Speciation distribution and mass balance of copper and zinc in urban rain, sediments, and road runoff.

PubMed

Zuo, Xiaojun; Fu, Dafang; Li, He

2012-11-01

Heavy metal pollution in road runoff had caused widespread concern since the last century. However, there are little references on metal speciation in multiple environmental media (e.g., rain, road sediments, and road runoff). Our research targeted the investigation of metal speciation in rain, road sediments, and runoff; the analysis of speciation variation and mass balance of metals among rain, road sediments, and runoff; the selection of main factors by principal component analysis (PCA); and the establishment of equation to evaluate the impact of rain and road sediments to metals in road runoff. Sequential extraction procedure contains five steps for the chemical fractionation of metals. Flame atomic absorption spectrometry (Shimadzu, AA-6800) was used to determine metal speciation concentration, as well as the total and dissolved fractions. The dissolved fractions for both Cu and Zn were dominant in rain. The speciation distribution of Zn was different from that of Cu in road sediments, while speciation distribution of Zn is similar to that of Cu in runoff. The bound to carbonates for both Cu and Zn in road sediments were prone to be dissolved by rain. The levels of Cu and Zn in runoff were not obviously influenced by rain, but significantly influenced by road sediments. The masses for both Cu and Zn among rain, road sediments, and road runoff approximately meet the mass balance equation for all rainfall patterns. Five principal factors were selected for metal regression equation based on PCA, including rainfall, average rainfall intensity, antecedent dry periods, total suspended particles, and temperature. The established regression equations could be used to predict the effect of road runoff on receiving environments.

Heavy metal contents of road-deposited sediment along the urban-rural gradient around Beijing and its potential contribution to runoff pollution.

PubMed

Zhao, Hongtao; Li, Xuyong; Wang, Xiaomei

2011-09-01

Understanding the contribution of road-deposited sediment (RDS) and its washoff process is essential for controlling urban runoff pollution. Ninety-seven RDS samples were collected along the urban-suburban-rural gradient from areas of five administrative units in the Beijing metropolitan region, including central urban (UCA), urban village (UVA), central suburban county (CSA), rural town (RTA), and rural village (RVA) areas. RDS washoff was evaluated with different particle sizes using a rainfall simulator. Heavy metal elements (i.e., Cr, Cu, Ni, Pb, and Zn) were estimated in both RDS and runoff samples. The RDS mass per unit area increased in the order UCA (21 ± 24 g/m(2)) ≈ CSA (20 ± 16 g/m(2)) < RTA (59 ± 63 g/m(2)) < RVA (147 ± 112 g/m(2)) ≈ UVA (147 ± 198 g/m(2)). Compared to RDS from the other administrative units, RDS from the UCA and CSA had higher metal concentrations and higher proportions of smaller particles, whereas that from the RVA and UVA had larger quantities of metals per unit area. UCA and CSA had lower potential runoff pollution contributions per unit area. Our findings imply that controlling the first flush in the UCA and CSA, and improving existing street cleaning methods and road surface conditions in the TRA, UVA, and RVA will be appropriate strategies for controlling runoff pollution from RDS.

Comparison of heavy metal loads in stormwater runoff from major and minor urban roads using pollutant yield rating curves.

PubMed

Davis, Brett; Birch, Gavin

2010-08-01

Trace metal export by stormwater runoff from a major road and local street in urban Sydney, Australia, is compared using pollutant yield rating curves derived from intensive sampling data. The event loads of copper, lead and zinc are well approximated by logarithmic relationships with respect to total event discharge owing to the reliable appearance of a first flush in pollutant mass loading from urban roads. Comparisons of the yield rating curves for these three metals show that copper and zinc export rates from the local street are comparable with that of the major road, while lead export from the local street is much higher, despite a 45-fold difference in traffic volume. The yield rating curve approach allows problematic environmental data to be presented in a simple yet meaningful manner with less information loss. Copyright 2010 Elsevier Ltd. All rights reserved.

Modelling heavy metals build-up on urban road surfaces for effective stormwater reuse strategy implementation.

PubMed

Hong, Nian; Zhu, Panfeng; Liu, An

2017-12-01

Urban road stormwater is an alternative water resource to mitigate water shortage issues in the worldwide. Heavy metals deposited (build-up) on urban road surface can enter road stormwater runoff, undermining stormwater reuse safety. As heavy metal build-up loads perform high variabilities in terms of spatial distribution and is strongly influenced by surrounding land uses, it is essential to develop an approach to identify hot-spots where stormwater runoff could include high heavy metal concentrations and hence cannot be reused if it is not properly treated. This study developed a robust modelling approach to estimating heavy metal build-up loads on urban roads using land use fractions (representing percentages of land uses within a given area) by an artificial neural network (ANN) model technique. Based on the modelling results, a series of heavy metal load spatial distribution maps and a comprehensive ecological risk map were generated. These maps provided a visualization platform to identify priority areas where the stormwater can be safely reused. Additionally, these maps can be utilized as an urban land use planning tool in the context of effective stormwater reuse strategy implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

EVALUATION OF RETENTION POND AND CONSTRUCTED WETLAND BMPS FOR TREATING PARTICULATE-BOUND HEAVY METALS IN URBAN STORMWATER RUNOFF - 2007

EPA Science Inventory

The sources of heavy metals in urban stormwater runoff are diverse (e.g., highways, road surfaces, roofs) and the release of metals into the environment is governed by several complex mechanisms. Heavy metals in stormwater are associated with suspended particulate materials that ...

EVALUATION OF RETENTION POND AND CONSTRUCTED WETLAND BMPS FOR TREATING PARTICULATE-BOUND HEAVY METALS IN URBAN STORMWATER RUNOFF

EPA Science Inventory

The sources of heavy metals in urban stormwater runoff are numerous (e.g., highways, road surfaces, roofs) and the release of metals into the environment is governed by several complex mechanisms. Heavy metals in stormwater are associated with suspended particulate materials tha...

Distributions of typical contaminant species in urban short-term storm runoff and their fates during rain events: a case of Xiamen City.

PubMed

Wei, Qunshan; Zhu, Gefu; Wu, Peng; Cui, Li; Zhang, Kaisong; Zhou, Jingjing; Zhang, Wenru

2010-01-01

The pollutants in urban storm runoff, which lead to an non-point source contamination of water environment around cities, are of great concerns. The distributions of typical contaminants and the variations of their species in short term storm runoff from different land surfaces in Xiamen City were investigated. The concentrations of various contaminants, including organic matter, nutrients (i.e., N and P) and heavy metals, were significantly higher in parking lot and road runoff than those in roof and lawn runoff. The early runoff samples from traffic road and parking lot contained much high total nitrogen (TN 6-19 mg/L) and total phosphorus (TP 1-3 mg/L). A large proportion (around 60%) of TN existed as total dissolved nitrogen (TDN) species in most runoff. The percentage of TDN and the percentage of total dissolved phosphorus remained relatively stable during the rain events and did not decrease as dramatically as TN and TP. In addition, only parking lot and road runoff were contaminated by heavy metals, and both Pb (25-120 microg/L) and Zn (0.1-1.2 mg/L) were major heavy metals contaminating both runoff. Soluble Pb and Zn were predominantly existed as labile complex species (50%-99%), which may be adsorbed onto the surfaces of suspended particles and could be easily released out when pH decreased. This would have the great impact to the environment.

Untreated runoff quality from roof and road surfaces in a low intensity rainfall climate.

PubMed

Charters, Frances J; Cochrane, Thomas A; O'Sullivan, Aisling D

2016-04-15

Sediment and heavy metals in stormwater runoff are key pollutants of urban waterways, and their presence in stormwater is driven by climatic factors such as rainfall intensity. This study describes the total suspended solids (TSS) and heavy metal concentrations found in runoff from four different urban surfaces within a residential/institutional catchment, in a climate where rainfall is typically of low intensity (<5.1mm·h(-1)). The results were compared to untreated runoff quality from a compilation of international studies. The road runoff had the highest TSS concentrations, while copper and galvanized roof runoff had the highest copper and zinc concentrations, respectively. Pollutant concentrations were found to be significantly different between surfaces; quantification and prediction of pollutant contributions from urban surfaces should thus take account of the different surface materials, instead of being aggregated into more generalized categories such as land use. The TSS and heavy metal concentrations were found to be at the low to medium end of ranges observed internationally, except for total copper and zinc concentrations generated by dissolution of copper and galvanized roofing material respectively; these concentrations were at least as high as those reported internationally. TSS wash-off from the roofs was seen to be a source-limited process, where all available TSS is washed off during the rain event despite the low intensity rainfall, whereas both road TSS and heavy metals wash-off from roof and road surfaces appeared to all be transport-limited and therefore some carryover of pollutants occurs between rain events. A first flush effect was seen from most surfaces for TSS, but not for heavy metals. This study demonstrates that in low intensity rainfall climates, quantification of untreated runoff quality from key individual surface types in a catchment are needed to enable development of targeted and appropriately sized stormwater treatment systems. Copyright © 2016 Elsevier B.V. All rights reserved.

A three-stage treatment system for highly polluted urban road runoff.

PubMed

Hilliges, Rita; Schriewer, Alexander; Helmreich, Brigitte

2013-10-15

A three-stage treatment device for polluted urban road runoff was installed and tested at a highly trafficked urban road over a period of one year. In the first stage coarse material and particles from the runoff are removed by a special gutter system. The second stage eliminates particles using a hydrodynamic separator. In the third stage dissolved pollutants are adsorbed in a filter unit with lignite as filter material. Twenty-four rain events were sampled over the one year period and analyzed for dissolved and particulate copper (Cu), zinc (Zn), lead (Pb), suspended solids (SS), total organic carbon (TOC), sodium (Na), and pH value. The treatment system was able to safely retain all relevant pollutants during the investigated period, except Na. In the effluent of the treatment device Pb could never be detected, values measured for Zn were in the range of the detection limit. Cu, the element most frequently detected in the effluent, never exceeded the critical value of 50 μg/L set by the German Federal Soil Protection Act and Ordinance. The median Cu concentration in the effluent of the treatment system was 8.13 μg/L. The treatment system proved to be very effective. Highly polluted road runoff can be purified by the system to an extent that no contamination risk for soil and groundwater remains when infiltrated into the soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modelling Urban diffuse pollution in groundwater

NASA Astrophysics Data System (ADS)

Jato, Musa; Smith, Martin; Cundy, Andrew

2017-04-01

Diffuse urban pollution of surface and ground waters is a growing concern in many cities and towns. Traffic-derived pollutants such as salts, heavy metals and polycyclic aromatic hydrocarbons (PAHs) may wash off road surfaces in soluble or particulate forms which later drain through soils and drainage systems into surface waters and groundwater. In Brighton, about 90% of drinking water supply comes from groundwater (derived from the Brighton Chalk block). In common with many groundwater sources the Chalk aquifer has been relatively extensively monitored and assessed for diffuse rural contaminants such as nitrate, but knowledge on the extent of contamination from road run-off is currently lacking. This project examines the transfer of traffic-derived contaminants from the road surface to the Chalk aquifer, via urban drainage systems. A transect of five boreholes have been sampled on a monthly basis and groundwater samples analysed to examine the concentrations of key, mainly road run-off derived, hydrocarbon and heavy metal contaminants in groundwater across the Brighton area. Trace concentrations of heavy metals and phenols have been observed in groundwater. Electrical conductivity changes in groundwater have also been used to assess local changes in ionic strength which may be associated with road-derived contaminants. This has been supplemented by systematic water and sediment sampling from urban gully pots, with further sampling planned from drainage and settlement ponds adjacent to major roads, to examine initial road to drainage system transport of major contaminants.

Contribution of atmospheric dry deposition to stormwater loads for PAHs and trace metals in a small and highly trafficked urban road catchment.

PubMed

Al Ali, Saja; Debade, Xavier; Chebbo, Ghassan; Béchet, Béatrice; Bonhomme, Céline

2017-12-01

A deep understanding of pollutant buildup and wash-off is essential for accurate urban stormwater quality modeling and for the development of stormwater management practices, knowing the potential adverse impacts of runoff pollution on receiving waters. In the context of quantifying the contribution of airborne pollutants to the contamination of stormwater runoff and assessing the need of developing an integrated AIR-WATER modeling chain, loads of polycyclic aromatic hydrocarbons (PAHs) and metal trace elements (MTEs) are calculated in atmospheric dry deposits, stormwater runoff, and surface dust stock within a small yet highly trafficked urban road catchment (~ 30,000 vehicles per day) near Paris. Despite the important traffic load and according to the current definition of "atmospheric" source, atmospheric deposition did not account for more than 10% of the PAHs and trace metal loads in stormwater samples for the majority of the events, based on the ratio of deposition to stormwater. This result shows that atmospheric deposition is not a major source of pollutants in stormwater, and thus, linking the air and water compartment in a modeling chain to have more accurate estimates of pollutant loads in stormwater runoff might not be relevant. Comparison of road dust with water samples demonstrates that only the fine fraction of the available stock is eroded during a rainfall event. Even if the atmosphere mostly generates fine particles, the existence of other sources of fine particles to stormwater runoff is highlighted.

Trees and Streets as Drivers of Urban Stormwater Nutrient Pollution.

PubMed

Janke, Benjamin D; Finlay, Jacques C; Hobbie, Sarah E

2017-09-05

Expansion of tree cover is a major management goal in cities because of the substantial benefits provided to people, and potentially to water quality through reduction of stormwater volume by interception. However, few studies have addressed the full range of potential impacts of trees on urban runoff, which includes deposition of nutrient-rich leaf litter onto streets connected to storm drains. We analyzed the influence of trees on stormwater nitrogen and phosphorus export across 19 urban watersheds in Minneapolis-St. Paul, MN, U.S.A., and at the scale of individual streets within one residential watershed. Stormwater nutrient concentrations were highly variable across watersheds and strongly related to tree canopy over streets, especially for phosphorus. Stormwater nutrient loads were primarily related to road density, the dominant control over runoff volume. Street canopy exerted opposing effects on loading, where elevated nutrient concentrations from trees near roads outweighed the weak influence of trees on runoff reduction. These results demonstrate that vegetation near streets contributes substantially to stormwater nutrient pollution, and therefore to eutrophication of urban surface waters. Urban landscape design and management that account for trees as nutrient pollution sources could improve water quality outcomes, while allowing cities to enjoy the myriad benefits of urban forests.

Land cover controls on summer discharge and runoff solution chemistry of semi-arid urban catchments

NASA Astrophysics Data System (ADS)

Gallo, Erika L.; Brooks, Paul D.; Lohse, Kathleen A.; McLain, Jean E. T.

2013-04-01

SummaryRecharge of urban runoff to groundwater as a stormwater management practice has gained importance in semi-arid regions where water resources are scarce and urban centers are growing. Despite this trend, the importance of land cover in controlling semi-arid catchment runoff quantity and quality remains unclear. Here we address the question: How do land cover characteristics control the amount and quality of storm runoff in semi-arid urban catchments? We monitored summertime runoff quantity and quality from five catchments dominated by distinct urban land uses: low, medium, and high density residential, mixed use, and commercial. Increasing urban land cover increased runoff duration and the likelihood that a rainfall event would result in runoff, but did not increase the time to peak discharge of episodic runoff. The effect of urban land cover on hydrologic responses was tightly coupled to the magnitude of rainfall. At distinct rainfall thresholds, roads, percent impervious cover and the stormwater drainage network controlled runoff frequency, runoff depth and runoff ratios. Contrary to initial expectations, runoff quality did not vary in repose to impervious cover or land use. We identified four major mechanisms controlling runoff quality: (1) variable solute sourcing due to land use heterogeneity and above ground catchment connectivity; (2) the spatial extent of pervious and biogeochemically active areas; (3) the efficiency of overland flow and runoff mobilization; and (4) solute flushing and dilution. Our study highlights the importance of the stormwater drainage systems characteristics in controlling urban runoff quantity and quality; and suggests that enhanced wetting and in-stream processes may control solute sourcing and retention. Finally, we suggest that the characteristics of the stormwater drainage system should be integrated into stormwater management approaches.

Rainwater utilization and storm pollution control based on urban runoff characterization.

PubMed

Zhang, Mulan; Chen, Hao; Wang, Jizhen; Pan, Gang

2010-01-01

The characteristics of urban runoffs and their impact on rainwater utilization and storm pollution control were investigated in three different functional areas of Zhengzhou City, China. The results showed that in the same rain event the pollutant loads (chemical oxygen demand (COD) and total suspended solids (TSS)) in the sampling areas were in the order of industrial area > commercial area > residential area, and within the same area the COD and TSS concentrations of road runoffs were higher than those of roof runoffs. The first flush effects in roof and road runoffs were observed, hence the initial rainwater should be treated separately to reduce rainwater utilization cost and control storm pollution. The initial roof rainfall of 2 mm in residential area, 5 mm in commercial area and 10 mm in industrial area, and the initial road rainfall of 4 mm in residential area and all the road rainfall in commercial and industrial areas should be collected and treated accordingly before direct discharge or utilization. Based on the strong correlation between COD and TSS (R2, 0.87-0.95) and the low biodegradation capacity (biochemical oxygen demand BOD5/COD < 0.3), a sedimentation process and an effective filtration system composed of soil and slag were designed to treat the initial rainwater, which could remove over 90% of the pollutant loads. The above results may help to develop better rainwater utilization and pollution control strategies for cities with water shortages.

Impact of climate change on runoff pollution in urban environments

NASA Astrophysics Data System (ADS)

Coutu, S.; Kramer, S.; Barry, D. A.; Roudier, P.

2012-12-01

Runoff from urban environments is generally contaminated. These contaminants mostly originate from road traffic and building envelopes. Facade envelopes generate lead, zinc and even biocides, which are used for facade protection. Road traffic produces particles from tires and brakes. The transport of these pollutants to the environment is controlled by rainfall. The interval, duration and intensity of rainfall events are important as the dynamics of the pollutants are often modeled with non-linear buildup/washoff functions. Buildup occurs during dry weather when pollution accumulates, and is subsequently washed-off at the time of the following rainfall, contaminating surface runoff. Climate predictions include modified rainfall distributions, with changes in both number and intensity of events, even if the expected annual rainfall varies little. Consequently, pollutant concentrations in urban runoff driven by buildup/washoff processes will be affected by these changes in rainfall distributions. We investigated to what extent modifications in future rainfall distributions will impact the concentrations of pollutants present in urban surface runoff. The study used the example of Lausanne, Switzerland (temperate climate zone). Three emission scenarios (time horizon 2090), multiple combinations of RCM/GCM and modifications in rain event frequency were used to simulate future rainfall distributions with various characteristics. Simulated rainfall events were used as inputs for four pairs of buildup/washoff models, in order to compare future pollution concentrations in surface runoff. In this way, uncertainty in model structure was also investigated. Future concentrations were estimated to be between ±40% of today's concentrations depending on the season and, importantly, on the choice of the RCM/GCM model. Overall, however, the dominant factor was the uncertainty inherent in buildup/washoff models, which dominated over the uncertainty in future rainfall distributions. Consequently, the choice of a proper buildup/washoff model, with calibrated site-specific coefficients, is a major factor in modeling future runoff concentrations from contaminated urban surfaces.

Study on road surface source pollution controlled by permeable pavement

NASA Astrophysics Data System (ADS)

Zheng, Chaocheng

2018-06-01

The increase of impermeable pavement in urban construction not only increases the runoff of the pavement, but also produces a large number of Non-Point Source Pollution. In the process of controlling road surface runoff by permeable pavement, a large number of particulate matter will be withheld when rainwater is being infiltrated, so as to control the source pollution at the source. In this experiment, we determined the effect of permeable road surface to remove heavy pollutants in the laboratory and discussed the related factors that affect the non-point pollution of permeable pavement, so as to provide a theoretical basis for the application of permeable pavement.

Treatment of suspended solids and heavy metals from urban stormwater runoff by a tree box filter.

PubMed

Geronimo, F K F; Maniquiz-Redillas, M C; Tobio, J A S; Kim, L H

2014-01-01

Particulates, inorganic and toxic constituents are the most common pollutants associated with urban stormwater runoff. Heavy metals such as chromium, nickel, copper, zinc, cadmium and lead are found to be in high concentration on paved roads or parking lots due to vehicle emissions. In order to control the rapid increase of pollutant loads in stormwater runoff, the Korean Ministry of Environment proposed the utilization of low impact developments. One of these was the application of tree box filters that act as a bioretention treatment system which executes filtration and sorption processes. In this study, a tree box filter located adjacent to an impervious parking lot was developed to treat suspended solids and heavy metal concentrations from urban stormwater runoff. In total, 11 storm events were monitored from July 2010 to August 2012. The results showed that the tree box filter was highly effective in removing particulates (up to 95%) and heavy metals (at least 70%) from the urban stormwater runoff. Furthermore, the tree box filter was capable of reducing the volume runoff by 40% at a hydraulic loading rate of 1 m/day and below.

Multiple evaluations of the removal of pollutants in road runoff by soil infiltration.

PubMed

Murakami, Michio; Sato, Nobuyuki; Anegawa, Aya; Nakada, Norihide; Harada, Arata; Komatsu, Toshiya; Takada, Hideshige; Tanaka, Hiroaki; Ono, Yoshiro; Furumai, Hiroaki

2008-05-01

Groundwater replenishment by infiltration of road runoff is expected to be a promising option for ensuring a sustainable urban water cycle. In this study, we performed a soil infiltration column test using artificial road runoff equivalent to approximately 11-12 years of rainfall to evaluate the removal of pollutants by using various chemical analyses and bioassay tests. These results indicated that soil infiltration treatment works effectively to remove most of the pollutants such as organic matter (chemical oxygen demand (CODMn) and dissolved organic carbon (DOC)), P species, polycyclic aromatic hydrocarbons (PAHs), numerous heavy metals and oestrogenic activities. Bioassay tests, including algal growth inhibition test, Microtox and mutagen formation potential (MFP) test, also revealed effective removal of toxicities by the soils. However, limited amounts of NO3, Mn, Ni, alkaline earth metals, perfluorooctane sulphonate (PFOS) and perfluorooctane sulphonamide (FOSA) were removed by the soils and they possibly reach the groundwater and cause contamination.

Screening procedure to assess the impact of urban stormwater temperature to populations of brown trout in receiving water.

PubMed

Rossi, Luca; Hari, Renata E

2007-07-01

The discharge of urban stormwater may cause a sudden temperature increase in receiving waters that may be harmful to fish and other aquatic organisms. A screening procedure is proposed with temperature thresholds for the runoff from roofs and roads as well as for the receiving water system to protect brown trout from thermal damage. The stormwater temperature is calculated on the basis of a simple thermodynamic estimate for different latitudes. Only receiving waters with maximum daily mean temperatures of 22 degrees C (T1) are considered potential habitats for brown trout. The maximum temperature for a 1-h exposure time with a safety margin for 100% survival is 25 degrees C (T2), the sudden temperature change at the beginning of a rain event must not exceed 7 degrees C (T3), and fish-egg development requires the daily maximum temperature in winter to be below 12 degrees C (T4). Examples of stormwater runoff from roof or road surfaces from Switzerland validate our approach within +/-0.5 degrees C. Effects of runoff into receiving waters without detailed data can be predicted within +/-0.8 degrees C. With the restriction by T1, T2 seems not to be an acute problem at Swiss latitudes. T3 could play a role, especially if a large amount of runoff is discharged in small and rather cool rivers and streams. Finally, T4 deserves more attention than hitherto given. The proposed procedure may be a useful tool for assessing the influence of urban stormwater on the temperature of the receiving waters, particularly with regard to predicting the thermal impacts of urban or suburban runoff to populations of brown trout.

Experimental study of water fluxes in a residential area: 2. Road infiltration, runoff and evaporation

NASA Astrophysics Data System (ADS)

Ragab, R.; Rosier, P.; Dixon, A.; Bromley, J.; Cooper, J. D.

2003-08-01

Lack of accurate data has led some hydrologists and city planners to assume that urban infiltration is zero and runoff is 100% of the rainfall. These assumptions lead to an over estimation of road runoff volume and an underestimation of direct recharge to groundwater, which is already rising under some UK cities. This study investigates infiltration and runoff processes and quantifies the percentage of rainfall that contributes to storm drainage, and that which infiltrates through different types of road surface. Access tubes were installed for measuring soil water content using a neutron probe in three car parks, a road and a grass site at the Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford. Storm drainage was recorded at the exit of the Thamesmead Estate in Crowmarsh Gifford, just before the drain joins the River Thames at Wallingford. Rainfall and water table depth were also recorded. Weekly measurements of soil moisture content indicated that the top 40 cm layer is not influenced by water-table fluctuations and, therefore, positive changes in soil moisture could be attributed to infiltration of rainfall through the surface. Depending on the nature of the surface, subsurface layers, level of traffic, etc., between 6 and 9% of rainfall was found to infiltrate through the road surfaces studied. The storm drainage generated by road runoff revealed a flow pattern similar to that of the receiving watercourse (River Thames) and increased with the increase of infiltration and soil water content below the road surface. The ratio of runoff to rainfall was 0·7, 0·9 and 0·5 for annual, winter (October-March) and summer (April-September) respectively. As the results of the infiltration indicated that 6 to 9% of annual rainfall infiltrates through the road surface, this means that evaporation represents, 21-24% of annual rainfall, with more evaporation taking place during summer than winter.

Export Mechanisms of Persistent Toxic Substances (PTSs) in Urban Land Uses during Rainfall-Runoff Events: Experimental and Modeling Studies

NASA Astrophysics Data System (ADS)

Zheng, Y.; Luo, X.; Lin, Z.

2016-12-01

The urban environment has a variety of Persistent Toxic Substances (PTS), such as Polycyclic Aromatic Hydrocarbons (PAHs) and mercury. Soil in pervious lands and dust deposited on impervious surfaces are two major sinks of PTSs in urbanized areas, which could contribute significant nonpoint source loadings of PTSs to adjacent waterbodies during rainfall-runoff events and therefore jeopardize aquatic ecosystems. However, PTSs have been much less understood regarding their export mechanisms in urban land uses, and efforts to model nonpoint source pollution processes of PTSs have been rare. We designed and performed in-lab rainfall-runoff simulation experiments to investigate transport of PAHs and mercury by runoff from urban soils. Organic petrology analysis (OPA) techniques were introduced to analyze the soil and sediment compositions. Our study revealed the limitation of the classic enrichment theory which attributes enrichment of pollutants in eroded sediment solely to the sediment's particle size distribution and adopts simple relationships between enrichment ratio and sediment flux. We found that carbonaceous materials (CMs) in soil are the direct and major sorbents for PAHs and mercury, and highly different in content, mobility and adsorption capacity for the PTSs. Anthropogenic CMs like black carbon components largely control the transport of soil PAHs, while humic substances have a dominant influence on the transport of soil mercury. A model was further developed to estimate the enrichment ratio of PAHs, which innovatively applies the fugacity concept.We also conducted field studies on export of PAHs by runoff from urban roads. A variable time-step model was developed to simulate the continuous cycles of PAH buildup and washoff on urban roads. The dependence of the pollution level on antecedent weather conditions was investigated and embodied in the model. The applicability of this approach and its value to environmental management was demonstrated by a case study in Beijing, China. Overall, our studies advanced the understanding of nonpoint source pollution of PTSs in the urban environment. The quantitative approaches developed can help improve existing nonpoint source pollution models. The study results also have important implications to watershed water quality management.

Influence of land use on the quantity and quality of runoff along Israel's coastal strip

NASA Astrophysics Data System (ADS)

Goldshleger, Naftaly; Asaf, Lior; Maor, Alon; Garzuzi, Jamil Jamil

2013-04-01

This study presents an analysis of the quantity and quality of urban runoff from various land uses by remote-sensing and GIS technology coupled with hydrological and chemical monitoring. The study areas were located in the cities of Herzliya and Ra'anana, in Israel's coastal plain, where extensive urbanization has taken place over the last 30 years. Land uses in urban basins were analyzed; rain and runoff were measured and sampled at measurement stations representing different land uses (residential, industrial, commercial, roads, gas station). The aim was to analyze land uses by different remote-sensing and GIS techniques, to evaluate the quality and quantity of urban storm water from various land uses, and to verify a method for predicting the impact of urban land uses on quantity and quality of urban storm water. The quality of urban storm water from residential areas was generally very high, and the water is suitable for reuse or direct recharge into the local aquifer. In light of the serious state of the Israeli water sector and the large amounts of unused runoff produced by Israel's cities, together with the high quality of urban storm water drained from the residential areas, it is important to exploit this water source

Diffuse emission and control of copper in urban surface runoff.

PubMed

Boller, M A; Steiner, M

2002-01-01

Copper washed off from roofs and roads is considered to be a major contribution to diffuse copper pollution of urban environments. In order to guarantee sustainable protection of soils and water, the long-term strategy is to avoid or replace copper containing materials on roofs and fagades. Until achievement of this goal, a special adsorber system is suggested to control the diffuse copper fluxes by retention of copper by a mixture of granulated iron-hydroxide (GEH) and calcium carbonate. Since future stormwater runoff concepts are based on decentralised runoff infiltration into the underground, solutions are proposed which provide for copper retention in infiltration sites using GEH adsorption layers. The example of a large copper façade of which the runoff is treated in an adsorption trench reveals the first full-scale data on façade runoff and adsorber performance. During the first year of investigation average façade runoff concentrations in the range of 1-10 mg Cu/l are reduced by 96-99% in the adsorption ditch.

Role of urban surface roughness in road-deposited sediment build-up and wash-off

NASA Astrophysics Data System (ADS)

Zhao, Hongtao; Jiang, Qian; Xie, Wenxia; Li, Xuyong; Yin, Chengqing

2018-05-01

Urban road surface roughness is one of the most important factors in estimation of surface runoff loads caused by road-deposited sediment (RDS) wash-off and design of its control measures. However, because of a lack of experimental data to distinguish the role of surface roughness, the effects of surface roughness on RDS accumulation and release are not clear. In this study, paired asphalt and concrete road surfaces and rainfall simulation designs were used to distinguish the role of surface roughness in RDS build-up and wash-off. Our results showed that typical asphalt surfaces often have higher depression depths than typical concrete surfaces, indicating that asphalt surfaces are relatively rougher than concrete surface. Asphalt surfaces can retain a larger RDS amount, relative higher percentage of coarser particles, larger RDS wash-off loads, and lower wash-off percentage, than concrete surfaces. Surface roughness has different effects in RDS motilities with different particle sizes during rainfall runoff, and the settleable particles (44-149 μm) were notably influenced by it. Furthermore, the first flush phenomenon tended to be greater on relatively smooth surfaces than relatively rough surfaces. Overall, surface roughness plays an important role in influencing the complete process of RDS build-up and wash-off on different road characteristics.

Coho salmon spawner mortality in western US urban watersheds: bioinfiltration prevents lethal storm water impacts.

PubMed

Spromberg, Julann A; Baldwin, David H; Damm, Steven E; McIntyre, Jenifer K; Huff, Michael; Sloan, Catherine A; Anulacion, Bernadita F; Davis, Jay W; Scholz, Nathaniel L

2016-04-01

Adult coho salmon Oncorhynchus kisutch return each autumn to freshwater spawning habitats throughout western North America. The migration coincides with increasing seasonal rainfall, which in turn increases storm water run-off, particularly in urban watersheds with extensive impervious land cover. Previous field assessments in urban stream networks have shown that adult coho are dying prematurely at high rates (>50%). Despite significant management concerns for the long-term conservation of threatened wild coho populations, a causal role for toxic run-off in the mortality syndrome has not been demonstrated.We exposed otherwise healthy coho spawners to: (i) artificial storm water containing mixtures of metals and petroleum hydrocarbons, at or above concentrations previously measured in urban run-off; (ii) undiluted storm water collected from a high traffic volume urban arterial road (i.e. highway run-off); and (iii) highway run-off that was first pre-treated via bioinfiltration through experimental soil columns to remove pollutants.We find that mixtures of metals and petroleum hydrocarbons - conventional toxic constituents in urban storm water - are not sufficient to cause the spawner mortality syndrome. By contrast, untreated highway run-off collected during nine distinct storm events was universally lethal to adult coho relative to unexposed controls. Lastly, the mortality syndrome was prevented when highway run-off was pretreated by soil infiltration, a conventional green storm water infrastructure technology.Our results are the first direct evidence that: (i) toxic run-off is killing adult coho in urban watersheds, and (ii) inexpensive mitigation measures can improve water quality and promote salmon survival. Synthesis and applications . Coho salmon, an iconic species with exceptional economic and cultural significance, are an ecological sentinel for the harmful effects of untreated urban run-off. Wild coho populations cannot withstand the high rates of mortality that are now regularly occurring in urban spawning habitats. Green storm water infrastructure or similar pollution prevention methods should be incorporated to the maximal extent practicable, at the watershed scale, for all future development and redevelopment projects, particularly those involving transportation infrastructure.

[Monitoring and analysis on evolution process of rainfall runoff water quality in urban area].

PubMed

Dong, Wen; Li, Huai-En; Li, Jia-Ke

2013-02-01

In order to find the water quality evolution law and pollution characteristics of the rainfall runoff from undisturbed to the neighborhood exit, 6 times evolution process of rainfall runoff water quality were monitored and analyzed from July to October in 2011, and contrasted the clarification efficiency of the grassland to the roof runoff rudimentarily at the same time. The research showed: 1. the results of the comparison from "undisturbed, rainfall-roof, rainfall runoff-road, rainfall-runoff the neighborhood exit runoff " showed that the water quality of the undisturbed rain was better than that from the roof and the neighborhood exist, but the road rainfall runoff water quality was the worst; 2. the average concentrations of the parameters such as COD, ammonia nitrogen and total nitrogen all exceeded the Fifth Class of the Surface Water Quality Standard except for the soluble total phosphorus from undisturbed rainfall to the neighborhood exit; 3. the runoff water quality of the short early fine days was better than that of long early fine days, and the last runoff water quality was better than that of the initial runoff in the same rainfall process; 4. the concentration reduction of the grassland was notable, and the reduction rate of the grassland which is 1.0 meter wide of the roof runoff pollutants such as COD and nitrogen reached 30%.

The impact of road salt runoff on methanogens and other lacustrine prokaryotes

NASA Astrophysics Data System (ADS)

Sprague, E.; Dupuis, D.; Koretsky, C.; Docherty, K. M.

2017-12-01

Road salt deicers are widely used in regions that experience icy winters. The resulting saline runoff can negatively impact freshwater lake ecosystems. Saline runoff can cause density stratification, resulting in persistently anoxic hypolimnia. This may result in a shift in the structure of the hypolimnetic prokaryotic community, with potential increases in anaerobic and halotolerant taxa. Specifically, anoxia creates a habitat suitable for the proliferation of obligately anaerobic Archaeal methanogens. As a result, more persistent and expanded anoxic zones due to road salt runoff have the potential to increase hypolimnetic methane concentrations. If a portion of this methane is released to the atmosphere, it could be a currently uncharacterized contributor to atmospheric greenhouse gas emissions. This study examines two urban, eutrophic lakes with significant road salt influx and one rural, eutrophic lake with little road salt influx. All three lakes are located in southwest Michigan. Samples were taken from the water column at every meter at the deepest part of each lake, with a sample from the sediment-water interface, in May, August, and November 2016 and February 2017. The V4 and V5 hypervariable regions of the 16S rRNA gene in Bacteria and Archaea were amplified and sequenced using an Illumina MiSeq approach. Abundance of the mcrA gene, a marker for Archaeal methyl coenzyme A reductase, was quantified using qPCR. Water column methane levels, sediment methane production, water surface methane flux and a suite of supporting geochemical parameters were measured to determine changes in redox stratification in each lake and across seasons. Results indicate significant changes in the 16S rRNA-based community associated with depth, season, salinity and lake. Cyanobacteria, Actinobacteria, and Proteobacteria were among the phyla with the highest overall relative abundance. Sediment samples had more copies of the mcrA gene than the water column samples. In most seasons, hypolimnia in the urban lakes had 550 to 900 µM more methane and epilimnia had small but consistently higher concentrations of methane than the rural lake. These results indicate that road salt contamination can directly and indirectly affect prokaryotic communities and has the potential to increase methane release from lakes.

Hydrologic monitoring for Chicago’s Sustainable Streetscapes Program

USGS Publications Warehouse

Duncker, James J.; Morrow, William S.

2016-04-05

The Chicago Department of Transportation’s Sustainable Streetscapes Program is an innovative program that strives to convert Chicago’s neighborhood commercial areas, riverwalks, and bicycle facilities into active, attractive places for Chicagoans to live, work, and play. The objective of each project is to create flourishing public places while improving the ability of infrastructure to support dense urban living. The U.S. Geological Survey (USGS), in cooperation with the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC), and the Chicago Department of Transportation (CDOT), is monitoring the pre- and postconstruction hydrologic characteristics of an urban corridor on the south side of Chicago that is being renovated using sustainable streetscapes technology.The CDOT Sustainable Streetscapes Program utilizes urban stormwater best-management practices (BMPs) to reduce the storm runoff to the local combined sewer system. The urban stormwater BMPs include permeable pavement, bioswales, infiltration basins, and planters. The urban stormwater BMPs are designed to capture the first flush of storm runoff through features that enhance the infiltration of stormwater runoff to shallow groundwater.The hydrology of the Sustainable Streetscapes Program area is being monitored to evaluate the impacts and effectiveness of the urban stormwater BMP’s. Continuous monitoring of rainfall, sewer flows, stormwater runoff, soil moisture, and groundwater levels will give engineers and scientists measured data to define baseline pre- and postconstruction conditions for the evaluation of the BMPs.Three tipping-bucket rain gages are located along the project corridor. The data provide information on the intensity and volume of rainfall. Rainfall can be highly variable even over a small area like the project corridor.Continuous recording meters are located at specific locations in the combined sewers to record water level and flow during both dry weather (mostly sanitary flow) and wet weather conditions (stormwater runoff in addition to the sanitary flow). Sanitary flow is the largest source of flow in the combined sewers during dry weather, and stormwater runoff and sanitary flow combine during wet weather. The sewer flow data allow engineers and scientists to calculate total runoff volume for selected storm events.Wells are located within the project corridor to record water levels and help determine the direction of movement of groundwater in response to rainfall and snowmelt. In urban settings with aging sewer systems, groundwater can seep into the sewers or combined sewage can seep from the sewers into the local groundwater system. The groundwater data are also important in evaluating the overall impacts of increased infiltration resulting from BMPs.Data from wells show the relative water levels of shallow groundwater, water levels in the combined sewer system, and nearby surface-water channels within the project corridor. In some aging urban sewer systems, the local combined sewer system lies below the water table and receives substantial amounts of groundwater inflow, which can significantly reduce the amount of additional water the sewer system can accept.The bioswale along the south side of West Cermak Road near South Throop Street functions to infiltrate stormwater runoff from the road. Stormwater on the road surface initially drains to the curb and then flows along the curb until it reaches a curb cut-out. Materials within the bioswale allow stormwater to infiltrate and reduce the load to the combined sewer.A common feature in urban areas are curbside catch basins that collect stormwater runoff from paved streets. Stormwater drains first to the curb and then flows along the curb to the catch basin. Lateral sewer pipe connects the catch basin to the combined sewer beneath the street. The use of permeable pavers along the curbs in the project study reach let stormwater infiltrate before it reaches the curb, thus reducing the amount of stormwater draining to the combined sewers.Water-level data from catch basins in the project study area show the effects of permeable pavers in reducing the stormwater drainage to the combined sewers.

Rain Garden Research of EPA's Urban Watershed Research Facility (Poster)

EPA Science Inventory

Rain gardens are vegetated depressions designed to capture and infiltrate stormwater runoff from impervious surfaces such as roofs, parking lots, and roads. The potential benefits compared to traditional curb and gutter drainage systems include peak flow attenuation in receiving ...

Rain Garden Research at EPA's Urban Watershed Research Facility

EPA Science Inventory

Rain gardens are vegetated depressions designed to capture and infiltrate stormwater runoff from impervious surfaces such as roofs, parking lots, and roads. The potential benefits compared to traditional curb and gutter drainage systems include peak flow attenuation in receiving...

Green Infrastructure and Watershed-Scale Hydrology in Mixed Land Cover System

EPA Science Inventory

Urbanization results in replacement of pervious areas (e.g., vegetation, topsoil) with impervious surfaces such as roads, roofs, and parking lots, which cause reductions in interception, evapotranspiration, and infiltration, and increases in surface runoff (overland flow) and pol...

Urban infrastructure and water management—Science capabilities of the U.S. Geological Survey

USGS Publications Warehouse

Fisher, Shawn C.; Fanelli, Rosemary M.; Selbig, William R.

2016-04-29

Managing the urban-water cycle has increasingly become a challenge for water-resources planners and regulators faced with the problem of providing clean drinking water to urban residents. Sanitary and combined sanitary and storm sewer networks convey wastewater to centralized treatment plants. Impervious surfaces, which include roads, parking lots, and buildings, increase stormwater runoff and the efficiency by which runoff is conveyed to nearby stream channels; therefore, impervious surfaces increase the risk of urban flooding and alteration of natural ecosystems. These challenges will increase with the expansion of urban centers and the probable effects of climate change on precipitation patterns. Understanding the urban-water cycle is critical to effectively manage water resources and to protect people, infrastructure, and urban-stream ecosystems. As a leader in water-supply, wastewater, and stormwater assessments, the U.S. Geological Survey has the expertise and resources needed to monitor, model, and interpret data related to the urban-water cycle and thereby enable water-resources managers to make informed decisions.

Road traffic impact on urban water quality: a step towards integrated traffic, air and stormwater modelling.

PubMed

Fallah Shorshani, Masoud; Bonhomme, Céline; Petrucci, Guido; André, Michel; Seigneur, Christian

2014-04-01

Methods for simulating air pollution due to road traffic and the associated effects on stormwater runoff quality in an urban environment are examined with particular emphasis on the integration of the various simulation models into a consistent modelling chain. To that end, the models for traffic, pollutant emissions, atmospheric dispersion and deposition, and stormwater contamination are reviewed. The present study focuses on the implementation of a modelling chain for an actual urban case study, which is the contamination of water runoff by cadmium (Cd), lead (Pb), and zinc (Zn) in the Grigny urban catchment near Paris, France. First, traffic emissions are calculated with traffic inputs using the COPERT4 methodology. Next, the atmospheric dispersion of pollutants is simulated with the Polyphemus line source model and pollutant deposition fluxes in different subcatchment areas are calculated. Finally, the SWMM water quantity and quality model is used to estimate the concentrations of pollutants in stormwater runoff. The simulation results are compared to mass flow rates and concentrations of Cd, Pb and Zn measured at the catchment outlet. The contribution of local traffic to stormwater contamination is estimated to be significant for Pb and, to a lesser extent, for Zn and Cd; however, Pb is most likely overestimated due to outdated emissions factors. The results demonstrate the importance of treating distributed traffic emissions from major roadways explicitly since the impact of these sources on concentrations in the catchment outlet is underestimated when those traffic emissions are spatially averaged over the catchment area.

Storm water runoff concentration matrix for urban areas.

PubMed

Göbel, P; Dierkes, C; Coldewey, W G

2007-04-01

The infrastructure (roads, sidewalk, commercial and residential structures) added during the land development and urbanisation process is designed to collect precipitation and convey it out of the watershed, typically in existing surface water channels, such as streams and rivers. The quality of surface water, seepage water and ground water is influenced by pollutants that collect on impervious surfaces and that are carried by urban storm water runoff. Heavy metals, e.g. lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), polycyclic aromatic hydrocarbons (PAH), mineral oil hydrocarbons (MOH) and readily soluble salts in runoff, contribute to the degradation of water. An intensive literature search on the distribution and concentration of the surface-dependent runoff water has been compiled. Concentration variations of several pollutants derived from different surfaces have been averaged. More than 300 references providing about 1300 data for different pollutants culminate in a representative concentration matrix consisting of medians and extreme values. This matrix can be applied to long-term valuations and numerical modelling of storm water treatment facilities.

Comparison between snowmelt-runoff and rainfall-runoff nonpoint source pollution in a typical urban catchment in Beijing, China.

PubMed

Chen, Lei; Zhi, Xiaosha; Shen, Zhenyao; Dai, Ying; Aini, Guzhanuer

2018-01-01

As a climate-driven event, nonpoint source (NPS) pollution is caused by rainfall- or snowmelt-runoff processes; however, few studies have compared the characteristics and mechanisms of these two kinds of NPS processes. In this study, three factors relating to urban NPS, including surface dust, snowmelt, and rainfall-runoff processes, were analyzed comprehensively by both field sampling and laboratory experiments. The seasonal variation and leaching characteristics of pollutants in surface dust were explored, and the runoff quality of snowmelt NPS and rainfall NPS were compared. The results indicated that dusts are the main sources of urban NPS and more pollutants are deposited in dust samples during winter and spring. However, pollutants in surface dust showed a low leaching ratio, which indicated most NPS pollutants would be carried as particulate forms. Compared to surface layer, underlying snow contained higher chemical oxygen demand, total suspended solids (TSS), Cu, Fe, Mn, and Pb concentrations, while the event mean concentration of most pollutants in snowmelt tended to be higher in roads. Moreover, the TSS and heavy metal content of snowmelt NPS was always higher than those of rainfall NPS, which indicated the importance of controlling snowmelt pollution for effective water quality management.

