽  
Cytoskeletal Filament ◽  
A Cell ◽  
Cytoskeletal Networks ◽  
Filament Network

The interaction of motor proteins with intracellular filaments is required for transport processes and force generation in cells. Within a cell, crosslinking proteins organize cytoskeletal filaments both temporally and spatially to create dynamic, and structurally diverse networks. The architecture of these networks changes both the mechanics as well as the transport dynamics; however, the effects on transport are less well understood. Here, we compare the transport dynamics of myosin II motor proteins moving on model cytoskeletal networks created by common crosslinking proteins. We observe that motor dynamics change predictably based on the microstructure of the underlying networks and discuss how this can be utilized by cells to achieve specific transport goals.

scholarly journals A Simple Procedure for Evaluating Global Cosmogenic 14C Production in the Atmosphere Using Neutron Monitor Data

Radiocarbon ◽  
2002 ◽  
Vol 44 (1) ◽  
pp. 149-157 ◽  
Author(s):  
D C Lowe ◽  
W Allan
Keyword(s):  
Time Series ◽  
Solar Cycle ◽  
Atomic Oxygen ◽  
Atmospheric Transport ◽  
Simple Procedure ◽  
Oxidation Mechanism ◽  
Temporal Distribution ◽  
Transport Processes ◽  
Solar Cycle 23 ◽  
Monitor Data

Radiocarbon (14C) produced by cosmogenic processes in the atmosphere reacts rapidly with atomic oxygen to form 14CO. The primary sink for this species is oxidation by the OH radical, the single most important oxidation mechanism for pollutants in the atmosphere. Hence, knowledge of the spatial and temporal distribution of 14CO allows important inferences to be made about atmospheric transport processes and the distribution of OH. Because the chemical lifetime of 14CO against OH attack is relatively short, 1–3 months, its distribution in the atmosphere should show modulations due to changes in 14C production caused by variations in the solar cycle. In this work we present a simple methodology to provide a time series of global 14C production to help interpret time series of atmospheric 14CO measurements covering the whole of solar cycle 23. We use data from neutron monitors, a readily available proxy for global 14C production, and show that an existing 6-year time series of 14CO data from Baring Head, New Zealand, tracks changes in global 14C production at the onset of solar cycle 23.

Sign in / Sign up

Export Citation Format

Share Document