Monitoring and modeling of runoff from a natural and an urbanized part of a small stream catchment

NASA Astrophysics Data System (ADS)

Kalicz, P.; Kucsara, M.; Gribovszki, Z.; Erős, M.; Csáfordi, P.

2012-04-01

Runoff processes in natural catchments are significantly different compared to urbanized areas. Human impacts are manifested in high amount of paved surfaces like roofs, roads, parking plots and the compacted soils of quasi natural areas like public gardens and parks. Decay of permeability and storage capacity both induce higher amount of runoff. The common practice to treat the increased volume of runoff is to collect in pipes and drain to a stream as soon as possible. These interventions induce flash floods with smaller time of concentration and higher flood peaks as normal food waves therefore strongly load discharge capacity of stream channel. Streams in urban areas are strongly modified and regulated. Sometimes the stream channel are dredged out to increase the discharge capacity. In worst case some smaller brooks are crowded with lid to increase urbanized habitat. Many climate change scenarios predict higher probability of heavy storm events, therefore increasing volume of runoff induces higher demands of strongly modified and enormous concrete channels. This study presents one year monitoring of a small stream comparing runoff from natural, rural and urban sections. In this paper we also introduce the process of a model setup and an evaluation to investigate the weak points of a stream section in urbanized areas. The pilot area of this research is the Rák Brook which is the second largest stream of city Sopron (western Hungary). The natural headwater catchment is long-term research area of Hidegvíz Valley Project, therefore we had a good basis to extend the research catchment monitoring in the direction of urbanized lower part of the stream. Seven monitoring points are established along the longitudinal section of the stream. In each point the water stage is recorded continuously beside several other water quality parameters. These data sets help the later validation of the hydrodynamic model.

Modeling ephemeral gully erosion from unpaved roads: Equifinality and implications for scenario analysis

USDA-ARS?s Scientific Manuscript database

Modeling gully erosion in urban areas is challenging due to difficulties with equifinality and parameter identification, which complicates quantification of management impacts on runoff and sediment production. We calibrated a model (AnnAGNPS) of an ephemeral gully network that formed on unpaved ro...

Simulated rain events on an urban roadway to understand the dynamics of mercury mobilization in stormwater runoff.

PubMed

Eckley, Chris S; Branfireun, Brian

2009-08-01

This research focuses on mercury (Hg) mobilization in stormwater runoff from an urban roadway. The objectives were to determine: how the transport of surface-derived Hg changes during an event hydrograph; the influence of antecedent dry days on the runoff Hg load; the relationship between total suspended sediments (TSS) and Hg transport, and; the fate of new Hg input in rain and its relative importance to the runoff Hg load. Simulated rain events were used to control variables to elucidate transport processes and a Hg stable isotope was used to trace the fate of Hg inputs in rain. The results showed that Hg concentrations were highest at the beginning of the hydrograph and were predominantly particulate bound (HgP). On average, almost 50% of the total Hg load was transported during the first minutes of runoff, underscoring the importance of the initial runoff on load calculations. Hg accumulated on the road surface during dry periods resulting in the Hg runoff load increasing with antecedent dry days. The Hg concentrations in runoff were significantly correlated with TSS concentrations (mean r(2)=0.94+/-0.09). The results from the isotope experiments showed that the new Hg inputs quickly become associated with the surface particles and that the majority of Hg in runoff is derived from non-event surface-derived sources.

Assessing the toxicity and risk of salt-impacted winter road runoff to the early life stages of freshwater mussels in the Canadian province of Ontario.

PubMed

Prosser, R S; Rochfort, Q; McInnis, R; Exall, K; Gillis, P L

2017-11-01

In temperate urbanized areas where road salting is used for winter road maintenance, the level of chloride in surface waters has been increasing. While a number of studies have shown that the early-life stages of freshwater mussels are particularly sensitive to salt; few studies have examined the toxicity of salt-impacted winter road runoff to the early-life stages of freshwater mussels to confirm that chloride is the driver of toxicity in this mixture. This study examines the acute toxicity of field-collected winter road runoff to the glochidia of wavy-rayed lampmussels (Lampsilis fasciola) (48 h exposure) and newly released juvenile fatmucket mussels (Lampsilis siliquoidea) (<1 week old; 96 h exposure) under different water hardness. The chronic toxicity (28 d) to older juvenile L. siliquoidea (7-12 months old) was also investigated. The 48-h EC50 and 96-h LC50 for L. fasciola glochidia and L. siliquoidea juveniles exposed to different dilutions of road run-off created with moderately hard synthetic water (∼80 mg CaCO 3 /L) were 1177 (95% confidence interval (CI): 1011-1344 mg Cl - /L) and 2276 mg Cl - /L (95% CI: 1698-2854 mg Cl - /L), respectively. These effect concentrations correspond with the toxicity of chloride reported in other studies, indicating that chloride is likely the driver of toxicity in salt-impacted road-runoff, with other contaminants (e.g., metals, polycyclic aromatic hydrocarbons) playing a de minimis role. Toxicity data from the current study and literature and concentrations of chloride in the surface waters of Ontario were used to conduct a probabilistic risk assessment of chloride to early-life stage freshwater mussels. The assessment indicated that chronic exposure to elevated chloride levels could pose a risk to freshwater mussels; further investigation is warranted to ensure that the most sensitive organisms are protected. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Distribution of heavy metals in road dust along an urban-rural gradient in Massachusetts

NASA Astrophysics Data System (ADS)

Apeagyei, Eric; Bank, Michael S.; Spengler, John D.

2011-04-01

Human exposures to particulate matter emitted from on-road motor vehicles include complex mixtures of metals from tires, brakes, parts wear and resuspended road dust. The aim of this study was to assess road dust for metals associated with motor vehicle traffic, particularly those metals coming from brake and tire wears. We hypothesized that the road dust would show significant difference in both composition and concentration by traffic type, road class and by location. X-ray fluorescence (XRF) analyses of 115 parked car tires showed Zn and Ca were likely associated with tire wear dust. XRF results of three used brake pads indicated high concentrations of Fe, Ti, Cu, Ba, Mo and Zr. To assess heavy metal exposures associated with tires and brake wear adjacent to roads of varying traffic and functional classes, 85 samples of road dust were collected from road surfaces adjacent to the curb and analyzed by XRF. Median concentrations for Fe, Ca and K were greater than Ti (1619 ppm), with concentration ratios of Fe: Ca: K: Ti [16:5:3:1]. Cumulative frequency distribution graphs showed distribution of Fe, Ba, Cu, and Mo were similar regardless of road traffic rating. However, Zn, Ti, and Zr varied significantly ( p < 0.05) with traffic ratings of roadways (heavy > moderate > low traffic). Fe, Ba, Cu, and Mo also had similar distributions regardless of road class while composition of Zn, Ti, and Zr varied significantly across road class ( p < 0.05) (Major roads > Minor roads > highway). In comparing urban road dust to rural road dust, we observed Fe, Ca, K, and Ti were significantly greater in urban road dust ( p < 0.05). In urban road dust the Fe: Ca: K: Ti relationship with median Ti of 2216 ppm was 12: 6: 3.5: 1. These results indicate that roadway dust may be important sources of metals for runoff water and localized resuspended particulate matter.

Seasonal Drivers of Dissolved Metal Transport During Infiltration of Road Runoff in an Urban Roadside Environment

NASA Astrophysics Data System (ADS)

Mullins, A.; Bain, D.

2017-12-01

Infiltration-based green infrastructure (GI) is being increasingly applied in urban areas, systems characterized by substantial legacy contamination and complicated hydrology. However, it is not clear how the application of green infrastructure changes the geochemistry of urban roadside environments. Most current research on GI focuses on small sets of chemical parameters (e.g. road salt, nitrogen and phosphorous species) over relatively short time periods, limiting comprehensive understanding of geochemical function. This work measures changes in groundwater infiltration rate and dissolved metal concentrations in two infiltration trenches in Pittsburgh, PA to evaluate function and measure dissolved metal transport from the system over time. Two distinct geochemical regimes seem to be driven by seasonality: road de-icer exchange and microbial driven summer reducing conditions. Interactions between these geochemical regimes and variability in infiltration rate control the flux of different metals, varying with metal chemistry. These findings suggest the adoption of infiltration based green infrastructure will likely create complicated patterns of legacy contamination transport to downstream receptors.

Characterization of heavy metal desorption from road-deposited sediment under acid rain scenarios.

PubMed

Zhao, Bo; Liu, An; Wu, Guangxue; Li, Dunzhu; Guan, Yuntao

2017-01-01

Road-deposited sediments (RDS) on urban impervious surfaces are important carriers of heavy metals. Dissolved heavy metals that come from RDS influenced by acid rain, are more harmful to urban receiving water than particulate parts. RDS and its associated heavy metals were investigated at typical functional areas, including industrial, commercial and residential sites, in Guangdong, Southern China, which was an acid rain sensitive area. Total and dissolved heavy metals in five particle size fractions were analyzed using a shaking method under acid rain scenarios. Investigated heavy metals showed no difference in the proportion of dissolved fraction in the solution under different acid rain pHs above 3.0, regardless of land use. Dissolved loading of heavy metals related to organic carbon content were different in runoff from main traffic roads of three land use types. Coarse particles (>150μm) that could be efficiently removed by conventional street sweepers, accounted for 55.1%-47.1% of the total dissolved metal loading in runoff with pH3.0-5.6. The obtained findings provided a significant scientific basis to understand heavy metal release and influence of RDS grain-size distribution and land use in dissolved heavy metal pollution affected by acid rain. Copyright © 2016. Published by Elsevier B.V.

Linking source characterisation and human health risk assessment of metals to rainfall characteristics.

PubMed

Liu, An; Mummullage, Sandya; Ma, Yukun; Egodawatta, Prasanna; Ayoko, Godwin A; Goonetilleke, Ashantha

2018-07-01

Metals deposited on urban road surfaces and incorporated in stormwater runoff are discharged into receiving waters, influencing their quality and can pose human health risks. Effective design of stormwater treatment measures is closely dependent on the in-depth understanding of stormwater pollutant sources and the associated health risks. The study discussed in this paper has linked the sources of metals in stormwater runoff and the accompanying human health risk to rainfall characteristics. The study outcomes confirmed that the metal contributions to stormwater runoff from the primary sources were in the order of sea salt > soil > traffic. Although traffic contributes a relatively lower percentage to wash-off, the human health risks posed by traffic sourced metals were relatively much higher. This implies that traffic sources should receive particular attention in treating stormwater. These outcomes have the potential to contribute to enhancing effective source control measures in order to safeguard natural waterways from polluted road wash-off. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Treatment of Urban Runoff Pollutants by a Multilayer Biofiltration System].

PubMed

Wang, Xiao-lu; Zuo, Jian-e; Gan, Li-li; Xing, Wei; Miao, Heng-feng; Ruan, Wen-quan

2015-07-01

In order to control the non-point source pollution from road runoff in Wuxi City effectively, a multilayer biofiltration system was designed to remove a variety of pollutants according to the characteristics of road runoff in Wuxi, and the experimental research was carried out to study the effect on rainwater pollution purification. The results show that the system has a good performance on removing suspended solids (SS), organic pollutant (COD), nitrogen and phosphorus: all types of multilayer biofiltration systems have a high removal rate for SS, which can reach 90%. The system with activated carbon (GAC) has higher removal rates for COD and phosphorus. The system with zeolite (ZFM) has a relatively better removal efficiency for nitrogen. The addition of wood chips in the system can significantly improve the system efficiency for nitrogen removal. Between the two configurations of layered and distributed wood chips, configurations of distributed wood chips reach higher COD, phosphorus and nitrogen pollutants removal efficiencies since they can reduce the release of wood chips dissolution.

Physicochemical conditions and properties of particles in urban runoff and rivers: Implications for runoff pollution.

PubMed

Wang, Qian; Zhang, Qionghua; Wu, Yaketon; Wang, Xiaochang C

2017-04-01

In this study, to gain an improved understanding of the fate and fractionation of particle-bound pollutants, we evaluated the physicochemical conditions and the properties of particles in rainwater, urban runoff, and rivers of Yixing, a city with a large drainage density in the Taihu Lake Basin, China. Road runoff and river samples were collected during the wet and dry seasons in 2015 and 2016. There were significant differences between the physicochemical conditions (pH, oxidation-reduction potential (ORP), and electroconductivity (EC)) of rainwater, runoff, and rivers. The lowest pH and highest ORP values of rainwater provide the optimal conditions for leaching of particle-bound pollutants such as heavy metals. The differences in the physicochemical conditions of the runoff and rivers may contribute to the redistribution of pollutants between particulate and dissolved phases after runoff is discharged into waterways. Runoff and river particles were mainly composed of silt and clay (<63 μm, 88.3%-90.7%), and runoff particles contained a higher proportion of nano-scale particles (<1 μm) but a lower proportion of submicron-scale particles (1-16 μm) than rivers. The ratio of turbidity to TSS increased with the proportion of fine particles and was associated with the accumulation of pollutants and settling ability of particles, which shows that it can be used as an index when monitoring runoff pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Can additional urban development have major impacts on streamflow of a peri-urban catchment? A case study from Portugal

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Walsh, Rory; Nunes, João; Steenhuis, Tammo; de Lima, João; Coelho, Celeste; Ferreira, António

2016-04-01

It is well known that urban development brings about changes in hydrological response. Relatively little, however, is known about impacts on streamflow during urban development in the Mediterranean climate. This paper examines changes in streamflow resulting from the construction of an enterprise park, a major road and apartment blocks in a small partially urbanized peri-urban catchment (6.2 km2) in central Portugal. These developments led to an increase in urban area from 32% to 40% over a five-year period (hydrological years 2008/09-2012/13). In the initial two-year period minor land-use changes increased impervious surfaces from 12.8% to 13.2%. The subsequent three-year period led to a further 17.2% increase in impervious area. Streamflow was recorded by a V-notch weir at the catchment outlet. Rainfall was recorded at a weather station 0.5km north of the catchment, and by five tipping-bucket raingauges installed in January 2011 within the study catchment. Annual runoff and storm runoff coefficients ranged from 14% to 21% and 9% to 14%, respectively, recorded in 2011/12 and 2012/13. Although these differences in runoff were caused in part by variation in rainfall, the comparison between 2009/10 (pre-) and 2012/13 (post-additional urban development), with broadly similar rainfall (887mm vs 947mm, respectively) and evapotranspiration (740mm vs 746mm), showed a 43% increase in storm runoff (from 90mm to 129mm), resulting from additional overland flow generated largely by the 4.4% increase in impervious surfaces. The additional urban development also led to changes in hydrograph parameters. The increase in storm runoff was not progressive over the study period, but regression lines of storm runoff against rainstorm parameters exhibited higher vertical positions in 2012/13 than 2008/09. Increasing peak flows, however, were more progressive over the study period, with annual regression lines displaying higher vertical positions, but with a clear distance between pre- and post- additional urban development periods. Response time to rainfall reduced from 60-75 minutes to 40 minutes and recession time fell from 21.3-29.5 h to 7.4-8.7 h, respectively. The relatively low runoff and storm runoff coefficients given the extent of urban land-use is due to the dispersed urban pattern and movement of at least part of the overland flow from impervious surfaces into pervious soils (within urban areas and/or downslope woodland and abandoned fields). High soil permeability, linked to the sandstone and limestone bedrock, favours the establishment of water sinks. The additional extension of observed urban development during the study period, however, also included partial routing of overland flow from additional impervious surfaces into the stream network, enhancing flow connectivity, thus, increasing storm runoff and providing quicker hydrologic response. Urban planning should consider the landscape mosaic of peri-urban areas in order to maximize water infiltration and minimize the impacts on streamflow regime and urban flooding.

Constructed wetlands in UK urban surface drainage systems.

PubMed

Shutes, B; Ellis, J B; Revitt, D M; Scholes, L N L

2005-01-01

This paper presents the outcome of an inventory of planted wetland systems in the UK which are classified according to land use type and are all examples of sustainable drainage systems. The introduction of constructed wetlands to treat surface runoff essentially followed a 1997 Environment Agency for England and Wales report advocating the use of "soft engineered" facilities including wetlands in the context of sustainable development and Agenda 21. Subsequently published reports by the UK Construction Industry Research and Information Association (CIRIA) have promoted the potential benefits to both developer and the community of adopting constructed wetlands and other vegetated systems as a sustainable drainage approach. In addition, the UK Environment Agency and Highways Agency (HA) have recently published their own design criteria and requirements for vegetative control and treatment of road runoff. A case study of the design and performance of a constructed wetland system for the treatment of road runoff is discussed. The performance of these systems will be assessed in terms of their design criteria, runoff loadings as well as vegetation and structure maintenance procedures. The differing design approaches in guidance documents published in the UK by the Environment Agency, CIRIA and HA will also be evaluated.

SORPTION OF CU AND ZN TO KAOLINITE AND IRON OXIDE: EFFECTS OF HUMIC ACID AND IONIC STRENGTH AND IMPLICATIONS FOR STORMWATER RUNOFF

EPA Science Inventory

Heavy metals are common pollutants in wet weather flows and urban waterways. Changes in ionic strength, whether from mixing with saline waters, road salt, or from the large osmotic adjustment needed for the Microtox toxicity assay, affect the aqueous chemistry of stormwater runof...

Assessing the polycyclic aromatic hydrocarbon (PAH) pollution of urban stormwater runoff: a dynamic modeling approach.

PubMed

Zheng, Yi; Lin, Zhongrong; Li, Hao; Ge, Yan; Zhang, Wei; Ye, Youbin; Wang, Xuejun

2014-05-15

Urban stormwater runoff delivers a significant amount of polycyclic aromatic hydrocarbons (PAHs), mostly of atmospheric origin, to receiving water bodies. The PAH pollution of urban stormwater runoff poses serious risk to aquatic life and human health, but has been overlooked by environmental modeling and management. This study proposed a dynamic modeling approach for assessing the PAH pollution and its associated environmental risk. A variable time-step model was developed to simulate the continuous cycles of pollutant buildup and washoff. To reflect the complex interaction among different environmental media (i.e. atmosphere, dust and stormwater), the dependence of the pollution level on antecedent weather conditions was investigated and embodied in the model. Long-term simulations of the model can be efficiently performed, and probabilistic features of the pollution level and its risk can be easily determined. The applicability of this approach and its value to environmental management was demonstrated by a case study in Beijing, China. The results showed that Beijing's PAH pollution of road runoff is relatively severe, and its associated risk exhibits notable seasonal variation. The current sweeping practice is effective in mitigating the pollution, but the effectiveness is both weather-dependent and compound-dependent. The proposed modeling approach can help identify critical timing and major pollutants for monitoring, assessing and controlling efforts to be focused on. The approach is extendable to other urban areas, as well as to other contaminants with similar fate and transport as PAHs. Copyright © 2014 Elsevier B.V. All rights reserved.

[Analysis of hydrodynamics parameters of runoff erosion and sediment-yielding on unpaved road].

PubMed

Huang, Peng-Fei; Wang, Wen-Long; Luo, Ting; Wang, Zhen; Wang, Zheng-Li; Li, Ren

2013-02-01

By the method of field runoff washout experiment, a simulation study was conducted on the relationships between the soil detachment rate and the hydrodynamic parameters on unpaved road, and the related quantitative formulas were established. Under the conditions of different flow discharges and road gradients, the averaged soil detachment rate increased with increasing flow discharge and road gradient, and the relationships between them could be described by a power function. As compared with road gradient, flow discharge had greater effects on the soil detachment rate. The soil detachment rate had a power relation with water flow velocity and runoff kinetic energy, and the runoff kinetic energy was of importance to the soil detachment rate. The soil detachment rate was linearly correlated with the unit runoff kinetic energy. The averaged soil erodibility was 0.120 g m-1.J-F-1, and the averaged critical unit runoff kinetic energy was 2.875 g.m-1.J-1. Flow discharge, road gradient, and unit runoff kinetic energy could be used to accurately describe the soil erosion process and calculate the soil erosion rate on unpaved road.

Control of Sediment Export From The Forest Road Prism

Treesearch

Johnny M. Grace

2002-01-01

The effectiveness of four road turn-out ditch treatments (vegetation, rip-rap, sediment fences, and settling basins) in reducing sediment export to the forest floor was evaluated. These four runoff control method are commonly prescribed to control forest road runoff and sediments. The study utilized runoff samplers, runoff diversion walls, sediment filter bags, and...

Roads to ruin: conservation threats to a sentinel species across an urban gradient.

PubMed

Feist, Blake E; Buhle, Eric R; Baldwin, David H; Spromberg, Julann A; Damm, Steven E; Davis, Jay W; Scholz, Nathaniel L

2017-12-01

Urbanization poses a global challenge to species conservation. This is primarily understood in terms of physical habitat loss, as agricultural and forested lands are replaced with urban infrastructure. However, aquatic habitats are also chemically degraded by urban development, often in the form of toxic stormwater runoff. Here we assess threats of urbanization to coho salmon throughout developed areas of the Puget Sound Basin in Washington, USA. Puget Sound coho are a sentinel species for freshwater communities and also a species of concern under the U.S. Endangered Species Act. Previous studies have demonstrated that stormwater runoff is unusually lethal to adult coho that return to spawn each year in urban watersheds. To further explore the relationship between land use and recurrent coho die-offs, we measured mortality rates in field surveys of 51 spawning sites across an urban gradient. We then used spatial analyses to measure landscape attributes (land use and land cover, human population density, roadways, traffic intensity, etc.) and climatic variables (annual summer and fall precipitation) associated with each site. Structural equation modeling revealed a latent urbanization gradient that was associated with road density and traffic intensity, among other variables, and positively related to coho mortality. Across years within sites, mortality increased with summer and fall precipitation, but the effect of rainfall was strongest in the least developed areas and was essentially neutral in the most urbanized streams. We used the best-supported structural equation model to generate a predictive mortality risk map for the entire Puget Sound Basin. This map indicates an ongoing and widespread loss of spawners across much of the Puget Sound population segment, particularly within the major regional north-south corridor for transportation and development. Our findings identify current and future urbanization-related threats to wild coho, and show where green infrastructure and similar clean water strategies could prove most useful for promoting species conservation and recovery. © 2017 by the Ecological Society of America.

Deicing chemicals as source of constituents of highway runoff

USGS Publications Warehouse

Granato, G.E.

1996-01-01

The dissolved major and trace constituents of deicing chemicals as a source of constituents in highway runoff must be quantified for interpretive studies of highway runoff and its effects on surface water and groundwater. Dissolved constituents of the deicing chemicals-sodium chloride, calcium chloride, and premix (a mixture of sodium and calcium chloride)-were determined by analysis of salt solutions created in the laboratory and are presented as mass ratios to chloride. Deicing chemical samples studied are about 98 and 97 percent pure sodium chloride and calcium chloride, respectively: however, each has a distinct major and trace ion constituent signature. The greatest impurity in sodium chloride road sail samples was sulfate, followed by calcium, potassium, bromide, vanadium, magnesium, fluoride, and other constituents with a ratio to chloride of less than 0.0001 by mass. The greatest impurity in the calcium chloride road salt samples was sodium, followed by potassium, sulfate, bromide, silica, fluoride. strontium, magnesium, and other constituents with a ratio to chloride of less than 0.0001 by mass. Major constituents of deicing chemicals in highway runoff may account for a substantial source of annual chemical loads. Comparison of estimated annual loads and first flush concentrations of deicing chemical constituents in highway runoff with those reported in the literature indicate that although deicing chemicals are not a primary source of trace constituents, they are not a trivial source, either. Therefore, deicing chemicals should be considered as a source of many major and trace constituents in highway and urban runoff.

Using chloride and other ions to trace sewage and road salt in the Illinois Waterway

USGS Publications Warehouse

Kelly, W.R.; Panno, S.V.; Hackley, Keith C.; Hwang, H.-H.; Martinsek, A.T.; Markus, M.

2010-01-01

Chloride concentrations in waterways of northern USA are increasing at alarming rates and road salt is commonly assumed to be the cause. However, there are additional sources of Cl- in metropolitan areas, such as treated wastewater (TWW) and water conditioning salts, which may be contributing to Cl- loads entering surface waters. In this study, the potential sources of Cl- and Cl- loads in the Illinois River Basin from the Chicago area to the Illinois River's confluence with the Mississippi River were investigated using halide data in stream samples and published Cl- and river discharge data. The investigation showed that road salt runoff and TWW from the Chicago region dominate Cl- loads in the Illinois Waterway, defined as the navigable sections of the Illinois River and two major tributaries in the Chicago region. Treated wastewater discharges at a relatively constant rate throughout the year and is the primary source of Cl- and other elements such as F- and B. Chloride loads are highest in the winter and early spring as a result of road salt runoff which can increase Cl- concentrations by up to several hundred mg/L. Chloride concentrations decrease downstream in the Illinois Waterway due to dilution, but are always elevated relative to tributaries downriver from Chicago. The TWW component is especially noticeable downstream under low discharge conditions during summer and early autumn when surface drainage is at a minimum and agricultural drain tiles are not flowing. Increases in population, urban and residential areas, and roadways in the Chicago area have caused an increase in the flux of Cl- from both road salt and TWW. Chloride concentrations have been increasing in the Illinois Waterway since around 1960 at a rate of about 1 mg/L/a. The increase is largest in the winter months due to road salt runoff. Shallow groundwater Cl- concentrations are also increasing, potentially producing higher base flow concentrations. Projected increases in population and urbanization over the next several decades suggest that the trend of increasing Cl- concentrations and loads will continue. Given the susceptibility of aquatic ecosystems to increasing Cl- concentrations, especially short-term spikes following snow melts, deleterious effects on riverine ecosystems would be expected. ?? 2010 Elsevier Ltd. All rights reserved.

SSUIS - a research model for predicting suspended solids loads in stormwater runoff from urban impervious surfaces.

PubMed

Brodie, Ian M

2012-01-01

Suspended solids from urban impervious surfaces (SSUIS) is a spreadsheet-based model that predicts the mass loading of suspended solids (SS) in stormwater runoff generated from impervious urban surfaces. The model is intended to be a research tool and incorporates several particle accumulation and washoff processes. Development of SSUIS is based on interpretation of storm event data obtained from a galvanised iron roof, a concrete car park and a bitumen road located in Toowoomba, Australia. SSUIS is a source area model that tracks the particle mass balance on the impervious surface and within its lateral drain to a point of discharge. Particles are separated into two groups: free and detained, depending on the rainfall energy required for surface washoff. Calibration and verification of SSUIS against the Toowoomba SS data yielded R(2) values ranging from 0.60 to 0.98. Parameter sensitivity analysis and an example of how SSUIS can be applied to predict the treatment efficiency of a grass swale are also provided.

Catchment-scale evaluation of pollution potential of urban snow at two residential catchments in southern Finland.

PubMed

Sillanpää, Nora; Koivusalo, Harri

2013-01-01

Despite the crucial role of snow in the hydrological cycle in cold climate conditions, monitoring studies of urban snow quality often lack discussions about the relevance of snow in the catchment-scale runoff management. In this study, measurements of snow quality were conducted at two residential catchments in Espoo, Finland, simultaneously with continuous runoff measurements. The results of the snow quality were used to produce catchment-scale estimates of areal snow mass loads (SML). Based on the results, urbanization reduced areal snow water equivalent but increased pollutant accumulation in snow: SMLs in a medium-density residential catchment were two- to four-fold higher in comparison with a low-density residential catchment. The main sources of pollutants were related to vehicular traffic and road maintenance, but also pet excrement increased concentrations to a high level. Ploughed snow can contain 50% of the areal pollutant mass stored in snow despite its small surface area within a catchment.

Tropical stormwater floods: a sustainable solution

NASA Astrophysics Data System (ADS)

Molinie, Jack; Bade, Francois; Nagau, Jimmy; Nuiro, Paul

2017-04-01

Stormwater management is one of the most difficult problem of urban and suburban area. The urban runoff volume related to rain intensity and surfaces properties can lead to flood. Thereby, urban flooding creates considerable infrastructure problem, economics and human damages. In tropical countries, burgeoning human population coupled with unplanned urbanization altered the natural drainage. Consequently, classical intense rain around 100 cm/h produces frequent street flooding. In our case, we study the management of intense tropical rain, by using a network of individual rain storage tanks. The study area is economical and industrial zone installed in a coastal plain , with seventy per cent of impermeable surface (roads, parking lots, building roof, …) and thirty per cent of wetland (mangrove, …). Our solution is to delay the routes and parking lots runoff to the roof one. We propose sustainable individual water storage and a real time dynamical management, which permit to control the roof water arrival in the stormwater culvert. During the remaining time, the stored rainwater can be used for domestic activities instead of the use of drinking water.

Geomorphic characteristics and classification of Duluth-area streams, Minnesota

USGS Publications Warehouse

Fitzpatrick, Faith A.; Peppler, Marie C.; DePhilip, Michele M.; Lee, Kathy E.

2006-01-01

In 2003 and 2004, a geomorphic assessment of streams in 20 watersheds in the Duluth, Minn., area was conducted to identify and summarize geomorphic characteristics, processes, disturbance mechanisms, and potential responses to disturbance. Methods used to assess the streams included watershed characterization, descriptions of segment slopes and valley types, historical aerial photograph interpretation, and rapid field assessments and intensive field surveys of stream reaches. Geomorphic conditions were summarized into a segment-scale classification with 15 categories mainly based on drainage-network position and slope, and, secondarily, based on geologic setting, valley type, and dominant geomorphic processes. Main causes of geomorphic disturbance included historical logging and agriculture, and ongoing urban development, human-caused channel alterations, road and storm sewer drainage, ditching, hiking trails, and gravel pits or quarries. Geomorphic responses to these disturbances are dependent on a combination of drainage-network position, slope, and geologic setting. Geologic setting is related to drainage-network position because the geologic deposits parallel the Lake Superior shoreline. Headwater streams in large watersheds flow over glacial deposits above altitudes of about 1,200 feet (ft). Headwater tributaries and upper main stems have ditch-like channels with gentle slopes and no valleys. Urban development and road drainage cause increased runoff and flood peaks in these segments resulting in channel widening. Below about 1,200 ft, main-stem segments generally are affected by bedrock type and structure and have steep slopes and confined or entrenched valleys. Increases in flood peaks do not cause incision or widening in the bedrock-controlled valleys; instead, the flow and scour areas are expanded. Feeder tributaries to these main stems have steep, confined valleys and may be sources for sediment from urban areas, road runoff, or storm sewer outfalls. Main-stem segments near the glacial deposits/surficial bedrock contact (1,000–1,200 ft) have the most potential for response to disturbance because they tend to have narrow valleys with sandy glacial lakeshore deposits and moderate slopes. Increases in flood peaks (from upstream increases in runoff) increase the potential for landslides and mass wasting from valley sides as well as channel widening.

Reopening abandoned forest roads in northern Idaho, USA: Quantification of runoff, sediment concentration, infiltration, and interrill erosion parameters

Treesearch

R. B. Foltz; N. S. Copeland; W. J. Elliot

2009-01-01

This study measured runoff and sediment concentration from the tire track and from the non-tire track to determine infiltration, interrill erodibility, and vegetative cover impacts of reopening an abandoned forest road. Runoff was lowest on the non-track portion of the abandoned road and highest on the reopened road. Sediment concentrations were significantly higher on...

Basin-Scale Reconstruction of Flood Characteristics in a Small Urban Waterhsed

NASA Astrophysics Data System (ADS)

Miller, A. J.; Smith, J. A.; Baeck, M. L.

2006-05-01

Intense short-duration summer thunderstorms are primarily responsible for the occurrence of extreme floods in small, highly urban watersheds. In these systems hydrologic response is rapid and the role of urban infrastructure (impervious cover, storm drain networks, stormwater retention facilities, engineered channels, road embankments, bridges and culverts, and floodplain fill and regrading) has potentially important consequences for runoff generation and for flood-wave propagation. The occurrence of even a single well- documented extreme event provides an opportunity to improve our understanding of the relationships between temporal and spatial patterns of precipitation, natural and anthropogenic landscape features, and the dynamics of flood behavior. We report on combined field and modeling studies of a record flood (Qpk ~ 250 m3s-1) that occurred on 7 July 2004 in the 14.3 km2 Dead Run watershed in suburban Baltimore, Maryland. Flood peaks were reconstructed for nine locations in the watershed and streamflow hydrographs were derived for four locations where complete or partial stage records were recovered; these were compared with precipitation mass-balance estimates using bias-corrected radar rainfall data in order to examine the spatial pattern of runoff ratios, lag times, and cumulative properties of the flood wave as it advanced downstream. Flood behavior in part reflects the role of capacity constraints in the storm drain network and of ponding and storage of overbank flow by physical barriers such as road embankments and culverts. The results can be used to improve predictions of flood response to other hydrometeorological events and provide insight on sensitivity of flood behavior to patterns of urban development and infrastructure.

Recharge beneath low-impact design rain gardens and the influence of El Niño Southern Oscillation on urban, coastal groundwater resources

NASA Astrophysics Data System (ADS)

Newcomer, M. E.; Gurdak, J. J.

2011-12-01

Groundwater resources in urban, coastal environments are highly vulnerable to increased human pressures and climate variability. Impervious surfaces, such as buildings, roads, and parking lots prevent infiltration, reduce recharge to underlying aquifers, and increase contaminants in surface runoff that often overflow sewage systems. To mitigate these effects, cities worldwide are adopting low impact design (LID) approaches that direct runoff into natural vegetated systems, such as rain gardens that reduce, filter, and slow stormwater runoff, and are hypothesized to increase infiltration and recharge rates to aquifers. The effects of LID on recharge rates and quality is unknown, particularly during intense precipitation events for cities along the Pacific coast in response to interannual variability of the El Niño Southern Oscillation (ENSO). Using vadose zone monitoring sensors and instruments, I collected and monitored soil, hydraulic, and geochemical data to quantify the rates and quality of infiltration and recharge to the California Coastal aquifer system beneath a LID rain garden and traditional turf-lawn setting in San Francisco, CA. The data were used to calibrate a HYDRUS-3D model to simulate recharge rates under historical and future variability of ENSO. Understanding these processes has important implications for managing groundwater resources in urban, coastal environments.

Road Salts as Environmental Constraints in Urban Pond Food Webs

PubMed Central

Van Meter, Robin J.; Swan, Christopher M.

2014-01-01

Freshwater salinization is an emerging environmental filter in urban aquatic ecosystems that receive chloride road salt runoff from vast expanses of impervious surface cover. Our study was designed to evaluate the effects of chloride contamination on urban stormwater pond food webs through changes in zooplankton community composition as well as density and biomass of primary producers and consumers. From May – July 2009, we employed a 2×2×2 full-factorial design to manipulate chloride concentration (low = 177 mg L−1 Cl−/high = 1067 mg L−1 Cl−), gray treefrog (Hyla versicolor) tadpoles (presence/absence) and source of stormwater pond algae and zooplankton inoculum (low conductance/high conductance urban ponds) in 40, 600-L mesocosms. Road salt did serve as a constraint on zooplankton community structure, driving community divergence between the low and high chloride treatments. Phytoplankton biomass (chlorophyll [a] µg L−1) in the mesocosms was significantly greater for the high conductance inoculum (P<0.001) and in the high chloride treatment (P = 0.046), whereas periphyton biomass was significantly lower in the high chloride treatment (P = 0.049). Gray treefrog tadpole time to metamorphosis did not vary significantly between treatments. However, mass at metamorphosis was greater among tadpoles that experienced a faster than average time to metamorphosis and exposure to high chloride concentrations (P = 0.039). Our results indicate differential susceptibility to chloride salts among algal resources and zooplankton taxa, and further suggest that road salts can act as a significant environmental constraint on urban stormwater pond communities. PMID:24587259

Spatio-temporal dynamics of sediment sources in a peri-urban Mediterranean catchment

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Walsh, Rory; Blake, William; Kikuchi, Ryunosuke; Ferreira, António

2017-04-01

Sediment fluxes driven by hydrological processes lead to natural soil losses, but human activities, such as urbanization, influence hydrology and promote erosion, altering the landscape and sediment fluxes. In peri-urban areas, comprising a mixture of semi-natural and man-made land-uses, understanding sediment fluxes is still a research challenge. This study investigates spatial and temporal dynamics of fluvial sediments in a rapidly urbanizing catchment. Specific objectives are to understand the main sources of sediments relating to different types of urban land disturbance, and their variability driven by (i) weather, season and land-use changes through time, and (ii) sediment particle size. The study was carried out Ribeira dos Covões, a peri-urban catchment (6.2km2) in central Portugal. The climate is humid Mediterranean, with mean annual temperature and rainfall of 15˚ C and 892 mm, respectively. The geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). The catchment has an average slope of 9˚ , but includes steep slopes of up to 46˚ . The land-use is a complex mosaic of woodland (56%), urban (40%) and agricultural (4%) land parcels, resulting from urbanization occurring progressively since 1973. Urbanization since 2010 has mainly comprised the building of a major road, covering 1% of the catchment area, and the ongoing construction of an enterprise park, occupying 5% of the catchment. This study uses a multi-proxy sediment fingerprinting approach, based on X-Ray Fluorescence (XRF) analyses to characterize the elemental geochemistry of sediments collected within the stream network after three storm events in 2012 and 2015. A range of statistical techniques, including hierarchical cluster analysis, was used to identify discriminant sediment properties and similarities between fine bed-sediment samples of tributaries and downstream sites. Quantification of sediment supply from upstream sub-catchments was undertaken using a Bayesian unmixing model. Geochemical signatures of sub-catchment sediment varied significantly with lithology and type of urban influence, but a tendency for limestone sub-catchments to be more urbanized made it difficult to isolate the influence of each factor. Nevertheless, differences in sub-catchment geochemistry between the survey dates indicate significant changes through time in both the relative importance and character of urban impacts. In 2012 the sandstone sub-catchment provided 88%, 92% and 93% of the <63μm, 63μm-125μm and 125μm-2000μm sediment, respectively, with most sediment deriving from the enterprise park site undergoing deforestation and construction. Most of the remaining sediment derived from the construction of the major road in the limestone sub-catchment. In 2015, however, sediment losses within the catchment appear to have been significantly reduced by planned and accidental retention basins below the enterprise park and major road construction sites, respectively. Nevertheless, the landscape disturbance provided by these constructional sites was of much greater importance than sediment mobilization in urban areas with paved roads and other impervious surfaces. The greatest heavy metal concentrations, however, were recorded in sediments deriving from road runoff. Despite the positive impact of retention basins in reducing sediment delivery from human disturbed areas, sediment connectivity could be reduced further by dispersing and filtering upslope runoff from urban surfaces more systematically into woodland sink areas.

Evaluation of Seasonality in Shallow Groundwater Dynamics and Storage in an Urban Prairie Nature Preserve Using a High-Frequency Sensing Network

NASA Astrophysics Data System (ADS)

Rivera, V. A.; Hernandez-Gonzalez, L. M.; Phillips, C. B.; Nair, A.; Negri, M. C.; Gnaedinger, K. J.; Miller, W. M.; Packman, A. I.

2017-12-01

Changing regional climate applies stresses to urban areas in the form of altered weather patterns, requiring new strategies for stormwater runoff management and flood mitigation. At the same time, the proportion of people residing in urban areas is increasing and cities are turning to greenspace as a tool for managing runoff. Gensburg Markham Prairie (GMP), located in Markham, Illinois south of Chicago, is an urban prairie nature preserve and a U.S. National Natural Landmark. Owned by Northeastern Illinois University and managed by the Nature Conservancy, GMP receives runoff from surrounding urban areas and provides valuable stormwater storage, while also hosting high biodiversity and providing critical habitat for sensitive and endemic. A successful management strategy for GMP should preserve both of these valuable ecosystem services. To understand GMP's role within the urban environment, we installed a suite of instruments in 2016 and 2017 to measure surface and groundwater levels, rainfall, soil moisture, and electrical conductivity throughout the prairie. This monitoring network includes 40 sensors collecting high frequency data (every 30 minutes). We are also collecting monthly distributed surface and groundwater samples to quantify a range of anions and cations that signal potentially detrimental anthropogenic impacts on the prairie. In addition, we are using historical and ongoing plant distribution surveys to explore the interactions between spatial patterns in vegetation and water dynamics in the prairie. The high measurement frequency and large diversity of sensor types supports holistic investigation of the response of the prairie to diverse events, including summer thunderstorms, winter road salt runoff, and spring snowmelt. The 18 months of data collected to date reveals clear patterns in response to weather events with influence from soil type and spatial variables. We are using time-series analysis with MODFLOW modelling to explore surface-groundwater interactions within the site and the effects of seasonality on the prairie's capacity for storage of stormwater runoff. This analysis supports development of management strategies to preserve the prairie's ecological diversity and provide a basis for regional-scale design of green infrastructure for flood control.

Assessment of pollution in road runoff using a Bufo viridis biological assay.

PubMed

Dorchin, A; Shanas, U

2010-12-01

Road runoff is a major source of environmental pollution, significantly threatening nearby aquatic habitats. Chemical analyses indicate high pollutant concentrations in the road's "first flush", but bioassays are more advantageous for addressing the cumulative effects of the numerous pollutants within the runoff. We used Bufo viridis embryos and larvae to assess the toxicity of road runoff from two major highways in Israel. We show, for the first time, that exposure to midseason runoff not only has an adverse effect on growth and development rates of B. viridis larvae but can also lead to increased rates of morphological deformations. Seasonal first flushes, despite having higher metal concentrations, did not adversely affect the toad larvae, apparently due to a counter effect of organic matter that potentially served as a supplementary energy resource. Road runoff can be a major cause for a qualitative decrease in the quality of aquatic habitats threatening amphibians in Israel. Copyright © 2010 Elsevier Ltd. All rights reserved.

Urban flood mitigation planning for Guwahati: A case of Bharalu basin.

PubMed

Sarmah, Tanaya; Das, Sutapa

2018-01-15

Guwahati, the capital city of Assam and the gateway to the seven north-eastern Indian states, is located in the Brahmaputra valley-one of the most flood prone regions of the world. The city receives an average annual rainfall of 1688 mm and is highly vulnerable towards frequent urban floods because of uncontrolled dumping of solid waste and siltation have choked the natural water channels. This coupled with the absence of an integrated drainage network and rapid urbanisation causes floods in many parts of the city, after a quick downpour. Bharalu river is the main natural water channel of the city and Bharalu basin is the most vulnerable one. The present paper is an attempt to plan for urban flood mitigation, by designing an integrated drainage network for the Bharalu basin which includes the low-lying urbanized areas bordered by the Guwahati-Shillong Road, the Radha Gobindo Baruah Road and the Rajgarh Road. Data regarding land use, flood level, rainfall, urban pattern and vulnerability towards urban flood were collected from available literature, field survey to find highest water level for 11.4 km road stretch, expert opinion survey from 18 experts and feedback from 77 community elders who have been residing in the city since the 1980s. The Bharalu basin is divided into seven drainage blocks and storm run-off has been calculated based on the inputs. Seven different trapezoidal drainage sections were designed to form an integrated drainage network which is 'self-healing' to a certain extent. This can serve as a template for the other catchment basins and to design a drainage network for the entire Guwahati city, thereby reducing urban flood hazard to a significant extent. The study illustrates the necessity of an urban flood mitigation planning approach in sub-Himalayan urban settlements such as Guwahati. Copyright © 2017 Elsevier Ltd. All rights reserved.

Persistent Urban Impacts on Surface Water Quality Mediated by Stormwater Recharge

NASA Astrophysics Data System (ADS)

Gabor, R. S.; Brooks, P. D.; Neilson, B. T.; Bowen, G. J.; Jameel, M. Y.; Hall, S. J.; Eiriksson, D.; Millington, M. R.; Gelderloos, A.

2016-12-01

Growing population centers along mountain watersheds put added stress on sensitive hydrologic systems and create water quality impacts downstream. We examined the mountain-to-urban transition in watersheds on Utah's Wasatch Front to identify mechanisms by which urbanization impacts water resources. Rivers in the Wasatch flow from the mountains directly into an urban landscape, where they are subject to channelization, stormwater runoff systems, and urban inputs to water quality from sources such as road salt and fertilizer. As part of an interdisciplinary effort within the iUTAH project, multiple synoptic surveys were performed and a variety of measurements were made, including basic water chemistry along with discharge, water isotopes, and nutrients. Red Butte Creek, a stream in Salt Lake City, does not show significant urban impact to water quality until several kilometers after it enters the city where concentrations of solutes such as chloride and nitrate more than triple in a gaining reach. Groundwater springs discharging to this gaining section demonstrate urban-impacted water chemistry, suggesting that during baseflow a contaminated alluvial aquifer significantly controls stream chemistry. By combining hydrometric and hydrochemical observations we were able to estimate that these groundwater springs were 17-20% urban runoff. We were then able to predict the chemistry of urban runoff that feeds into the alluvial aquifer. Samples collected from storm culverts, roofs, and asphalt during storms had chemistry values within the range of those predicted by the mixing model. This evidence that urbanization affects the water quality of baseflow through impacted groundwater suggests that stormwater mitigation may not be sufficient for protecting urban watersheds, and quantifying these persistent groundwater mediated impacts is necessary to evaluate the success of restoration efforts. By comparing these results from Red Butte Creek with similar studies from other rivers in the Wasatch Front and other alluvial systems, we can quantify how characteristics such as discharge patterns and land-use determine alluvial recharge controls on surface water quality.

Influence of storm characteristics on soil erosion and storm runoff

Treesearch

Johnny M. III Grace

2008-01-01

Unpaved forest roads can be major sources of sediment from forested watersheds. Storm runoff from forest roads are a concern due to their potential delivery of sediments and nutrients to stream systems resulting in degraded water quality. The volume and sediment concentrations of stormwater runoff emanating from forest roads can be greatly influenced by storm...

Predicting forest road surface erosion and storm runoff from high-elevation sites

Treesearch

J. M. Grace III

2017-01-01

Forest roads are a concern in management because they represent areas of elevated risks associated with soil erosion and storm runoff connectivity to stream systems. Storm runoff emanating from forest roads and their connectivity to downslope resources can be influenced by a myriad of factors, including storm characteristics, management practices, and the interaction...

Rainfall-runoff relationships and water-quality assessment of Coon Creek watershed, Anoka County, Minnesota

USGS Publications Warehouse

Arntson, A.D.; Tornes, L.H.

1985-01-01

Water-quality characteristics were determined based on 14 water samples from 4 sites and 1 bottom-mate rial sample from each site. Results of the analyses indicated that streams draining urban areas carry the highest concentrations of most constituents sampled. Sand Creek at Xeon Boulevard, which drains the most urbanized area, had the highest mean concentration of metals, chloride, dissolved solids, and suspended sediment. Concentrations of total phosphorus ranged from 0.04 to 0.43 milligram per liter at the rural sites on County Ditch 58 at Andover Boulevard and Coon Creek at Raddison Road. Average phosphorus concentrations at the rural sites are comparable to concentrations at the urban sites.

Pollutant concentrations and pollution loads in stormwater runoff from different land uses in Chongqing.

PubMed

Wang, Shumin; He, Qiang; Ai, Hainan; Wang, Zhentao; Zhang, Qianqian

2013-03-01

To investigate the distribution of pollutant concentrations and pollution loads in stormwater runoff in Chongqing, six typical land use types were selected and studied from August 2009 to September 2011. Statistical analysis on the distribution of pollutant concentrations in all water samples shows that pollutant concentrations fluctuate greatly in rainfall-runoff, and the concentrations of the same pollutant also vary greatly in different rainfall events. In addition, it indicates that the event mean concentrations (EMCs) of total suspended solids (TSS) and chemical oxygen demand (COD) from urban traffic roads (UTR) are significantly higher than those from residential roads (RR), commercial areas (CA), concrete roofs (CR), tile roofs (TRoof), and campus catchment areas (CCA); and the EMCs of total phosphorus (TP) and NH3-N from UTR and CA are 2.35-5 and 3 times of the class-II standard values specified in the Environmental Quality Standards for Surface Water (GB 3838-2002). The EMCs of Fe, Pb and Cd are also much higher than the class-III standard values. The analysis of pollution load producing coefficients (PLPC) reveals that the main pollution source of TSS, COD and TP is UTR. The analysis of correlations between rainfall factors and EMCs/PLPC indicates that rainfall duration is correlated with EMCs/PLPC of TSS for TRoof and TP for UTR, while rainfall intensity is correlated with EMCs/PLPC of TP for both CR and CCA. The results of this study provide a reference for better management of non-point source pollution in urban regions.

Nonpoint Source Road Salt Pollution from Urban Stormwater

NASA Astrophysics Data System (ADS)

DeGaetano, S.; Walter, M. T.

2014-12-01

In colder climates, such as the Northeast, road salts are commonly applied to deice roads in order to increase pedestrian and driver safety. This study was conducted to establish the mass if NaCl entering the local aquatic systems from Cornell's campus. Using trail cameras, two typical storm water pipes (draining into Cascadilla Creek) were monitored to determine the volume of runoff on an hourly bases. Grab samples were taken three times a week obtain storm water chloride concentration. In general, the average measured salt concentration was found to be 3.61 g/L, while high precipitation events Cl- concentration spiked to levels exceeding 12 g/L (≈ 20 g/L of salt). Combining runoff volumes and salt concentration values, a mass per drainage area was calculated for each monitored pipe. Outfall #1, located just upstream from the Wilson Synchrotron Module, expelled 262,300 kg of salt over a 42-day period of data collection while Outfall#2 discharged 4160 kg during the same period. These results were averaged and then applied to the total impervious area on Cornell's campus to approximate the total mass of sodium chloride leaving campus during the period of data collection.

Particle size distribution and perchlorate levels in settled dust from urban roads, parks, and roofs in Chengdu, China.

PubMed

Li, Yiwen; Shen, Yang; Pi, Lu; Hu, Wenli; Chen, Mengqin; Luo, Yan; Li, Zhi; Su, Shijun; Ding, Sanglan; Gan, Zhiwei

2016-01-01

A total of 27 settled dust samples were collected from urban roads, parks, and roofs in Chengdu, China to investigate particle size distribution and perchlorate levels in different size fractions. Briefly, fine particle size fractions (<250 μm) were the dominant composition in the settled dust samples, with mean percentages of 80.2%, 69.5%, and 77.2% for the urban roads, roofs, and the parks, respectively. Perchlorate was detected in all of the size-fractionated dust samples, with concentrations ranging from 73.0 to 6160 ng g(-1), and the median perchlorate levels increased with decreasing particle size. The perchlorate level in the finest fraction (<63 μm) was significantly higher than those in the coarser fractions. To our knowledge, this is the first report on perchlorate concentrations in different particle size fractions. The calculated perchlorate loadings revealed that perchlorate was mainly associated with finer particles (<125 μm). An exposure assessment indicated that exposure to perchlorate via settled road dust intake is safe to both children and adults in Chengdu, China. However, due to perchlorate mainly existing in fine particles, there is a potential for perchlorate to transfer into surface water and the atmosphere by runoff and wind erosion or traffic emission, and this could act as an important perchlorate pollution source for the indoor environment, and merits further study.

Understanding the factors influencing the removal of heavy metals in urban stormwater runoff.

PubMed

Maniquiz-Redillas, Marla C; Kim, Lee-Hyung

2016-01-01

In this research, an infiltration trench equipped with an extensive pretreatment and filter bed consisting of woodchip, sand and gravel was utilized as a low impact development technique to manage stormwater runoff from a highly impervious road with particular emphasis on heavy metal removal. Findings revealed that the major factors influencing the removal of heavy metals were the concentration of the particulate matters and heavy metals in runoff, runoff volume and flow rates. The reduction of heavy metals was enhanced by sedimentation of particulates through pretreatment. Fine particles (<2 mm) had the most significant amount of heavy metals, thus, enhanced adsorption and filtration using various filter media were important design considerations. Sediment was most highly attached on the surface area of woodchip than to other filter media like sand, gravel and geotextile. It is suggested that maintenance must be performed after the end of the winter season wherein high sediment rate was observed to maintain the efficiency of the treatment system.

Evaluation of the relative roles of a vegetative filter strip and a biofiltration swale in a treatment train for road runoff.

PubMed

Flanagan, Kelsey; Branchu, Philippe; Ramier, David; Gromaire, Marie-Christine

2017-02-01

In order to determine the relative importance of a vegetative filter strip and a biofiltration swale in a treatment train for road runoff, US EPA Storm Water Management Model was used to model infiltration and runoff from the filter strip. The model consisted of a series of subcatchments representing the road, the filter strip and the side-slopes of the swale. Simulations were carried out for different rain scenarios representing a variety of climatic conditions. In addition, a sensitivity analysis was conducted for the model's different parameters (soil characteristics and initial humidity, roughness, geometry, etc.). This exercise showed that for the system studied, the majority of road runoff is treated by the filter strip rather than the biofiltration swale, an effect observed especially during periods of low-intensity rainfall. Additionally, it was observed that the combination of infiltration of road runoff in the filter strip and direct rainfall on the system leads to a significant and variable dilution of the runoff reaching the swale. This result has important implications for evaluating the treatment efficiency of the system.

Streamflow gains and losses along San Francisquito Creek and characterization of surface-water and ground-water quality, southern San Mateo and northern Santa Clara counties, California, 1996-97

USGS Publications Warehouse

Metzger, Loren F.

2002-01-01

San Francisquito Creek is an important source of recharge to the 22-square-mile San Francisquito Creek alluvial fan ground-water subbasin in the southern San Mateo and northern Santa Clara Counties of California. Ground water supplies as much as 20 percent of the water to some area communities. Local residents are concerned that infiltration and consequently ground-water recharge would be reduced if additional flood-control measures are implemented along San Francisquito Creek. To improve the understanding of the surface-water/ground-water interaction between San Francisquito Creek and the San Francisquito Creek alluvial fan, the U.S. Geological Survey (USGS) estimated streamflow gains and losses along San Francisquito Creek and determined the chemical quality and isotopic composition of surface and ground water in the study area.Streamflow was measured at 13 temporary streamflow-measurement stations to determine streamflow gains and losses along a 8.4-mile section of San Francisquito Creek. A series of five seepage runs between April 1996 and May 1997 indicate that losses in San Francisquito Creek were negligible until it crossed the Pulgas Fault at Sand Hill Road. Streamflow losses increased between Sand Hill Road and Middlefield Road where the alluvial deposits are predominantly coarse-grained and the water table is below the bottom of the channel. The greatest streamflow losses were measured along a 1.8-mile section of the creek between the San Mateo Drive bike bridge and Middlefield Road; average losses between San Mateo Drive and Alma Street and from there to Middlefield Road were 3.1 and 2.5 acre-feet per day, respectively.Downstream from Middlefield Road, streamflow gains and losses owing to seepage may be masked by urban runoff, changes in bank storage, and tidal effects from San Francisco Bay. Streamflow gains measured between Middlefield Road and the 1200 block of Woodland Avenue may be attributable to urban runoff and (or) ground-water inflow. Water-level measurements from nearby wells indicate that the regional water table may coincide with the channel bottom along this reach of San Francisquito Creek, particularly during the winter and early spring when water levels usually reach their maximum. Streamflow losses resumed below the 1200 block of Woodland Avenue, extending downstream to Newell Road. Discharge from a large storm drain between Newell Road and East Bayshore Road may account for the streamflow gains measured between these sites. Streamflow gains were measured between East Bayshore Road and the Palo Alto Municipal Golf Course, but this reach is difficult to characterize because of the probable influence of high tides.Estimated average streamflow losses totaled approximately 1,050 acre-feet per year for the reaches between USGS stream gage 11164500 at Stanford University (upstream of Junipero Serra Boulevard) and the Palo Alto Municipal Golf Course, including approximately 595 acre-feet per year for the 1.8-mile section between San Mateo Drive and Middlefield Road. Approximately 58 percent, or 550 acre-feet, of the total estimated average annual recharge from San Francisquito Creek occurs between the San Mateo Drive and Middlefield Road sites.The chemical composition of San Francisquito Creek water varies as a function of seasonal changes in hydrologic conditions. Measurements of specific conductance indicate that during dry weather and low flow, the dissolved-solids concentrations tends to be high, and during wet weather, the concentration tends to be low owing to dilution by surface water. Compared with water samples from upstream sites at USGS stream gage 11164500 and San Mateo Drive, the samples from the downstream sites at Alma Street and Woodland Avenue had low specific conductance; low concentrations of magnesium, sodium, sulfate, chloride, boron, and total dissolved solids; high nutrient concentrations; and light isotopic compositions indicating that urban runoff constitutes most of the streamflow

Sediment Export from Forest Road Turn-outs: A Study Design and Preliminary Results

Treesearch

Johnny M. Grace

1998-01-01

This paper reports the design and preliminary results of a study that evaluates the effects of commonly prescribed forest road runoff control treatments. A study design which utilizes runoff samplers, runoff diversion walls, sediment filter bags, and erosion stakes to evaluate sediment transport through runoff control treatments is documented. The study design will...

Topographic and road control of mega-gullies in Kinshasa (DR Congo)

NASA Astrophysics Data System (ADS)

Makanzu Imwangana, Fils; Dewitte, Olivier; Ntombi, Médard; Moeyersons, Jan

2014-07-01

Diachronic mapping (1957, 1967, 2007 and 2010) shows an exponentially growing mega-gully network since roads were constructed through in the forests and plantations which occupied the sandy soils of the high town of Kinshasa. We found that the spatial occurrence of the mega-gullies (width ≥ 5 m) in this newly urbanized environment is controlled by two factors. First, there is a topographic control, given by the relation S = 0.00008A- 1.459, with S being the slope gradient (m m- 1) of the soil surface at the gully head and A the drainage area (ha) above the head. There is also a ‘road’ control, expressed by S = 22.991Lc- 1.999, with Lc being the cumulated length of roads in the basin above the gully head. The co-existence of both controls reflects the fact that the local sands are highly permeable and hence roads are more important generators of continuous runoff. The S-A relation noted above should not be applied outside the town where the road network is less dense. In contrast, the S-Lc relation may be used in both the town and rural areas underlain by porous soils where roads are the only generators of continuous runoff. We further conclude that the high town of Kinshasa is one of the most vulnerable places for gullying, and gullying can potentially transform the town into a badland. ‘Artisanal’ gully treatment is more successful than generally believed and the S-Lc relation can be a tool for mega-gully prevention.

Hydrologic data from urban watersheds in the Tampa Bay area, Florida

USGS Publications Warehouse

Lopez, Miguel A.; Michaelis, D.M.

1979-01-01

Hydrologic data are being collected in 10 urbanized watersheds located in the Tampa Bay area, Florida. The gaged watersheds have impervious areas that range from 19 percent for a residential watershed in north Tampa to nearly 100 percent for a downtown Tampa watershed. Land-use types, including roads, residential, commercial, industrial, institutional, recreational , and open space, have been determined for each watershed. Rainfall and storm runoff data collected since 1971 for one site and since 1975 for six other sites through September 1976, have been processed. These data are recorded at 5-minute intervals and are stored in the U. S. Geological Survey WATSTORE unit values file. Daily rainfall at 12 sites and daily pan evaporation at one site have been stored in the WATSTORE daily values file. Chemical and biological analyses of storm runoff for six sites, base flow for seven sites, and analyses of bottom material for seven sites are also stored in the WATSTORE water-quality files. Rainfall and storm runoff for selected storms, daily rainfall, and daily pan-evaporation data are summarized in this report. Water-quality analyses of all water-quality samples also are listed. (Woodard-USGS).

Assessment of suspended solids concentration in highway runoff and its treatment implication.

PubMed

Hallberg, M; Renman, G

2006-09-01

It is understood that the major pollution from storm water is related to the content of particulate matter. One treatment practice is based on the first flush, i.e. detention of the initial part of the runoff that is considered to contain the highest concentrations of pollutants. This study has evaluated the concentration of total suspended solids in 30 consecutive runoff events during the winter season for an area of 6.7 hectares. A six-lane highway (E4) that has an annual average daily traffic load of 120,000 dominates the area and road de-icing salt (NaCl) and studded tires were in regular use during the studied period. The effluent standard for wastewater of 60 mg TSS per litre applied in EU was used to assess the treatment requirement of storm water. In only two of the events the event mean concentration was below 60 mg 1(-1). In four runoff events a partial event mean concentration below 60 mg 1(-1) was found, in 26 %, 12 %, 11 %, and 2 % respectively of the runoff volume. This would suggest that a capture of the initial part of the runoff for subsequent treatment is less applicable in this type of urban watershed.

Analysis of long-term trends (1950–2009) in precipitation, runoff and runoff coefficient in major urban watersheds in the United States

USGS Publications Warehouse

Velpuri, N.M.; Senay, G.B.

2013-01-01

This study investigates the long-term trends in precipitation, runoff and runoff coefficient in major urban watersheds in the United States. The seasonal Mann–Kendall trend test was performed on monthly precipitation, runoff and runoff coefficient data from 1950 to 2009 obtained from 62 urban watersheds covering 21 major urban centers in the United States. The results indicate that only five out of 21 urban centers in the United States showed an uptrend in precipitation. Twelve urban centers showed an uptrend in runoff coefficient. However, six urban centers did not show any trend in runoff coefficient, and three urban centers showed a significant downtrend. The highest rate of change in precipitation, runoff and runoff coefficient was observed in the Houston urban watershed. Based on the results obtained, we also attributed plausible causes for the trends. Our analysis indicated that while a human only influence is observed in most of the urban watersheds, a combined climate and human influence is observed in the central United States.

Size- and density-distributions and sources of polycyclic aromatic hydrocarbons in urban road dust.

PubMed

Murakami, Michio; Nakajima, Fumiyuki; Furumai, Hiroaki

2005-11-01

Polycyclic aromatic hydrocarbons (PAHs) present in size- and density-fractionated road dust were measured to identify the important fractions in urban runoff and to analyse their sources. Road dust was collected from a residential area (Shakujii) and a heavy traffic area (Hongo Street). The sampling of road dust from the residential area was conducted twice in different seasons (autumn and winter). The collected road dust was separated into three or four size-fractions and further fractionated into light (<1.7 g/cm3) and heavy (>1.7 g/cm3) fractions by using cesium chloride solution. Light particles constituted only 4.0+/-1.4%, 0.69+/-0.03% and 3.4+/-1.0% of the road dust by weight for Shakujii (November), Shakujii (February) and Hongo Street, respectively but contained 28+/-10%, 33+/-3% and 44+/-8% of the total PAHs, respectively. The PAH contents in the light fractions were 1-2 orders of magnitude higher than those in the heavy fractions. In the light fractions, the 12PAH contents in February were significantly higher than the 12PAH contents in November (P<0.01), whereas in the heavy fractions, no significant difference was found (P>0.05). Cluster analysis revealed that there was a significant difference in the PAH profiles between locations rather than between size-fractions, density-fractions and sampling times. Multiple regression analysis indicated that asphalt/pavement was the major source of Shakujii road dust, and that tyre and diesel vehicle exhaust were the major sources of finer and coarser fractions collected from Hongo Street road dust, respectively.

Automatic Classification of Aerial Imagery for Urban Hydrological Applications

NASA Astrophysics Data System (ADS)

Paul, A.; Yang, C.; Breitkopf, U.; Liu, Y.; Wang, Z.; Rottensteiner, F.; Wallner, M.; Verworn, A.; Heipke, C.

2018-04-01

In this paper we investigate the potential of automatic supervised classification for urban hydrological applications. In particular, we contribute to runoff simulations using hydrodynamic urban drainage models. In order to assess whether the capacity of the sewers is sufficient to avoid surcharge within certain return periods, precipitation is transformed into runoff. The transformation of precipitation into runoff requires knowledge about the proportion of drainage-effective areas and their spatial distribution in the catchment area. Common simulation methods use the coefficient of imperviousness as an important parameter to estimate the overland flow, which subsequently contributes to the pipe flow. The coefficient of imperviousness is the percentage of area covered by impervious surfaces such as roofs or road surfaces. It is still common practice to assign the coefficient of imperviousness for each particular land parcel manually by visual interpretation of aerial images. Based on classification results of these imagery we contribute to an objective automatic determination of the coefficient of imperviousness. In this context we compare two classification techniques: Random Forests (RF) and Conditional Random Fields (CRF). Experimental results performed on an urban test area show good results and confirm that the automated derivation of the coefficient of imperviousness, apart from being more objective and, thus, reproducible, delivers more accurate results than the interactive estimation. We achieve an overall accuracy of about 85 % for both classifiers. The root mean square error of the differences of the coefficient of imperviousness compared to the reference is 4.4 % for the CRF-based classification, and 3.8 % for the RF-based classification.

Assessment of water quality, road runoff, and bulk atmospheric deposition, Guanella Pass area, Clear Creek and Park Counties, Colorado, water years 1995-97

USGS Publications Warehouse

Stevens, Michael R.

2001-01-01

The Guanella Pass road, located about 40 miles west of Denver, Colorado, between the towns of Georgetown and Grant, has been designated a scenic byway and is being considered for reconstruction. The purpose of this report is to present an assessment of hydrologic and water-quality conditions in the Guanella Pass area and provide baseline data for evaluation of the effects of the proposed road reconstruction. The data were collected during water years 1995-97 (October 1, 1995, to September 30, 1997).Based on Colorado water-quality standards, current surface-water quality near Guanella Pass road was generally acceptable for specified use classifications of recreation, water supply, agriculture, and aquatic life. Streams had small concentrations of dissolved solids, nutrients, trace elements, and suspended sediment. An exception was upper Geneva Creek, which was acidic and had relatively large concentrations of iron, zinc, and other trace elements related to acid-sulfate weathering. Concentrations of many water-quality constituents, especially particle-related phases and suspended sediment, increased during peak snowmelt and rainstorm events and decreased to prerunoff concentrations at the end of runoff periods. Some dissolved (filtered) trace-element loads in Geneva Creek decreased during rainstorms when total recoverable loads remained generally static or increased, indicating a phase change that might be explained by adsorption of trace elements to suspended sediment during storm runoff.Total recoverable iron and dissolved zinc exceeded Colorado stream-water-quality standards most frequently. Exceedances for iron generally occurred during periods of high suspended-sediment transport in several streams. Zinc standards were exceeded in about one-half the samples collected in Geneva Creek 1.5 miles upstream from Grant.Lake-water quality was generally similar to that of area streams. Nitrogen and phosphorus ratios calculated for Clear and Duck Lakes indicated that phytoplankton in the lakes were probably phosphorus-limited. Measures of trophic status (secchi depth, total phosphorus, and chlorophyll-a) indicated that Duck and Clear Lakes were oligotrophic in 1997.Ground water had relatively low specific conductance (range 24 to 584 microsiemens per centimeter) and did not exceed U.S. Environmental Protection Agency drinking-water standards, except for samples collected from a single well, which exceeded the Proposed Maximum Contaminant Level for uranium.Runoff from the Guanella Pass road enters streams through surface channels connected to culverts and roadside ditches. Fifty-six percent of the total number of culvert and roadside-ditch drainage features on the Guanella Pass road showed evidence of recent surface runoff connection to an adjacent stream. Road runoff is generated during snowmelt and during summer rainstorms.At a road cross-drain culvert monitored continuously for discharge (water years 1996-97), most runoff (77 to 96 percent) was a result of snowmelt, and runoff from the road preceded the basinwide peak streamflow, resulting in sediment and water-quality constituent inputs to the stream when the stream?s capacity for dilution of the road runoff was low. Specific conductance of road-runoff samples ranged from 14 to 468 microsiemens per centimeter. Major-ion composition of some samples indicated effects from deicing salt (sodium chloride) and dust inhibitor (magnesium chloride) applied to sections of the road, but changes in the stream concentrations that might be attributed to the runoff were brief and relatively small.Nutrients were commonly measured in road-runoff samples at larger concentrations than in streamflow. Concentrations of nitrate and ammonia, especially during rainfall-generated road runoff, were more similar to the concentrations in precipitation than to the concentrations in stream water. Concentrations of ammonia plus organic nitrogen (total as N) (range less than 0.2 to 24 milligrams per liter) and t

Runoff thresholds and land-to-marine ecosystem connectivity in a dry tropical setting: St. John, US Virgin Islands

NASA Astrophysics Data System (ADS)

Ramos-Scharron, C. E.; LaFevor, M. C.; Roy, J.

2017-12-01

Developing a conceptually sound yet practical understanding of runoff and sediment delivery from human occupied lands to tropical ocean waters still represents a pivotal need of coral reef management worldwide. In the dry tropical and ephemeral streamflow setting that typifies the small watersheds ( 1s km2) draining the US Virgin Islands, changes in hydrologic and sediment delivery dynamics provoked by unsurfaced road networks represent a major threat to coral reefs and other sensitive marine ecosystems. Through a combined empirical and modeling approach, this study evaluates how road building and associated stormflow restoration strategies affect rainfall thresholds for runoff generation at varying spatial scales and their impact on land-to-sea connectivity. Rainfall thresholds and runoff coefficients for precipitation excess on unpaved roads are 2-3 mm and 22-30% (respectively) or a full order of magnitude different from those for undisturbed hillslopes and watersheds. Here we discuss the use of a `volume-to-breakthrough' inspired index to predict the potential of road runoff to reach downslope portions of the watershed and the coastline as runon. The index integrates the effects of storm-by-storm runoff accumulation for every road drainage point with its flow distance to specific locations along the stream network. While large runoff volumes and short flow distances imply a relatively high connectivity potential, small volumes and long distances are associated to low delivery potential. The index has proven able to discern observed runoff responses under a variety of road-stream network scenarios and rainfall conditions. These results enhance our understanding of ephemeral stream hydrology and are serving to improve coral reef management strategies throughout the Northeastern Caribbean.

Frequency analysis of urban runoff quality in an urbanizing catchment of Shenzhen, China

NASA Astrophysics Data System (ADS)

Qin, Huapeng; Tan, Xiaolong; Fu, Guangtao; Zhang, Yingying; Huang, Yuefei

2013-07-01

This paper investigates the frequency distribution of urban runoff quality indicators using a long-term continuous simulation approach and evaluates the impacts of proposed runoff control schemes on runoff quality in an urbanizing catchment in Shenzhen, China. Four different indicators are considered to provide a comprehensive assessment of the potential impacts: total runoff depth, event pollutant load, Event Mean Concentration, and peak concentration during a rainfall event. The results obtained indicate that urban runoff quantity and quality in the catchment have significant variations in rainfall events and a very high rate of non-compliance with surface water quality regulations. Three runoff control schemes with the capacity to intercept an initial runoff depth of 5 mm, 10 mm, and 15 mm are evaluated, respectively, and diminishing marginal benefits are found with increasing interception levels in terms of water quality improvement. The effects of seasonal variation in rainfall events are investigated to provide a better understanding of the performance of the runoff control schemes. The pre-flood season has higher risk of poor water quality than other seasons after runoff control. This study demonstrates that frequency analysis of urban runoff quantity and quality provides a probabilistic evaluation of pollution control measures, and thus helps frame a risk-based decision making for urban runoff quality management in an urbanizing catchment.

Assessing the Impact of Urbanization on Direct Runoff Using Improved Composite CN Method in a Large Urban Area.

PubMed

Li, Chunlin; Liu, Miao; Hu, Yuanman; Shi, Tuo; Zong, Min; Walter, M Todd

2018-04-17

Urbanization is one of the most widespread anthropogenic activities, which brings a range of physical and biochemical changes to hydrological system and processes. Increasing direct runoff caused by land use change has become a major challenge for urban ecological security. Reliable prediction of the quantity and rate of surface runoff is an inherently difficult and time-consuming task for large ungauged urban areas. In this study, we combined Geographic Information System and remote sensing technology with an improved Soil Conservation Service curve number model to evaluate the effects of land use change on direct runoff volume of the four-ring area in Shenyang, China, and analyzed trends of direct runoff at different scales. Through analyzing trends of direct runoff from 1984 to 2015 at different scales, we explored how urbanization and other potential factors affect direct runoff changes. Total direct runoff volume increased over time, and trends varied from the inner urban area to suburban area. Zones 1 and 2 had a tendency toward decreasing direct runoff volume and risks, while Zones 3 and 4 showed gradual increases at both regional and pixel scales. The most important influence on direct runoff change was urban surface change caused by urbanization. This study presents a framework for identifying hotspots of runoff increase, which can provide important guidance to urban managers in future green infrastructure planning, in the hopes of improving the security of urban water ecological patterns.

Assessing the Impact of Urbanization on Direct Runoff Using Improved Composite CN Method in a Large Urban Area

PubMed Central

Li, Chunlin; Liu, Miao; Hu, Yuanman; Shi, Tuo; Zong, Min; Walter, M. Todd

2018-01-01

Urbanization is one of the most widespread anthropogenic activities, which brings a range of physical and biochemical changes to hydrological system and processes. Increasing direct runoff caused by land use change has become a major challenge for urban ecological security. Reliable prediction of the quantity and rate of surface runoff is an inherently difficult and time-consuming task for large ungauged urban areas. In this study, we combined Geographic Information System and remote sensing technology with an improved Soil Conservation Service curve number model to evaluate the effects of land use change on direct runoff volume of the four-ring area in Shenyang, China, and analyzed trends of direct runoff at different scales. Through analyzing trends of direct runoff from 1984 to 2015 at different scales, we explored how urbanization and other potential factors affect direct runoff changes. Total direct runoff volume increased over time, and trends varied from the inner urban area to suburban area. Zones 1 and 2 had a tendency toward decreasing direct runoff volume and risks, while Zones 3 and 4 showed gradual increases at both regional and pixel scales. The most important influence on direct runoff change was urban surface change caused by urbanization. This study presents a framework for identifying hotspots of runoff increase, which can provide important guidance to urban managers in future green infrastructure planning, in the hopes of improving the security of urban water ecological patterns. PMID:29673182

Sediment production and runoff from forest road sideslopes

Treesearch

Johnny M. Grace; Robert Rummer; Bryce J. Stokes

1997-01-01

Sediment and runoff production from three erosion control treatments were investigated on a newly constructed road during a two-year study period. The treatments included a wood excelsior erosion mat, native grass species, and exotic grass species. Sediment and runoff production were significantly reduced on both the cutslope and fillslope by the treatments. Grass...

[Heavy metals pollution and analysis of seasonal variation runoff in Xi'an].

PubMed

Yuan, Hong-Lin; Li, Xing-Yu; Wang, Xiao-Chang

2014-11-01

In order to explore heavy metals pollution situation,changes in characteristics, the correlation between each heavy mental and pollution source analysis of Xi'an various regions in different season in one year. This study collected several samples of Xi'an rainfall typical urban trunk roads throughout the year in 2013 and used inductively coupled plasma mass spectrometry (ICP-MS) to determine the level of Fe, Mn, Pb, Zn, Al, Cd of the samples, then, analyzed the seasonal change of heavy mental. Studies have shown that: the heavy metal of Xi'an road runoff pollutes seriously, the concentration of Fe over three times of the national standard and maintain the higher levels throughout the year, meanwhile the concentration with the intensity of human activities increases. The concentration of Mn and Zn in one year show a trends: winter > autumn > summer> spring. Pb concentration increases with the increase in traffic volume, while showing: winter > spring > summer > autumn. Factor analysis shows: Fe and Al was affected by the same sources-natural sources; Zn, Cd affected by anthropogenic sources of large; Mn, Pb affected by the larger traffic sources.

Grand Forks - East Grand Forks Urban Water Resources Study. Flood Control Appendix.

DTIC Science & Technology

1981-07-01

Reach 4) is served by an extensive network of roads 4 ,! and railroads. U.S. Highway -2, Demers Avenue, and Minnesota Avenue pro- vide easy access to...their current focus of employment and social activity. It would require the construction of a new transportation and utility network at immense local...115 205 (1) See figure 4. (2) Outside study area; not to be devoped . Table 2 - Estimated peak runoff 10-year frequency Peak flow Existing Future

Reopening abandoned forest roads in northern Idaho, USA: quantification of runoff, sediment concentration, infiltration, and interrill erosion parameters.

PubMed

Foltz, R B; Copeland, N S; Elliot, W J

2009-06-01

This study measured runoff and sediment concentration from the tire track and from the non-tire track to determine infiltration, interrill erodibility, and vegetative cover impacts of reopening an abandoned forest road. Runoff was lowest on the non-track portion of the abandoned road and highest on the reopened road. Sediment concentrations were significantly higher on the reopened road. Increased sediment concentrations were attributed to decreased vegetative cover, rather than traffic-induced changes in the physical soil properties of the reopened road. Thirty years of no traffic and vegetation regrowth was not sufficient to allow recovery of infiltration to values similar to an undisturbed forest. The study also found a significant dynamic behavior in interrill erodibility with respect to antecedent rainfall. Forest road erosion models that fail to account for this change will overestimate sediment yields.

A novel approach to model dynamic flow interactions between storm sewer system and overland surface for different land covers in urban areas

NASA Astrophysics Data System (ADS)

Chang, Tsang-Jung; Wang, Chia-Ho; Chen, Albert S.

2015-05-01

In this study, we developed a novel approach to simulate dynamic flow interactions between storm sewers and overland surface for different land covers in urban areas. The proposed approach couples the one-dimensional (1D) sewer flow model (SFM) and the two-dimensional (2D) overland flow model (OFM) with different techniques depending on the land cover type of the study areas. For roads, pavements, plazas, and so forth where rainfall becomes surface runoff before entering the sewer system, the rainfall-runoff process is simulated directly in the 2D OFM, and the runoff is drained to the sewer network via inlets, which is regarded as the input to 1D SFM. For green areas on which rainfall falls into the permeable ground surface and the generated direct runoff traverses terrain, the deduction rate is applied to the rainfall for reflecting the soil infiltration in the 2D OFM. For flat building roofs with drainage facilities allowing rainfall to drain directly from the roof to sewer networks, the rainfall-runoff process is simulated using the hydrological module in the 1D SFM where no rainfall is applied to these areas in the 2D OFM. The 1D SFM is used for hydraulic simulations in the sewer network. Where the flow in the drainage network exceeds its capacity, a surcharge occurs and water may spill onto the ground surface if the pressure head in a manhole exceeds the ground elevation. The overflow discharge from the sewer system is calculated by the 1D SFM and considered a point source in the 2D OFM. The overland flow will return into the sewer network when it reaches an inlet that connects to an un-surcharged manhole. In this case, the inlet is considered as a point sink in the 2D OFM and an inflow to a manhole in the 1D SFM. The proposed approach was compared to other five urban flood modelling techniques with four rainfall events that had previously recorded inundation areas. The merits and drawbacks of each modelling technique were compared and discussed. Based on the simulated results, the proposed approach was found to simulate floodings closer to the survey records than other approaches because the physical rainfall-runoff phenomena in urban environment were better reflected.

Causes of highway road dust toxicity to an estuarine amphipod: Evaluating the effects of nicotine.

PubMed

Hiki, Kyoshiro; Nakajima, Fumiyuki; Tobino, Tomohiro

2017-02-01

Urban road dust can potentially have adverse effects on ecosystems if it is discharged into receiving waters. This study investigated the causes of highway road dust toxicity by performing sediment toxicity identification evaluation (TIE) tests with an estuarine amphipod, Grandidierella japonica. In addition to metals and polycyclic aromatic hydrocarbons, which are traditionally considered to be the major toxicants in road runoff, we focused on dissolved nicotine as a causative toxicant. The sediment TIE results suggested that organic contaminants contributed to the majority of toxicity, and that the contribution of unionized nicotine to the toxicity was the highest among the chemicals considered. However, additional mortality tests with 48-h pulsed nicotine exposure demonstrated that exposure to nicotine at the same concentration as the baseline level in TIE tests did not cause significant 10-day amphipod mortality. Thus, the road dust toxicity could not be explained only by unionized nicotine, thereby suggesting contributions from joint effects of the measured toxicants and the presence of other unmeasured factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Methodology for the Characterization and Management of Nonpoint Source Water Pollution

DTIC Science & Technology

1992-09-01

Nonpoint Source water pollution management tool. However, the stormwater runoff sampling program conducted at the Air Force Academy for validation proved...17 Nationwide Urban Runoff Program (NUEP) . 19 Urban Runoff Pollutant Characteristics . 20 Annual Urban Runoff Loads . . . . . . . 22...55 Sampling Plan . . . . . . . . . . . . . . . . 55 Samples for Baseline Data. ... . . .... 56 Samples for Runoff Data

Monitor-based evaluation of pollutant load from urban stormwater runoff in Beijing.

PubMed

Liu, Y; Che, W; Li, J

2005-01-01

As a major pollutant source to urban receiving waters, the non-point source pollution from urban runoff needs to be well studied and effectively controlled. Based on monitoring data from urban runoff pollutant sources, this article describes a systematic estimation of total pollutant loads from the urban areas of Beijing. A numerical model was developed to quantify main pollutant loads of urban runoff in Beijing. A sub-procedure is involved in this method, in which the flush process influences both the quantity and quality of stormwater runoff. A statistics-based method was applied in computing the annual pollutant load as an output of the runoff. The proportions of pollutant from point-source and non-point sources were compared. This provides a scientific basis for proper environmental input assessment of urban stormwater pollution to receiving waters, improvement of infrastructure performance, implementation of urban stormwater management, and utilization of stormwater.

Prairie and turf buffer strips for controlling runoff from paved surfaces.

PubMed

Steinke, K; Stier, J C; Kussow, W R; Thompson, A

2007-01-01

Eutrophication of surface waters due to nonpoint source pollution from urban environments has raised awareness of the need to decrease runoff from roads and other impervious surfaces. These concerns have led to precautionary P application restrictions on turf and requirements for vegetative buffer strips. The impacts of two plant communities and three impervious/pervious surface ratios were assessed on runoff water quality and quantity. A mixed forb/grass prairie and a Kentucky bluegrass (Poa pratensis L.) blend were seeded and runoff was monitored and analyzed for total volume, total P, soluble P, soluble organic P, bioavailable P, total suspended solids, and total organic suspended solids. Mean annual runoff volumes, all types of mean annual P nutrient losses, and sediment loads were not significantly affected by treatments because over 80% of runoff occurred during frozen soil conditions. Total P losses from prairie and turf were similar, averaging 1.96 and 2.12 kg ha(-1) yr(-1), respectively. Vegetation appeared to be a likely contributor of nutrients, particularly from prairie during winter dormancy. When runoff occurred during non-frozen soil conditions turf allowed significantly (P < or = 0.10) lower runoff volumes compared with prairie vegetation and the 1:2 and 1:4 impervious/pervious surface ratios had less runoff than the 1:1 ratio (P < or = 0.05). In climates where the majority of runoff occurs during frozen ground conditions, vegetative buffers strips alone are unlikely to dramatically reduce runoff and nutrient loading into surface waters. Regardless of vegetation type or size, natural nutrient biogeochemical cycling will cause nutrient loss in surface runoff waters, and these values may represent baseline thresholds below which values cannot be obtained.

[Pollution load and the first flush effect of BOD5 and COD in urban runoff of Wenzhou City].

PubMed

Wang, Jun; Bi, Chun-juan; Chen, Zhen-lou; Zhou, Dong

2013-05-01

Four typical rainfalls were monitored in two different research areas of Wenzhou Municipality. Concentrations of BOD5 and COD in six different urban runoffs were measured. In addition the event mean concentration (EMC), M (V) curve and BOD5/COD of pollutant were calculated. The results showed that concentrations of BOD5 and COD in different urban runoffs of Wenzhou ranged from ND to 69.21 mg x L(-1) and ND to 636 mg x L(-1). Concentrations of BOD5 and COD in different urban runoffs were decreasing over time, so it is greatly significant to manage the initial runoff for reducing organic pollution. Judged by EMC of BOD5 and COD in these five rainfalls, concentrations of pollutant in some urban runoffs were out of the integrated wastewater discharge standard. If these runoffs flowed into river, it would cause environmental pressure to the next level receiving water bodies. According to the M (V) curve, the first flush effect of COD in most urban runoffs was common; while the first flush effect of BOD5 was same as that of COD. The result also showed that organic pollution was serious at the beginning of runoff. The underlying surface type could affect the concentration of BOD5 and COD in urban runoff. While the results of BOD5/COD also suggested that biodegradation was considered as one of the effective ways to decrease the pollution load of organics in urban runoff, and the best management plans (BMPs) should be selected for various urban runoff types for the treatment of organic pollution.

Urbanisation impacts on storm runoff along a rural-urban gradient

NASA Astrophysics Data System (ADS)

Miller, James David; Hess, Tim

2017-09-01

Urbanisation alters the hydrological response of catchments to storm events and spatial measures of urban extent and imperviousness are routinely used in hydrological modelling and attribution of runoff response to land use changes. This study evaluates whether a measure of catchment urban extent can account for differences in runoff generation from storm events along an rural-urban gradient. We employed a high-resolution monitoring network across 8 catchments in the south of the UK - ranging from predominantly rural to heavily urbanised - over a four year period, and from this selected 336 storm events. Hydrological response was compared using volume- and scaled time-based hydrograph metrics within a statistical framework that considered the effect of antecedent soil moisture. Clear differences were found between rural and urban catchments, however above a certain threshold of urban extent runoff volume was relatively unaffected by changes and runoff response times were highly variable between catchments due to additional hydraulic controls. Results indicate a spatial measure of urbanisation can generally explain differences in the hydrological response between rural and urban catchments but is insufficient to explain differences between urban catchments along an urban gradient. Antecedent soil moisture alters the volume and timing of runoff generated in catchments with large rural areas, but was not found to affect the runoff response where developed areas are much greater. The results of this study suggest some generalised relationships between urbanisation and storm runoff are not represented in observed storm events and point to limitations in using a simplified representations of the urban environment for attribution of storm runoff in small urban catchments. The study points to the need for enhanced hydrologically relevant catchment descriptors specific to small urban catchments and more focused research on the role of urban soils and soil moisture in storm runoff generation in mixed land-use catchments.

Simulating the effect of flow path roughness to examine how green infrastructure restores urban runoff timing and magnitude

Treesearch

Yang Yang; Theodore A. Endreny; David J. Nowak

2015-01-01

Impervious land cover was the choice for many urban development projects in order to accelerate runoff and reduce the depth and duration of local flooding, however this led to increases in downstream runoff characterized by large, flashy peak flows. Urban ecosystem restoration now involves slowing down urban runoff to restore local hydrology with green infrastructure,...

[Pollution load and the first flush effect of phosphorus in urban runoff of Wenzhou City].

PubMed

Zhou, Dong; Chen, Zhen-lou; Bi, Chun-juan

2012-08-01

Five typical rainfalls were monitored in two different research areas of Wenzhou municipality. The pH and concentrations of total phosphorus (TP), dissolved phosphorus (DP), particulate phosphorus (PP), total inorganic carbon (TIC), total organic carbon (TOC), total suspended substances (TSS), BOD5 and COD in six different kinds of urban runoff were measured. The results showed that, the concentrations of TP, DP and PP in different kinds of urban runoff of Wenzhou ranged from 0.01 to 4.32 mg x L(-1), ND to 0.88 mg x L(-1) and ND to 4.31 mg x L(-1), respectively. In the early stages of runoff process PP was dominated, while in the later, the proportion of DP in most of the runoff samples would show a rising trend, especially in roof and outlet runoff. Judged by the event mean concentration (EMC) of TP and DP in these five rainfalls, some kinds of urban runoff could cause environmental pressure to the next level receiving water bodies. Meanwhile, the differences among the TP and DP content (maximum, minimum and mean content) in various urban runoffs were significant, and so were the differences among various rainfall events. According to the M (V) curve, the first flush effect of TP in most kinds of urban runoff was common; while the first flush effect of DP was more difficult to occur comparing with TP. Not only the underlying surface types but also many physico-chemical properties of runoff could affect the concentration of TP in urban runoff. All the results also suggested that different best management plans (BMPs) should be selected for various urban runoff types for the treatment of phosphorus pollution, and reducing the concentration of TSS is considered as one of the effective ways to decrease the pollution load of phosphorus in urban runoff.

Pesticides in storm runoff from agricultural and urban areas in the Tuolumne River basin in the vicinity of Modesto, California

USGS Publications Warehouse

Kratzer, Charles R.

1998-01-01

The occurrence, concentrations, and loads of dissolved pesticides in storm runoff were compared for two contrasting land uses in the Tuolumne River Basin, California, during two different winter storms: agricultural areas (February 1994) and the Modesto urban area (February 1995). Both storms followed the main application period of pesticides on dormant almond orchards. Eight samples of runoff from agricultural areas were collected from a Tuolumne River site, and 10 samples of runoff from urban areas were collected from five storm drains. All samples were analyzed for 46 pesticides. Six pesticides were detected in runoff from agricultural areas, and 15 pesticides were detected in runoff from urban areas. Chlorpyrifos, diazinon, dacthal (DCPA), metolachlor, and simazine were detected in almost every sample. Median concentrations were higher in the runoff from urban areas for all pesticides except napropamide and simazine. The greater occurrence and concentrations in storm drains is partly attributed to dilution of agricultural runoff by nonstorm base-flow in the Tuolumne River and by storm runoff from nonagricultural and nonurban land. In most cases, the occurrence and relative concentrations of pesticides found in storm runoff from agricultural and urban areas were related to reported pesticide application. Pesticide concentrations in runoff from agricultural areas were more variable during the storm hydrograph than were concentrations in runoff from urban areas. All peak pesticide concentrations in runoff from agricultural areas occurred during the rising limb of the storm hydrograph, whereas peak concentrations in the storm drains occurred at varying times during the storm hydrograph. Transport of pesticides from agricultural areas during the February 1994 storm exceeded transport from urban areas during the February 1995 storm for chlorpyrifos, diazinon, metolachlor, napropamide, and simazine. Transport of DCPA was about the same from agricultural and urban sources, and the main source of transport for the other pesticides could not be determined because of concentrations less than the method detection limit.

Anthropogenic Sources of Arsenic and Copper to Sediments of a Suburban Lake, 1964-1998

NASA Astrophysics Data System (ADS)

Rice, K. C.; Conko, K. M.; Hornberger, G. M.

2002-05-01

Nonpoint-source pollution from urbanization is becoming a widespread problem. Long-term monitoring data are necessary to document geochemical processes in urban settings and changes in sources of chemical contaminants over time. In the absence of long-term data, lake-sediment cores can be used to reconstruct past processes, because they serve as integrators of sources of pollutants from the contributing airshed and catchment. Lake Anne is a 10.9-ha man-made lake in a 235-ha suburban catchment in Reston, Virginia, with a population density of 1,116 people/km2. Three sediment cores, collected in 1996 and 1997, indicate increasing concentrations of arsenic and copper since 1964, when the lake was formed. The cores were compared to a core collected from a forested catchment in the same airshed that showed no increases in concentrations of these elements. Neither an increase in atmospheric deposition nor diagenesis and remobilization were responsible for the trends in the Lake Anne cores. Mass balances of sediment, arsenic, and copper were calculated using 1998 data on precipitation, streamwater, road runoff, and a laboratory leaching experiment on pressure-treated lumber. Sources of arsenic to the lake in 1998 were in-lake leaching of pressure-treated lumber (52%) and streamwater (47%). Road runoff was a greater (93%) source of copper than leaching of pressure-treated lumber (4%). Atmospheric deposition was an insignificant source (<3%) of both elements. Urbanization of the catchment was confirmed as a major cause of the increasing arsenic and copper in the lake cores through an annual historical reconstruction of the deposition of sediment, arsenic, and copper to the lake for 1964-1997. Aerial photography indicated that the area of roads and parking lots in the catchment increased to 26% by 1997 and that the number of docks on the lake also increased over time. The increased mass of arsenic and copper in the lake sediments corresponded to the increased amount of pressure-treated lumber in the lake, and the mass of copper also corresponded to the increase in paved surfaces in the catchment.

Transportation and Hydrology Studies of the U.S. Geological Survey in New England

USGS Publications Warehouse

Lombard, Pamela J.

2016-03-23

In New England, the USGS is conducting investigations to improve flood flow estimation techniques, to define channel characteristics at bankfull discharge, and to document storm tide as a result of major coastal storms. Current locally focused investigations include examination of flow frequency in rural, urban, and small watersheds; documentation of extreme inland floods along with flood-frequency updates; examination of the effects of roadway blasting on groundwater quality; and determinations of the effects of road salting on the quality of runoff and receiving waters.

Hydrologic data for urban storm runoff in the Denver metropolitan area, Colorado

USGS Publications Warehouse

Gibbs, Johnnie W.; Doefer, John T.

1982-01-01

Urban storm-runoff data collected from April through September 1981 from nine Denver Nationwide Urban Runoff Program sites, urban storm-runoff data collected from April 1980 through September 1981 from ten South Platte River Study sites, and rainfall-runoff simulation data from two sites for June 1980 and May 1981 are presented in this report. The Denver Nationwide Urban Runoff Program sites were two single-family residential areas, two multifamily residential areas, one commercial area (shopping center), one mixed commercial and multifamily residential area, one natural area (open space), and two detention ponds. The South Platte River Study sites were six tributaries of the South Platte River and four instream sites on the South Platte River. The tributary sites were Bear Creek at mouth, at Sheridan; Harvard Gulch at Harvard Park, at Denver; Sanderson Gulch at mouth, at Denver; Weir Gulch at mouth, at Denver; Lakewood Gulch at mouth, at Denver; and Cherry Creek at Denver. The instream sites were South Platte River at Littleton; South Platte River at Florida Avenue, at Denver; South Platte River at Denver; and South Platte River at 50th Avenue, at Denver. The rainfall-runoff simulation sites were North Avenue at Denver Federal Center, at Lakewood and Rooney Gulch at Rooney Ranch, near Morrison. Precipitation, rainfall-runoff, water-quality data, and basin characteristics were collected at the urban storm-runoff sites. The urban storm-runoff data may be used to characterize runoff loading for various land-use types in Denver and other semiarid regions. (USGS)

Toxicity characterization of urban stormwater with bioanalytical tools.

PubMed

Tang, Janet Y M; Aryal, Rupak; Deletic, Ana; Gernjak, Wolfgang; Glenn, Eva; McCarthy, David; Escher, Beate I

2013-10-01

Stormwater harvesting has become an attractive alternative strategy to address the rising demand for urban water supply due to limited water sources and population growth. Nevertheless, urban stormwater is also a major source of surface water pollution. Runoff from different urban catchments with source contributions from anthropogenic activities and various land uses causes variable contaminant profiles, thus posing a challenging task for environmental monitoring and risk assessment. A thorough understanding of raw stormwater quality is essential to develop appropriate treatment facilities for potential indirect potable reuse of stormwater. While some of the key chemical components have previously been characterized, only scarce data are available on stormwater toxicity. We benchmarked stormwater samples from urban, residential and industrial sites across various Australian capital cities against samples from the entire water cycle, from sewage to drinking water. Six biological endpoints, targeting groups of chemicals with modes of toxic action of particular relevance for human and environmental health, were investigated: non-specific toxicity (Microtox and combined algae test), the specific modes of action of phytotoxicity (combined algae test), dioxin-like activity (AhR-CAFLUX), and estrogenicity (E-SCREEN), as well as reactive toxicity encompassing genotoxicity (umuC) and oxidative stress (AREc32). Non-specific toxicity was highly variable across sites. The baseline toxicity equivalent concentrations of the most polluted samples were similar to secondary treated effluent from wastewater treatment plants. Phytotoxicity results correlated well with the measured herbicide concentrations at all sites. High estrogenicity was found in two sampling events and could be related to sewage overflow. Genotoxicity, dioxin-like activity, and oxidative stress response were evident in only three of the samples where the stormwater drain was beside a heavy traffic road, confirming that road runoff is the potential source of contaminants, while the bioanalytical equivalent concentrations (BEQ) of these samples were similar to those of raw sewage. This study demonstrates the benefit of bioanalytical tools for screening-level stormwater quality assessment, forming the basis for the evaluation of future stormwater treatment and reuse schemes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of the capability of low-impact development practices for the removal of heavy metal from urban stormwater runoff.

PubMed

Maniquiz-Redillas, Marla C; Kim, Lee-Hyung

2016-09-01

Low-impact development (LID) and green infrastructure (GI) have recently become well-known methods to capture, collect, retain, and remove pollutants in stormwater runoff. The research was conducted to assess the efficiency of LID/GI systems applied in removing the particulate and dissolved heavy metals (Zn, Pb, Cu, Ni, Cr, Cd, and Fe) from urban stormwater runoff. A total of 82 storm events were monitored over a four-year period (2010-2014) on six LID/GI systems including infiltration trenches, tree box filter, rain garden, and hybrid constructed wetlands employed for the management of road, parking lot, and roof runoff. It was observed that the heavy metal concentration increased proportionally with the total suspended solids concentration. Among the heavy metal constituents, Fe appeared to be highly particulate-bound and was the easiest to remove followed by Zn and Pb; while metals such as Cr, Ni, Cu, and Cd were mostly dissolved and more difficult to remove. The mass fraction ratios of metal constituents at the effluent were increased relative to the influent. All the systems performed well in the removal of particulate-bound metals and were more efficient for larger storms greater than 15 mm wherein more particulate-bound metals were generated compared to smaller storms less than 5 mm that produced more dissolved metals. The efficiency of the systems in removing the particulate-bound metals was restricted during high average/peak flows; that is, high-intensity storms events and when heavy metals have low concentration levels.

Implementation of an urban irrigation and a biofiltration system in the urban canopy model CLM-U

NASA Astrophysics Data System (ADS)

Demuzere, Matthias; Coutts, Andrew; Göhler, Maren; Diels, Jan; Gebert, Luke; Wouters, Hendrik; Van Lipzig, Nicole

2013-04-01

A recent review by Coutts et al. (2012) points out that to date the role of water in influencing urban climates through both irrigation and the support of urban vegetation receives less attention. Impervious urban surfaces prevent infiltration, and runoff is rapidly exported away from urban environments via the stormwater network. This produces a deficit of water in urban areas, and reduces soil moisture levels - a deficit that is often balanced by imported potable water to maintain a healthy vegetation via irrigation. Because of long-term dry spells over large areas of Australia in the last decades, State Governments introduced compulsory and voluntary strategies to encourage water saving across the community - including outdoor water restrictions. In this respect, residents have adapted gardening approaches by planting more drought-tolerant species. Each of these factors of drought, water restrictions and xeric gardens, along with the reduced health of urban vegetation, may further exacerbate urban warming and energy demands. In this respect, this study explores possible pathways towards a more Water Sensitive Urban Design (WSUD), implementing a decentralisation of water supply via residential rainwater tanks that collect run-off water from the roofs, an urban irrigation system connected to these rainwater tanks and bio-infiltration systems in which the impervious road fraction drains. All changes are implemented in the Community Land Model - Urban (CLM-U) and several sensitivity tests are performed for the residential area of Preston (Melbourne, Australia) in order to answer the question on how much water is actually needed to maintain healthy vegetation and where this water should come from. Can rainwater tanks provide a sufficient capacity to irrigate bio-infiltration systems or will it be necessary to apply high-quality potable water? In addition, this research can also be used to quantify the role of WSUD with respect to thermal comfort.

Assessing the Source-to-Stream Transport of Benzotriazoles during Rainfall and Snowmelt in Urban and Agricultural Watersheds.

PubMed

Parajulee, Abha; Lei, Ying Duan; De Silva, Amila O; Cao, Xiaoshu; Mitchell, Carl P J; Wania, Frank

2017-04-18

While benzotriazoles (BTs) are ubiquitous in urban waters, their sources and transport remain poorly characterized. We aimed to elucidate the origin and hydrological pathways of BTs in Toronto, Canada, by quantifying three BTs, electrical conductivity, and δ 18 O in high-frequency streamwater samples taken during two rainfall and one snowmelt event in two watersheds with contrasting levels of urbanization. Average concentrations of total BTs (∑BT) were 1.3 to 110 times higher in the more urbanized Mimico Creek watershed relative to the primarily agricultural and suburban Little Rouge Creek. Strong correlations between upstream density of major roads and total BT concentrations or BT composition within all events implicate vehicle fluids as the key source of BTs in both watersheds. Sustained historical releases of BTs within the Mimico Creek watershed have likely led to elevated ∑BT in groundwater, with elevated concentrations observed during baseflow that are diluted by rainfall and surface runoff. In contrast, relatively constant concentrations, caused by mixing of equally contaminated baseflow and rainfall/surface runoff, are observed in the Little Rouge Creek throughout storm hydrographs, with an occasional first flush occurring at a subsite draining suburban land. During snowmelt, buildup of BTs in roadside snowpiles and preferential partitioning of BTs to the liquid phase of a melting snowpack leads to early peaks in ∑BT in both streams, except the sites in the Little Rouge Creek with low levels of vehicle traffic. Overall, a history of BT release and land use associated with urbanization have led to higher levels of BTs in urban areas and provide a glimpse into future BT dynamics in mixed use, (sub)urbanizing areas.

Determining the Chemical and Biological Availability of Zinc in Urban Stormwater Retention Ponds

NASA Astrophysics Data System (ADS)

Camponelli, K.; Casey, R.; Lev, S. M.; Landa, E. R.; Snodgrass, J.

2005-12-01

Highway runoff has the potential to negatively impact receiving systems due to transport of contaminants that accumulate on road surfaces. Metals such as copper and zinc are major components of automobile brake pads and tires, respectively. As these automobile parts are degraded, these metal containing particulates are deposited on the roadway and are washed into storm water retention ponds and surface water bodies during precipitation events. It has been estimated that 15 to 60% of the Zn in urban stormwater runoff comes from tire wear and that tire wear is a significant source of Zn to the environment with release inventories comparable to waste incineration sources. In urban and sub-urban systems, this large source of Zn can accumulate in stormwater retention ponds which serve as habitat for a variety of species. Understanding the chemical and biological availability of Zn to biota is integral to assessing the habitat quality of retention ponds. This study is a first effort to relate the amount and speciation of Zn in a retention pond to Zn inputs through highway-derived runoff events. In addition, results suggest that the chemical speciation and availability of particulate Zn can be related to the bioavailability and toxicity of Zn to pond organisms (i.e. larval amphibians). The study site in Owings Mills, MD is located next to a four-lane highway from which it receives runoff through a single culvert. Five species of anurans are known to utilize the pond as a breeding site and Zn in amphibian tissues and retention pond sediments were highly elevated at this site in 2001 and 2002. A recent analysis of pond sediments, soils, roadway dust and storm water collected at this site suggests that roadway particulate matter transported during runoff events is the dominant source of Zn in this system. Overall, Zn and other trace metals were found to be most abundant in the clay sized faction of pond sediments and soils. The pond cores were found to have higher Zn and Cu concentrations at both the surface and a deeper interval possibly related to a change in land use during the pond's history. Pond sediments are above natural soil background for both Zn and Cu and represent mixing between the roadway particulates and local soils. It is therefore likely that these particulates are the primary source of metals to the pond.

[Effect of antecedent dry weather period on urban storm runoff pollution load].

PubMed

Li, Li-qing; Yin, Cheng-qing; Kong, Ling-li; He, Qing-ci

2007-10-01

Twelve storm events were surveyed at Shilipu catchment in Wuhan City through three-year monitoring regime. The flow discharges, total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in runoff were measured to study the mechanism of urban stormwater runoff pollution. The relationship between the event pollution load and the antecedent dry weather period was identified to discuss the influence of the urban surface sanitation management, operation of sewer pipe maintenance and rainfall characteristics on the urban stormwater runoff pollution. It was found that the antecedent dry weather period and runoff amount were the important determining factors in the generation of urban stormwater runoff pollution. The event pollution load was positively correlated to the antecedent dry weather period between two rainfall events (R2 = 0.95, p < 0.01). It was the most important hydrological factor influencing the events pollution loads. The best regression equation to estimate pollution load for storm events was developed based on the antecedent dry weather period and runoff depth. Source control including improving urban street sweeping activities and operation of sewer pipe maintenance should be made to reduce the amount of available pollutant over the dry days. It is important alternative to control urban stormwater runoff pollution for Hanyang District.

Treatment of heavy metals by iron oxide coated and natural gravel media in Sustainable urban Drainage Systems.

PubMed

Norris, M J; Pulford, I D; Haynes, H; Dorea, C C; Phoenix, V R

2013-01-01

Sustainable urban Drainage Systems (SuDS) filter drains are simple, low-cost systems utilized as a first defence to treat road runoff by employing biogeochemical processes to reduce pollutants. However, the mechanisms involved in pollution attenuation are poorly understood. This work aims to develop a better understanding of these mechanisms to facilitate improved SuDS design. Since heavy metals are a large fraction of pollution in road runoff, this study aimed to enhance heavy metal removal of filter drain gravel with an iron oxide mineral amendment to increase surface area for heavy metal scavenging. Experiments showed that amendment-coated and uncoated (control) gravel removed similar quantities of heavy metals. Moreover, when normalized to surface area, iron oxide coated gravels (IOCGs) showed poorer metal removal capacities than uncoated gravel. Inspection of the uncoated microgabbro gravel indicated that clay particulates on the surface (a natural product of weathering of this material) augmented heavy metal removal, generating metal sequestration capacities that were competitive compared with IOCGs. Furthermore, when the weathered surface was scrubbed and removed, metal removal capacities were reduced by 20%. When compared with other lithologies, adsorption of heavy metals by microgabbro was 10-70% higher, indicating that both the lithology of the gravel, and the presence of a weathered surface, considerably influence its ability to immobilize heavy metals. These results contradict previous assumptions which suggest that gravel lithology is not a significant factor in SuDS design. Based upon these results, weathered microgabbro is suggested to be an ideal lithology for use in SuDS.

Forest soil erosion prediction as influenced by wildfire and roads

NASA Astrophysics Data System (ADS)

Cao, L.; Brooks, E. S.; Elliot, W.

2017-12-01

Following a wildfire, the risk of erosion is greatly increased. Forest road networks may change the underlying topography and alter natural flow paths. Flow accumulation and energy can be redistributed by roads and alter soil erosion processes. A LiDAR (Light Detection and Ranging) DEM makes it possible to quantify road topography, and estimate how roads influence surface runoff and sediment transport in a fire-disturbed watershed. With GIS technology and a soil erosion model, this study was carried out to evaluate the effect of roads on erosion and sediment yield following the Emerald Fire southwest of Lake Tahoe. The GeoWEPP model was used to estimate onsite erosion and offsite sediment delivery from each hillslope polygon and channel segment before and after fire disturbance in part of the burned area. The GeoWEPP flow path method was used to estimate the post-fire erosion rate of each GIS pixel. A 2-m resolution LiDAR DEM was used as the terrain layer. The Emerald Fire greatly increased onsite soil loss and sediment yields within the fire boundary. Following the fire, 78.71% of the burned area had predicted sediment yields greater than 4 Mg/ha/yr, compared to the preburn condition when 65.3% of the study area was estimated to generate a sediment yield less than 0.25 Mg/ha/yr. Roads had a remarkable influence on the flow path simulation and sub-catchments delineation, affecting sediment transport process spatially. Road segments acted as barriers that intercepted overland runoff and reduced downslope flow energy accumulation, therefore reducing onsite soil loss downslope of the road. Roads also changed the boundary of sub-catchment and defined new hydrological units. Road segments can transport sediment from one sub-catchment to another. This in turn leads to the redistribution of sediment and alters sediment yield for some sub-catchments. Culverts and road drain systems are of vital importance in rerouting runoff and sediment. Conservation structures can be installed to avoid sediment deposition or debris accumulation on the road surface. On the other hand, the outlets of culverts might be at a high risk of increasing downstream channel erosion due to the large amount of runoff. This implies that conservation measurements should be considered to control the runoff and sediment output from culverts.

Characterizing dry deposition of mercury in urban runoff

USGS Publications Warehouse

Fulkerson, M.; Nnadi, F.N.; Chasar, L.S.

2007-01-01

Stormwater runoff from urban surfaces often contains elevated levels of toxic metals. When discharged directly into water bodies, these pollutants degrade water quality and impact aquatic life and human health. In this study, the composition of impervious surface runoff and associated rainfall was investigated for several storm events at an urban site in Orlando, Florida. Total mercury in runoff consisted of 58% particulate and 42% filtered forms. Concentration comparisons at the start and end of runoff events indicate that about 85% of particulate total mercury and 93% of particulate methylmercury were removed from the surface before runoff ended. Filtered mercury concentrations showed less than 50% reduction of both total and methylmercury from first flush to final flush. Direct comparison between rainfall and runoff at this urban site indicates dry deposition accounted for 22% of total inorganic mercury in runoff. ?? 2007 Springer Science+Business Media B.V.

Pollution loads in urban runoff and sanitary wastewater.

PubMed

Taebi, Amir; Droste, Ronald L

2004-07-05

While more attention has been paid in recent years to urban point source pollution control through the establishment of wastewater treatment plants in many developing countries, no considerable planning nor any serious measures have been taken to control urban non-point source pollution (urban stormwater runoff). The present study is a screening analysis to investigate the pollution loads in urban runoff compared to point source loads as a first prerequisite for planning and management of receiving water quality. To compare pollutant loads from point and non-point urban sources, the pollutant load is expressed as the weight of pollutant per hectare area per year (kg/ha.year). Unit loads were estimated in stormwater runoff, raw sanitary wastewater and secondary treatment effluents in Isfahan, Iran. Results indicate that the annual pollution load in urban runoff is lower than the annual pollution load in sanitary wastewater in areas with low precipitation but it is higher in areas with high precipitation. Two options, namely, advanced treatment (in lieu of secondary treatment) of sanitary wastewater and urban runoff quality control systems (such as detention ponds) were investigated as controlling systems for pollution discharges into receiving waters. The results revealed that for Isfahan, as a low precipitation urban area, advanced treatment is a more suitable option, but for high precipitation urban areas, urban surface runoff quality control installations were more effective for suspended solids and oxygen-demanding matter controls, and that advanced treatment is the more effective option for nutrient control.

Urban Runoff and Nutrients Loading Control from Sustainable BMPs (Invited)

NASA Astrophysics Data System (ADS)

Xiao, Q.

2009-12-01

Climate change alters hydrodynamic and nutrient dynamic in both large and small geographic scales. These changes in our freshwater system directly affect drinking water, food production, business, and all aspects of our life. Along with climate change is increasing urbanization which alters natural landscape. Urban runoff has been identified as one of many potential drivers of the decline of pelagic fishes in san Francisco Bay-Delta region. Recent found of Pyrethroids in American River has increased scientists, public, and policy makers’ concern about our fresh water system. Increasing our understanding about the fundamental hydrodynamic, nutrient dynamics, and the transport mechanics of runoff and nutrients are important for future water resource and ecosystem management. Urbanization has resulted in significantly increasing the amount of impervious land cover. Most impervious land covers are hydrophobic that alters surface runoff because of the effects on surface retention storage, rainfall interception, and infiltration. Large volumes of excess storm runoff from urbanized areas cause flooding, water pollution, groundwater recharge deficits, destroyed habitat, beach closures, and toxicity to aquatic organisms. Parking lot alone accounts for more than 11% of these impervious surfaces. Contrast to impervious parking lot, turfgrass can accouter for 12% of urban land in California. Irrigated urban landscapes create considerable benefits to our daily living. However, the use of fertilizers and pesticides has caused environmental problems. Preventing fertilizers and pesticides from entering storm drains is an important goal for both landscape and storm runoff managers. Studies of urban runoff have found that the most fertilizers and pesticides are from dry weather runoff which conveys pollutants to sidewalks, streets, and storm drains. Controlling surface runoff is critical to preventing these pollutants from entering storm drains and water bodies. Large scale construction of runoff retention basins and treatment facilities to meet TMDL (Total Maximum Daily Load) regulations are not cost-effective or practical. An alternative approach is to control runoff and nutrients on-site through installation of decentralized BMPs that detain and infiltrate runoff before it reaches storm drains. Recent developed green-infrastructure which integrating engineered soil and trees to reduce runoff and nutrients loading is a self-sustained best management practice (BMP). This BMP has been testing and used in urban runoff control. In Davis, CA this type of BMPs were installed in a parking lot and a residential property to evaluate the system’s effectiveness on reducing storm runoff and pollutant loading from the parking lot and irrigated landscape. Storm runoff and pollutant loading were measured and monitored during February 2007 thru May 2009 from the parking lot. The BMP reduced surface runoff and nutrients by 88.8% and 95.3%, respectively. In the residential irrigated landscape, the dry-weather runoff was monitored during 2007 irrigation season, the BMP captured almost all dry weather runoff. The performance of these BMPs demonstrated their potential use for reducing runoff and nutrients loading. Control urban runoff from these 23% landscape (i.e., parking lot and irrigated turf grass) could largely alter the runoff and nutrients transport and their dynamic in our water system.

[Characterization and source apportionment of pollutants in urban roadway runoff in Chongqing].

PubMed

Zhang, Qian-Qian; Wang, Xiao-Ke; Hao, Li-Ling; Hou, Pei-Qiang; Ouyang, Zhi-Yun

2012-01-01

By investigating surface runoff from urban roadway in Chongqing, we assessed the characteristics of surface runoff pollution and the effect of rainfall intensity and antecedent dry weather period on water quality. Using multivariate statistical analysis of data of runoff quality, potential pollutants discharged from urban roadway runoff were identified. The results show that the roadway runoff has high levels of COD, TP and TN, the EMC were 60.83-208.03 mg x L(-1), 0.47-1.01 mg x L(-1) and 2.07-5.00 mg x L(-1) respectively, being the main pollutants; The peaks of pollutant concentration are ahead of or synchronous with the peak of runoff volume; the peaks of pollutant concentrations are mostly occurred within 10 minutes of rainfall. The heavy metal concentrations fluctuate dentately during runoff proceeding. Two potential pollution sources to urban roadway runoff apportioned by using principal component analysis are: vehicle's traffic loss and atmospheric dry and wet deposition, and municipal wastes.

Contribution and loading estimation of organochlorine pesticides from rain and canopy throughfall to runoff in an urban environment.

PubMed

Zhang, Wei; Ye, Youbin; Tong, Yindong; Ou, Langbo; Hu, Dan; Wang, Xuejun

2011-01-30

Concentrations of OCPs in rain, canopy throughfall, and runoff water were measured in the Beijing metropolitan area during the rainy seasons from 2006 to 2007. This study was conducted to calculate the fluxes of OCPs in rain and canopy throughfall, as well as their contributions to runoff. At urban sites, the contribution of HCB and ΣHCHs from rainfall accounted for approximately 50% of the mass in runoff. At the site with significant coverage of landscaping trees, the HCB, ΣHCHs, and ΣDDTs from the net canopy throughfall accounted for approximately 10% of the mass in the runoff. Based on the data obtained in this study, loadings of OCPs (in μg) in rain, net canopy throughfall, and runoff water were calculated. The input of OCPs from rain and canopy throughfall water accounted for a significant portion of urban runoff. In cities undergoing rapid urban sprawl, monitoring and control of the transport of OCPs in urban runoff are essential for effective control of environmental hazards in surface water bodies. Copyright © 2010 Elsevier B.V. All rights reserved.

Design and Construction of an Urban Runoff Research Facility

PubMed Central

Wherley, Benjamin G.; White, Richard H.; McInnes, Kevin J.; Fontanier, Charles H.; Thomas, James C.; Aitkenhead-Peterson, Jacqueline A.; Kelly, Steven T.

2014-01-01

As the urban population increases, so does the area of irrigated urban landscape. Summer water use in urban areas can be 2-3x winter base line water use due to increased demand for landscape irrigation. Improper irrigation practices and large rainfall events can result in runoff from urban landscapes which has potential to carry nutrients and sediments into local streams and lakes where they may contribute to eutrophication. A 1,000 m2 facility was constructed which consists of 24 individual 33.6 m2 field plots, each equipped for measuring total runoff volumes with time and collection of runoff subsamples at selected intervals for quantification of chemical constituents in the runoff water from simulated urban landscapes. Runoff volumes from the first and second trials had coefficient of variability (CV) values of 38.2 and 28.7%, respectively. CV values for runoff pH, EC, and Na concentration for both trials were all under 10%. Concentrations of DOC, TDN, DON, PO4-P, K+, Mg2+, and Ca2+ had CV values less than 50% in both trials. Overall, the results of testing performed after sod installation at the facility indicated good uniformity between plots for runoff volumes and chemical constituents. The large plot size is sufficient to include much of the natural variability and therefore provides better simulation of urban landscape ecosystems. PMID:25146420

Influence of urbanization pattern on stream flow of a peri-urban catchment under Mediterranean climate

NASA Astrophysics Data System (ADS)

Ferreira, Carla S. S.; Walsh, Rory P. D.; Ferreira, António J. D.; Steenhuis, Tammo S.; Coelho, Celeste A. O.

2015-04-01

The demand for better life quality and lower living costs created a great pressure on peri-urban areas, leading to significant land-use changes. The complexity of mixed land-use patterns, however, presents a challenge to understand the hydrological pathways and streamflow response involved in such changes. This study assesses the impact of a actively changing Portuguese peri-urban area on catchment hydrology. It focuses on quantifying streamflow delivery from contributing areas, of different land-use arrangement and the seasonal influence of the Mediterranean climate on stream discharge. The study focuses on Ribeira dos Covões a small (6 km2) peri-urban catchment on the outskirts of Coimbra, one of the main cities in central Portugal. Between 1958 and 2012 the urban area of the catchment expanded from 8% to 40%, mostly at the expense of agriculture (down from 48% to 4%), with woodland now accounting for the remaining 56% of the catchment area. The urban area comprises contrasting urban settings, associated with older discontinuous arrangement of buildings and urban structures and low population density (<25 inhabitants/km), and recent well-defined urban cores dominated by apartment blocks and high population density (9900 inhabitants/km). The hydrological response of the catchment has been monitored since 2007 by a flume installed at the outlet. In 2009, five rainfall gauges and eight additional water level recorders were installed upstream, to assess the hydrological response of different sub-catchments, characterized by distinct urban patterns and either limestone or sandstone lithologies. Annual runoff coefficients range between 14% and 22%. Changes in annual baseflow index (36-39% of annual rainfall) have been small with urbanization (from 34% to 40%) during the monitoring period itself. Annual runoff coefficients were lowest (14-7%) on catchments >80% woodland and highest (29% on sandstone; 18% on limestone) in the most urbanized (49-53% urban) sub-catchments. Percentage impermeable surface seems to control streamflow particularly during dry periods. Winter runoff was 2-4 times higher than total river flow in the summer dry season in highly urbanized areas, but was 21-fold higher in winter in the least urbanized sub-catchment, denoting greater flow connectivity enhanced by increased soil moisture. Although impermeable surfaces are prone to generate overland flow, the proximity to the stream network is an important parameter determining their hydrological impacts. During the monitoring period, the enlargement of 2% of the urban area at downslope locations in the Covões sub-catchment, led to a 6% increase in the runoff coefficient. In contrast, the urban area increase from 9 to 25% mainly in upslope parts of the Quinta sub-catchment did not increase the peak streamflow due to downslope infiltration and surface retention opportunities. Despite impermeable surfaces enhance overland flow, some urban features (e.g. walls and road embankments) promote surface water retention. The presence of artificial drainage systems, on the other hand, enhances flow connectivity, leading to increasing peak flow and quicker response times (~10 minutes versus 40-50 minutes) as in the Covões sub-catchment. Urbanization impact on streamflow responses may be minimized through planning the land-use mosaic so as to maximize infiltration opportunities. Knowledge of the influence of distinct urban mosaics on flow connectivity and stream discharge is therefore important to landscape managers and should guide urban planning in order to minimize flood hazards.

EVALUATION OF CONSTRUCTED WETLAND AND RETENTION POND BMPS FOR ATTENUATING MICROBIAL CONTAMINANTS IN URBAN STORMWATER RUNOFF

EPA Science Inventory

This project investigated the use of constructed wetlands and retention ponds for decreasing microbial concentrations from urban stormwater runoff. Increased urbanization has resulted in a larger percentage of impervious areas which cause large quantities of stormwater runoff an...

LABORATORY-SCALE SIMULATION OF RUNOFF RESPONSE FROM PERVIOUS-IMPERVIOUS SYSTEMS

EPA Science Inventory

Urban development yields landscapes that are composites of impervious and pervious areas, with a consequent reduction in infiltration and increase in stormwater runoff. Although basic rainfall-runoff models are used in the vast majority of runoff prediction in urban landscapes, t...

Environmental exposure of road borders to zinc.

PubMed

Blok, J

2005-09-15

The emissions of zinc along roads originating from tyre wear, corrosion of safety fence and other traffic-related sources have been quantified and validated by measured long-term loads in road run-off and airborne solids (drift) for 29 published case studies. The distribution pattern over the road border at various distances from the edge of the paved surface is assessed on the basis of 38 published case studies with measured concentrations in soil. For the impact assessment, the road border is differentiated into a zone that is part of the "technosphere" and the "target zone" beyond that technosphere that can be considered as part of the receiving environment. The "technosphere" of the road includes the central reservation, the hard and the soft shoulder or, if one or both shoulders are not present, the so-called obstacle "free zone" that is defined by road engineers. Pollution within the technosphere may require appropriate management of solid disposal and isolation from groundwater to prevent further distribution of pollutants to the environment. In the target zone along regional roads, the zinc load is about 4 mg/m(2) year and this is of the same order of magnitude as that of atmospheric deposition in areas beyond the influence of roads (background). In the target zone along highways, the zinc load is increased in comparison to the background deposition. The average load of about 38 mg/m(2) year is similar to that in fertilised agricultural land. Because most of the emitted zinc stays in the technosphere, the total amount entering this target zone along highways is limited. From the 140 tons of zinc per year that is released from tyre wear in The Netherlands, 64 tons is emitted in the urban area, 6.5 tons reaches to the target zones of all roads and only 1.1 tons of zinc will enter the target zone along highways. This amount will be further decreased by the application of porous asphalt in the near future. The emission from safety fence corrosion does not enter the target zone. Only in special cases, such as bridges, crossings and squares the release of zinc from these sources may enter the aquatic environment by the discharge of run-off.

A new installation for treatment of road runoff: up-flow filtration by porous polypropylene media.

PubMed

Lee, B C; Matsui, S; Shimizu, Y; Matsuda, T; Tanaka, Y

2005-01-01

We installed a new device on a paved road to treat runoff from a roadway surface. All the stormwater runoff was transferred into the device and the runoff equivalent to 10 mm/hr or less was treated. The treatment method consists of sedimentation and up-flow filtration with porous polypropylene (PPL) processes. The treated runoff was discharged into the existing storm drainage pipe. The average removal efficiency of the initial runoff at the beginning of rainfall which has high pollution intensity was about 90% for SS, about 70% for COD, about 40% for total phosphorus (T-P), about 80% for Pb and Cd, about 70% for Zn, Cu, Mn and Cr, and about 60% for polycyclic aromatic hydrocarbons (PAHs). The overall removal efficiencies of the experiment that ran for four months remained > 60% of SS, > 40% of COD, > 60% of heavy metals, and > 40% of PAHs. The PPL is excellent for removing smaller size particulates of suspended solids, which originate basically from diesel exhaust, as well as larger size particulates from automobile tires, asphalt roads, and other accumulated source(s) of clay and sand, etc.

Hydrologic data for urban storm runoff from three localities in the Denver metropolitan area, Colorado

USGS Publications Warehouse

Ellis, Sherman R.

1978-01-01

Urban storm-runoff data, collected from 1975 to 1977, on three catchment areas in the Denver, Colo., metropolitan area are presented. The catchment are predominantly a single-family residential catchment area in Littleton, a multifamily residential and commercial catchment area in Lakewood, and a high-density residential and commercial catchment area in Denver. Precipitation, rainfall-runoff, snowmelt-runoff, water-quality (common constituents, nutrients, biochemical oxygen demand, coliform bacteria, and solids, trace elements, and pesticides), and catchment-area data are necessary to use the U.S. Environmental Protection Agency 's Storm Water Management Model II. The urban storm-runoff data may be used by planning, water-management, and environmental-protection agencies to assess the impact of urban storm runoff on the hydrologic system. (Woodard-USGS)

Efficiencies of multilayer infiltration systems for the removal of urban runoff pollutants.

PubMed

Hou, Lizhu; Liu, Fang; Feng, Chuanping; Wan, Li

2013-01-01

Current rates of urban development will result in water runoff becoming a major complication of urban water pollution. To address the worsening situation regarding water resource shortage and pollution, novel multilayer infiltration systems were designed and their effectiveness for removing pollutants in urban runoff tested experimentally. The multilayer infiltration systems effectively removed most pollutants, including organic matter (chemical oxygen demand (CODCr)), total nitrogen (TN), ammonia-nitrogen (NH4(+)-N) and total phosphorus (TP). CODCr, TN, NH4(+)-N, and TP were reduced by 68.67, 23.98, 82.66 and 92.11%, respectively. The main mechanism for nitrogen removal was biological nitrogen removal through nitrification and denitrification. Phosphorus in the urban runoff was removed mainly by fixation processes in the soil, such as adsorption and chemical precipitation. The results indicate that the proposed novel system has potential for removal of pollutants from urban runoff and subsequent reuse of the treated water.

Snowmelt Runoff: A New Focus of Urban Nonpoint Source Pollution

PubMed Central

Zhu, Hui; Xu, Yingying; Yan, Baixing; Guan, Jiunian

2012-01-01

Irregular precipitation associated with global climate change had been causing various problems in urban regions. Besides the runoff due to rainfall in summer, the snowmelt runoff in early spring could also play an important role in deteriorating the water quality of the receiving waters. Due to global climate change, the snowfall has increased gradually in individual regions, and snowstorms occur more frequently, which leads to an enhancement of snowmelt runoff flow during the melting seasons. What is more, rivers just awaking from freezing cosntitute a frail ecosystem, with poor self-purification capacity, however, the urban snowmelt runoff could carry diverse pollutants accumulated during the winter, such as coal and/or gas combustion products, snowmelting agents, automotive exhaust and so on, which seriously threaten the receiving water quality. Nevertheless, most of the research focused on the rainfall runoff in rainy seasons, and the study on snowmelt runoff is still a neglected field in many countries and regions. In conclusion, due to the considerable water quantity and the worrisome water quality, snowmelt runoff in urban regions with large impervious surface areas should be listed among the important targets in urban nonpoint source pollution management and control. PMID:23202881

Snowmelt runoff: a new focus of urban nonpoint source pollution.

PubMed

Zhu, Hui; Xu, Yingying; Yan, Baixing; Guan, Jiunian

2012-11-30

Irregular precipitation associated with global climate change had been causing various problems in urban regions. Besides the runoff due to rainfall in summer, the snowmelt runoff in early spring could also play an important role in deteriorating the water quality of the receiving waters. Due to global climate change, the snowfall has increased gradually in individual regions, and snowstorms occur more frequently, which leads to an enhancement of snowmelt runoff flow during the melting seasons. What is more, rivers just awaking from freezing constitute a frail ecosystem, with poor self-purification capacity, however, the urban snowmelt runoff could carry diverse pollutants accumulated during the winter, such as coal and/or gas combustion products, snowmelting agents, automotive exhaust and so on, which seriously threaten the receiving water quality. Nevertheless, most of the research focused on the rainfall runoff in rainy seasons, and the study on snowmelt runoff is still a neglected field in many countries and regions. In conclusion, due to the considerable water quantity and the worrisome water quality, snowmelt runoff in urban regions with large impervious surface areas should be listed among the important targets in urban nonpoint source pollution management and control.

Assessing the Impact of Urban Runoff in Recreational Beaches in South Carolina and Florida Using Culturable and QPCR Fecal Indicator

EPA Science Inventory

Urban/suburban runoff carries a variety of pollutants that often includes bacterial pathogens and indicators of fecal contamination. The objective of this study was to assess the microbial water quality of recreational beaches impacted solely by urban runoff through the use of cu...

Urban Stormwater Runoff. Instructor Guide. Working for Clean Water: An Information Program for Advisory Groups.

ERIC Educational Resources Information Center

Simko, Robert A.

Urban stormwater runoff collects pollutants from many parts of a city and is an important consideration in water quality planning. Presented is an instructor's guide for a learning session covering various aspects of urban runoff including pollutant sources, management practices, and regulatory programs. Intended for citizen advisory groups, this…

Urban Runoff Impact on the qPCR Signal of Enterococci and Other Alternative Fecal Indicators in a Tropical Beach

EPA Science Inventory

In order to effectively control inputs of contamination to coastal recreational waters, an improved understanding of the impact of both point and non-point sources of urban runoff is needed. In this study, we focused on the effect of non-point source urban runoff on the enterococ...

The Effects Of Urban Landscape Patterns On Rainfall-Runoff Processes At Small Scale

NASA Astrophysics Data System (ADS)

Chen, L.

2016-12-01

Many studies have indicated that urban landscape change may alter rainfall-runoff processes. However, how urban landscape pattern affect this process is little addressed. In this study, the hydrological effects of landscape pattern on rainfall-runoff processes at small-scale was explored. Twelve residential blocks with independent drainage systems in Beijing were selected as case study areas. Impervious metrics of these blocks, i.e., total impervious area (TIA) and directly connected impervious area (DCIA), were identified. A drainage index describing catchment general drainage load and the overland flow distance, Ad, was estimated and used as one of the landscape spatial metrics. Three scenarios were designed to test the potential influence of impervious surface pattern on runoff processes. Runoff variables including total and peak runoff depth (Qt and Qp) were simulated under different rainfall conditions by Storm Water Management Model (SWMM). The relationship between landscape patterns and runoff variables were analyzed, and further among the three scenarios. The results demonstrated that, in small urban blocks, spatial patterns have inherent influences on rainfall-runoff processes. Specifically, (1) Imperviousness acts as effective indicators in predicting both Qt and Qp. As rainfall intensity increases, the major affecting factor changes from DCIA to TIA for both Qt and Qp; (2) Increasing the size of drainage area dominated by each drainage inlet will benefit the block peak flow mitigation; (3) Different spatial concentrations of impervious surfaces have inherent influences on Qp, when impervious surfaces located away from the outlet can reduce the peak flow discharge. These findings may provide insights into the role of urban landscape patterns in driving rainfall-runoff responses in urbanization, which is essential for urban planning and stormwater management.

On storm movement and its applications

NASA Astrophysics Data System (ADS)

Niemczynowicz, Janusz

Rainfall-runoff models applicable for design and analysis of sewage systems in urban areas are further developed in order to represent better different physical processes going on on an urban catchment. However, one important part of the modelling procedure, the generation of the rainfall input is still a weak point. The main problem is lack of adequate rainfall data which represent temporal and spatial variations of the natural rainfall process. Storm movement is a natural phenomenon which influences urban runoff. However, the rainfall movement and its influence on runoff generation process is not represented in presently available urban runoff simulation models. Physical description of the rainfall movement and its parameters is given based on detailed measurements performed on twelve gauges in Lund, Sweden. The paper discusses the significance of the rainfall movement on the runoff generation process and gives suggestions how the rainfall movement parameters may be used in runoff modelling.

Modeling urban storm rainfall runoff from diverse underlying surfaces and application for control design in Beijing.

PubMed

Ouyang, Wei; Guo, Bobo; Hao, Fanghua; Huang, Haobo; Li, Junqi; Gong, Yongwei

2012-12-30

Managing storm rainfall runoff is paramount in semi-arid regions with urban development. In Beijing, pollution prevention in urban storm runoff and storm water utilization has been identified as the primary strategy for urban water management. In this paper, we sampled runoff during storm rainfall events and analyzed the concentration of chemical oxygen demand (COD), total suspended solids (TSS) and total phosphorus (TP) in the runoff. Furthermore, the first flush effect of storm rainfall from diverse underlying surfaces was also analyzed. With the Storm Water Management Model (SWMM), the different impervious rates of underlying surfaces during the storm runoff process were expressed. The removal rates of three typical pollutants and their interactions with precipitation and underlying surfaces were identified. From these rates, the scenarios regarding the urban storm runoff pollution loading from different designs of underlying previous rates were assessed with the SWMM. First flush effect analysis showed that the first 20% of the storm runoff should be discarded, which can help in utilizing the storm water resource. The results of this study suggest that the SWMM can express in detail the storm water pollution patterns from diverse underlying surfaces in Beijing, which significantly affected water quality. The scenario analysis demonstrated that impervious rate adjustment has the potential to reduce runoff peak and decrease pollution loading. Copyright © 2012 Elsevier Ltd. All rights reserved.

Trace elements and organic compounds in streambed sediment and aquatic biota from the Sacramento River Basin, California, October and November 1995

USGS Publications Warehouse

MacCoy, Dorene E.; Domagalski, Joseph L.

1999-01-01

Elevated levels of trace elements and hydrophobic organic compounds were detected in streambed sediments and aquatic biota [Asiatic clam (Corbicula fluminea) or bottom-feeding fish] of the Sacramento River Basin, California, during October and November 1995. Trace elements detected included cadmium, copper, mercury, lead, and zinc. Elevated levels of cadmium, copper, and zinc in the upper Sacramento River are attributed to a mining land use, and elevated levels of zinc and lead in an urban stream, and possibly in the lower Sacramento River, are attributed to urban runoff processes. Elevated levels of mercury in streambed sediment are attributed to either past mercury mining or to the use of mercury in past gold mining operations. Mercury mining was an important land use within the Coast Ranges in the past and gold mining was an important land use of the Sierra Nevada in the past. Mercury was the only trace element found in elevated levels in the tissue of aquatic biota, and those levels also could be attributed to either mining or urban runoff. Hydrophobic organic compounds also were detected in streambed sediments and aquatic biota. The most frequently detected compounds were DDT and its breakdown products, dieldrin, oxychlordane, and toxaphene. Differences were found in the types of compounds detected at agricultural sites and the urban site. Although both types of sites had measurable concentrations of DDT or its breakdown products, the urban site also had measurable concentrations of pesticides used for household pest control. Few semivolatile compounds were detected in the streambed sediments of any site. The semivolatile compound p-cresol, a coal-tar derivative associated with road maintenance, was found in the highest concentration.

A Review of Semivolatile and Volatile Organic Compounds in Highway Runoff and Urban Stormwater

USGS Publications Warehouse

Lopes, Thomas J.; Dionne, Shannon G.

1998-01-01

Many studies have been conducted since 1970 to characterize concentrations of semivolatile organic compounds (SVOCs) in highway runoff and urban stormwater. To a lesser extent, studies also have characterized concentrations of volatile organic compounds (VOCs), estimated loads of SVOCs, and assessed potential impacts of these contaminants on receiving streams. This review evaluates the quality of existing data on SVOCs and VOCs in highway runoff and urban storm- water and summarizes significant findings. Studies related to highways are emphasized when possible. The review included 44 articles and reports that focused primarily on SVOCs and VOCs. Only 17 of these publications are related to highways, and 5 of these 17 are themselves review papers. SVOCs in urban stormwater and sediments during the late 1970's to mid-1980's were the subject of most studies. Criteria used to evaluate data quality included documentation of sampling protocols, analytical methods, minimum reporting limit (MRL) or method detection limit (MDL), qualityassurance protocols, and quality-control samples. The largest deficiency in documenting data quality was that only 10 percent of the studies described where water samples were collected in the stream cross section. About 80 percent of SVOCs in runoff are in the suspended solids. Because suspended solids can vary significantly even in narrow channels, concentrations from discrete point samples and contaminant loads estimated from those samples are questionable without information on sample location or how well streamflow was mixed. Thirty percent or fewer of the studies documented the MRL, MDL, cleaning of samplers, or use of field quality-control samples. Comparing results of different studies and evaluating the quality of environmental data, especially for samples with low concentrations, is difficult without this information. The most significant factor affecting SVOC concentrations in water is suspended solids concentration. In sediment, the most significant factors affecting SVOC concentrations are organic carbon content and distance from sources such as highways and power plants. Petroleum hydrocarbons, oil and grease, and polycyclic aromatic hydrocarbons (PAHs) in crankcase oil and vehicle emissions are the major SVOCs detected in highway runoff and urban stormwater. The few loading factors and regression equations that were developed in the 1970's and 1980's have limited use in estimating current (1998) loads of SVOCs on a national scale. These factors and equations are based on few data and use inconsistent units, and some are independent of rainfall. Also, more cars on the road today have catalytic converters, and fuels that were used in 1998 are cleaner than when loading factors and regression equations were developed. Comparisons to water-quality and sedimentquality criteria and guidelines indicate that PAHs, phenolic compounds, and phthalates in runoff and sediment exceeded U.S. Environmental Protection Agency drinking-water and aquatic-life standards and guidelines. PAHs in stream sediments adjacent to highways have the highest potential for adverse effects on receiving streams. Few data exist on VOCs in highway runoff. VOCs were detected in precipitation adjacent to a highway in England, and chloromethane, toluene, xylenes, 1,2,4-trimethylbenzene, and 1,2,3-trichloropropane were detected in runoff from a highway in Texas. In urban stormwater, gasoline-related compounds were detected in as many as 23 percent of the samples. Land use could be the most significant factor affecting the occurrence of VOCs, with highest concentrations of VOCs found in industrial areas. Temperature is another factor affecting the occurrence and concentrations of VOCs. Urban land surfaces are the primary nonpoint source of VOCs in stormwater. However, the atmosphere is a potential source of hydrophilic VOCs in stormwater, especially during cold seasons when partitioning of VOCs from air into water i

Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs

NASA Astrophysics Data System (ADS)

Seo, Y.; Choi, N.-J.; Schmidt, A. R.

2013-05-01

This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA) to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute to direct runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA), IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs

NASA Astrophysics Data System (ADS)

Seo, Y.; Choi, N.-J.; Schmidt, A. R.

2013-09-01

This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA) to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute directly to the runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA), IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Driving in traffic: short-range sensing for urban collision avoidance

NASA Astrophysics Data System (ADS)

Thorpe, Chuck E.; Duggins, David F.; Gowdy, Jay W.; MacLaughlin, Rob; Mertz, Christoph; Siegel, Mel; Suppe, Arne; Wang, Chieh-Chih; Yata, Teruko

2002-07-01

Intelligent vehicles are beginning to appear on the market, but so far their sensing and warning functions only work on the open road. Functions such as runoff-road warning or adaptive cruise control are designed for the uncluttered environments of open highways. We are working on the much more difficult problem of sensing and driver interfaces for driving in urban areas. We need to sense cars and pedestrians and curbs and fire plugs and bicycles and lamp posts; we need to predict the paths of our own vehicle and of other moving objects; and we need to decide when to issue alerts or warnings to both the driver of our own vehicle and (potentially) to nearby pedestrians. No single sensor is currently able to detect and track all relevant objects. We are working with radar, ladar, stereo vision, and a novel light-stripe range sensor. We have installed a subset of these sensors on a city bus, driving through the streets of Pittsburgh on its normal runs. We are using different kinds of data fusion for different subsets of sensors, plus a coordinating framework for mapping objects at an abstract level.

Multivariate analysis for stormwater quality characteristics identification from different urban surface types in macau.

PubMed

Huang, J; Du, P; Ao, C; Ho, M; Lei, M; Zhao, D; Wang, Z

2007-12-01

Statistical analysis of stormwater runoff data enables general identification of runoff characteristics. Six catchments with different urban surface type including roofs, roadway, park, and residential/commercial in Macau were selected for sampling and study during the period from June 2005 to September 2006. Based on univariate statistical analysis of data sampled, major pollutants discharged from different urban surface type were identified. As for iron roof runoff, Zn is the most significant pollutant. The major pollutants from urban roadway runoff are TSS and COD. Stormwater runoff from commercial/residential and Park catchments show high level of COD, TN, and TP concentration. Principal component analysis was further done for identification of linkages between stormwater quality and urban surface types. Two potential pollution sources were identified for study catchments with different urban surface types. The first one is referred as nutrients losses, soil losses and organic pollutants discharges, the second is related to heavy metals losses. PCA was proved to be a viable tool to explain the type of pollution sources and its mechanism for different urban surface type catchments.

Quality characterization and impact assessment of highway runoff in urban and rural area of Guangzhou, China.

PubMed

Gan, Huayang; Zhuo, Muning; Li, Dingqiang; Zhou, Yongzhang

2008-05-01

Accurate knowledge of the quality and environmental impact of the highway runoff in Pear River Delta, South China is required to assess this important non-point pollution source. This paper presents the quality characterization and environmental impact assessment of rainfall runoff from highways in urban and rural area of Guangzhou, the largest city of Pear River Delta over 1 year's investigation. Multiple regression and Pearson correlation analysis were used to determine influence of the rainfall characteristics on water quality and correlations among the constituents in highway runoff. The results and analysis indicates that the runoff water is nearly neutral with low biodegradability. Oil and grease (O&G), suspended solids (SS) and heavy metals are the dominant pollutants in contrast to the low level of nutrient constituents in runoff. Quality of highway runoff at rural site is better than that of at urban site for most constituents. Depth and antecedent dry period are the main rainfall factors influencing quality of highway runoff. The correlation patterns among constituents in highway runoff at urban site are consistent with their dominant phases in water. Strong correlations (r > or = 0.80) are found among chemical oxygen demand (COD), total phosphorus, Cu and Zn as well as conductivity, nitrate nitrogen and total nitrogen. O&G, COD, SS and Pb in highway runoff at urban site substantially exceed their concentrations in receiving water of Pear River. The soil directly discharged by highway runoff at rural site has contaminated seriously by heavy metals in surface layer accompanying with pH conversion from original acidic to alkaline at present.

Seasonal variations in rainfall-induced soil erosion from forest roads in a Mediterranean area

NASA Astrophysics Data System (ADS)

Jordán, Antonio; Zavala, Lorena M.; Gil, Juan

2014-05-01

1. INTRODUCTION Land use change and the development of rural and eco-tourist activities have contributed to a strong development of forest roads in Spain during recent decades. Most of forest roads cause significant hydrological and geomorphological impacts at different scales, altering the runoff-runon patterns, the direction and properties of runoff water, and subsurface water flow. Some of these effects are caused by the removal of native vegetation from backslopes (Martínez-Zavala et al., 2008), which contributes to increased soil erosion and sediment yield in areas where natural soil erosion risk is usually low (Jordán and Martínez-Zavala, 2008; Jordán-López et al., 2009). Rainfall intensity, soil moisture, slope and vegetation cover are key factors for erosion risk in forest roads (Jordán and Martínez-Zavala, 2008; Cao et al., 2013). 2. METHODS Sixty backslopes with plant cover varying between dense shrubs and bare soil were selected. Rainfall simulations (90 mm/h during 20 minutes) were performed in winter (December 2012 - January 2013) and summer (August - September 2013) to study the effect of rainstorms at the end and beginning of the rainy season. Surface runoff was collected to determine runoff rates and sediment yields. Plant cover, rock fragment cover and the area covered by biological crusts were determined at each plot. Slope was determined with a portable clinometer (all selected plots were in the range 41-76%). 3. RESULTS Although soil loss was increased in winter, when soil moisture is higher, small differences were observed at vegetation cover above 75%. Plant cover above 40% considerably reduced sediment yield and runoff flow. In contrast, differences triggered between different plots with decreasing vegetation cover. In bare areas, rock fragments and biological crusts (mosses, lichens, liverworts and fungi) caused great differences between bare areas both during summer and winter periods. REFERENCES Cao, L., Zhang, K., Dai, H., Liang, Y. 2013. Modeling interrill erosion on unpaved roads in the Loess Plateau of China, Land Degradation & Development. DOI: 10.1002/ldr.2253 Jordán, A., Martínez-Zavala, L. 2008. Soil loss and runoff rates on unpaved forest roads in southern Spain after simulated rainfall. Forest Ecology and Management 255, 913-919. DOI: 10.1016/j.foreco.2007.10.002. Jordán-López, A., Martínez-Zavala, L., Bellinfante, N. 2009. Impact of different parts of unpaved forest roads on runoff and sediment yield in a Mediterranean area. Science of the Total Environment 407, 937-944. DOI: 10.1016/j.scitotenv.2008.09.047. Martínez-Zavala, L., Jordán López, A., Bellinfante, N. 2008. Seasonal variability of runoff and soil loss on forest road backslopes under simulated rainfall. Catena 74, 73-79. DOI: 10.1016/j.catena.2008.03.006.

A fresh look at road salt: aquatic toxicity and water-quality impacts on local, regional, and national scales.

PubMed

Corsi, Steven R; Graczyk, David J; Geis, Steven W; Booth, Nathaniel L; Richards, Kevin D

2010-10-01

A new perspective on the severity of aquatic toxicity impact of road salt was gained by a focused research effort directed at winter runoff periods. Dramatic impacts were observed on local, regional, and national scales. Locally, samples from 7 of 13 Milwaukee, Wisconsin area streams exhibited toxicity in Ceriodaphnia dubia and Pimephales promelas bioassays during road-salt runoff. Another Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays. The maximum chloride concentration was 7730 mg/L. Regionally, in southeast Wisconsin, continuous specific conductance was monitored as a chloride surrogate in 11 watersheds with urban land use from 6.0 to 100%. Elevated specific conductance was observed between November and April at all sites, with continuing effects between May and October at sites with the highest specific conductance. Specific conductance was measured as high as 30,800 μS/cm (Cl = 11,200 mg/L). Chloride concentrations exceeded U.S. Environmental Protection Agency (USEPA) acute (860 mg/L) and chronic (230 mg/L) water-quality criteria at 55 and 100% of monitored sites, respectively. Nationally, U.S. Geological Survey historical data were examined for 13 northern and 4 southern metropolitan areas. Chloride concentrations exceeded USEPA water-quality criteria at 55% (chronic) and 25% (acute) of the 168 monitoring locations in northern metropolitan areas from November to April. Only 16% (chronic) and 1% (acute) of sites exceeded criteria from May to October. At southern sites, very few samples exceeded chronic water-quality criteria, and no samples exceeded acute criteria.

Empirical assessment of effects of urbanization on event flow hydrology in watersheds of Canada's Great Lakes-St Lawrence basin

NASA Astrophysics Data System (ADS)

Trudeau, M. P.; Richardson, Murray

2016-10-01

We conducted an empirical hydrological analysis of high-temporal resolution streamflow records for 27 watersheds within 11 river systems in the Greater Toronto Region of the Canadian Great Lakes basin. Our objectives were to model the event-scale flow response of watersheds to urbanization and to test for scale and threshold effects. Watershed areas ranged from 37.5 km2 to 806 km2 and urban percent land cover ranged from less than 0.1-87.6%. Flow records had a resolution of 15-min increments and were available over a 42-year period, allowing for detailed assessment of changes in event-scale flow response with increasing urban land use during the post-freshet period (May 26 to November 15). Empirical statistical models were developed for flow characteristics including total runoff, runoff coefficient, eightieth and ninety-fifth percentile rising limb event runoff and mean rising limb event acceleration. Changes in some of these runoff metrics began at very low urban land use (<4%). Urban land use had a very strong influence on total runoff and event-scale hydrologic characteristics, with the exception of 80th percentile flows, which had a curvilinear relationship with urban cover. Event flow acceleration increased with increasing urban cover, thus causing 80th percentile runoff depths to be reached sooner. These results indicate the potential for compromised water balance when cumulative changes are considered at the watershed scale. No abrupt or threshold changes in hydrologic characteristics were identified along the urban land use gradient. A positive interaction of urban percent land use and watershed size indicated a scale effect on total runoff. Overall, the results document compromised hydrologic stability attributable to urbanization during a period with no detectable change in rainfall patterns. They also corroborate literature recommendations for spatially distributed low impact urban development techniques; measures would be needed throughout the urbanized area of a watershed to dampen event-scale hydrologic responses to urbanization. Additional research is warranted into event-scale hydrologic trends with urbanization in other regions, in particular rising limb event flow accelerations.

Stormwater runoff quality in correlation to land use and land cover development in Yongin, South Korea.

PubMed

Paule, M A; Memon, S A; Lee, B-Y; Umer, S R; Lee, C-H

2014-01-01

Stormwater runoff quality is sensitive to land use and land cover (LULC) change. It is difficult to understand their relationship in predicting the pollution potential and developing watershed management practices to eliminate or reduce the pollution risk. In this study, the relationship between LULC change and stormwater runoff quality in two separate monitoring sites comprising a construction area (Site 1) and mixed land use (Site 2) was analyzed using geographic information system (GIS), event mean concentration (EMC), and correlation analysis. It was detected that bare land area increased, while other land use areas such as agriculture, commercial, forest, grassland, parking lot, residential, and road reduced. Based on the analyses performed, high maximum range and average EMCs were found in Site 2 for most of the water pollutants. Also, urban areas and increased conversion of LULC into bare land corresponded to degradation of stormwater quality. Correlation analysis between LULC and stormwater quality showed the influence of different factors such as farming practices, geographical location, and amount of precipitation, vegetation loss, and anthropogenic activities in monitoring sites. This research found that GIS application was an efficient tool for monthly monitoring, validation and statistical analysis of LULC change in the study area.

MULTIDISCIPLINARY APPROACH TO STORMWATER MANAGEMENT IN URBAN AREAS

EPA Science Inventory

Uncaptured stormwater runoff from urban and urbanizing areas has negative impacts on both terrestrial and aquatic ecosystems. Alters hydrologic regimes through conversion of precipitation to runoff, lowers extent of infiltration. Aggravates nonpoint source pollution issues.

A MULTIDISCIPLINARY APPROACH TO MANAGING STORMWATER RUNOFF IN AN URBAN WATERSHED

EPA Science Inventory

Increased impervious surface (e.g., roofs, pavement) due to urbanization can lead to excess runoff throughout a watershed, overwhelming the existing stormwater infrastructure. High volumes of runoff, delivered to receiving streams over short durations at high flow rates, negative...

Potential contributions of mature prairie and turfgrass to phosphorus in urban runoff.

PubMed

Steinke, K; Kussow, W R; Stier, J C

2013-07-01

Urban vegetative plantings are considered desirable to mitigate and filter stormwater runoff and nonpoint-source pollution. Phosphorus fertilization of turfgrass may enhance P in urban runoff; however, the amount of P from nonfertilized, native vegetation that could potentially replace some turf is not known. This study was conducted to measure the relative contributions of nonfertilized, native prairie vegetation and fertilized turfgrass to runoff water and P loads. Six replicates of side-by-side mature urban prairie and turfgrass were monitored for mean annual runoff volumes and P loads, biomass production, vegetative nutrient composition, and changes in soil moisture. Vegetation type did not significantly affect seasonal or annual runoff volumes or P loads. The mean annual total P loads of 0.46 kg ha for prairie and 0.28 kg ha for turfgrass were significant and comparable to those reported by other researchers when studied separately. Total P concentrations in runoff water from prairie and turf vegetation were above USEPA limits, averaging 1.86 and 1.63 mg L, respectively, over 2 yr. Averaged across 2 yr, 78% of runoff P was collected when the soil was frozen. Biomass P reductions over the period of November to April were strongly related to quantities of runoff total P from frozen soil ( = 0.874). Phosphorus losses from urban areas appeared to be primarily correlated with runoff depth, not vegetation type, because correlation coefficients revealed 86 and 45% of the Year 1 and Year 2 total P loads were directly accounted for by runoff volumes. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Comparison of conceptually based and regression rainfall-runoff models, Denver Metropolitan area, Colorado, and potential applications in urban areas

USGS Publications Warehouse

Lindner-Lunsford, J. B.; Ellis, S.R.

1987-01-01

Multievent, conceptually based models and a single-event, multiple linear-regression model for estimating storm-runoff quantity and quality from urban areas were calibrated and verified for four small (57 to 167 acres) basins in the Denver metropolitan area, Colorado. The basins represented different land-use types - light commercial, single-family housing, and multi-family housing. Both types of models were calibrated using the same data set for each basin. A comparison was made between the storm-runoff volume, peak flow, and storm-runoff loads of seven water quality constituents simulated by each of the models by use of identical verification data sets. The models studied were the U.S. Geological Survey 's Distributed Routing Rainfall-Runoff Model-Version II (DR3M-II) (a runoff-quantity model designed for urban areas), and a multievent urban runoff quality model (DR3M-QUAL). Water quality constituents modeled were chemical oxygen demand, total suspended solids, total nitrogen, total phosphorus, total lead, total manganese, and total zinc. (USGS)

Modeling the Effect of Summertime Heating on Urban Runoff Temperature

NASA Astrophysics Data System (ADS)

Thompson, A. M.; Gemechu, A. L.; Norman, J. M.; Roa-Espinosa, A.

2007-12-01

Urban impervious surfaces absorb and store thermal energy, particularly during warm summer months. During a rainfall/runoff event, thermal energy is transferred from the impervious surface to the runoff, causing it to become warmer. As this higher temperature runoff enters receiving waters, it can be harmful to coldwater habitat. A simple model has been developed for the net energy flux at the impervious surfaces of urban areas to account for the heat transferred to runoff. Runoff temperature is determined as a function of the physical characteristics of the impervious areas, the weather, and the heat transfer between the moving film of runoff and the heated impervious surfaces that commonly exist in urban areas. Runoff from pervious surfaces was predicted using the Green- Ampt Mein-Larson infiltration excess method. Theoretical results were compared to experimental results obtained from a plot-scale field study conducted at the University of Wisconsin's West Madison Agricultural Research Station. Surface temperatures and runoff temperatures from asphalt and sod plots were measured throughout 15 rainfall simulations under various climatic conditions during the summers of 2004 and 2005. Average asphalt runoff temperatures ranged from 23.2°C to 37.1°C. Predicted asphalt runoff temperatures were in close agreement with measured values for most of the simulations (average RMSE = 4.0°C). Average pervious runoff temperatures ranged from 19.7° to 29.9°C and were closely approximated by the rainfall temperature (RMSE = 2.8°C). Predicted combined asphalt and sod runoff temperatures using a flow-weighted average were in close agreement with observed values (average RMSE = 3.5°C).

Characterization of Stormwater Runoff from a Light Rail Transit Area.

PubMed

Sajjad, Raja Umer; Kim, Kyoung Jin; Memon, Sheeraz; Sukhbaatar, Chinzorig; Paule, Ma Cristina; Lee, Bum-Yeon; Lee, Chang-Hee

2015-09-01

The monitoring of stormwater runoff from Light Rail Transit (LRT) facilities is insufficient in many regions around the world. In this study, runoff quality and quantity were monitored during operational and non-operational LRT phases during 2010-2013. The event mean concentration (EMC) of pollutants showed little statistical variability during both phases. The antecedent dry day (ADD) showed a strong to moderate positive correlation with most pollutant EMCs during the non-operational phase. The existence and magnitude of the first flush from LRT runoff was found to be similar to those from other transportation land uses. The comparison of LRT runoff data with an adjacent road bridge site showed that the pollutant EMC and unit load were 2 to 9 times higher from the road bridge. It was suggested that LRT automated operation and the elevated track makes this transportation mode a viable option for the management of non-point source pollution.

Hydrologic data for urban storm runoff from nine sites in the Denver metropolitan area, Colorado

USGS Publications Warehouse

Gibbs, Johnnie W.

1981-01-01

Urban storm-runoff data were collected April through September 1980, from nine urbanrunoff sites in the Denver metropolitan area, and are presented in this report. The sites consist of two single-family residential areas, two multi-family residential areas, one commercial area (shopping center), one mixed commercial and multi-family residential area, one native area (open space), and two detention ponds. Precipitation, rainfall-runoff, water-quality (common constituents, nutrients, coliform bacteria, solids, and trace elements) and basin-area data are necessary to use the U.S. Geological Survey 's Distributed Routing Rainfall-Runoff Model, Version II. The urban storm-runoff data may be used to characterize runoff pollution loading for various land-use types in Denver and other semi-arid regions. (USGS)

Forecasting land use change and its environmental impact at a watershed scale.

PubMed

Tang, Z; Engel, B A; Pijanowski, B C; Lim, K J

2005-07-01

Urban expansion is a major driving force altering local and regional hydrology and increasing non-point source (NPS) pollution. To explore these environmental consequences of urbanization, land use change was forecast, and long-term runoff and NPS pollution were assessed in the Muskegon River watershed, located on the eastern coast of Lake Michigan. A land use change model, LTM, and a web-based environmental impact model, L-THIA, were used in this study. The outcomes indicated the watershed would likely be subjected to impacts from urbanization on runoff and some types of NPS pollution. Urbanization will slightly or considerably increase runoff volume, depending on the development rate, slightly increase nutrient losses in runoff, but significantly increase losses of oil and grease and certain heavy metals in runoff. The spatial variation of urbanization and its impact were also evaluated at the subwatershed scale and showed subwatersheds along the coast of the lake and close to cities would have runoff and nitrogen impact. The results of this study have significant implications for urban planning and decision making in an effort to protect and remediate water and habitat quality of Muskegon Lake, which is one of Lake Michigan's Areas of Concern (AOC), and the techniques described here can be used in other areas.

KINEROS2-AGWA: Model Use, Calibration, and Validation

NASA Technical Reports Server (NTRS)

Goodrich, D C.; Burns, I. S.; Unkrich, C. L.; Semmens, D. J.; Guertin, D. P.; Hernandez, M.; Yatheendradas, S.; Kennedy, J. R.; Levick, L. R..

2013-01-01

KINEROS (KINematic runoff and EROSion) originated in the 1960s as a distributed event-based model that conceptualizes a watershed as a cascade of overland flow model elements that flow into trapezoidal channel model elements. KINEROS was one of the first widely available watershed models that interactively coupled a finite difference approximation of the kinematic overland flow equations to a physically based infiltration model. Development and improvement of KINEROS continued from the 1960s on a variety of projects for a range of purposes, which has resulted in a suite of KINEROS-based modeling tools. This article focuses on KINEROS2 (K2), a spatially distributed, event-based watershed rainfall-runoff and erosion model, and the companion ArcGIS-based Automated Geospatial Watershed Assessment (AGWA) tool. AGWA automates the time-consuming tasks of watershed delineation into distributed model elements and initial parameterization of these elements using commonly available, national GIS data layers. A variety of approaches have been used to calibrate and validate K2 successfully across a relatively broad range of applications (e.g., urbanization, pre- and post-fire, hillslope erosion, erosion from roads, runoff and recharge, and manure transport). The case studies presented in this article (1) compare lumped to stepwise calibration and validation of runoff and sediment at plot, hillslope, and small watershed scales; and (2) demonstrate an uncalibrated application to address relative change in watershed response to wildfire.

KINEROS2/AGWA: Model use, calibration and validation

USGS Publications Warehouse

Goodrich, D.C.; Burns, I.S.; Unkrich, C.L.; Semmens, Darius J.; Guertin, D.P.; Hernandez, M.; Yatheendradas, S.; Kennedy, Jeffrey R.; Levick, Lainie R.

2012-01-01

KINEROS (KINematic runoff and EROSion) originated in the 1960s as a distributed event-based model that conceptualizes a watershed as a cascade of overland flow model elements that flow into trapezoidal channel model elements. KINEROS was one of the first widely available watershed models that interactively coupled a finite difference approximation of the kinematic overland flow equations to a physically based infiltration model. Development and improvement of KINEROS continued from the 1960s on a variety of projects for a range of purposes, which has resulted in a suite of KINEROS-based modeling tools. This article focuses on KINEROS2 (K2), a spatially distributed, event-based watershed rainfall-runoff and erosion model, and the companion ArcGIS-based Automated Geospatial Watershed Assessment (AGWA) tool. AGWA automates the time-consuming tasks of watershed delineation into distributed model elements and initial parameterization of these elements using commonly available, national GIS data layers. A variety of approaches have been used to calibrate and validate K2 successfully across a relatively broad range of applications (e.g., urbanization, pre- and post-fire, hillslope erosion, erosion from roads, runoff and recharge, and manure transport). The case studies presented in this article (1) compare lumped to stepwise calibration and validation of runoff and sediment at plot, hillslope, and small watershed scales; and (2) demonstrate an uncalibrated application to address relative change in watershed response to wildfire.

Urban nonpoint source pollution buildup and washoff models for simulating storm runoff quality in the Los Angeles County.

PubMed

Wang, Long; Wei, Jiahua; Huang, Yuefei; Wang, Guangqian; Maqsood, Imran

2011-07-01

Many urban nonpoint source pollution models utilize pollutant buildup and washoff functions to simulate storm runoff quality of urban catchments. In this paper, two urban pollutant washoff load models are derived using pollutant buildup and washoff functions. The first model assumes that there is no residual pollutant after a storm event while the second one assumes that there is always residual pollutant after each storm event. The developed models are calibrated and verified with observed data from an urban catchment in the Los Angeles County. The application results show that the developed model with consideration of residual pollutant is more capable of simulating nonpoint source pollution from urban storm runoff than that without consideration of residual pollutant. For the study area, residual pollutant should be considered in pollutant buildup and washoff functions for simulating urban nonpoint source pollution when the total runoff volume is less than 30 mm. Copyright © 2011 Elsevier Ltd. All rights reserved.

Performance of vegetated swales for improving road runoff quality in a moderate traffic urban area.

PubMed

Leroy, Marie-Charlotte; Portet-Koltalo, Florence; Legras, Marc; Lederf, Franck; Moncond'huy, Vincent; Polaert, Isabelle; Marcotte, Stéphane

2016-10-01

In recent years, due to their economic and ecological advantages, green infrastructures for stormwater management have been widely implemented. The present study focused on vegetated swales and compared two vegetated covers, grassed or planted with macrophytes in order to evaluate their performance in terms of water quality improvement. These swales collected runoff of a moderately busy road (<2500vehday(-1)) in a commercial area. Twelve storm events were analyzed over a two year period with measurement of total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total hydrocarbons (THC), total phosphorous (TP), total Kjeldahl nitrogen (TKN), trace elements and 16 polycyclic aromatic hydrocarbons (PAHs). The grass cover led to poor results due to lower retention of soil particles on which trace elements and PAHs are bounded. The swales planted with macrophytes, with a deeper root system more capable of retaining soil particles, led to reductions of concentrations from 17 to 45% for trace elements such as lead, zinc and copper and 30% for the 16 PAHs in infiltrated waters. In addition, the macrophyte cover showed lower variability of pollutant concentrations in infiltrated waters compared to incoming waters. This buffering capacity is interesting to mitigate the impact of moderate peak pollution on surface water or ground water quality. Copyright © 2016 Elsevier B.V. All rights reserved.

Understanding re-distribution of road deposited particle-bound pollutants using a Bayesian Network (BN) approach.

PubMed

Liu, An; Wijesiri, Buddhi; Hong, Nian; Zhu, Panfeng; Egodawatta, Prasanna; Goonetilleke, Ashantha

2018-05-08

Road deposited pollutants (build-up) are continuously re-distributed by external factors such as traffic and wind turbulence, influencing stormwater runoff quality. However, current stormwater quality modelling approaches do not account for the re-distribution of pollutants. This undermines the accuracy of stormwater quality predictions, constraining the design of effective stormwater treatment measures. This study, using over 1000 data points, developed a Bayesian Network modelling approach to investigate the re-distribution of pollutant build-up on urban road surfaces. BTEX, which are a group of highly toxic pollutants, was the case study pollutants. Build-up sampling was undertaken in Shenzhen, China, using a dry and wet vacuuming method. The research outcomes confirmed that the vehicle type and particle size significantly influence the re-distribution of particle-bound BTEX. Compared to heavy-duty traffic in commercial areas, light-duty traffic dominates the re-distribution of particles of all size ranges. In industrial areas, heavy-duty traffic re-distributes particles >75 μm, and light-duty traffic re-distributes particles <75 μm. In residential areas, light-duty traffic re-distributes particles >300 μm and <75 μm and heavy-duty traffic re-distributes particles in the 300-150 μm range. The study results provide important insights to improve stormwater quality modelling and the interpretation of modelling outcomes, contributing to safeguard the urban water environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Recent findings related to measuring and modeling forest road erosion

Treesearch

W. J. Elliot; R. B. Foltz; P. R. Robichaud

2009-01-01

Sediment is the greatest pollutant of forest streams. In the absence of wildfire, forest road networks are usually the main source of sediment in forest watersheds. An understanding of forest road erosion processes is important to aid in predicting sediment delivery from roads to streams. The flowpath followed by runoff is the key to understanding road erosion...

Osmotically driven membrane process for the management of urban runoff in coastal regions.

PubMed

Li, Zhenyu; Valladares Linares, Rodrigo; Abu-Ghdaib, Muhannad; Zhan, Tong; Yangali-Quintanilla, Victor; Amy, Gary

2014-01-01

An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier to reject runoff-derived contaminants. The process was demonstrated by a lab scale testing using synthetic urban runoff (as the feed solution) and synthetic seawater (as the draw solution). The submerged forward osmosis process was conducted under neutral, acidic and natural organic matter fouling condition, respectively. Forward osmosis flux decline was mainly attributed to the dilution of seawater during a semi-batch process in lab scale testing. However, it is possible to minimize flux decrease by maintaining a constant salinity at the draw solution side. Various changes in urban runoff water quality, including acidic conditions (acid rain) and natural organic matter presence, did not show significant effects on the rejection of trace metals and phosphorus, but influenced salt leakage and the rejection of nitrate and total nitrogen. Rejection of trace metals varied from 98% to 100%, phosphorus varied from 97% to 100, nitrate varied from 52% to 94% and total nitrogen varied from 65% to 85% under different feed water conditions. The work described in this study contributes to an integrated system of urban runoff management, seawater desalination and possible power generation in coastal regions to achieve a sustainable solution to the water-energy nexus. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quantifying the effects of stream channels on storm water quality in a semi-arid urban environment

NASA Astrophysics Data System (ADS)

Gallo, Erika L.; Lohse, Kathleen A.; Brooks, Paul D.; McIntosh, Jennifer C.; Meixner, Thomas; McLain, Jean E. T.

2012-11-01

SummaryStormwater drainage systems can have a large effect on urban runoff quality, but it is unclear how ephemeral urban streams alter runoff hydrochemistry. This problem is particularly relevant in semi-arid regions, where urban storm runoff is considered a renewable water resource. Here we address the question: how do stream channels alter urban runoff hydrochemistry? We collected synoptic stormwater samples during three rainfall-runoff events from nine ephemeral streams reaches (three concrete or metal, three grass, three gravel) in Tucson, Arizona. We identified patterns of temporal and spatial (longitudinal) variability in concentrations of conservative (chloride and isotopes of water) and reactive solutes (inorganic-N, soluble reactive phosphorous, sulfate-S, dissolved organic carbon (DOC) and nitrogen, and fecal indicator bacteria). Water isotopes and chloride (Cl) concentrations indicate that solute flushing and evapoconcentration alter temporal patterns in runoff hydrochemistry, but not spatial hydrochemical responses. Solute concentrations and stream channel solute sourcing and retention during runoff were significantly more variable at the grass reaches (CV = 2.3 - 144%) than at the concrete or metal (CV = 1.6 - 107%) or gravel reaches (CV = 1.9 - 60%), which functioned like flow-through systems. Stream channel soil Cl and DOC decreased following a runoff event (Cl: 12.1-7.3 μg g-1 soil; DOC: 87.7-30.1 μg g-1 soil), while soil fecal indicator bacteria counts increased (55-215 CFU g-1 soil). Finding from this study suggest that the characteristics of the ephemeral stream channel substrate control biogeochemical reactions between runoff events, which alter stream channel soil solute stores and the hydrochemistry of subsequent runoff events.

Estimating subcatchment runoff coefficients using weather radar and a downstream runoff sensor.

PubMed

Ahm, Malte; Thorndahl, Søren; Rasmussen, Michael R; Bassø, Lene

2013-01-01

This paper presents a method for estimating runoff coefficients of urban drainage subcatchments based on a combination of high resolution weather radar data and flow measurements from a downstream runoff sensor. By utilising the spatial variability of the precipitation it is possible to estimate the runoff coefficients of the separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678 ha) located in the city of Aarhus, Denmark. The study has proven that it is possible to use corresponding measurements of the relative rainfall distribution over the catchment and downstream runoff measurements to identify the runoff coefficients at subcatchment level.

Statistical analysis of vegetation and stormwater runoff in an urban watershed during summer and winter storms in Portland, Oregon, U.S

Treesearch

Geoffrey H. Donovan; David T. Butry; Megan Y. Mao

2016-01-01

Past research has examined the effect of urban trees, and other vegetation, on stormwater runoff using hydrological models or small-scale experiments. However, there has been no statistical analysis of the influence of vegetation on runoff in an intact urban watershed, and it is not clear how results from small-scale studies scale up to the city level. Researchers...

[Off-line control of runoff pollution by filtering ditch-pond system in urban tourist areas].

PubMed

Chen, Qing-Feng; Shan, Bao-Qing; Yin, Cheng-Qing; Hu, Cheng-Xiao

2007-10-01

An off-line filtering ditch-pond system for controlling storm runoff pollution in urban tourist areas was developed, which could retain the first flush effectively, resulting in the decrease of pollutant concentration and suspended solid average grain size, and the improvement of pollutant retention in runoff. This system could be an effective treatment system for storm runoff pollution, particularly for the scarcity of available land use in urban areas. In 2005, the yearly retention rates of TSS, COD, TN and TP were 86.4%, 85.5%, 83.9% and 82.9%, and during a storm event on June 26, the retention rates of runoff volume, TSS, COD, TN and TP were 67.9%, 97.0%, 89.2%, 94.9% and 96.2%, respectively. This system could also retain most of the suspended solids in runoff.

Urban Runoff and Combined Sewer Overflow.

ERIC Educational Resources Information Center

Field, Richard; Gardner, Bradford B.

1978-01-01

Presents a literature review of wastewater treatment, covering publications of 1976-77. This review includes areas such as: (1) urban runoff quality and quantity; (2) urban hydrology; (3) management practices; and (4) combined sewer overflows. A list of 140 references is also presented. (HM)

Wildlife friendly roads: the impacts of roads on wildlife in urban areas and potential remedies

USGS Publications Warehouse

Riley, Seth P D; Brown, Justin L.; Sikich, Jeff A.; Schoonmaker, Catherine M.; Boydston, Erin E.

2014-01-01

Roads are one of the most important factors affecting the ability of wildlife to live and move within an urban area. Roads physically replace wildlife habitat and often reduce habitat quality nearby, fragment the remaining habitat, and cause increased mortality through vehicle collisions. Much ecological research on roads has focused on whether animals are successfully crossing roads, or if the road is a barrier to wildlife movement, gene flow, or functional connectivity. Roads can alter survival and reproduction for wildlife, even among species such as birds that cross roads easily. Here we examine the suite of potential impacts of roads on wildlife, but we focus particularly on urban settings. We report on studies, both in the literature and from our own experience, that have addressed wildlife and roads in urban landscapes. Although road ecology is a growing field of study, relatively little of this research, and relatively few mitigation projects, have been done in urban landscapes. We also draw from the available science on road impacts in rural areas when urban case studies have not fully addressed key topics.

[Pollution Characteristics of Surface Runoff of Typical Town in Chongqing City].

PubMed

Wang, Long-tao; Duan, Bing-zheng; Zhao, Jian-wei; Hua, Yu-mei; Zhu, Duan-wei

2015-08-01

Six kinds of impermeable underlying surface, cement tile roof, asbestos roof, cement flat roof, residential concrete pavement, asphalt pavement of restaurants, asphalt pavement of oil depot, and a combined sewer overflow canal in the Jiansheng town of Dadukou district in Chongqing city were chosen as sample plots to study the characteristics of nutritional pollutants and heavy metals in town runoff. The research showed that the average mass concentrations of TSS, COD, TN, TP in road runoff were (1681.2 +/- 677.2), (1154.7 +/- 415.5), (12.07 +/- 2.72), (3.32 +/- 1.15) mgL(-1), respectively. These pollutants were higher than those in roof runoff which were (13.3 +/- 6.5), (100.4 +/- 24.8), (3.58 +/- 0.70), (0.10 +/- 0.02) mg x L(-1), respectively. TDN accounted for 62.60% +/- 34.38% of TN, and TDP accounted for 42.22% +/- 33.94% of TP in the runoff of impermeable underlying surface. Compared with the central urban runoff, town runoff in our study had higher mass concentrations of these pollutants. The mass concentrations of TSS, COD, TDN, TN, TDP and TP in the combined sewer overflow were (281.57 +/- 308.38), (231.21 +/- 42.95), (8.16 +/- 2.78), (10.60 +/- 3.94), (0.38 +/- 0.23) and (1.51 +/- 0.75) mg x L(-1), respectively. The average levels of heavy metals in this kind of runoff did not exceed the class VI level of the surface water environmental quality standard. Most pollutants in the combined sewer overflow had first flush. However, this phenomenon was very rare for TSS. There was a significant positive correlation between TSS and COD, TP in the combined sewer overflow. And this correlation was significant between NH4+ -N and TP, TDP, TN, TDP. However, a negative correlation existed between NO3- -N and all other indicators.

A Fresh Look at Road Salt: Aquatic Toxicity and Water-Quality Impacts on Local, Regional, and National Scales

PubMed Central

2010-01-01

A new perspective on the severity of aquatic toxicity impact of road salt was gained by a focused research effort directed at winter runoff periods. Dramatic impacts were observed on local, regional, and national scales. Locally, samples from 7 of 13 Milwaukee, Wisconsin area streams exhibited toxicity in Ceriodaphnia dubia and Pimephales promelas bioassays during road-salt runoff. Another Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays. The maximum chloride concentration was 7730 mg/L. Regionally, in southeast Wisconsin, continuous specific conductance was monitored as a chloride surrogate in 11 watersheds with urban land use from 6.0 to 100%. Elevated specific conductance was observed between November and April at all sites, with continuing effects between May and October at sites with the highest specific conductance. Specific conductance was measured as high as 30 800 μS/cm (Cl = 11 200 mg/L). Chloride concentrations exceeded U.S. Environmental Protection Agency (USEPA) acute (860 mg/L) and chronic (230 mg/L) water-quality criteria at 55 and 100% of monitored sites, respectively. Nationally, U.S. Geological Survey historical data were examined for 13 northern and 4 southern metropolitan areas. Chloride concentrations exceeded USEPA water-quality criteria at 55% (chronic) and 25% (acute) of the 168 monitoring locations in northern metropolitan areas from November to April. Only 16% (chronic) and 1% (acute) of sites exceeded criteria from May to October. At southern sites, very few samples exceeded chronic water-quality criteria, and no samples exceeded acute criteria. PMID:20806974

A fresh look at road salt: Aquatic toxicity and water-quality impacts on local, regional, and national scales

USGS Publications Warehouse

Corsi, S.R.; Graczyk, D.J.; Geis, S.W.; Booth, N.L.; Richards, K.D.

2010-01-01

A new perspective on the severity of aquatic toxicity impact of road salt was gained by a focused research effort directed at winter runoff periods. Dramatic impacts were observed on local, regional, and national scales. Locally, samples from 7 of 13 Milwaukee, Wisconsin area streams exhibited toxicity in Ceriodaphnia dubia and Pimephales promelas bioassays during road-salt runoff. Another Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays. The maximum chloride concentration was 7730 mg/L. Regionally, in southeast Wisconsin, continuous specific conductance was monitored as a chloride surrogate in 11 watersheds with urban land use from 6.0 to 100%. Elevated specific conductance was observed between November and April at all sites, with continuing effects between May and October at sites with the highest specific conductance. Specific conductance was measured as high as 30 800 ??S/cm (Cl = 11 200 mg/L). Chloride concentrations exceeded U.S. Environmental Protection Agency (USEPA) acute (860 mg/L) and chronic (230 mg/L) water-quality criteria at 55 and 100% of monitored sites, respectively. Nationally, U.S. Geological Survey historical data were examined for 13 northern and 4 southern metropolitan areas. Chloride concentrations exceeded USEPA water-quality criteria at 55% (chronic) and 25% (acute) of the 168 monitoring locations in northern metropolitan areas from November to April. Only 16% (chronic) and 1% (acute) of sites exceeded criteria from May to October. At southern sites, very few samples exceeded chronic water-quality criteria, and no samples exceeded acute criteria. ?? 2010 American Chemical Society.

Management of Urban Stormwater Runoff in the Chesapeake Bay Watershed

USGS Publications Warehouse

Hogan, Dianna M.

2008-01-01

Urban and suburban development is associated with elevated nutrients, sediment, and other pollutants in stormwater runoff, impacting the physical and environmental health of area streams and downstream water bodies such as the Chesapeake Bay. Stormwater management facilities, also known as Best Management Practices (BMPs), are increasingly being used in urban areas to replace functions, such as flood protection and water quality improvement, originally performed by wetlands and riparian areas. Scientists from the U.S. Geological Survey (USGS) have partnered with local, academic, and other Federal agency scientists to better understand the effectiveness of different stormwater management systems with respect to Chesapeake Bay health. Management of stormwater runoff is necessary in urban areas to address flooding and water quality concerns. Improving our understanding of what stormwater management actions may be best suited for different types of developed areas could help protect the environmental health of downstream water bodies that ultimately receive runoff from urban landscapes.

Estimation of urban runoff and water quality using remote sensing and artificial intelligence.

PubMed

Ha, S R; Park, S Y; Park, D H

2003-01-01

Water quality and quantity of runoff are strongly dependent on the landuse and landcover (LULC) criteria. In this study, we developed a more improved parameter estimation procedure for the environmental model using remote sensing (RS) and artificial intelligence (AI) techniques. Landsat TM multi-band (7bands) and Korea Multi-Purpose Satellite (KOMPSAT) panchromatic data were selected for input data processing. We employed two kinds of artificial intelligence techniques, RBF-NN (radial-basis-function neural network) and ANN (artificial neural network), to classify LULC of the study area. A bootstrap resampling method, a statistical technique, was employed to generate the confidence intervals and distribution of the unit load. SWMM was used to simulate the urban runoff and water quality and applied to the study watershed. The condition of urban flow and non-point contaminations was simulated with rainfall-runoff and measured water quality data. The estimated total runoff, peak time, and pollutant generation varied considerably according to the classification accuracy and percentile unit load applied. The proposed procedure would efficiently be applied to water quality and runoff simulation in a rapidly changing urban area.

Tracing the origin and mobilization of Glyphosate and AMPA in a vineyard catchment

NASA Astrophysics Data System (ADS)

Gassmann, Matthias; Olsson, Oliver; Payraudeau, Sylvain; Imfeld, Gwenaël; Kümmerer, Klaus

2014-05-01

Pesticides residues are often found in storm-water runoff in agricultural areas. There are several pathways along which pesticides may be transported from their application point towards the river. Although the primary target of pesticide application is the agricultural area, wind drift transports pesticide droplets to non-target areas. Furthermore, miss-operation of application machines results in the deposition of pesticides at filter strips or roads from where they can be washed off. Therefore, it may be difficult to identify the origin of pesticides in storm-water runoff. However, management of water quality requires that critical source areas are clearly delineated in order to effectively reduce water pollution. In the Rouffach catchment, a 42.7 ha vineyard catchment in France, Glyphosate and its transformation product AMPA occurred frequently and in high concentrations in runoff water during rainfall-runoff events in 2008. In order to identify the source areas of Glyphosate residue pollution and its mobilization, we used here a combination of sampling data analysis techniques and distributed pollutant transfer modelling. Available sampling data allowed for an analysis by Normalized Cumulative Loads (NCL) at a high temporal resolution (10 min). The results imply that pollutant mobilization took place mainly at the beginning of an event. This First Flush suggests a wash off of substances from impervious surfaces such as roads. This assumption was confirmed by local hydrological knowledge about infiltration rates in the vineyard, which were not exceeded by rainfall intensities in most considered events. Additionally, the distributed process-based reactive transport model ZIN-AgriTra was used as a learning tool to evaluate the pesticide mobilization and export processes. The hydrological model was successfully calibrated and validated for long high-resolution time series of discharge data. Pesticide export modelling focused on the first rainfall-runoff event following the first significant Glyphosate application in 2008. Assuming only target Glyphosate application, hardly any export of Ghyphosate and AMPA occurred. Therefore, non-target application at adjacent roads was introduced into the model. By assuming different mobilization processes of substances on the roads, our results show that storage of sorbed pesticides (e.g. road sides, unpaved roads) and storage without sorption (e.g. plant surface, paved roads) significantly contributed to the total pesticide residue export. Concluding, it is likely that the major part of pesticides in runoff of the Rouffach catchment originates from the roads rather than from the vine growing areas and that the mobilization process is a combination of both sorptive and non-sorptive substance storage. Thus, avoiding non-target pesticide application could largely help to mitigate water contamination in this catchment.

Pioneering Techniques to Determine Wastewater and Urban Runoff Loads in Karst Spring Systems

NASA Astrophysics Data System (ADS)

Hasenmueller, E. A.; Criss, R. E.

2010-12-01

Comparison of urban and rural springs quantifies the magnitude and sources of water quality degradation in east-central Missouri. Urban springs consistently display a suite of impairment characteristics including increases in: (1) specific conductance; (2) coliform bacteria; (3) total suspended solids (TSS); (4) nutrient concentrations including N, P, and S species; (5) B concentration; (6) heavy metal concentrations such as Cd, Cr, and Pb; and (7) temperature variability. Several dozen springs, representing a range in magnitude and recharge area land use, were sampled in and around St. Louis, MO. In addition, effluent from the Duckett Creek Treatment Plant was sampled to ascertain the chemistry of municipal waste waters in the area. Sodium perborate is a primary ingredient in bleaching agents for detergents, and therefore B is found in very high concentrations in waste waters (> 240 ppb) compared to background levels (< 20 ppb) in carbonate-hosted springs. Consequently, B provides an excellent, conservative tracer of sewage contributions to groundwater systems, and this study has shown that several urban springs comprise > 25% waste water. High B concentrations correlate well with increased nutrient contents and high E. coli and total coliform levels, which also suggest large sewage contributions to the shallow groundwater. Elevated specific conductance in these springs is primarily due to road salt contamination of these Ca-Mg-bicarbonate waters. In marked contrast to natural springs, Na and Cl can even be the dominant ions in urban springs, so they are useful indicators of urban runoff. High concentrations of Na and Cl ions persist well into late summer, confirming stable isotope models for the ~ 1 year residence time of these shallow groundwaters. Further, specific conductance, temperature, and TSS are highly variable in urban springs because of amplified throughput of storm water runoff; in fact, many detention basins directly feed into cave systems. Dissolved oxygen (DO) and pH are useful indicators of the nature of subsurface groundwater environments. In particular, springs with no known cave passage typically have low DO and pH (< 60% saturation and < 7.7, respectively), as is common in goundwaters that do not communicate with the atmosphere. However, springs draining open cave systems have higher DO and pH (60 - 90% saturation and > 7.7, respectively) due to the equilibration of DO with the overlying cave atmosphere and the degassing of carbon dioxide. This pair of parameters might provide a novel means to detect undiscovered caves.

CONSTRUCTED WETLANDS VS. RETENTION POND BMPS: MESOCOSM STUDIES FOR IMPROVED POLLUTANT MANAGEMENT IN URBAN STORMWATER TREATMENT

EPA Science Inventory

Increased urbanization has increased the amount of directly connected impervious area that results in large quantities of stormwater runoff. This runoff can contribute significant amounts of debris and pollutants to receiving waters. Urban watershed managers often incorporate b...

Simulation and assessment of urbanization impacts on runoff metrics: insights from landuse changes

NASA Astrophysics Data System (ADS)

Zhang, Yongyong; Xia, Jun; Yu, Jingjie; Randall, Mark; Zhang, Yichi; Zhao, Tongtiegang; Pan, Xingyao; Zhai, Xiaoyan; Shao, Quanxi

2018-05-01

Urbanization-induced landuse changes alter runoff regimes in complex ways. In this study, a detailed investigation of the urbanization impacts on runoff regimes is provided by using multiple runoff metrics and with consideration of landuse dynamics. A catchment hydrological model is modified by coupling a simplified flow routing module of the urban drainage system and landuse dynamics to improve long-term urban runoff simulations. Moreover, multivariate statistical approach is adopted to mine the spatial variations of runoff metrics so as to further identify critical impact factors of landuse changes. The Qing River catchment as a peri-urban catchment in the Beijing metropolitan area is selected as our study region. Results show that: (1) the dryland agriculture is decreased from 13.9% to 1.5% of the total catchment area in the years 2000-2015, while the percentages of impervious surface, forest and grass are increased from 63.5% to 72.4%, 13.5% to 16.6% and 5.1% to 6.5%, respectively. The most dramatic landuse changes occur in the middle and downstream regions; (2) The combined landuse changes do not alter the average flow metrics obviously at the catchment outlet, but slightly increase the high flow metrics, particularly the extreme high flows; (3) The impacts on runoff metrics in the sub-catchments are more obvious than those at the catchment outlet. For the average flow metrics, the most impacted metric is the runoff depth in the dry season (October ∼ May) with a relative change from -10.9% to 11.6%, and the critical impact factors are the impervious surface and grass. For the high flow metrics, the extreme high flow depth is increased most significantly with a relative change from -0.6% to 10.5%, and the critical impact factors are the impervious surface and dryland agriculture; (4) The runoff depth metrics in the sub-catchments are increased because of the landuse changes from dryland agriculture to impervious surface, but are decreased because of the landuse changes from dryland agriculture or impervious surface to grass or forest. The results of this study provide useful information for urban planning such as Sponge City design.

Peak Flow Responses to Forest Harvesting and Roads in the Maritime Regions of the Pacific Northwest: A Preferential Hillslope Runoff Perspective

NASA Astrophysics Data System (ADS)

Alila, Y.; Schnorbus, M.

2005-12-01

The debate regarding peak flow responses to forest clearcutting and road building in the maritime regions of the Pacific Northwest has attracted much attention over the past several decades and its outcome is an important scientific and operational concern. Although there appears to be general consensus that small peak discharge events are increased following forest management activities, little conclusive evidence exists regarding the impact of forest management activities on large events. Statistical tests in traditional paired watershed studies have been used to accept or reject hypotheses regarding peak flow responses to clearcutting and roads but provided no insight into watershed processes and other factors leading to their outcome. Furthermore, statistical analyses of peak flow responses to forestry activities in traditional paired watershed studies are confounded by the many factors that may contribute to management effects on watershed hydrology as well as by issues such as shortness of streamflow records and climate variability. To this end, a new perspective is offered in the debate regarding peak flow responses to clearcutting and road building in the maritime regions of the Pacific Northwest by combining numerical modeling with high-quality hydro-meteorological data collected at the 10-km2 Carnation Creek on the west coast of Vancouver Island, British Columbia (BC). In this approach we explicitly account for changes in evapotranspiration loss, forest road construction and, in particular, introduce the concept of the competing influences of matrix versus preferential hillslope runoff. For scenarios involving road construction, forest clearcutting (52% cut rate) and roads and clearcutting combined, peak discharge increases decrease with decreasing event frequency and statistically significant ( = 0.05) increases in peak flow are confined to events with a 1 year or lower return period. For a range of return periods from 0.17 to 20 years, the effect (i.e. increase in peak discharge) of clearcutting alone is more severe than roads alone whereas the combined effect of roads and clearcutting is equal to the addition of the isolated treatments effects. The lower efficiency of the forest canopy in intercepting rainfall for large storms compared to small storms and the increasing proportion of preferential flow in hillslope runoff as event size increases appears to be the main reason for the declining peak flow response to clearcutting. Changes in soil moisture conditions are thought to be relatively unimportant given the significance of preferential hillslope runoff. The weakening response of peak flows to roads with increasing event size is related to higher subsurface flow rates associated with preferential flow coupled with a general lowering of the water table below road cuts; this reduces direct channel interception of hillslope runoff and tends to offset gains in channel flow from direct culvert discharge from the road network.

[Total pollution features of urban runoff outlet for urban river].

PubMed

Luo, Hong-Bing; Luo, Lin; Huang, Gu; He, Qiang; Liu, Ping

2009-11-01

The urban stormwater runoff discharged to urban river, especially to rainfall source river, cannot be ignored. In this study, the Futian River watershed in Shenzhen city in a typical southern city of China is taken as the research object. In order to guide the pollution control for urban river, the eighteen rainfall events were monitored, and the total pollution features of the urban runoff outlet for this urban river were analyzed and discussed by using the process of pollutographs, the identifying to first flush, event mean concentration (EMC), etc. Results show that the concentrations of COD, SS, TN, TP and BOD5 are ten times more than the grade V of the environmental quality standards for surface water during the runoff time; the pollution caused by heavy metals (Cr, Ge, Cu, Hg and As) in runoff at a typical rainfall event is serious; the average and range of pollutant concentration at this runoff outlet in study area are evidently higher than at Shapingba in Chongqing city of China and at Silerwood in Canada, but are lower than at Shilipu in Wuhan city of China. The first flushes of COD, SS, BOD5, especially COD and SS, are evident, but the TN and TP are not. The average EMC of COD, TN, TP and BOD5 are 224.14, 571.15, 5.223, 2.04, 143.5 mg/L, respectively. To some extent, the EMC of COD is about two times of the value of the near cities, Macao and Zhuhai. The EMC of TN and TP are obviously higher than Beijing, Guangzhou and Shanghai. To compared with foreign counties, the EMC of the study area in Shenzhen is obviously much higher than the cities of Korean, USA and Canada. So the total pollution caused by the urban surface runoff in study area is serious and necessary to be treated.

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff.

PubMed

Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Cahn, Michael

2017-05-15

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

IMPEDIMENTS AND SOLUTIONS TO SUSTAINABLE, WATERSHED-SCALE URBAN STORMWATER MANAGEMENT: LESSONS FROM AUSTRALIA AND THE UNITED STATES

EPA Science Inventory

In urban and exurban areas, stormwater runoff is a primary stressor on surface waters (streams, wetlands, lakes, estuaries, and coastal waters). Conventional urban stormwater drainage systems often route runoff directly to streams and rivers, thus exacerbating pollutant inputs a...

Large microplastic particles in sediments of tributaries of the River Thames, UK - Abundance, sources and methods for effective quantification.

PubMed

Horton, Alice A; Svendsen, Claus; Williams, Richard J; Spurgeon, David J; Lahive, Elma

2017-01-15

Sewage effluent input and population were chosen as predictors of microplastic presence in sediments at four sites in the River Thames basin (UK). Large microplastic particles (1mm-4mm) were extracted using a stepwise approach to include visual extraction, flotation and identification using Raman spectroscopy. Microplastics were found at all four sites. One site had significantly higher numbers of microplastics than other sites, average 66 particles 100g -1 , 91% of which were fragments. This site was downstream of a storm drain outfall receiving urban runoff; many of the fragments at this site were determined to be derived of thermoplastic road-surface marking paints. At the remaining three sites, fibres were the dominant particle type. The most common polymers identified included polypropylene, polyester and polyarylsulphone. This study describes two major new findings: presence of microplastic particles in a UK freshwater system and identification of road marking paints as a source of microplastics. This study is the first to quantify microplastics of any size in river sediments in the UK and links their presence to terrestrial sources including sewage and road marking paints. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Permeable pavement and stormwater management systems: a review.

PubMed

Imran, H M; Akib, Shatirah; Karim, Mohamed Rehan

2013-01-01

Uncontrolled stormwater runoff not only creates drainage problems and flash floods but also presents a considerable threat to water quality and the environment. These problems can, to a large extent, be reduced by a type of stormwater management approach employing permeable pavement systems (PPS) in urban, industrial and commercial areas, where frequent problems are caused by intense undrained stormwater. PPS could be an efficient solution for sustainable drainage systems, and control water security as well as renewable energy in certain cases. Considerable research has been conducted on the function of PPS and their improvement to ensure sustainable drainage systems and water quality. This paper presents a review of the use of permeable pavement for different purposes. The paper focuses on drainage systems and stormwater runoff quality from roads, driveways, rooftops and parking lots. PPS are very effective for stormwater management and water reuse. Moreover, geotextiles provide additional facilities to reduce the pollutants from infiltrate runoff into the ground, creating a suitable environment for the biodegradation process. Furthermore, recently, ground source heat pumps and PPS have been found to be an excellent combination for sustainable renewable energy. In addition, this study has identified several gaps in the present state of knowledge on PPS and indicates some research needs for future consideration.

Biodegradability and Molecular Composition of Dissolved Organic Nitrogen in Urban Stormwater Runoff and Outflow Water from a Stormwater Retention Pond.

PubMed

Lusk, Mary G; Toor, Gurpal S

2016-04-05

Dissolved organic nitrogen (DON) can be a significant part of the reactive N in aquatic ecosystems and can accelerate eutrophication and harmful algal blooms. A bioassay method was coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) to determine the biodegradability and molecular composition of DON in the urban stormwater runoff and outflow water from an urban stormwater retention pond. The biodegradability of DON increased from 10% in the stormwater runoff to 40% in the pond outflow water and DON was less aromatic and had lower overall molecular weight in the pond outflow water than in the stormwater runoff. More than 1227 N-bearing organic formulas were identified with FT-ICR-MS in the stormwater runoff and pond outflow water, which were only 13% different in runoff and outflow water. These molecular formulas represented a wide range of biomolecules such as lipids, proteins, amino sugars, lignins, and tannins in DON from runoff and pond outflow water. This work implies that the urban infrastructure (i.e., stormwater retention ponds) has the potential to influence biogeochemical processes in downstream water bodies because retention ponds are often a junction between the natural and the built environment.

Vulnerability Analysis and Evaluation of Urban Road System in Tianjin

NASA Astrophysics Data System (ADS)

Liu, Y. Q.; Wu, X.

In recent years, with the development of economy, the road construction of our country has entered into a period of rapid growth. The road transportation network has been expanding and the risk of disasters is increasing. In this paper we study the vulnerability of urban road system in Tianjin. After analyzed many risk factors of the urban road system security, including road construction, road traffic and the natural environment, we proposed an evaluation index of vulnerability of urban road system and established the corresponding evaluation index system. Based on the results of analysis and comprehensive evaluation, appropriate improvement measures and suggestions which may reduce the vulnerability of the road system and improve the safety and reliability of the road system are proposed.

Urban Runoff: National Management Measures

EPA Pesticide Factsheets

This helps citizens and municipalities in urban areas protect bodies of water from polluted runoff . These scientifically sound techniques are the best practices known today. The guidance helps states to implement their nonpoint source control program.

A review of the bioretention system for sustainable storm water management in urban areas

NASA Astrophysics Data System (ADS)

Shafique, Muhammad

2016-10-01

Bioretention basins/rain garden is a very suitable low-impact development (LID) practice for storm water management around the globe. By using this practice in urban areas, flash flooding problems can be decreased and the environment of an area can be improved. The concept of bioretention was introduced a few decades ago and has been proven to be the best management practice (BMP) for storm water in urban areas. Due to urbanisation, natural surface areas are converted into hard surfaces such as roads, through which water cannot infiltrate into the ground. Due to this, infiltration decreases and surface run-off increases, which causes depletion of ground water continuously. In this study, we mainly explain the bioretention concept and its function as derived from different studies. This review includes different scientists' results for the performance of the bioretention system at different locations. A summary of the research findings by different scientists on the performance of bioretention systems is also provided, including the hydrologic and water quality performances. Finally, future work necessary to enhance the performance and widespread use of bioretention systems is also explained.

The scaling structure of the global road network

PubMed Central

Giometto, Andrea; Shai, Saray; Bertuzzo, Enrico; Mucha, Peter J.; Rinaldo, Andrea

2017-01-01

Because of increasing global urbanization and its immediate consequences, including changes in patterns of food demand, circulation and land use, the next century will witness a major increase in the extent of paved roads built worldwide. To model the effects of this increase, it is crucial to understand whether possible self-organized patterns are inherent in the global road network structure. Here, we use the largest updated database comprising all major roads on the Earth, together with global urban and cropland inventories, to suggest that road length distributions within croplands are indistinguishable from urban ones, once rescaled to account for the difference in mean road length. Such similarity extends to road length distributions within urban or agricultural domains of a given area. We find two distinct regimes for the scaling of the mean road length with the associated area, holding in general at small and at large values of the latter. In suitably large urban and cropland domains, we find that mean and total road lengths increase linearly with their domain area, differently from earlier suggestions. Scaling regimes suggest that simple and universal mechanisms regulate urban and cropland road expansion at the global scale. As such, our findings bear implications for global road infrastructure growth based on land-use change and for planning policies sustaining urban expansions. PMID:29134071

The scaling structure of the global road network.

PubMed

Strano, Emanuele; Giometto, Andrea; Shai, Saray; Bertuzzo, Enrico; Mucha, Peter J; Rinaldo, Andrea

2017-10-01

Because of increasing global urbanization and its immediate consequences, including changes in patterns of food demand, circulation and land use, the next century will witness a major increase in the extent of paved roads built worldwide. To model the effects of this increase, it is crucial to understand whether possible self-organized patterns are inherent in the global road network structure. Here, we use the largest updated database comprising all major roads on the Earth, together with global urban and cropland inventories, to suggest that road length distributions within croplands are indistinguishable from urban ones, once rescaled to account for the difference in mean road length. Such similarity extends to road length distributions within urban or agricultural domains of a given area. We find two distinct regimes for the scaling of the mean road length with the associated area, holding in general at small and at large values of the latter. In suitably large urban and cropland domains, we find that mean and total road lengths increase linearly with their domain area, differently from earlier suggestions. Scaling regimes suggest that simple and universal mechanisms regulate urban and cropland road expansion at the global scale. As such, our findings bear implications for global road infrastructure growth based on land-use change and for planning policies sustaining urban expansions.

Polycyclic aromatic hydrocarbons in storm runoff from urban and coastal South Carolina.

PubMed

Ngabe, B; Bidleman, T F; Scott, G I

2000-06-08

Stormwater runoff was collected in urbanized areas of South Carolina to investigate the levels and sources of polycyclic aromatic hydrocarbons (PAHs). Mean concentrations of total PAHs in runoff (sum(PAHs), 14 compounds), determined by gas chromatography-mass spectrometry, were 5590 ng/l in the city of Columbia and 282 ng/l in the coastal community of Murrells Inlet. Lower concentrations were found in estuarine water at Murrells Inlet (mean = 35 ng/l) and at undeveloped North Inlet estuary (13 ng/l). The PAH profiles in Columbia and Murrells Inlet runoff were similar to those of atmospheric particulate matter and unlike those in used crankcase oil. Examination of the aliphatic fraction of Columbia runoff samples by gas chromatography with flame ionization detection showed patterns that were more similar to used crankcase oil than to urban aerosols.

Improved methods to estimate the effective impervious area in urban catchments using rainfall-runoff data

NASA Astrophysics Data System (ADS)

Ebrahimian, Ali; Wilson, Bruce N.; Gulliver, John S.

2016-05-01

Impervious surfaces are useful indicators of the urbanization impacts on water resources. Effective impervious area (EIA), which is the portion of total impervious area (TIA) that is hydraulically connected to the drainage system, is a better catchment parameter in the determination of actual urban runoff. Development of reliable methods for quantifying EIA rather than TIA is currently one of the knowledge gaps in the rainfall-runoff modeling context. The objective of this study is to improve the rainfall-runoff data analysis method for estimating EIA fraction in urban catchments by eliminating the subjective part of the existing method and by reducing the uncertainty of EIA estimates. First, the theoretical framework is generalized using a general linear least square model and using a general criterion for categorizing runoff events. Issues with the existing method that reduce the precision of the EIA fraction estimates are then identified and discussed. Two improved methods, based on ordinary least square (OLS) and weighted least square (WLS) estimates, are proposed to address these issues. The proposed weighted least squares method is then applied to eleven urban catchments in Europe, Canada, and Australia. The results are compared to map measured directly connected impervious area (DCIA) and are shown to be consistent with DCIA values. In addition, both of the improved methods are applied to nine urban catchments in Minnesota, USA. Both methods were successful in removing the subjective component inherent in the analysis of rainfall-runoff data of the current method. The WLS method is more robust than the OLS method and generates results that are different and more precise than the OLS method in the presence of heteroscedastic residuals in our rainfall-runoff data.

High-resolution surface connectivity measurements and runoff dynamics in five urban watersheds in Knoxville, TN

NASA Astrophysics Data System (ADS)

Epps, T.

2015-12-01

Impervious surfaces and stormwater drainage networks transmit rainfall quickly to urban stream systems with greater frequency, volume, energy, and pollutant loadings than in predevelopment conditions. This has a well-established negative impact on stream ecology, channel morphology, and water quality. Green infrastructure retrofits for urban drainage systems promote more natural hydrologic pathways by disconnecting concentrated flows. However, they are expensive due to high land costs and physical constraints. If a systematic strategy for siting green infrastructure is sought to restore natural flows throughout an urban catchment, greater knowledge of the drainage patterns and areas contributing frequent surface runoff is necessary. Five diverse urban watersheds in Knoxville, TN, were assessed using high-resolution topography, land cover, and artificial drainage network data to identify how surface connectivity differs among watersheds and contributes to altered flow regimes. Rainfall-runoff patterns were determined from continuous rainfall and streamflow monitoring over the previous ten years. Fine-scale flowpath connectivity of impervious surfaces was measured by both a binary approach and by a method incorporating runoff potential by saturation excess. The effect of the spatial distribution of connected surfaces was investigated by incorporating several distance-weighting schema along established urban drainage flowpaths. Statistical relationships between runoff generation and connectivity were measured to determine the ability of these different measures of connectivity to predict runoff thresholds, frequency, volumes, and peak flows. Initial results suggest that rapid assessment of connected surficial flowpaths can be used to identify known green infrastructure assets and highly connected impervious areas and that the differences in connectivity measured between watersheds reflects differing runoff patterns observed in monitored data.

Investigating the influence of heavy metals on macro-invertebrate assemblages using Partial Cononical Correspondence Analysis (pCCA)

NASA Astrophysics Data System (ADS)

Beasley, Gary; Kneale, Pauline E.

This paper defines the spectrum of impairment to stream macroinvertebrates arising from urban runoff. Field sampling of stream sediments at 62 sites across Yorkshire, UK was used to investigate the influence of heavy metals and habitat on macroinvertebrate family distribution using partial Canonical Correspondence Analysis (pCCA). Increasing urbanization and trafficking was associated with increasing levels of metal pollution but, even when traffic is light, family numbers can be reduced by 50%. Industrial areas and motorway runoff depress macroinvertebrate numbers but drainage from streets with no off-road parking in residential areas can have similar impacts. The heavy metals in the sediment accounted for approximately 24% of the variation in macroinvertebrate community composition while the physical habitat variables used in RIVPACS (River InVertebrate Prediction And Classification System) (Wright, 2000) accounted for an additional 30%. Zinc and nickel were the main metal influences regardless of the time of sampling; at these sites copper is less than critical. Results agree with those reported in other studies in which families mainly from the orders Ephemeroptera (mayfly), Plecoptera (stonefly) and Tricoptera (caddisfly) displayed metal sensitivity in that they were absent from metal polluted streams. However, within each of these orders, a continuum of sensitivity is evident: this highlights the risks of generalising on orders rather than using family or indeed species data.

Estuarine and Riverine Areas Final Programmatic Environmental Assessment

DTIC Science & Technology

2004-06-25

sources in the study area include WWTP spray field runoff, urban and agricultural runoff, septic tank leachate , landfill leachate , silviculture...overland sheet flow. Urban and agricultural runoff are sources of fecal and total coliform and fecal streptococcus bacteria. Septic tank leachate and...in leachate from experiments using sand showed the greatest mobility of tungsten. Outdoor exposures and accelerated aging tests studied the

Plot-, farm-, and watershed-scale effects of coffee cultivation in runoff and sediment production in western Puerto Rico.

PubMed

Ramos-Scharrón, Carlos E; Figueroa-Sánchez, Yasiel

2017-11-01

The combination of a topographically abrupt wet-tropical setting with the high level of soil exposure that typifies many sun-grown coffee farms represents optimal conditions for high erosion rates. Although traditionally considered as a main cause for water resource degradation, limited empirical evidence has existed to document its true contribution. This study relies on plot-scale experimental results conducted in western Puerto Rico to assess the impact of cultivated surfaces and farm access roads on runoff and sediment production from the plot to the farm and watershed scales. Results show that unsurfaced and graveled road surfaces produce one- to two-orders of magnitude more per unit area runoff than cultivated lands. Similarly, erosion rates from unsurfaced roads are about 102 g m -2 per cm of rainfall and these are two-orders of magnitude greater than from actively cultivated surfaces. Mitigation practices such as uncompacting road surfaces by ripping and gravel application reduce onsite erosion rates to 0.6% and 8% of unsurfaced conditions, respectively. At the farm scale, coffee farms are estimated to produce sediment at a rate of 12-18 Mg ha -1 yr -1 , and roads are undoubtedly the dominant sediment source responsible for 59-95% of the total sediment produced. The costs associated to ameliorating erosion problems through road graveling are high. Therefore, a combined approach that treats road erosion onsite with one that traps sediment before it reaches river networks is the viable solution to this problem. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is Climate Chang Responsible to Recent Urban Flooding in Devloping Cities in Africa? A Case study of Addis Ababa City, Ethiopia

NASA Astrophysics Data System (ADS)

Moges, Semu; Raschid-Sally, Liqa; Gebremichael, Mekonnen

2013-04-01

Cities in Africa show extraordinary expansion of the built environment and imperviousness of the surface condition. Addis Ababa is a case in point, where over the priod of 1984 to 2002, the city asphalted area has increased from 4.72 sq.km (1984) to 27.7 sq.km (2002). Similarly the paved area has expanded five fold from the original 11.1 sq.km, whilst the built environment expanded from 60.1 to 212.7 sq.km. Using hydrological modeling, we demonstrated due to the surface condition change, runoff generation potential has shown significant increase from 28% (in 1984) to 45% (in 2002), showing over 60% change in the runoff volume. The changing condition of the surface is increasing anabtedly, worsening the flooding condition. Similarly, climate change study shows likely increase of precipitation in and around Addis Ababa by about 13 to 17% and comparative increase in flooding. Unlike many cities in Europe, cities in developing countries are confronted with impact emanating from climate change as well as surface condition change. The impact of flooding caused due to the expansion of built environment is found to be more significant in the short term that the climate change, however, the climate change may dominate the long term future of flooding pattern as cities mature towards 2050. Therefore, It is important to view the impacts expansion of built environment and climate change in tandem in future time horizon since the dominance of the impact is different in different temporal scale. In the case of Addis Ababa, we strongly present the following four suggesions: i) the city adminstration re-estabilish the abandoned flood and drainage department of the city as the main flood regulatory and management body working in tandem with Addis Ababa Roads Authority, Water Supply and Sanitation Authority and Urban Planning Authority; ii) The old design guidlines for palnning and design of urban drainage system is not working any more (assumed stationarity condition), we suggest the planning and design criteria of urban drainage systems be immediately revised and incorporated to reflect the new reality of hydrologial non-stationarity; iii) for Addis Ababa City to be Resilient, we suggest implementation of 'Best Managemnt Practice" that incorporates arresting runoff from the source for benefial use, application of runoff treatment practices (open space, infiltration galleries, retardnat ponds, etc) and flood flow control drainage system based on new design criteria, and iv) instituting improved weather forecasting and early warning system.

Characterization of wash-off from urban impervious surfaces and SuDS design criteria for source control under semi-arid conditions.

PubMed

Andrés-Doménech, Ignacio; Hernández-Crespo, Carmen; Martín, Miguel; Andrés-Valeri, Valerio C

2018-01-15

Knowledge about pollutant wash-off from urban impervious surfaces is a key feature for developing effective management strategies. Accordingly, further information is required about urban areas under semi-arid climate conditions at the sub-catchment scale. This is important for designing source control systems for pollution. In this study, a characterization of pollutant wash-off has been performed over sixteen months, at the sub-catchment scale for urban roads as impervious surfaces. The study was conducted in Valencia, Spain, a city with a Mediterranean climate. The results show high event mean concentrations for suspended solids (98mg/l), organic matter (142mgCOD/l, 25mgBOD 5 /l), nutrients (3.7mgTN/l, 0.4mgTP/l), and metals (0.23, 0.32, 0.62 and 0.17mg/l for Cu, Ni, Pb, and Zn, respectively). The results of the runoff characterization highlight the need to control this pollution at its source, separately from wastewater because of their different characteristics. The wash-off, defined in terms of mobilized mass (g/m 2 ) fits well with both process-based and statistical models, with the runoff volume and rainfall depth being the main explanatory variables. Based on these results and using information collected from hydrographs and pollutographs, an approach for sizing sustainable urban drainage systems (SuDS), focusing on water quality and quantity variables, has been proposed. By setting a concentration-based target (TSS discharged to receiving waters <35mg/l), the results indicate that for a SuDS type detention basin (DB), an off-line configuration performs better than an on-line configuration. The resulting design criterion, expressed as SuDS volume per unit catchment area, assuming a DB type SuDS, varies between 7 and 10l/m 2 . Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing the Magnitude of Polycyclic Aromatic Hydrocarbon Loading from Road Surfaces and Its Effect on Algal Productivity

DOT National Transportation Integrated Search

2010-06-01

The hypotheses of the study were that PAHs washing off roads would retard the growth of aquatic life-supporting algae and promote the growth of harmful, toxin-producing algae in estuaries, such as the Chesapeake Bay. Runoff from various road surfaces...

Rapid modification of urban land surface temperature during rainfall

NASA Astrophysics Data System (ADS)

Omidvar, H.; Bou-Zeid, E.; Song, J.; Yang, J.; Arwatz, G.; Wang, Z.; Hultmark, M.; Kaloush, K.

2017-12-01

We study the runoff dynamics and heat transfer over urban pavements during rainfall. A kinematic wave approach is combined with heat storage and transfer schemes to develop a model for impervious (with runoff) and pervious (without runoff) pavements. The resulting framework is a numerical prognostic model that can simulate the temperature fields in the subsurface and runoff layers to capture the rapid cooling of the surface, as well as the thermal pollution advected in the runoff. Extensive field measurements were then conducted over experimental pavements in Arizona to probe the physics and better represent the relevant processes in the model, and then to validate the model. The experimental data and the model results were in very good agreements, and their joint analysis elucidated the physics of the rapid heat transfer from the subsurface to the runoff layer. Finally, we apply the developed model to investigate how the various hydrological and thermal properties of the pavements, as well as ambient environmental conditions, modulate the surface and runoff thermal dynamics, what is the relative importance of each of them, and how we can apply the model mitigate the adverse impacts of urbanization.

Using the KINEROS2 modeling framework to evaluate the increase in storm runoff from residential development in a semi-arid environment

USGS Publications Warehouse

Kennedy, Jeffrey R.; Goodrich, David C.; Unkrich, Carl L.

2013-01-01

The increase in runoff from urbanization is well known; one extreme example comes from a 13 hectare residential neighborhood in southeast Arizona where runoff was 27 times greater than an adjacent grassland watershed over a forty‐month period from 2005 to 2008. Rainfall‐runoff modeling using the newly‐described KINEROS2 urban element and tension infiltrometer measurements indicate that 17±14 percent of this increase in runoff is due to a 53 percent decrease in the saturated hydraulic conductivity of constructed pervious areas, as compared to the undeveloped grassland. Directly connected impervious areas, primarily streets and driveways, cause 56 percent of the increase in runoff, and indirectly connected impervious areas, primarily rooftops and sidewalks, and a decrease in canopy interception account for the remaining 27 percent increase. Tension infiltrometer measurements show that saturated hydraulic conductivity (Ks) is about double in the grassland watershed than in the urban watershed, 6.2 ± 3.5mm/hr and 2.9 ± 1.6mm/hr, respectively. Ks in the urban watershed identified from calibrating the rainfall‐runoff model to measured runoff is 9.5 ± 2.8 mm/hr—higher than what was measured but much lower than the 26 mm/hr value indicated by a soil‐texture based KINEROS2 parameter look‐up table. A new component of the KINEROS2 modeling framework, the urban element, forms the basis for the model by simulating a contiguous row of houses and the adjoining street as a series of pervious and impervious overland flow planes. Tests using different levels of discretization found that watershed geometry can be represented in a simplified manner, although more detailed discretization led to better model performance.

Trace Metals in Urban Stormwater Runoff and their Management

NASA Astrophysics Data System (ADS)

Li, T.; Hall, K.; Li, L. Y.; Schreier, H.

2009-04-01

In past decades, due to the rapid urbanization, land development has replaced forests, fields and meadows with impervious surfaces such as roofs, parking lots and roads, significantly affecting watershed quality and having an impact on aquatic systems. In this study, non-point source pollution from a diesel bus loop was assessed for the extent of trace metal contamination of Cu, Mn, Fe, and Zn in the storm water runoff. The study was carried out at the University of British Columbia (UBC) in the Greater Vancouver Regional District (GVRD) of British Columbia, Canada. Fifteen storm events were monitored at 3 sites from the diesel bus loop to determine spatial and temporal variations of dissolved and total metal concentrations in the storm water runoff. The dissolved metal concentrations were compared with the provincial government discharge criteria and the bus loop storm water quality was also compared with previous studies conducted across the GVRD urban area. To prevent storm water with hazardous levels of contaminants from being discharged into the urban drainage system, a storm water catch basin filter was installed and evaluated for its efficiency of contaminants removal. The perlite filter media adsorption capacities for the trace metals, oil and grease were studied for better maintenance of the catch basin filter. Dissolved copper exceeded the discharge criteria limit in 2 out of 15 cases, whereas dissolved zinc exceeded the criteria in 4 out of 15 cases, and dissolved manganese was below the criteria in all of the events sampled. Dissolved Cu and Zn accounted for 36 and 45% of the total concentration, whereas Mn and Fe only accounted for 20 and 4% of their total concentration, respectively. Since they are more mobile and have higher bioaccumulation potentials, Zn and Cu are considered to be more hazardous to the aquatic environment than Fe and Mn. With high imperviousness (100%) and intensive traffic at the UBC diesel bus loop, trace metal concentrations were 3, 0.7, 9, and 3.2 times higher than the GVRD urban area limits for Cu, Mn, Fe, and Zn, respectively. The filter showed high and stable capture efficiencies in total metals (Cu 62%, Mn 75%, Fe 83%, Zn 62%), dissolved metals (Cu 39%, Mn 37%, Fe 47%, Zn 32%), turbidity (72%), and suspended solids (74%) removal during the first month of operation. After that, there was gradual degradation. The catch basin filter performance improved significantly for the suspended solids and total metal removal after cleaning. However, the perlite filter medium showed poor performance for dissolved metal removal in the second study period. Based on the findings, a catch basin filter is effective in storm water management to control suspended solids loading from storm water runoff.

Characterization of runoff from various urban catchments at different spatial scales in Beijing, China.

PubMed

Zhang, W; Che, W; Liu, D K; Gan, Y P; Lv, F F

2012-01-01

In order to investigate the characterization of runoff in storm sewer from various urban catchments, three monitoring systems at different spatial scales have been installed separately. They have been held since July 2010 in urban area of Beijing (China). The monitoring data revealed that chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), and NH(3)-N values significantly exceed the Class V surface water quality standard developed by Ministry of Environmental Protection of the People's Republic of China (MEP). A surface solids buildup and wash off model for small watershed was adopted to analyze and discuss the process of a runoff pollutant discharge. More than a half of pollutant parameters presented a good fit to the model. However, a slightly worse-fit to the wash off model appeared in less than half of the data. Due to the influence of sewer sediments, sewer system characteristics, catchment characteristics, and other reasons, first flush was seldom observed in storm sewer runoff from these three survey areas. Meanwhile, the correlation between TSS and any other pollutant was analyzed according to cumulative load of pollutants in runoff events. An event mean concentrations (EMCs) approach was adopted to quantify the pollution of runoff. EMCs of various pollutants in storm sewer runoff between different rainfall events were slightly higher than the typical values observed in similar areas at home and abroad, according to other studies reported in literature. Based on quantitative analysis, it can be concluded that urban non-point source pollution is recognized as the major causes of quality deterioration in the receiving water bodies. This is after the point source pollution has been controlled substantially in Beijing. An integrated strategy, which combines centralized and decentralized control, along with the conditions of meteorology, hydrology, urban planning, existing drainage system, etc., will be an effective and economic approach to urban runoff pollution control.

Effects of forest road amelioration techniques on soil bulk density, surface runoff, sediment transport, soil moisture and seedling growth

Treesearch

Randy K. Kolka; Mathew F. Smidt

2004-01-01

Although numerous methods have been used to retire roads, new technologies have evolved that can potentially ameliorate soil damage, lessen ,the generation of nonpoint source pollution and increase tree productivity on forest roads. In this study we investigated the effects of three forest road amelioration techniques, subsoiling, recontouring and traditional...

PAH related effects on fish in sedimentation ponds for road runoff and potential transfer of PAHs from sediment to biota.

PubMed

Grung, Merete; Petersen, Karina; Fjeld, Eirik; Allan, Ian; Christensen, Jan H; Malmqvist, Linus M V; Meland, Sondre; Ranneklev, Sissel

2016-10-01

Road runoff is an important source of pollution to the aquatic environment, and sedimentation ponds have been installed to mitigate effects on the aquatic environment. The purpose of this study was to investigate if a) fish from sedimentation ponds were affected by road pollution and; b) the transfer of PAHs from road runoff material to aquatic organisms was substantial. Minnow from a sedimentation pond (Skullerud) near Oslo (Norway) had higher levels of CYP1A enzyme and DNA stand breaks than minnow from the nearby river, but high concentrations of PAH-metabolites in bile revealed that both populations were highly exposed. Principal component analysis revealed that CYP1A and age of fish were correlated, while levels of PAH-metabolites were not correlated to CYP1A or DNA damage. Minnow from a lake un-affected by traffic had much lower levels of PAH-metabolites than the exposed fish, and also an improved condition. The latter results indicate that fish health was affected by road runoff. A closer investigation of PAH levels of the ecosystems of two sedimentation ponds (Skullerud and Vassum) and nearby environments were conducted. The concentration of the 16 EPA PAHs in sediments of the sedimentation ponds were high (1900-4200ngg(-1)), and even higher levels were observed in plants. Principal component analysis of selected ion chromatograms of PAHs showed a clear separation of plants vs. sediments. The plants preferentially accumulated the high molecular PAHs, both from sedimentation ponds with a petrogenic PAH isomer ratio in sediments; and from a lake with pyrogenic PAH isomer ratio in sediments. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact of land-use on water pollution in a rapidly urbanizing catchment in China

NASA Astrophysics Data System (ADS)

Khu, Soon-Thiam; Qin, Huapeng

2010-05-01

Many catchments in developing countries are undergoing fast urbanization which is usually characterized by population increase, economic growth as well as drastic changes of land-use from natural/rural to urban area. During the urbanization process, some catchments experience water quality deterioration due to rapid increase of pollution loads. Nonpoint source pollution resulting from storm water runoff has been recognized as one of the major causes of pollutants in many cities in developing countries. The composition of land-use for a rapidly urbanizing catchment is usually heterogeneous, and this may result in significant spatial variations of storm runoff pollution and increase the difficulties of water quality management in the catchment. The Shiyan Reservoir catchment, a typical rapidly urbanizing area in China, is chosen as the study area, and temporary monitoring sites were set at the outlets of its 6 sub-catchments to synchronously measured rainfall, runoff and water quality during 4 storm events. Three indicators, event pollutant loads per unit area (EPL), event mean concentration (EMC) and pollutant loads transported by the first 50% of runoff volume (FF50), were used to describe the runoff pollution for different pollutants (such as COD, BOD, NH3-N, TN, TP and SS) in each sub-catchment during the storm events; and the correlations between runoff pollution spatial variations and land-use patterns were tested by Spearman's rank correlation analysis. The results indicated that similar spatial variation trends were found for different pollutants (EPL or EMC) in light storm events, which strongly correlate with the proportion of residential land-use; however, they have different trends in heavy storm events, which correlate with the different proportional combination of residential, industrial, agricultural and bare land-use. It is also shown that it is necessary to consider some pervious land-use types in runoff pollution monitoring or management for a rapidly urbanizing area, particularly in heavy storm.

Parking lot sealcoat: An unrecognized source of urban polycyclic aromatic hydrocarbons

USGS Publications Warehouse

Mahler, B.J.; Van Metre, P.C.; Bashara, T.J.; Wilson, J.T.; Johns, D.A.

2005-01-01

Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous contaminant in urban environments. Although numerous sources of PAHs to urban runoff have been identified, their relative importance remains uncertain. We show that a previously unidentified source of urban PAHs, parking lot sealcoat, may dominate loading of PAHs to urban water bodies in the United States. Particles in runoff from parking lots with coal-tar emulsion sealcoat had mean concentrations of PAHs of 3500 mg/kg, 65 times higher than the mean concentration from unsealed asphalt and cement lots. Diagnostic ratios of individual PAHs indicating sources are similar for particles from coal-tar emulsion sealed lots and suspended sediment from four urban streams. Contaminant yields projected to the watershed scale for the four associated watersheds indicate that runoff from sealed parking lots could account for the majority of stream PAH loads.

Exploring the Linkage between Urban Flood Risk and Spatial Patterns in Small Urbanized Catchments of Beijing, China

PubMed Central

Yao, Lei; Chen, Liding; Wei, Wei

2017-01-01

In the context of global urbanization, urban flood risk in many cities has become a serious environmental issue, threatening the health of residents and the environment. A number of hydrological studies have linked urban flooding issues closely to the spectrum of spatial patterns of urbanization, but relatively little attention has been given to small-scale catchments within the realm of urban systems. This study aims to explore the hydrological effects of small-scaled urbanized catchments assigned with various landscape patterns. Twelve typical residential catchments in Beijing were selected as the study areas. Total Impervious Area (TIA), Directly Connected Impervious Area (DCIA), and a drainage index were used as the catchment spatial metrics. Three scenarios were designed as different spatial arrangement of catchment imperviousness. Runoff variables including total and peak runoff depth (Qt and Qp) were simulated by using Strom Water Management Model (SWMM). The relationship between catchment spatial patterns and runoff variables were determined, and the results demonstrated that, spatial patterns have inherent influences on flood risks in small urbanized catchments. Specifically: (1) imperviousness acts as an effective indicator in affecting both Qt and Qp; (2) reducing the number of rainwater inlets appropriately will benefit the catchment peak flow mitigation; (3) different spatial concentrations of impervious surfaces have inherent influences on Qp. These findings provide insights into the role of urban spatial patterns in driving rainfall-runoff processes in small urbanized catchments, which is essential for urban planning and flood management. PMID:28264521

Exploring the Linkage between Urban Flood Risk and Spatial Patterns in Small Urbanized Catchments of Beijing, China.

PubMed

Yao, Lei; Chen, Liding; Wei, Wei

2017-02-28

In the context of global urbanization, urban flood risk in many cities has become a serious environmental issue, threatening the health of residents and the environment. A number of hydrological studies have linked urban flooding issues closely to the spectrum of spatial patterns of urbanization, but relatively little attention has been given to small-scale catchments within the realm of urban systems. This study aims to explore the hydrological effects of small-scaled urbanized catchments assigned with various landscape patterns. Twelve typical residential catchments in Beijing were selected as the study areas. Total Impervious Area ( TIA ), Directly Connected Impervious Area ( DCIA ), and a drainage index were used as the catchment spatial metrics. Three scenarios were designed as different spatial arrangement of catchment imperviousness. Runoff variables including total and peak runoff depth ( Q t and Q p ) were simulated by using Strom Water Management Model (SWMM). The relationship between catchment spatial patterns and runoff variables were determined, and the results demonstrated that, spatial patterns have inherent influences on flood risks in small urbanized catchments. Specifically: (1) imperviousness acts as an effective indicator in affecting both Q t and Q p ; (2) reducing the number of rainwater inlets appropriately will benefit the catchment peak flow mitigation; (3) different spatial concentrations of impervious surfaces have inherent influences on Q p . These findings provide insights into the role of urban spatial patterns in driving rainfall-runoff processes in small urbanized catchments, which is essential for urban planning and flood management.

Hydrological Footprints of Urban Developments in the Lake Simcoe Watershed, Canada: A Combined Paired-Catchment and Change Detection Modeling Approach

NASA Astrophysics Data System (ADS)

Oni, S. K.; Futter, M. N.; Buttle, J. M.; Dillon, P.

2014-12-01

Urban sprawl and regional climate variability are major stresses on surface water resources in many places. The Lake Simcoe watershed (LSW) Ontario, Canada, is no exception. The LSW is predominantly agricultural but is experiencing rapid population growth due to its proximity to the greater Toronto area. This has led to extensive land use changes which have impacted its water resources and altered runoff patterns in some rivers draining to the lake. Here, we use a paired-catchment approach, hydrological change detection modelling and remote sensing analysis of satellite images to evaluate the impacts of land use change on the hydrology of the LSW (1994 to 2008). Results show that urbanization increased up to 16% in Lovers Creek, the most-urban impacted catchment. Annual runoff from Lovers Creek increased from 239 to 442 mm/yr in contrast to the reference catchment (Black River at Washago) where runoff was relatively stable with an annual mean of 474 mm/yr. Increased annual runoff from Lovers Creek was not accompanied by an increase in annual precipitation. Discriminant function analysis suggests that early (1992-1997; pre-major development) and late (2004-2009; fully urbanized) periods for Lovers Creek separated mainly based on model parameter sets related to runoff flashiness and evapotranspiration. As a result, parameterization in either period cannot be used interchangeably to produce credible runoff simulations in Lovers Creek due to greater scatter between the parameters in canonical space. Separation of early and late period parameter sets for the reference catchment was based on climate and snowmelt related processes. This suggests that regional climatic variability could be influencing hydrologic change in the reference catchment whereas urbanization amplified the regional natural hydrologic changes in urbanizing catchments of the LSW.

Interspecies variation in the susceptibility of adult Pacific salmon to toxic urban stormwater runoff.

PubMed

McIntyre, Jenifer K; Lundin, Jessica I; Cameron, James R; Chow, Michelle I; Davis, Jay W; Incardona, John P; Scholz, Nathaniel L

2018-07-01

Adult coho salmon (Oncorhynchus kisutch) prematurely die when they return from the ocean to spawn in urban watersheds throughout northwestern North America. The available evidence suggests the annual mortality events are caused by toxic stormwater runoff. The underlying pathophysiology of the urban spawner mortality syndrome is not known, and it is unclear whether closely related species of Pacific salmon are similarly at risk. The present study co-exposed adult coho and chum (O. keta) salmon to runoff from a high traffic volume urban arterial roadway. The spawners were monitored for the familiar symptoms of the mortality syndrome, including surface swimming, loss of orientation, and loss of equilibrium. Moreover, the hematology of both species was profiled by measuring arterial pH, blood gases, lactate, plasma electrolytes, hematocrit, and glucose. Adult coho developed behavioral symptoms within a few hours of exposure to stormwater. Various measured hematological parameters were significantly altered compared to coho controls, indicating a blood acidosis and ionoregulatory disturbance. By contrast, runoff-exposed chum spawners showed essentially no indications of the mortality syndrome, and measured blood hematological parameters were similar to unexposed chum controls. We conclude that contaminant(s) in urban runoff are the likely cause of the disruption of ion balance and pH in coho but not chum salmon. Among the thousands of chemicals in stormwater, future forensic analyses should focus on the gill or cardiovascular system of coho salmon. Because of their distinctive sensitivity to urban runoff, adult coho remain an important vertebrate indicator species for degraded water quality in freshwater habitats under pressure from human population growth and urbanization. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Distribution and disinfection of bacterial loadings associated with particulate matter fractions transported in urban wet weather flows.

PubMed

Dickenson, Joshua A; Sansalone, John J

2012-12-15

Urban runoff is a resource for reuse water. However, runoff transports indicator and pathogenic organisms which are mobilized from sources of fecal contamination. These organisms are entrained with particulate matter (PM) that can serve as a mobile substrate for these organisms. Within a framework of additional treatment for reuse of treated runoff which requires the management of PM inventories in unit operations and drainage systems there is a need to characterize organism distributions on PM and the disinfection potential thereof. This study quantifies total coliform, Escherichia coli, fecal streptococcus, and enterococcus generated from 25 runoff events. With the ubiquity and hetero-dispersivity of PM in urban runoff this study examines organism distributions for suspended, settleable and sediment PM fractions differentiated based on PM size and transport functionality. Hypochlorite is applied in batch to elaborate inactivation of PM-associated organisms for each PM fraction. Results indicate that urban runoff bacterial loadings of indicator organisms exceed U.S. wastewater reuse, recreational contact, and Australian runoff reuse criteria as comparative metrics. All monitored events exceeded the Australian runoff reuse criteria for E. coli in non-potable residential and unrestricted access systems. In PM-differentiated events, bacteriological mobilization primarily occurred in the suspended PM fraction. However, sediment PM shielded PM-associated coliforms at all hypochlorite doses, whereas suspended and settleable PM fractions provide less shielding resulting in higher inactivation by hypochlorite. Copyright © 2011 Elsevier Ltd. All rights reserved.

Water-quality characteristics of urban runoff and estimates of annual loads in the Tampa Bay area, Florida, 1975-80

USGS Publications Warehouse

Lopez, M.A.; Giovannelli, R.F.

1984-01-01

Rainfall, runoff, and water quality data were collected at nine urban watersheds in the Tampa Bay area from 1975 to 1980. Watershed drainage area ranged from 0.34 to 0.45 sq mi. Land use was mixed. Development ranged from a mostly residential watershed with a 19% impervious surface, to a commercial-residential watershed with a 61% impervious surface. Average biochemical oxygen demand concentrations of base flow at two sites and of stormwater runoff at five sites exceeded treated sewage effluent standards. Average coliform concentrations of stormwater runoff at all sites were several orders of magnitude greater than standards for Florida Class III receiving water (for recreation or propagation and management of fish and wildlife). Average concentrations of lead and zinc in stormwater runoff were consistently higher than Class III standards. Stormwater-runoff loads and base-flow concentrations of biochemical oxygen demand, chemical oxygen demand, total nitrogen, total organic nitrogen, total phosphorus, and lead were related to runoff volume, land use, urban development, and antecedent daily rainfall by multiple linear regression. Stormwater-runoff volume was related to pervious area, hydraulically connected impervious surfaces, storm rainfall, and soil-infiltration index. Base-flow daily discharge was related to drainage area and antecedent daily rainfall. The flow regression equations of this report were used to compute 1979 water-year loads of biochemical oxygen demand, chemical oxygen demand, total nitrogen, total organic nitrogen, total phosphorus , and total lead for the nine Tampa Bay area urban watersheds. (Lantz-PTT)

Distribution of the concentration of heavy metals associated with the sediment particles accumulated on road surfaces.

PubMed

Zafra, C A; Temprano, J; Tejero, I

2011-07-01

The heavy metal pollution caused by road run-off water constitutes a problem in urban areas. The metallic load associated with road sediment must be determined in order to study its impact in drainage systems and receiving waters, and to perfect the design of prevention systems. This paper presents data regarding the sediment collected on road surfaces in the city of Torrelavega (northern Spain) during a period of 65 days (132 samples). Two sample types were collected: vacuum-dried samples and those swept up following vacuuming. The sediment loading (g m(-2)), particle size distribution (63-2800 microm) and heavy metal concentrations were determined. The data showed that the concentration of heavy metals tends to increase with the reduction in the particle diameter (exponential tendency). The concentrations ofPb, Zn, Cu, Cr, Ni, Cd, Fe, Mn and Co in the size fraction <63 microm were 350, 630, 124, 57, 56, 38, 3231, 374 and 51 mg kg(-1), respectively (average traffic density: 3800 vehicles day(-1)). By increasing the residence time of the sediment, the concentration increases, whereas the ratio of the concentration between the different size fractions decreases. The concentration across the road diminishes when the distance between the roadway and the sampling siteincreases; when the distance increases, the ratio between size fractions for heavy metal concentrations increases. Finally, the main sources of heavy metals are the particles detached by braking (brake pads) and tyre wear (rubber), and are associated with particle sizes <125 microm.

[Transport and sources of runoff pollution from urban area with combined sewer system].

PubMed

Li, Li-Qing; Yin, Cheng-Qing

2009-02-15

Sampling and monitoring of runoff and sewage water in Wuhan urban area with combined sewer system were carried out during the period from 2003 to 2006, to study the transport and sources of runoff pollution at the catchment scale coupled with environmental geochemistry method. The results showed a change in quality between the runoff entering the sewer network and the combined storm water flow at the sewer's outlet. A significant increase was observed in the concentrations of total suspended solids (TSS), volatile suspended solids (VSS), COD, TN, and TP, and in the proportion of COD linked to particles. During the runoff production and transport, the concentrations of TSS and COD increased from 18.7 mg/L and 37.0 mg/L in roof runoff, to 225.3 mg/L and 176.5 mg/L in street runoff, and to 449.7 mg/L and 359.9 mg/L in combined storm water flow, respectively. The proportion of COD linked to particles was increased by 18%. In addition, the total phosphorus (P) and iron (Fe) contents in urban ground dust, storm drain sediment, sewage sewer sediment and combined sewer sediment were measured to identify the potential sources of suspended solids in the combined flow. The urban ground dust andstorm drain sediment wererich in Fe, whereas the sewage sewer sediment was rich in P. The P/Fe ratios in these groups were significantly distinct and able to differentiate them. A calculation of the two storm events based on the P/Fe rations showed that 56% +/- 26% of suspended solids in combined flow came from urban ground and storm drain. The rest wer e originated from the sewage sewer sediments which deposited in combined sewer on the dry weather days and were eroded on the wet weather days. The combined sewer network not only acts as a transport system, but also constitutes a physicochemical reactor that degrades the quality of urban water. Reducing the in-sewer pollution stocks would effectively control urban runoff pollution.

Oil removal from runoff with natural sorbing filter fillers.

PubMed

Mažeikienė, Aušra; Vaiškūnaitė, Rasa; Vaišis, Vaidotas

2014-08-01

The aim of this paper was to investigate the ability of Lithuanian sheep wool waste and reeds (Phragmites australis) to absorb oil from runoff when it flows through filters filled with these materials. The third material that was analysed, the synthetic sorbent Fibroil, was chosen for comparing the results. The laboratory experiments were performed in several stages, with the following being filtrated: tap water with a diesel admixture, road runoff contaminated with oils, and also suspended solids. The significance of this work is due to the high runoff filtering rate (∼10 m/h) and high oil concentrations in the runoff (50-230 mg/L) used in the experiment. In these cases the use of sorbents is limited. Wool waste and reed (Phragmites australis) fillers are quite efficient (98-99%) in oil removal from runoff at a 10 m/h filtering rate. However, wool fillers clog up quickly. Reeds of the genus Phragmites australis are a natural source for the production of oil sorbents. The results obtained in this experimental work can be used in the design of equipment for the treatment of oil-contaminated runoff from gas stations as well as sullage from roads and tunnels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of urban development on direct runoff to East Meadow Brook, Nassau County, Long Island, New York

USGS Publications Warehouse

Seaburn, G.E.

1969-01-01

The study described in this report is concerned with the effects of intensive urban development on direct runoff to East Meadow Brook, a southward-flowing stream in central Nassau County, N.Y., during the period 1937-66. The specific objectives of the study were (a) to relate indices of urban development to increases in the volume of annual direct runoff to the stream; (b) to compare hydrograph features at different periods during the transition of the drainage basin from rural to urban conditions; and (c) to compare the rainfall-runoff relations for periods before and after urban development.Periods of housing and street construction in the drainage basin correspond to three distinct periods of increased direct runoff after the base period 1937-43-namely, 1944-51, 1952-59, and 1960-62. During each period, the average annual direct runoff increased because of an increase in the area served by storm sewers that discharged into East Meadow Brook. The amount of land served by sewers increased from about 570 acres in 1943 to about 3,600 acres in 1962, or about 530 percent. During this same period, the average annual direct runoff increased from about 920 acre-feet per year to about 3,400 acre-feet per year, or about 270 percent.The shape of direct-runoff unit hydrographs of East Meadow Brook also changed during the period of study. The average peak discharge of a 1-hour-duration unit hydrograph increased from 313 cubic feet per second, for storms in 1937-43, to 776 cubic feet per second, for storms in 1960-62, or about 2.5 times. In addition, the widths of the unit hydrographs for 1960-62 at values of 50 and 75 percent of the peak discharge were 38 and 28 percent, respectively, the comparable widths of the unit hydrographs for 1937-43.An analysis of the rainfall-runoff relations for both preurban and urban conditions indicates that the direct runoff for both periods increased with the magnitude of the storm. However, the direct runoff during a period of urbanized conditions (1964- 66) was from 1.1 to 4.6 times greater than the corresponding runoff during the preurban period 1937-43, depending on the size of the individual storm.The volume of direct runoff from the parts of the subarea equipped with storm sewers that discharged into East Meadow Brook is estimated to have been roughly 3,000 acre-feet per year in 1960-62, or about 20 percent of the precipitation on those parts of the area.The increase in direct runoff probably represents a loss of ground-water recharge. However, because data changes in evapo-transpiration are insufficient and because the effects of recharge basins are unknown, adequate quantitative estimates of groundwater recharge can not be made.On the basis of the present zoning regulations and on assumption that an additional 320 acres in the Hempstead subarea will be serviced by storm sewers that discharge into East Meadow Brook, direct runoff from the subarea is expected to increase in the future to an estimated 4,000-4,500 acre-feet per year.

Long-term characterization of residential runoff and assessing potential surrogates of fecal indicator organisms.

PubMed

Reano, Dane C; Haver, Darren L; Oki, Lorence R; Yates, Marylynn V

2015-05-01

Investigations into the microbiological impacts of urban runoff on receiving water bodies, especially during storm conditions, have yielded general paradigms that influence runoff abatement and control management strategies. To determine whether these trends are present in other runoff sources, the physical, chemical, and microbiological components of residential runoff from eight neighborhoods in Northern and Southern California were characterized over the course of five years. Sampling occurred regularly and during storm events, resulting in 833 data sets. Analysis of runoff data assisted in characterizing residential runoff, elucidating differences between dry and storm conditions, and identifying surrogates capable of assessing microbiological quality. Results indicate that although microbial loading increases during storm events similar to urban runoff, annual microbial loading in these study sites principally occurs during dry conditions (24% storm, 76% dry). Generated artificial neural network and multiple linear regression models assessed surrogate performance by accurately predicting Escherichia coli concentrations from validation data sets (R(2) = 0.74 and 0.77, respectively), but required input from other fecal indicator organism (FIO) variables to maintain performance (R(2) = 0.27 and 0.18, respectively, without FIO). This long-term analysis of residential runoff highlights characteristics distinct from urban runoff and establishes necessary variables for determining microbiological quality, thus better informing future management strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Synopsis of Technical Issues for Monitoring Sediment in Highway and Urban Runoff

USGS Publications Warehouse

Bent, Gardner C.; Gray, John R.; Smith, Kirk P.; Glysson, G. Douglas

2000-01-01

Accurate and representative sediment data are critical for assessing the potential effects of highway and urban runoff on receiving waters. The U.S. Environmental Protection Agency identified sediment as the most widespread pollutant in the Nation's rivers and streams, affecting aquatic habitat, drinking water treatment processes, and recreational uses of rivers, lakes, and estuaries. Representative sediment data are also necessary for quantifying and interpreting concentrations, loads, and effects of trace elements and organic constituents associated with highway and urban runoff. Many technical issues associated with the collecting, processing, and analyzing of samples must be addressed to produce valid (useful for intended purposes), current, complete, and technically defensible data for local, regional, and national information needs. All aspects of sediment data-collection programs need to be evaluated, and adequate quality-control data must be collected and documented so that the comparability and representativeness of data obtained for highway- and urban-runoff studies may be assessed. Collection of representative samples for the measurement of sediment in highway and urban runoff involves a number of interrelated issues. Temporal and spatial variability in runoff result from a combination of factors, including volume and intensity of precipitation, rate of snowmelt, and features of the drainage basin such as area, slope, infiltration capacity, channel roughness, and storage characteristics. In small drainage basins such as those found in many highway and urban settings, automatic samplers are often the most suitable method for collecting samples of runoff for a variety of reasons. Indirect sediment-measurement methods are also useful as supplementary and(or) surrogate means for monitoring sediment in runoff. All of these methods have limitations in addition to benefits, which must be identified and quantified to produce representative data. Methods for processing raw sediment samples (including homogenization and subsampling) for subsequent analysis for total suspended solids or suspended-sediment concentration often increase variance and may introduce bias. Processing artifacts can be substantial if the methods used are not appropriate for the concentrations and particle-size distributions present in the samples collected. Analytical methods for determining sediment concentrations include the suspended-sediment concentration and the total suspended solids methods. Although the terms suspended-sediment concentration and total suspended solids are often used interchangeably to describe the total concentration of suspended solid-phase material, the analytical methods differ and can produce substantially different results. The total suspended solids method, which commonly is used to produce highway- and urban-runoff sediment data, may not be valid for studies of runoff water quality. Studies of fluvial and highway-runoff sediment data indicate that analyses of samples by the total suspended solids method tends to under represent the true sediment concentration, and that relations between total suspended solids and suspended-sediment concentration are not transferable from site to site even when grain-size distribution information is available. Total suspended solids data used to calculate suspended-sediment loads in highways and urban runoff may be fundamentally unreliable. Consequently, use of total suspended solids data may have adverse consequences for the assessment, design, and maintenance of sediment-removal best management practices. Therefore, it may be necessary to analyze water samples using the suspended-sediment concentration method. Data quality, comparability, and utility are important considerations in collection, processing, and analysis of sediment samples and interpretation of sediment data for highway- and urban-runoff studies. Results from sediment studies must be comparable and readily transf

Development of urban runoff model FFC-QUAL for first-flush water-quality analysis in urban drainage basins.

PubMed

Hur, Sungchul; Nam, Kisung; Kim, Jungsoo; Kwak, Changjae

2018-01-01

An urban runoff model that is able to compute the runoff, the pollutant loadings, and the concentrations of water-quality constituents in urban drainages during the first flush was developed. This model, which is referred to as FFC-QUAL, was modified from the existing ILLUDAS model and added for use during the water-quality analysis process for dry and rainy periods. For the dry period, the specifications of the coefficients for the discharge and water quality were used. During rainfall, we used the Clark and time-area methods for the runoff analyses of pervious and impervious areas to consider the effects of the subbasin shape; moreover, four pollutant accumulation methods and the washoff equation for computing the water quality each time were used. According to the verification results, FFC-QUAL provides generally similar output as the measured data for the peak flow, total runoff volume, total loadings, peak concentration, and time of peak concentration for three rainfall events in the Gunja subbasin. In comparison with the ILLUDAS, SWMM, and MOUSE models, there is little difference between these models and the model developed in this study. The proposed model should be useful in urban watersheds because of its simplicity and its capacity to model common pollutants (e.g., biological oxygen demand, chemical oxygen demand, Escherichia coli, suspended solids, and total nitrogen and phosphorous) in runoff. The proposed model can also be used in design studies to determine how changes in infrastructure will affect the runoff and pollution loads. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Understanding sediment sources in a peri-urban Mediterranean catchment using geochemical tracers

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Walsh, Rory; Kikuchi, Ryunosuke; Blake, Will

2016-04-01

One of the main physical environmental impacts of urbanization is an increase in suspended sediment concentrations and loads, particularly in the constructional phase. Impacts in peri-urban catchments characterized by a mosaic of urban and non-urban landscape elements with varying roles in acting as sources and sinks of overland flow and slope wash have received little attention, particularly in Mediterranean environments. The present study uses a sediment 'fingerprinting' approach to determine the main sediment sources in the peri-urban Ribeira dos Covões catchment (6.2km2) in Portugal and how they change during storm events following contrasting antecedent weather. The catchment, rural until 1972, underwent discontinuous urbanization in 1973-1993, followed by an urban consolidation phase. Currently, its land-use is a complex mosaic of woodland (56%), urban (40%) and agricultural (4%) land parcels. Distinct urban patterns include some well-defined urban residential centres, but also areas of discontinuous urban sprawl. Since 2010, a major road was built and an enterprise park has been under construction, covering 1% and 5% of the catchment, respectively. The catchment has a Mediterranean climate. The geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). Soils are generally deep (>3.0m), but shallow (<0.4m) on steeper limestone terrain. The catchment has an average slope of 9° , but includes steep slopes of up to 46° . The sediment fingerprinting methodology involved characterizing the chemical properties of sediments from individual upstream sub-catchments and comparing these to the properties of downstream transported fluvial material. Three fine bed-sediment sampling surveys were carried out after (i) a long dry period (21/09/2012), (ii) a winter storm of relatively high rainfall intensity (23.2mm day-1) (19/02/2015), and (iii) after several storms in Spring (22/04/2015). All samples were oven-dried (at 38° C) and sieved to obtain different particle size fractions (0.125-2.000mm, 0.063-0.125mm and <0.063mm). Seventeen stream sites were sampled plus a sample of sediment from a road surface immediately it entered the stream network. The elemental composition (40 elements) of each size fraction was assessed using a Niton X-ray fluorescence elemental analyser. Results show that rock type has a profound influence on the geochemical properties of bed-sediments. Catchment outlet sediment collected after the summer and a storm of high rainfall intensity following dry weather displayed geochemical properties closer to those of sediment from sandstone sub-catchments, and in particularly sediment from the enterprise park under construction. After the storm that followed very wet weather, however, limestone areas became of much greater significance as sediment sources, probably because of the high soil saturation. At limestone stream sites receiving runoff from the newly constructed road, fine bed-sediment geochemistry was found to be similar to that of road sediment, indicating a high contribution of this source. These results are supported by spatio-temporal differences in streamflow and suspended sediment concentrations at instrumented monitoring stations. It is concluded that this methodology represents a potentially useful tool to enable river managers to detect and assess sediment sources in urbanized and partly urbanized catchments, and to supporting them in designing and implementing effective land-use mosaics and site-specific measures to mitigate erosion.

[Effect of antecedent dry period on water quality of urban storm runoff pollution].

PubMed

Bian, Bo

2009-12-01

Identified the main factor influencing urban rainfall-runoff pollution provides a scientific basis for urban rainfall-runoff pollution control and management. Therefore, starting in May 2006, a study was conducted to characterize water quality from representative land uses types in Zhenjiang to analyse the effect of antecedent dry period on stormwater runoff quality. The results show that the beginning of rainfall, with the increase of antecedent dry periods, the percentages of less than 40 microm is increased, the correlation of the water quality parameters (TN, TP, Zn, Pb, Cu, TSS and COD) and antecedent dry period shows a significant positive correlation, dissolved pollutants in the initial period surface runoff is increased. These findings show that facilitating the recognition of antecedent dry periods is the main factor influencing the change in concentration and partitioning of pollutants to provide the scientific basis for non-point source pollution control and management.

Modelling and optimization of land use/land cover change in a developing urban catchment.

PubMed

Xu, Ping; Gao, Fei; He, Junchao; Ren, Xinxin; Xi, Weijin

2017-06-01

The impacts of land use/cover change (LUCC) on hydrological processes and water resources are mainly reflected in changes in runoff and pollutant variations. Low impact development (LID) technology is utilized as an effective strategy to control urban stormwater runoff and pollution in the urban catchment. In this study, the impact of LUCC on runoff and pollutants in an urbanizing catchment of Guang-Ming New District in Shenzhen, China, were quantified using a dynamic rainfall-runoff model with the EPA Storm Water Management Model (SWMM). Based on the simulations and observations, the main objectives of this study were: (1) to evaluate the catchment runoff and pollutant variations with LUCC, (2) to select and optimize the appropriate layout of LID in a planning scenario for reducing the growth of runoff and pollutants under LUCC, (3) to assess the optimal planning schemes for land use/cover. The results showed that compared to 2013, the runoff volume, peak flow and pollution load of suspended solids (SS), and chemical oxygen demand increased by 35.1%, 33.6% and 248.5%, and 54.5% respectively in a traditional planning scenario. The assessment result of optimal planning of land use showed that annual rainfall control of land use for an optimal planning scenario with LID technology was 65%, and SS pollutant load reduction efficiency 65.6%.

The capture and destruction of E. coli from simulated urban runoff using conventional bioretention media and iron oxide-coated sand

USDA-ARS?s Scientific Manuscript database

Given the magnitude of the threat to the quality of receiving water bodies posed by microbial pollutants in urban stormwater runoff, and the untested potential for their removal in bioretention systems, studies were performed to evaluate the removal efficiency of bacteria from simulated urban stormw...

Temporal and spatial responses of Chironomidae (Diptera) and other benthic invertebrates to urban stormwater runoff

Treesearch

Susan E. Gresens; Kenneth T. Belt; Jamie A. Tang; Daniel C. Gwinn; Patricia A. Banks

2007-01-01

In a longitudinal study of two streams whose lower reaches received unattenuated urban stormwater runoff, physical disturbance by stormflow was less important than the persistant unidentified chemical impacts of urban stormwater in limiting the distribution of Chironomidae, and Ephemeroptera, Trichoptera and Plecoptera (EPT). A hierarchical spatial analysis showed that...

Techniques for estimating the quantity and quality of storm runoff from urban watersheds of Jefferson County, Kentucky

USGS Publications Warehouse

Evaldi, R.D.; Moore, B.L.

1994-01-01

Linear regression models are presented for estimating storm-runoff volumes, and mean con- centrations and loads of selected constituents in storm runoff from urban watersheds of Jefferson County, Kentucky. Constituents modeled include dissolved oxygen, biochemical and chemical oxygen demand, total and suspended solids, volatile residue, nitrogen, phosphorus and phosphate, calcium, magnesium, barium, copper, iron, lead, and zinc. Model estimations are a function of drainage area, percentage of impervious area, climatological data, and land uses. Estimation models are based on runoff volumes, and concen- trations and loads of constituents in runoff measured at 6 stormwater outfalls and 25 streams in Jefferson County.

Sediment production from forest road surfaces.

Treesearch

Leslie Reid; T. Dunne

2011-01-01

Erosion on roads is an important source of fine-grained sediment in streams draining logged basins of the Pacific Northwest. Runoff rates and sediment concentrations from 10 road segments subject to a variety of traffic levels were monitored to produce sediment rating curves and unit hydrographs for different use levels and types of surfaces. These relationships are...

Forest road sideslopes and soil conservation techniques

Treesearch

Johnny M. Grace

2000-01-01

Forest road sideslopes have been identified as one of the major sources of erosion losses from managed forest systems. Stabilization by vegetation has shown the greatest potential for mitigation of soil erosion on forest road sideslopes. Sediment and runoff production from a wood excelsior erosion mat, native species vegetative mix, and exotic species vegetative mix...

Parking lot sealcoat: an unrecognized source of urban polycyclic aromatic hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbara J. Mahler; Peter C. Van Metre; Thomas J. Bashara

2005-08-01

Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous contaminant in urban environments. Although numerous sources of PAHs to urban runoff have been identified, their relative importance remains uncertain. The authors show that a previously unidentified source of urban PAHs, parking lot sealcoat, may dominate loading of PAHs to urban water bodies in the United States. Particles in runoff from parking lots with coal-tar emulsion sealcoat had mean concentrations of PAHs of 3500 mg/kg, 65 times higher than the mean concentration from unsealed asphalt and cement lots. Diagnostic ratios of individual PAHs indicating sources are similar for particles from coal-tar emulsion sealedmore » lots and suspended sediment from four urban streams. Contaminant yields projected to the watershed scale for the four associated watersheds indicate that runoff from sealed parking lots could account for the majority of stream PAH loads. 35 refs., 6 figs., 2 tabs.« less

WET-WEATHER POLLUTION PREVENTION BY PRODUCT SUBSTITUTION

EPA Science Inventory

A literature review of urban stormwater runoff and building/construction materials has shown that many materials such as galvanized metal, concrete, asphalt, and wood products, have the potential to release pollutants into urban stormwater runoff, and snowmelt. However, much of t...

Characterization and environmental management of stormwater runoff from road-salt storage facilities.

DOT National Transportation Integrated Search

2004-01-01

The objectives of this study were to assess the quantity and quality of salt-contaminated water generated from stormwater runoff at VDOT's salt storage facilities and to evaluate management/treatment alternatives to reduce costs and better protect th...

An urban runoff model designed to inform stormwater management decisions.

PubMed

Beck, Nicole G; Conley, Gary; Kanner, Lisa; Mathias, Margaret

2017-05-15

We present an urban runoff model designed for stormwater managers to quantify runoff reduction benefits of mitigation actions that has lower input data and user expertise requirements than most commonly used models. The stormwater tool to estimate load reductions (TELR) employs a semi-distributed approach, where landscape characteristics and process representation are spatially-lumped within urban catchments on the order of 100 acres (40 ha). Hydrologic computations use a set of metrics that describe a 30-year rainfall distribution, combined with well-tested algorithms for rainfall-runoff transformation and routing to generate average annual runoff estimates for each catchment. User inputs include the locations and specifications for a range of structural best management practice (BMP) types. The model was tested in a set of urban catchments within the Lake Tahoe Basin of California, USA, where modeled annual flows matched that of the observed flows within 18% relative error for 5 of the 6 catchments and had good regional performance for a suite of performance metrics. Comparisons with continuous simulation models showed an average of 3% difference from TELR predicted runoff for a range of hypothetical urban catchments. The model usually identified the dominant BMP outflow components within 5% relative error of event-based measured flow data and simulated the correct proportionality between outflow components. TELR has been implemented as a web-based platform for use by municipal stormwater managers to inform prioritization, report program benefits and meet regulatory reporting requirements (www.swtelr.com). Copyright © 2017. Published by Elsevier Ltd.

Simulation of quantity and quality of storm runoff for urban catchments in Fresno, California

USGS Publications Warehouse

Guay, J.R.; Smith, P.E.

1988-01-01

Rainfall-runoff models were developed for a multiple-dwelling residential catchment (2 applications), a single-dwelling residential catchment, and a commercial catchment in Fresno, California, using the U.S. Geological Survey Distributed Routing Rainfall-Runoff Model (DR3M-II). A runoff-quality model also was developed at the commercial catchment using the Survey 's Multiple-Event Urban Runoff Quality model (DR3M-qual). The purpose of this study was: (1) to demonstrate the capabilites of the two models for use in designing storm drains, estimating the frequency of storm runoff loads, and evaluating the effectiveness of street sweeping on an urban drainage catchment; and (2) to determine the simulation accuracies of these models. Simulation errors of the two models were summarized as the median absolute deviation in percent (mad) between measured and simulated values. Calibration and verification mad errors for runoff volumes and peak discharges ranged from 14 to 20%. The estimated annual storm-runoff loads, in pounds/acre of effective impervious area, that could occur once every hundred years at the commercial catchment was 95 for dissolved solids, 1.6 for the dissolved nitrite plus nitrate, 0.31 for total recoverable lead, and 120 for suspended sediment. Calibration and verification mad errors for the above constituents ranged from 11 to 54%. (USGS)

Variable Streamflow Contributions in Nested Subwatersheds of a US Midwestern Urban Watershed

DOE PAGES

Wei, Liang; Hubbart, Jason A.; Zhou, Hang

2017-09-09

Quantification of runoff is critical to estimate and control water pollution in urban regions, but variation in impervious area and land-use type can complicate the quantification of runoff. We quantified the streamflow contributions of subwatersheds and the historical changes in streamflow in a flood prone urbanizing watershed in US Midwest to guide the establishment of a future pollution-control plan. Streamflow data from five nested hydrological stations enabled accurate estimations of streamflow contribution from five subwatersheds with variable impervious areas (from 0.5% to 26.6%). We corrected the impact of Missouri river backwatering at the most downstream station by comparing its streamflowmore » with an upstream station using double-mass analysis combined with Bernaola-Galvan Heuristic Segmentation approach. We also compared the streamflow of the urbanizing watershed with seven surrounding rural watersheds to estimate the cumulative impact of urbanization on the streamflow regime. The two most urbanized subwatersheds contributed >365 mm streamflow in 2012 with 657 mm precipitation, which was more than fourfold greater than the two least urbanized subwatersheds. Runoff occurred almost exclusively over the most urbanized subwatersheds during the dry period. The frequent floods occurred and the same amount of precipitation produced ~100 mm more streamflow in 2008–2014 than 1967–1980 in the urbanizing watershed; such phenomena did not occur in surrounding rural watersheds. Our approaches provide comprehensive information for planning on runoff control and pollutant reduction in urban watersheds.« less

Variable Streamflow Contributions in Nested Subwatersheds of a US Midwestern Urban Watershed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Liang; Hubbart, Jason A.; Zhou, Hang

Quantification of runoff is critical to estimate and control water pollution in urban regions, but variation in impervious area and land-use type can complicate the quantification of runoff. We quantified the streamflow contributions of subwatersheds and the historical changes in streamflow in a flood prone urbanizing watershed in US Midwest to guide the establishment of a future pollution-control plan. Streamflow data from five nested hydrological stations enabled accurate estimations of streamflow contribution from five subwatersheds with variable impervious areas (from 0.5% to 26.6%). We corrected the impact of Missouri river backwatering at the most downstream station by comparing its streamflowmore » with an upstream station using double-mass analysis combined with Bernaola-Galvan Heuristic Segmentation approach. We also compared the streamflow of the urbanizing watershed with seven surrounding rural watersheds to estimate the cumulative impact of urbanization on the streamflow regime. The two most urbanized subwatersheds contributed >365 mm streamflow in 2012 with 657 mm precipitation, which was more than fourfold greater than the two least urbanized subwatersheds. Runoff occurred almost exclusively over the most urbanized subwatersheds during the dry period. The frequent floods occurred and the same amount of precipitation produced ~100 mm more streamflow in 2008–2014 than 1967–1980 in the urbanizing watershed; such phenomena did not occur in surrounding rural watersheds. Our approaches provide comprehensive information for planning on runoff control and pollutant reduction in urban watersheds.« less

Source or Sink: Investigating the role of storm water retention ponds in the urban landscape (Invited)

NASA Astrophysics Data System (ADS)

Lev, S.; Casey, R.; Ownby, D.; Snodgrass, J.

2009-12-01

The impact of human activities on surface water, groundwater and soil is nowhere more apparent than in urban and suburban systems. Dramatic changes to watersheds in urbanizing areas have led to changes in hydrology and an associated increase in the flux of sediment and contaminants to surface and ground waters. In an effort to mediate these impacts, Best Management Practices (BMP) have been established in order to increase infiltration of runoff and trap sediment and particulates derived from impervious surfaces before they enter surface waters. Perhaps the most ubiquitous BMP are storm water retention ponds. While these structures are designed to reduce runoff and particulate loading to urban streams, their addition to the urban landscape has created a large number of new wetland habitats. In the Red Run watershed, just outside of Baltimore, Maryland, 186 discrete natural or man-made wetland areas have been identified. Of these 186 wetland areas, 165 were created to manage stormwater and most were specifically designed as stormwater management ponds (i.e., human-created basins or depressions that hold runoff for some period during the annual hydrological year). Despite their abundance in the landscape, very little is known about how these systems impact the flux of stormwater pollutants or affect the organisms using these ponds as habitat. Results from a series of related projects in the Red Run watershed are presented here in an effort to summarize the range of issues associated with stormwater management ponds. The Red Run watershed is situated inside the Urban-Rural Demarcation Line (URDL) around Baltimore City and has been identified as a smart growth corridor by Baltimore County. This region is one of two areas in Baltimore County where new development is focused. In a series of investigations of soils, surface and ground waters, and amphibian and earthworm use of 68 randomly selected stormwater retention ponds from the Red Run watershed, a range of hydrologic, ecologic, and geochemical conditions have been identified. Results from these investigations suggest that pollutant conditions, specifically trace metals and chloride, limit the use of these ponds by amphibians and effect the distribution of earthworms within ponds. The soils in ponds associated with high use roadways contain elevated levels of PAHs, Zn and Cu and the groundwater beneath these same ponds tends to have elevated chloride levels year round. Pond and associated flood plain soils in these systems have been altered and exhibit elevated Na+ or Ca2+ concentrations suggesting years of interaction with road salt contaminated discharge. These Na+ and Ca2+ form soils affect the retention of dissolved trace metals with Ca-enriched soils potentially increasing the dissolved metal concentrations of surface and pore waters and enabling the transport of roadway derived metals to surface waters and Na-enriched soils scavenging trace metals from incoming runoff. The increase in dissolved metals may also increase the toxicity to amphibians and other organisms inhabiting the storm water ponds and ultimately, streams fed by ground water recharge from ponds. Our results to date suggest both the intended and unintended function of storm water ponds in urban landscapes are complicated and deserving of more attention.

Urban RoGeR: Merging process-based high-resolution flash flood model for urban areas with long-term water balance predictions

NASA Astrophysics Data System (ADS)

Weiler, M.

2016-12-01

Heavy rain induced flash floods are still a serious hazard and generate high damages in urban areas. In particular in the spatially complex urban areas, the temporal and spatial pattern of runoff generation processes at a wide spatial range during extreme rainfall events need to be predicted including the specific effects of green infrastructure and urban forests. In addition, the initial conditions (soil moisture pattern, water storage of green infrastructure) and the effect of lateral redistribution of water (run-on effects and re-infiltration) have to be included in order realistically predict flash flood generation. We further developed the distributed, process-based model RoGeR (Runoff Generation Research) to include the relevant features and processes in urban areas in order to test the effects of different settings, initial conditions and the lateral redistribution of water on the predicted flood response. The uncalibrated model RoGeR runs at a spatial resolution of 1*1m² (LiDAR, degree of sealing, landuse), soil properties and geology (1:50.000). In addition, different green infrastructures are included into the model as well as the effect of trees on interception and transpiration. A hydraulic model was included into RoGeR to predict surface runoff, water redistribution, and re-infiltration. During rainfall events, RoGeR predicts at 5 min temporal resolution, but the model also simulates evapotranspiration and groundwater recharge during rain-free periods at a longer time step. The model framework was applied to several case studies in Germany where intense rainfall events produced flash floods causing high damage in urban areas and to a long-term research catchment in an urban setting (Vauban, Freiburg), where a variety of green infrastructures dominates the hydrology. Urban-RoGeR allowed us to study the effects of different green infrastructures on reducing the flood peak, but also its effect on the water balance (evapotranspiration and groundwater recharge). We could also show that infiltration of surface runoff from areas with a low infiltration (lateral redistribution) reduce the flood peaks by over 90% in certain areas and situations. Finally, we also evaluated the model to long-term runoff observations (surface runoff, ET, roof runoff) and to flood marks in the selected case studies.

MICROORGANISMS DIE-OFF RATES IN URBAN STORMWATER RUNOFF

EPA Science Inventory

Urban stormwater runoff, a leading cause of water quality impairment related to human activities in lakes and reservoirs, can have significant negative effects on receiving water quality. It can also create human health concerns when these waters are used for drinking water reso...

MICROORGANISMS DIE-OFF RATES IN URBAN STORMWATER RUNOFF - 2005 VERSION

EPA Science Inventory

Urban stormwater runoff is a leading cause of water quality impairment in lakes and reservoirs. Stormwater discharges, with latent bacterial loads, can negatively impact receiving water quality and create human health concerns when these waters are used for drinking water resourc...

STORMWATER TREATMENT AT CRITICAL AREAS: EVALUATION OF FILTRATION MEDIA

EPA Science Inventory

Past research has identified urban runoff as a major contributor to the degradation of urban streams and rivers. Filtration, especially "slow" filtration, is of interest for stormwater runoff treatment because filters will work on intermittent flows without significant loss of ca...

OPPORTUNITY COSTS OF RESIDENTIAL BEST MANAGEMENT PRACTICES FOR STORMWATER RUNOFF CONTROL

EPA Science Inventory

Excess stormwater runoff is a serious problem in a large number of urban areas, causing flooding, water pollution, groundwater recharge deficits and ecological damage to urban streams. Solutions currently proposed to deal with this problem often involve large centralized infrastr...

Rainfall and runoff quantity and quality data collected at four urban land-use catchments in Fresno, California, October 1981-April 1983

USGS Publications Warehouse

Oltmann, R.N.; Guay, J.R.; Shay, J.M.

1987-01-01

Data were collected as part of the National Urban Runoff Program to characterize urban runoff in Fresno, California. Rainfall-runoff quantity and quality data are included along with atmospheric dry-deposition and street-surface particulate quality data. The data are presented in figures and tables that reflect four land uses: industrial, single-dwelling residential, multiple-dwelling residential, and commercial. A total of 255 storms were monitored for rainfall and runoff quantity. Runoff samples from 112 of these storms were analyzed for physical, organic, inorganic, and biological constituents. The majority of the remaining storms have pH and specific conductance data only. Ninety-two composite rain samples were collected. Of these, 63 were analyzed for physical, inorganic, and (or) organic constituents. The remaining rainfall samples have pH and specific conductance data only. Nineteen atmospheric deposition and 21 street-particulate samples were collected and analyzed for inorganic and organic constituents. The report also details equipment utilization and operation, and discusses data collection methods. (USGS)

Fate of hydrocarbon pollutants in source and non-source control sustainable drainage systems.

PubMed

Roinas, Georgios; Mant, Cath; Williams, John B

2014-01-01

Sustainable drainage (SuDs) is an established method for managing runoff from developments, and source control is part of accepted design philosophy. However, there are limited studies into the contribution source control makes to pollutant removal, especially for roads. This study examines organic pollutants, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs), in paired source and non-source control full-scale SuDs systems. Sites were selected to cover local roads, trunk roads and housing developments, with a range of SuDs, including porous asphalt, swales, detention basins and ponds. Soil and water samples were taken bi-monthly over 12 months to assess pollutant loads. Results show first flush patterns in storm events for solids, but not for TPH. The patterns of removal for specific PAHs were also different, reflecting varying physico-chemical properties. The potential of trunk roads for pollution was illustrated by peak runoff for TPH of > 17,000 μg/l. Overall there was no significant difference between pollutant loads from source and non-source control systems, but the dynamic nature of runoff means that longer-term data are required. The outcomes of this project will increase understanding of organic pollutants behaviour in SuDs. This will provide design guidance about the most appropriate systems for treating these pollutants.

Evaluating the Hydrologic Performance of Low Impact Development Scenarios in a Micro Urban Catchment.

PubMed

Li, Chunlin; Liu, Miao; Hu, Yuanman; Han, Rongqing; Shi, Tuo; Qu, Xiuqi; Wu, Yilin

2018-02-05

As urbanization progresses, increasingly impervious surfaces have changed the hydrological processes in cities and resulted in a major challenge for urban stormwater control. This study uses the urban stormwater model to evaluate the performance and costs of low impact development (LID) scenarios in a micro urban catchment. Rainfall-runoff data of three rainfall events were used for model calibration and validation. The pre-developed (PreDev) scenario, post-developed (PostDev) scenario, and three LID scenarios were used to evaluate the hydrologic performance of LID measures. Using reduction in annual runoff as the goal, the best solutions for each LID scenario were selected using cost-effectiveness curves. The simulation results indicated that the three designed LID scenarios could effectively reduce annual runoff volumes and pollutant loads compared with the PostDev scenario. The most effective scenario (MaxPerf) reduced annual runoff by 53.4%, followed by the sponge city (SpoPerf, 51.5%) and economy scenarios (EcoPerf, 43.1%). The runoff control efficiency of the MaxPerf and SpoPerf scenarios increased by 23.9% and 19.5%, respectively, when compared with the EcoPerf scenario; however, the costs increased by 104% and 83.6%. The reduction rates of four pollutants (TSS, TN, TP, and COD) under the MaxPerf scenario were 59.8-61.1%, followed by SpoPerf (53.9-58.3%) and EcoPerf (42.3-45.4%), and the costs of the three scenarios were 3.74, 3.47, and 1.83 million yuan, respectively. These results can provide guidance to urban stormwater managers in future urban planning to improve urban water security.

Urban flood simulation and prioritization of critical urban sub-catchments using SWMM model and PROMETHEE II approach

NASA Astrophysics Data System (ADS)

Babaei, Sahar; Ghazavi, Reza; Erfanian, Mahdi

2018-06-01

Urban runoff increased due to augment of impervious surfaces. In order to flood mitigation during rainy season, determination of critical urban sub-catchments is very important for urban planners. Due to lack of information, adopting a simulation approach is one of the practical ways to identify the surcharged junctions and critical sub-catchments. Occurrence of destructive floods in the rainy seasons indicates the inappropriateness of the urban drainage system in Urmia. The main aims of this study were to estimate the surface runoff of urban sub-catchments using SWMM, to evaluate the accuracy of the drainage system of the study urban area and to prioritize sub-catchments using PROMETHEE II approach and SWMM. In the present study, the occurrence of rainfall event of the Urmia city (West Azerbaijan province, Iran) used for estimation of runoff depth. The study area was divided into 22 sub-catchments. For calibration and validation of model parameters, 3 rainfall events and their related runoff were measured. According to sensitivity analysis CN was the most sensitive parameter for model calibration. Amount of surcharged conduits and junctions indicates that the drainage system of the study area has not enough capacity for converting of the runoff and. For 10 year return period, depth of channels should increase by 20% for prevention of flooding in these sub-catchments. Sub-catchments were prioritized using PROMETHEE II approach and its results were compared with SWMM simulation outcomes. Based on SWMM simulation, S11, S7, S18, S16 and S1 sub-catchments are more critical sub-catchments respectively, while according to PROMETHEE method, S1, S11, S16, S14 and S18 are determined as the critical areas.

Evaluating the Hydrologic Performance of Low Impact Development Scenarios in a Micro Urban Catchment

PubMed Central

Li, Chunlin; Liu, Miao; Hu, Yuanman; Han, Rongqing; Shi, Tuo; Qu, Xiuqi; Wu, Yilin

2018-01-01

As urbanization progresses, increasingly impervious surfaces have changed the hydrological processes in cities and resulted in a major challenge for urban stormwater control. This study uses the urban stormwater model to evaluate the performance and costs of low impact development (LID) scenarios in a micro urban catchment. Rainfall-runoff data of three rainfall events were used for model calibration and validation. The pre-developed (PreDev) scenario, post-developed (PostDev) scenario, and three LID scenarios were used to evaluate the hydrologic performance of LID measures. Using reduction in annual runoff as the goal, the best solutions for each LID scenario were selected using cost-effectiveness curves. The simulation results indicated that the three designed LID scenarios could effectively reduce annual runoff volumes and pollutant loads compared with the PostDev scenario. The most effective scenario (MaxPerf) reduced annual runoff by 53.4%, followed by the sponge city (SpoPerf, 51.5%) and economy scenarios (EcoPerf, 43.1%). The runoff control efficiency of the MaxPerf and SpoPerf scenarios increased by 23.9% and 19.5%, respectively, when compared with the EcoPerf scenario; however, the costs increased by 104% and 83.6%. The reduction rates of four pollutants (TSS, TN, TP, and COD) under the MaxPerf scenario were 59.8–61.1%, followed by SpoPerf (53.9–58.3%) and EcoPerf (42.3–45.4%), and the costs of the three scenarios were 3.74, 3.47 and 1.83 million yuan, respectively. These results can provide guidance to urban stormwater managers in future urban planning to improve urban water security. PMID:29401747

Runoff of particle bound pollutants from urban impervious surfaces studied by analysis of sediments from stormwater traps.

PubMed

Jartun, Morten; Ottesen, Rolf Tore; Steinnes, Eiliv; Volden, Tore

2008-06-25

Runoff sediments from 68 small stormwater traps around the harbor of urban Bergen, Norway, were sampled and the concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and total organic carbon (TOC) were determined in addition to grain size. Our study provides empirical data from a large area in the interface between the urban and marine environment, studying the active transport of pollutants from land-based sources. The results of the analyses clearly demonstrate the importance of the urban environment representing a variety of contamination sources, and that stormwater runoff is an important dispersion mechanism of toxic pollutants. The concentrations of different pollutants in urban runoff sediments show that there are several active pollution sources supplying the sewage systems with PCBs, PAHs and heavy metals such as lead (Pb), zinc (Zn) and cadmium (Cd). The concentration of PCB7 in the urban runoff sediments ranged between < 0.0004 and 0.704 mg/kg. For PAH16, the concentration range was < 0.2-80 mg/kg, whereas the concentration ranges of Pb, Zn and Cd were 9-675, 51.3-4670 and 0.02-11.1 mg/kg respectively. Grain size distribution in 21 selected samples varied from a median particle diameter of 13 to 646 microm. However, several samples had very fine-grained particles even up to the 90 percentile of the samples, making them available for stormwater dispersion in suspended form. The sampling approach proposed in this paper will provide environmental authorities with a useful tool to examine ongoing urban contamination of harbors and similar recipients.

Stormwater runoff pollutant loading distributions and their correlation with rainfall and catchment characteristics in a rapidly industrialized city.

PubMed

Li, Dongya; Wan, Jinquan; Ma, Yongwen; Wang, Yan; Huang, Mingzhi; Chen, Yangmei

2015-01-01

Fast urbanization and industrialization in developing countries result in significant stormwater runoff pollution, due to drastic changes in land-use, from rural to urban. A three-year study on the stormwater runoff pollutant loading distributions of industrial, parking lot and mixed commercial and residential catchments was conducted in the Tongsha reservoir watershed of Dongguan city, a typical, rapidly industrialized urban area in China. This study presents the changes in concentration during rainfall events, event mean concentrations (EMCs) and event pollution loads per unit area (EPLs). The first flush criterion, namely the mass first flush ratio (MFFn), was used to identify the first flush effects. The impacts of rainfall and catchment characterization on EMCs and pollutant loads percentage transported by the first 40% of runoff volume (FF40) were evaluated. The results indicated that the pollutant wash-off process of runoff during the rainfall events has significant temporal and spatial variations. The mean rainfall intensity (I), the impervious rate (IMR) and max 5-min intensity (Imax5) are the critical parameters of EMCs, while Imax5, antecedent dry days (ADD) and rainfall depth (RD) are the critical parameters of FF40. Intercepting the first 40% of runoff volume can remove 55% of TSS load, 53% of COD load, 58% of TN load, and 61% of TP load, respectively, according to all the storm events. These results may be helpful in mitigating stormwater runoff pollution for many other urban areas in developing countries.

Stormwater Runoff Pollutant Loading Distributions and Their Correlation with Rainfall and Catchment Characteristics in a Rapidly Industrialized City

PubMed Central

Li, Dongya; Wan, Jinquan; Ma, Yongwen; Wang, Yan; Huang, Mingzhi; Chen, Yangmei

2015-01-01

Fast urbanization and industrialization in developing countries result in significant stormwater runoff pollution, due to drastic changes in land-use, from rural to urban. A three-year study on the stormwater runoff pollutant loading distributions of industrial, parking lot and mixed commercial and residential catchments was conducted in the Tongsha reservoir watershed of Dongguan city, a typical, rapidly industrialized urban area in China. This study presents the changes in concentration during rainfall events, event mean concentrations (EMCs) and event pollution loads per unit area (EPLs). The first flush criterion, namely the mass first flush ratio (MFFn), was used to identify the first flush effects. The impacts of rainfall and catchment characterization on EMCs and pollutant loads percentage transported by the first 40% of runoff volume (FF40) were evaluated. The results indicated that the pollutant wash-off process of runoff during the rainfall events has significant temporal and spatial variations. The mean rainfall intensity (I), the impervious rate (IMR) and max 5-min intensity (Imax5) are the critical parameters of EMCs, while Imax5, antecedent dry days (ADD) and rainfall depth (RD) are the critical parameters of FF40. Intercepting the first 40% of runoff volume can remove 55% of TSS load, 53% of COD load, 58% of TN load, and 61% of TP load, respectively, according to all the storm events. These results may be helpful in mitigating stormwater runoff pollution for many other urban areas in developing countries. PMID:25774922

The implementation of biofiltration systems, rainwater tanks and urban irrigation in a single-layer urban canopy model

NASA Astrophysics Data System (ADS)

Demuzere, Matthias; Coutts, Andrew; Goehler, Maren; Broadbent, Ashley; Wouters, Hendrik; van Lipzig, Nicole; Gebert, Luke

2015-04-01

Urban vegetation is generally considered as a key tool to modify the urban energy balance through enhanced evapotranspiration (ET). Given that vegetation is most effective when it is healthy, stormwater harvesting and retention strategies (such as water sensitive urban design) could be used to support vegetation and promote ET. This study presents the implementation of a vegetated lined bio-filtration system (BFS) combined with a rainwater tank (RWT) and urban irrigation system in the single-layer urban canopy model Community Land Model-Urban. Runoff from roof and impervious road surface fractions is harvested and used to support an adequate soil moisture level for vegetation in the BFS. In a first stage, modelled soil moisture dynamics are evaluated and found reliable compared to observed soil moisture levels from biofiltration pits in Smith Street, Melbourne (Australia). Secondly, the impact of BFS, RWT and urban irrigation on ET is illustrated for a two-month period in 2012 using varying characteristics for all components. Results indicate that (i) a large amount of stormwater is potentially available for indoor and outdoor water demands, including irrigation of urban vegetation, (ii) ET from the BFS is an order of magnitude larger compared to the contributions from the impervious surfaces, even though the former only covers 10% of the surface fraction and (iii) attention should be paid to the cover fraction and soil texture of the BFS, size of the RWT and the surface fractions contributing to the collection of water in the RWT. Overall, this study reveals that this model development can effectuate future research with state-of-the-art urban climate models to further explore the benefits of vegetated biofiltration systems as a water sensitive urban design tool optimised with an urban irrigation system to maintain healthy vegetation.

Effects of increased urbanization from 1970's to 1990's on storm-runoff characteristics in Perris Valley, California

USGS Publications Warehouse

Guay, J.R.

1996-01-01

Urban areas in Perris Valley, California, have more than tripled during the last 20 years. To quantify the effects of increased urbanization on storm runoff volumes and peak discharges, rainfall-runoff models of the basin were developed to simulate runoff for 1970-75 and 1990-93 conditions. Hourly rainfall data for 1949-93 were used with the rainfall-runoff models to simulate a long-term record of storm runoff. The hydrologic effects of increased urbanization from 1970-75 to 1990-93 were analyzed by comparing the simulated annual peak discharges and volumes, and storm runoff peaks, frequency of annual peak discharges and runoff volumes, and duration of storm peak discharges for each study period. A Log-Pearson Type-III frequency analysis was calculated using the simulated annual peaks to estimate the 2-, 5-, 10-, 25-, 50-, and 100-year recurrence intervals. The estimated 2-year discharge at the outlet of the basin was 646 cubic feet per second for the 1970-75 conditions and 1,328 cubic feet per second for the 1990-93 conditions. The 100-year discharge at the outlet of the basin was about 14,000 cubic feet per second for the 1970-75 and 1990-93 conditions. The station duration analysis used 925 model-simulated storm peaks from each basin to estimate the percent chance a peak discharge is exceeded. At the outlet of the basin, the chances of exceeding 100 cubic feet per second were about 33 percent under 1970-75 conditions and about 59 percent under 1990-93 conditions. The chance of exceeding 2,500 cubic feet per second at the outlet of the basin was less than 1 percent higher under the 1990-93 conditions than under the 1970-75 conditions. The increase in urbanization from the early 1970's to the early 1990's more than doubled the peak discharges with a 2-year return period. However, peak discharges with return periods greater than 50 years were not significantly affected by the change in urbanization.

Modeling of storm runoff and pollutant wash off processes during storm event in rapidly urbanizing catchment

NASA Astrophysics Data System (ADS)

Qin, H. P.; Yu, X. Y.; Khu, S. T.

2009-04-01

Many urban catchments in developing countries are undergoing fast economic growth, population expansion and land use/cover change. Due to the mixture of agricultural/industrial/residential land use or different urbanization level as well as lack of historical monitoring data in the developing area, storm-water runoff pollution modeling is faced with challenges of considerable spatial variations and data insufficiency. Shiyan Reservoir catchment is located in the rapidly urbanizing coastal region of Southeast China. It has six sub-catchments with largely different land use patterns and urbanization levels. A simple semi-distributed model was used to simulate the storm-water runoff pollution process during storm event in the catchment. The model adopted modified IHACRES model and exponential wash-off functions to describe storm-runoff and pollutant wash-off processes, respectively, in each of six sub-catchments. Temporary hydrological and water quality monitoring sites were set at the downstream section of each sub-catchment in Feb-May 2007, spanning non-rain and rain seasons. And the model was calibrated for storm-runoff and water quality data during two typical storm events with rainfall amount of 10mm/4hr and 73mm/5hr, respectively. The results indicated that the Nash-Sutcliffe (NS) coefficients are greater than 0.65 and 0.55 respectively for storm-runoff model calibration and validation. However although NS coefficients can reach 0.7~0.9 for pollutant wash-off model calibration based on measured data in each storm event, the simulation data can not fit well with the measured data in model validation. According to field survey observation, many litters and residuals were found to distribute in disorder in some sub-catchments or their drainage systems and to instantaneously wash off into the surface water when the rainfall amount and intensity are large enough. In order to improve storm-water runoff pollution simulation in the catchment, the variations of pollutant source and wash off processes in different storm intensity should be consider in future monitoring and model development. Keywords: storm runoff; wash off; urbanization; catchment modeling; litter; residual

MICROORGANISMS DIE-OFF RATES IN URBAN STORMWATER RUNOFF, 2006

EPA Science Inventory

Urban stormwater runoff is a leading cause of water quality impairment related to human activities in lakes and reservoirs. It can have significant negative effects on receiving water quality and can create human health concerns when these waters are used for drinking water resou...

WET-WEATHER POLLUTION PREVENTION THROUGH MATERIALS SUBSTITUTION AS PART OF INDUSTRIAL CONSTRUCTION

EPA Science Inventory

A literature review of urban stormwater runoff and building/construction materials has shown that many materials such as galvanized metal, concrete, asphalt, and wood products, have the potential to release pollutants into urban stormwater runoff and snowmelt. However, much of th...

EFFECTS OF LAND USE AND SEASON ON MICROORGANISM CONCENTRATIONS IN URBAN STORMWATER RUNOFF

EPA Science Inventory

This study investigated differences in pathogen and indicator organism concentrations in stormwater runoff between different urban land uses and seasons. Stormwater samples collected from storm sewers draining small municipal separate storm sewer systems shown to be free of cros...

TRADING ALLOWANCES FOR STORMWATER CONTROL: HYDROLOGY AND OPPORTUNITY COSTS

EPA Science Inventory

Excess stormwater runoff is a serious problem in a large number of urban areas, causing flooding, water pollution, groundwater recharge deficits and ecological damage to urban streams. It has been posited that to mitigate the effects of excess stormwater runoff, policy makers...

TRADING ALLOWANCES FOR STORMWATER CONTROL: HYDROLOGY AND OPPORTUNITY COSTS

EPA Science Inventory

Excess stormwater runoff is a serious problem in a large number of urban areas, causing flooding, water pollution, groundwater recharge deficits and ecological damage to urban streams. It has been posited that to mitigate the effects of excess stormwater runoff, policy makers cou...

Calibration and verification of a rainfall-runoff model and a runoff-quality model for several urban basins in the Denver metropolitan area, Colorado

USGS Publications Warehouse

Lindner-Lunsford, J. B.; Ellis, S.R.

1984-01-01

The U.S. Geological Survey 's Distributed Routing Rainfall-Runoff Model--Version II was calibrated and verified for five urban basins in the Denver metropolitan area. Land-use types in the basins were light commerical, multifamily housing, single-family housing, and a shopping center. The overall accuracy of model predictions of peak flows and runoff volumes was about 15 percent for storms with rainfall intensities of less than 1 inch per hour and runoff volume of greater than 0.01 inch. Predictions generally were unsatisfactory for storm having a rainfall intensity of more than 1 inch per hour, or runoff of 0.01 inch or less. The Distributed Routing Rainfall-Runoff Model-Quality, a multievent runoff-quality model developed by the U.S. Geological Survey, was calibrated and verified on four basins. The model was found to be most useful in the prediction of seasonal loads of constituents in the runoff resulting from rainfall. The model was not very accurate in the prediction of runoff loads of individual constituents. (USGS)

Roads influence movement and home ranges of a fragmentation-sensitive carnivore, the bobcat, in an urban landscape

USGS Publications Warehouse

Poessel, Sharon A; Boydston, Erin E.; Lyren, Lisa M.; Fisher, Robert N.; Burdett, Christopher L.; Alonso, Robert S.; Crooks, Kevin R.

2014-01-01

Roads in urbanized areas can impact carnivore populations by constraining their movements and increasing mortality. Bobcats (Lynx rufus) are felids capable of living in urban environments, but are sensitive to habitat fragmentation and, thus, useful indicators of landscape connectivity; in particular, bobcat habitat selection, movement, and mortality may be affected by roads. We analyzed movement patterns of 52 bobcats in southern California in three study sites and investigated: (1) how bobcats responded to two types of roads within their home ranges; (2) how they placed their home ranges with respect to roads within the study area; and (3) whether male and female bobcats differed in their behavioral responses to roads. Within home ranges, primary and secondary roads did not influence movements, but bobcats more frequently crossed secondary roads when road densities were higher within their home ranges, thus increasing mortality risk. However, road densities within each study site were several times higher than road densities within home ranges, suggesting bobcats selected against roaded areas in home-range placement. Male home ranges bordering roads were smaller than home ranges for other males, but male home ranges containing roads were larger than those without roads. Male bobcats also were more likely to cross roads than females, potentially reflecting larger male home range sizes. Our results suggest roads have important impacts on urban bobcats, with stronger effects on males than females, and continued efforts to mitigate the effects of roads on carnivores and other fragmentation-sensitive species would help promote connectivity conservation in urban systems.

Characteristics and transport of organochlorine pesticides in urban environment: air, dust, rain, canopy throughfall, and runoff.

PubMed

Zhang, Wei; Ye, Youbin; Hu, Dan; Ou, Langbo; Wang, Xuejun

2010-11-01

Characteristics and transport of organochlorine pesticides (OCPs) in urban multiple environments, including air, dust, rain, canopy throughfall, and runoff water, are explored in this study. Hexachlorocyclohexanes (HCHs) dominated in both air and rain water, and dichlorodiphenyltrichloroethane (DDT) related substances showed a higher affinity to dust. Relatively high concentrations of DDT and dichlorodiphenyldichloroethylene (DDE) in air, rain and dust imply that technical DDT in the environment has been degrading, and there may be unknown local or regional emission sources that contain DDTs in the study area. Source identification showed that DDTs in Beijing urban environments with a fresh signature may originate from the atmospheric transport from remote areas. The ratio of α-/γ-HCH in dust, rain, canopy throughfall and runoff were close to 1, indicating the possible use of lindane. OCPs in runoff were transported from various sources including rain, dust, and canopy throughfall. In runoff, DDTs and hexachlorobenzene (HCB) were mainly transported from dust, and HCHs were mainly from rain and canopy throughfall.

Characterising urban zinc generation to identify surface pollutant hotspots in a low intensity rainfall climate.

PubMed

Charters, F J; Cochrane, T A; O'Sullivan, A D

2017-09-01

Characterising stormwater runoff quality provides useful insights into the dynamics of pollutant generation and wash off rates. These can be used to prioritise stormwater management strategies. This study examined the effects of a low intensity rainfall climate on zinc contributions from different impermeable urban surface types. First flush (FF) and steady state samples were collected from seven different surfaces for characterisation, and the data were also used to calibrate an event-based pollutant load model to predict individual 'hotspot' surfaces across the catchment. Unpainted galvanised roofs generated very high concentrations of zinc, primarily in the more biologically available dissolved form. An older, unpainted galvanised roof had FF concentrations averaging 32,338 μg/L, while the new unpainted roof averaged 4,782 μg/L. Roads and carparks also had elevated zinc, but FF concentrations averaged only 822-1,584 μg/L. Modelling and mapping expected zinc loads from individual impermeable surfaces across the catchment identified specific commercial roof surfaces to be targeted for zinc management. The results validate a policy strategy to replace old galvanised roof materials and avoid unpainted galvanised roofing in future urban development for better urban water quality outcomes. In the interim, readily-implemented treatment options are required to help mitigate chronic zinc impacts on receiving waterways.

Effectively using urban landscapes to teach biodiversity and ecohydrology to introductory environmental science classes

NASA Astrophysics Data System (ADS)

MacAvoy, S. E.; van Doorn, A.; Pondell, C.

2016-12-01

Urban environments offer students interesting opportunities to explore and examine how human modified landscapes influence biodiversity, nutrient cycling, and water quality. Students demanding applied field experiences from their undergraduate environmental science (ENVS) programs can be well served in urban settings. Here, we present strategies for integrating urban areas into the undergraduate field experience. Urban locations provide an opportunity for a different type of local "field-work" than would otherwise be available. In the intro level undergraduate ENVS class, we use our campus, the surrounding neighborhood and city as well as a nearby National Park for field exercises. Activities include: assessing water quality from multiple sites, observing species composition and ecological succession using fallen logs, assessing biodiversity using biocubes and camera traps, investigating conservation strategies through the local zoo, and walking one mile transects through local urban ecosystems to observe and collect data on the animals, buildings, roads, litter and/or light sources in the surrounding area. These labs provide inspiration and hands on skills that students apply to their own self-selected projects at the end of the semester. In the second level majors class, we make use of our urban location to contrast water quality in parks and highly channelized urban streams, monitor populations of urban wildlife, and investigate the application of urban greening methods to reduce environmental impacts. Students spend labs immersed in streams and wetlands heavily impacted by the urban runoff their city generates to better understand the extent of human impact in an urban environment. Here we share lesson plans for field activities that can be completed with incoming undergraduate students, and show how these activities help students gain quantitative and investigative competency.

Off site transport of fungicides with snowmelt and rainfall runoff from golf course fairway turf

USDA-ARS?s Scientific Manuscript database

Pesticides associated with the turfgrass industry have been detected in storm runoff and surface waters of urban watersheds; inferring contaminant contributions from residential, urban, and recreational sources. Golf course turf often requires multiple applications of pesticides at rates that exceed...

TRADING ALLOWANCES FOR STORMWATER CONTROL: ACCOUNTING FOR CONTINUOUS HYDROLOGY AND OPPORTUNITY COSTS

EPA Science Inventory

Excess stormwater runoff is a serious problem in a large number of urban areas, causing flooding, water pollution, groundwater recharge deficits and ecological damage to urban streams. It has been posited that to mitigate the effects of excess stormwater runoff, policy makers cou...

PROSPECTS FOR ENHANCED GROUNDWATER RECHARGE VIA INFILTRATION OF URBAN STORMWATER RUNOFF: A CASE STUDY

EPA Science Inventory

The rain garden is an urban storm water best management practice that is used to infiltrate runoff close to its source, thereby disconnecting impervious area while providing an avenue for groundwater recharge. Groundwater recharge may provide additional benefits to aquatic ecosys...

Gastrointestinal symptoms among swimmers following rain events at a beach impacted by urban runoff

EPA Science Inventory

Gastrointestinal symptoms among swimmers following rain events at a beach impacted by urban runoff Timothy J. Wade, Reagan R. Converse, Elizabeth A. Sams, Ann H. Williams, Edward Hudgens, Alfred P. Dufour Gastrointestinal symptoms among swimmers have been associated with fecal ...

Evaluating the Capability of Grass Swale for the Rainfall Runoff Reduction from an Urban Parking Lot, Seoul, Korea

PubMed Central

Shafique, Muhammad; Kim, Reeho; Kyung-Ho, Kwon

2018-01-01

This field study elaborates the role of grass swale in the management of stormwater in an urban parking lot. Grass swale was constructed by using different vegetations and local soil media in the parking lot of Mapu-gu Seoul, Korea. In this study, rainfall runoff was first retained in soil and the vegetation layers of the grass swale, and then infiltrated rainwater was collected with the help of underground perforated pipe, and passed to an underground storage trench. In this way, grass swale detained a large amount of rainwater for a longer period of time and delayed peak discharge. In this field study, various real storm events were monitored and the research results were analyzed to evaluate the performance of grass swale for managing rainfall runoff in an urban area. From the analysis of field experiments, grass swale showed the significant rainfall runoff retention in different rain events. Grass swale markedly reduced total rainfall runoff volume and peak flow during the small storm events of intensity about 30 mm/h. From the analysis, on average rainfall runoff retention from the grass swale was found around 40 to 75% during the various small rain events. From the results, we can say that grass swale is a stormwater mitigation practice which can help avoid flash flooding problems in urban areas. PMID:29547567

Evaluating the Capability of Grass Swale for the Rainfall Runoff Reduction from an Urban Parking Lot, Seoul, Korea.

PubMed

Shafique, Muhammad; Kim, Reeho; Kyung-Ho, Kwon

2018-03-16

This field study elaborates the role of grass swale in the management of stormwater in an urban parking lot. Grass swale was constructed by using different vegetations and local soil media in the parking lot of Mapu-gu Seoul, Korea. In this study, rainfall runoff was first retained in soil and the vegetation layers of the grass swale, and then infiltrated rainwater was collected with the help of underground perforated pipe, and passed to an underground storage trench. In this way, grass swale detained a large amount of rainwater for a longer period of time and delayed peak discharge. In this field study, various real storm events were monitored and the research results were analyzed to evaluate the performance of grass swale for managing rainfall runoff in an urban area. From the analysis of field experiments, grass swale showed the significant rainfall runoff retention in different rain events. Grass swale markedly reduced total rainfall runoff volume and peak flow during the small storm events of intensity about 30 mm/h. From the analysis, on average rainfall runoff retention from the grass swale was found around 40 to 75% during the various small rain events. From the results, we can say that grass swale is a stormwater mitigation practice which can help avoid flash flooding problems in urban areas.

Sources and mechanisms of nitrate and orthophosphate transport in urban stormwater runoff from residential catchments.

PubMed

Yang, Yun-Ya; Toor, Gurpal S

2017-04-01

Nutrients export from residential catchments contributes to water quality impairment in urban water bodies. We investigated the concentrations, transport mechanisms, and sources of nitrate-nitrogen (NO 3 -N) and orthophosphate-phosphorus (PO 4 -P) in urban stormwater runoff generated in residential catchments in Tampa Bay, Florida, United States. Street runoff samples, collected over 21 storm events, were supplemented with rainfall and roof runoff samples from six representative residential catchments. Samples were analyzed for N and P forms, N and oxygen (O) isotopes of nitrate (δ 18 O-NO 3 - and δ 15 N-NO 3 - ), and δ 18 O and hydrogen (δD) isotopes of water (H 2 O). We found that the main NO 3 -N source in street runoff was atmospheric deposition (range: 35-64%), followed by chemical N fertilizers (range: 1-39%), and soil and organic N (range: 7-33%), whereas PO 4 -P in the street runoff likely originated from erosion of soil particles and mineralization from organic materials (leaves, grass clippings). The variability in the sources and concentrations of NO 3 -N and PO 4 -P across catchments is attributed to different development designs and patterns, use of various fill materials during land development, and landscaping practices. This data can be useful to develop strategies to offset the impacts of urban development (e.g., designs and patterns resulting in variable impervious areas) and management (e.g., fertilizer use, landscaping practices) on NO 3 -N and PO 4 -P transport in urban residential catchments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transfer of glyphosate and its degradate AMPA to surface waters through urban sewerage systems.

PubMed

Botta, Fabrizio; Lavison, Gwenaëlle; Couturier, Guillaume; Alliot, Fabrice; Moreau-Guigon, Elodie; Fauchon, Nils; Guery, Bénédicte; Chevreuil, Marc; Blanchoud, Hélène

2009-09-01

A study of glyphosate and aminomethyl phosphonic acid (AMPA) transfer in the Orge watershed (France) was carried out during 2007 and 2008. Water samples were collected in surface water, wastewater sewer, storm sewer and wastewater treatment plant (WWTP). These two molecules appeared to be the most frequently detected ones in the rivers and usually exceeded the European quality standard concentrations of 0.1microg L(-1) for drinking water. The annual glyphosate estimated load was 1.9 kg year(-1) upstream (agricultural zone) and 179.5 kg year(-1) at the catchment outlet (urban zone). This result suggests that the contamination of this basin by glyphosate is essentially from urban origin (road and railway applications). Glyphosate reached surface water prevalently through storm sewer during rainfall event. Maximum concentrations were detected in storm sewer just after a rainfall event (75-90 microg L(-1)). High concentrations of glyphosate in surface water during rainfall events reflected urban runoff impact. AMPA was always detected in the sewerage system. This molecule reached surface water mainly via WWTP effluent and also through storm sewer. Variations in concentrations of AMPA during hydrological episodes were minor compared to glyphosate variations. Our study highlights that AMPA and glyphosate origins in urban area are different. During dry period, detergent degradation seemed to be the major AMPA source in wastewater.

Temperature dynamics of stormwater runoff in Australia and the USA.

PubMed

Hathaway, J M; Winston, R J; Brown, R A; Hunt, W F; McCarthy, D T

2016-07-15

Thermal pollution of surface waters by urban stormwater runoff is an often overlooked by-product of urbanization. Elevated stream temperatures due to an influx of stormwater runoff can be detrimental to stream biota, in particular for cold water systems. However, few studies have examined temperature trends throughout storm events to determine how these thermal inputs are temporally distributed. In this study, six diverse catchments in two continents are evaluated for thermal dynamics. Summary statistics from the data showed larger catchments have lower maximum runoff temperatures, minimum runoff temperatures, and temperature variability. This reinforces the understanding that subsurface drainage infrastructure in urban catchments acts to moderate runoff temperatures. The catchments were also evaluated for the presence of a thermal first flush using two methodologies. Results showed the lack of a first flush under traditional assessment methodologies across all six catchments, supporting the results from a limited number of studies in literature. However, the time to peak temperature was not always coincident with the time to peak flow, highlighting the variability of thermal load over time. When a new first flush methodology was applied, significant differences in temperature were noted with increasing runoff depth for five of the six sites. This study is the first to identify a runoff temperature first flush, and highlights the need to carefully consider the appropriate methodology for such analyses. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence factors and prediction of stormwater runoff of urban green space in Tianjin, China: laboratory experiment and quantitative theory model.

PubMed

Yang, Xu; You, Xue-Yi; Ji, Min; Nima, Ciren

2013-01-01

The effects of limiting factors such as rainfall intensity, rainfall duration, grass type and vegetation coverage on the stormwater runoff of urban green space was investigated in Tianjin. The prediction equation of stormwater runoff was established by the quantitative theory with the lab experimental data of soil columns. It was validated by three field experiments and the relative errors between predicted and measured stormwater runoff are 1.41, 1.52 and 7.35%, respectively. The results implied that the prediction equation could be used to forecast the stormwater runoff of urban green space. The results of range and variance analysis indicated the sequence order of limiting factors is rainfall intensity > grass type > rainfall duration > vegetation coverage. The least runoff of green land in the present study is the combination of rainfall intensity 60.0 mm/h, duration 60.0 min, grass Festuca arundinacea and vegetation coverage 90.0%. When the intensity and duration of rainfall are 60.0 mm/h and 90.0 min, the predicted volumetric runoff coefficient is 0.23 with Festuca arundinacea of 90.0% vegetation coverage. The present approach indicated that green space is an effective method to reduce stormwater runoff and the conclusions are mainly applicable to Tianjin and the semi-arid areas with main summer precipitation and long-time interval rainfalls.

Reconnaissance sediment budget for selected watersheds of West Maui, Hawai‘i

USGS Publications Warehouse

Stock, Jonathan D.; Falinski, Kim A.; Callender, Tova

2016-01-12

Episodic runoff brings suspended sediment to the nearshore waters of West Maui, Hawaiʻi. Even small rainfalls create visible plumes over a few hours. We used mapping, field experiments, and analysis of recent (July 19–20, 2014) and historic rainfall to estimate sources of land-based pollution for two watersheds in West Maui: Honolua, and Honokōwai. Former agricultural fields and some unimproved roads are plausible sources for polluted runoff, but have saturated hydraulic conductivities greater than the 10–15 millimeters per hour (mm/hr) rainfalls of July 2014. These fields and roads showed minor evidence for storm runoff, and could not have contributed substantially to July 2014 plume generation. Since 1978, rain at intensities capable of causing runoff from former agricultural fields sustained for 1–2 hours is also rare; such intensities have 2–5 year recurrence rates in the north, and greater than 25 year recurrence rates to the south near Lahaina. Streambanks now eroding into historic terraces of sands, silts, and clays are a more plausible source. Although past large storms contributed to sediment loading, annual plume generation is now caused by smaller rainfalls eroding these near-stream legacy deposits. Treatments of former agricultural fields, roads, and reserve forests are consequently not likely to measurably affect sediment pollution from smaller, more frequent storms. Increased runoff from the development of West Maui has the potential to exacerbate sediment plumes from such storms unless there is an effective strategy to reduce bank erosion. Uncertainties in the extent and erosion rate of historic terraces, however, limit our ability to plan mitigation.

Evaluation of low impact development approach for mitigating flood inundation at a watershed scale in China.

PubMed

Hu, Maochuan; Sayama, Takahiro; Zhang, Xingqi; Tanaka, Kenji; Takara, Kaoru; Yang, Hong

2017-05-15

Low impact development (LID) has attracted growing attention as an important approach for urban flood mitigation. Most studies evaluating LID performance for mitigating floods focus on the changes of peak flow and runoff volume. This paper assessed the performance of LID practices for mitigating flood inundation hazards as retrofitting technologies in an urbanized watershed in Nanjing, China. The findings indicate that LID practices are effective for flood inundation mitigation at the watershed scale, and especially for reducing inundated areas with a high flood hazard risk. Various scenarios of LID implementation levels can reduce total inundated areas by 2%-17% and areas with a high flood hazard level by 6%-80%. Permeable pavement shows better performance than rainwater harvesting against mitigating urban waterlogging. The most efficient scenario is combined rainwater harvesting on rooftops with a cistern capacity of 78.5 mm and permeable pavement installed on 75% of non-busy roads and other impervious surfaces. Inundation modeling is an effective approach to obtaining the information necessary to guide decision-making for designing LID practices at watershed scales. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Study on Urban Road Traffic Safety Based on Matter Element Analysis

PubMed Central

Hu, Qizhou; Zhou, Zhuping; Sun, Xu

2014-01-01

This paper examines a new evaluation of urban road traffic safety based on a matter element analysis, avoiding the difficulties found in other traffic safety evaluations. The issue of urban road traffic safety has been investigated through the matter element analysis theory. The chief aim of the present work is to investigate the features of urban road traffic safety. Emphasis was placed on the construction of a criterion function by which traffic safety achieved a hierarchical system of objectives to be evaluated. The matter element analysis theory was used to create the comprehensive appraisal model of urban road traffic safety. The technique was used to employ a newly developed and versatile matter element analysis algorithm. The matter element matrix solves the uncertainty and incompatibility of the evaluated factors used to assess urban road traffic safety. The application results showed the superiority of the evaluation model and a didactic example was included to illustrate the computational procedure. PMID:25587267

Occurrence of organic wastewater compounds in drinking water, wastewater effluent, and the Big Sioux River in or near Sioux Falls, South Dakota, 2001-2004

USGS Publications Warehouse

Sando, Steven K.; Furlong, Edward T.; Gray, James L.; Meyer, Michael T.

2006-01-01

The U.S. Geological Survey (USGS) in cooperation with the city of Sioux Falls conducted several rounds of sampling to determine the occurrence of organic wastewater compounds (OWCs) in the city of Sioux Falls drinking water and waste-water effluent, and the Big Sioux River in or near Sioux Falls during August 2001 through May 2004. Water samples were collected during both base-flow and storm-runoff conditions. Water samples were collected at 8 sites, which included 4 sites upstream from the wastewater treatment plant (WWTP) discharge, 2 sites downstream from the WWTP discharge, 1 finished drinking-water site, and 1 WWTP effluent (WWE) site. A total of 125 different OWCs were analyzed for in this study using five different analytical methods. Analyses for OWCs were performed at USGS laboratories that are developing and/or refining small-concentration (less than 1 microgram per liter (ug/L)) analytical methods. The OWCs were classified into six compound classes: human pharmaceutical compounds (HPCs); human and veterinary antibiotic compounds (HVACs); major agricultural herbicides (MAHs); household, industrial,and minor agricultural compounds (HIACs); polyaromatic hydrocarbons (PAHs); and sterol compounds (SCs). Some of the compounds in the HPC, MAH, HIAC, and PAH classes are suspected of being endocrine-disrupting compounds (EDCs). Of the 125 different OWCs analyzed for in this study, 81 OWCs had one or more detections in environmental samples reported by the laboratories, and of those 81 OWCs, 63 had acceptable analytical method performance, were detected at concentrations greater than the study reporting levels, and were included in analyses and discussion related to occurrence of OWCs in drinking water, wastewater effluent, and the Big Sioux River. OWCs in all compound classes were detected in water samples from sampling sites in the Sioux Falls area. For the five sampling periods when samples were collected from the Sioux Falls finished drinking water, only one OWC was detected at a concentration greater than the study reporting level (metolachlor; 0.0040 ug/L). During base-flow conditions, Big Sioux River sites upstream from the WWTP discharge had OWC contributions that primarily were from nonpoint animal or crop agriculture sources or had OWC concentrations that were minimal. The influence of the WWTP discharge on OWCs at downstream river sites during base-flow conditions ranged from minimal influence to substantial influence depending on the sampling period. During runoff conditions, OWCs at sites upstream from the WWTP discharge probably were primarily contributed by nonpoint animal and/or crop agriculture sources and possibly by stormwater runoff from nearby roads. OWCs at sites downstream from the WWTP discharge probably were contributed by sources other than the WWTP effluent discharge, such as stormwater runoff from urban and/or agriculture areas and/or resuspension of OWCs adsorbed to sediment deposited in the Big Sioux River. OWC loads generally were substantially smaller for upstream sites than downstream sites during both base-flow and runoff conditions.discharge had OWC contributions that primarily were from nonpoint animal or crop agriculture sources or had OWC concentrations that were minimal. The influence of the WWTP discharge on OWCs at downstream river sites during base-flow conditions ranged from minimal influence to substantial influence depending on the sampling period. During runoff conditions, OWCs at sites upstream from the WWTP discharge probably were primarily contributed by nonpoint animal and/or crop agriculture sources and possibly by stormwater runoff from nearby roads. OWCs at sites downstream from the WWTP discharge probably were contributed by sources other than the WWTP effluent discharge, such as stormwater runoff from urban and/or agriculture areas and/or resuspension of OWCs adsorbed to sediment deposited in the Big Sioux River. OWC loads generally were substantially smaller for

Effectiveness of post-fire Burned Area Emergency Response (BAER) road treatments: Results from three wildfires

Treesearch

Randy B. Foltz; Peter Robichaud

2013-01-01

Wildland fires often cause extreme changes in the landscape that drastically influence surface runoff and soil erosion, which can impact forest resources, aquatic habitats, water supplies, public safety, and forest access infrastructure such as forest roads. Little information is available on the effectiveness of various post-fire road treatments, thus this study was...

Slope-area thresholds of road-induced gully erosion and consequent hillslope-channel interactions

Treesearch

Harry Alexander Katz; J. Michael Daniels; Sandra Ryan-Burkett

2014-01-01

Pikes Peak Highway is a partially paved road between Cascade, Colorado and the summit of Pikes Peak. Significant gully erosion is occurring on the hillslopes due to the concentration of surface runoff, the rearrangement of drainage pathways along the road surface and adjacent drainage ditches, and the high erodibility of weathered Pikes Peak granite that underlies the...

Effects of urban development on stormwater runoff characteristics for the Houston, Texas, metropolitan area

USGS Publications Warehouse

Liscum, Fred

2001-01-01

A study was done to estimate the effects of urban development in the Houston, Texas, metropolitan area on nine stormwater runoff characteristics. Three of the nine characteristics define the magnitude of stormwater runoff, and the remaining six characteristics describe the shape and duration of a storm hydrograph. Multiple linear regression was used to develop equations to estimate the nine stormwater runoff characteristics from basin and rainfall characteristics. Five basin characteristics and five rainfall characteristics were tested in the regressions to determine which basin and rainfall characteristics significantly affect stormwater runoff characteristics. Basin development factor was found to be significant in equations for eight of the nine stormwater runoff characteristics. Two sets of equations were developed, one for each of two regions based on soil type, from a database containing 1,089 storm discharge hydrographs for 42 sites compiled during 1964–89.The effects of urban development on the eight stormwater runoff characteristics were quantified by varying basin development factor in the equations and recomputing the stormwater runoff characteristics. The largest observed increase in basin development factor for region 1 (north of Buffalo Bayou) during the study resulted in corresponding increases in the characteristics that define magnitude of stormwater runoff ranging from about 40 percent (for direct runoff) to 235 percent (for peak yield); and corresponding decreases in the characteristics that describe hydrograph shape and duration ranging from about 22 percent (for direct runoff duration) to about 58 percent (for basin lag). The largest observed increase in basin development factor for region 2 (south of Buffalo Bayou) during the study resulted in corresponding increases in the characteristics that define magnitude of stormwater runoff ranging from about 33 percent (for direct runoff) to about 210 percent (for both peak flow and peak yield); and corresponding decreases in the characteristics that describe hydrograph shape and duration ranging from about 38 percent (for direct runoff duration) to about 64 percent (for basin lag). 

EVALUATING AN URBAN STREAM RESTORATION PROGRAM FOR IMPROVING WATER QUALITY, IN-STREAM HABITAT, AND BANK STABILITY

EPA Science Inventory

To improve water quality in urban and suburban areas, watershed managers often incorporate best management practices (BMPs) to reduce the quantity of runoff, as well as minimize pollutants and other stressors contained in stormwater runoff. It is well known that land use practice...

A Laboratory Simulation of Urban Runoff and the Potential for Hydrograph Prediction with Curve Numbers

USDA-ARS?s Scientific Manuscript database

Urban drainages are mosaics of pervious and impervious surfaces, and prediction of runoff hydrology with a lumped modeling approach using the NRCS curve number may be appropriate. However, the prognostic capability of such a lumped approach is complicated by routing and connectivity amongst infiltra...

Removing non-urban roads from the National Land Cover Database to create improved urban maps for the United States, 1992-2011

USGS Publications Warehouse

Soulard, Christopher E.; Acevedo, William; Stehman, Stephen V.

2018-01-01

Quantifying change in urban land provides important information to create empirical models examining the effects of human land use. Maps of developed land from the National Land Cover Database (NLCD) of the conterminous United States include rural roads in the developed land class and therefore overestimate the amount of urban land. To better map the urban class and understand how urban lands change over time, we removed rural roads and small patches of rural development from the NLCD developed class and created four wall-to-wall maps (1992, 2001, 2006, and 2011) of urban land. Removing rural roads from the NLCD developed class involved a multi-step filtering process, data fusion using geospatial road and developed land data, and manual editing. Reference data classified as urban or not urban from a stratified random sample was used to assess the accuracy of the 2001 and 2006 urban and NLCD maps. The newly created urban maps had higher overall accuracy (98.7 percent) than the NLCD maps (96.2 percent). More importantly, the urban maps resulted in lower commission error of the urban class (23 percent versus 57 percent for the NLCD in 2006) with the trade-off of slightly inflated omission error (20 percent for the urban map, 16 percent for NLCD in 2006). The removal of approximately 230,000 km2 of rural roads from the NLCD developed class resulted in maps that better characterize the urban footprint. These urban maps are more suited to modeling applications and policy decisions that rely on quantitative and spatially explicit information regarding urban lands.

Characterizing heavy metal build-up on urban road surfaces: implication for stormwater reuse.

PubMed

Liu, An; Liu, Liang; Li, Dunzhu; Guan, Yuntao

2015-05-15

Stormwater reuse is increasingly popular in the worldwide. In terms of urban road stormwater, it commonly contains toxic pollutants such as heavy metals, which could undermine the reuse safety. The research study investigated heavy metal build-up characteristics on urban roads in a typical megacity of South China. The research outcomes show the high variability in heavy metal build-up loads among different urban road sites. The degree of traffic congestion and road surface roughness was found to exert a more significant influence on heavy metal build-up rather than traffic volume. Due to relatively higher heavy metal loads, stormwater from roads with more congested traffic conditions or rougher surfaces might be suitable for low-water-quality required activities while the stormwater from by-pass road sections could be appropriate for relatively high-water-quality required purposes since the stormwater could be relatively less polluted. Based on the research outcomes, a decision-making process for heavy metals based urban road stormwater reuse was proposed. The new finding highlights the importance to undertaking a "fit-for-purpose" road stormwater reuse strategy. Additionally, the research results can also contribute to enhancing stormwater reuse safety. Copyright © 2015 Elsevier B.V. All rights reserved.

Modelling transport of storm-water pollutants using the distributed Multi-Hydro platform on an urban catchment near Paris

NASA Astrophysics Data System (ADS)

Hong, Yi; Bonhomme, Celine; Giangola-Murzyn, Agathe; Schertzer, Daniel; Chebbo, Ghassan

2015-04-01

Nowadays, the increasingly use of vehicles causes expanding contaminated storm-water runoff from roads and the associated quarters. Besides, the current utilization of city's separated sewer systems underlines the needs for evaluating precisely the growing impact of these polluted effluents on receiving water bodies. Nevertheless, traditional means of water quality modelling had shown its limits (Kanso, 2004), more accurate modelling schemes are hence required. In this paper, we found that the application of physically based and fully distributed model coupled with detailed high-resolution data is a promising approach to reproduce the various dynamics and interactions of water quantity/quality processes in urban or peri-urban environment. Over recent years, the physically based and spatially distributed numerical platform Multi-Hydro (MH) has been developed at Ecole des Ponts ParisTech (El-Tabach et al. , 2009 ; Gires et al., 2013 ; Giangola-Murzyn et al., 2014). This platform is particularly adapted for representing the hydrological processes for medium size watersheds, including the surface runoff, drainage water routing and the infiltrations on permeable zones. It is formed by the interactive coupling of several independent modules, which depend on generally used open-access models. In the framework of the ANR (French National Agency for Research) Trafipollu project, a new extension of MH, MH-quality, was set up for the water-quality modelling. MH-quality was used for the simulation of pollutant transport on a peri-urban and highly trafficked catchment located near Paris (Le Perreux-sur-Marne, 0.2 km2). The set-up of this model is based on the detailed description of urban land use features. For this purpose, 15 classes of urban land uses relevant to water quality modelling were defined in collaboration with the National Institute of Geography of France (IGN) using Digital Orthophoto Quadrangles (5cm). The delimitation of the urban catchment was then performed by operating a Digital Terrain Model which was generated by applying Lidar data (20cm), and by using GIS information of the drainage system. In addition to land use information, the implementation of different human activities allows a better evaluation of contamination. Experimental data such as rainfall intensities, particle size distribution and dry weather depositions are also used, in order to feed the model with realistic input data and parameters. The runoff and water quality are then simulated for a few rainfall events. Taking advantage of the available data of the continuous observations of precipitation, water discharges and turbidity at the outlet of the drainage systems, the sensitivity analysis is carried out in order to evaluate the performance of MH-quality and the most sensitive parameters. Using appropriate parameters, we are now able to follow the pollutant transport on our experimental urban catchment. The limitations and the perspectives of MH-quality are discussed as well.

A step towards considering the spatial heterogeneity of urban key features in urban hydrology flood modelling

NASA Astrophysics Data System (ADS)

Leandro, J.; Schumann, A.; Pfister, A.

2016-04-01

Some of the major challenges in modelling rainfall-runoff in urbanised areas are the complex interaction between the sewer system and the overland surface, and the spatial heterogeneity of the urban key features. The former requires the sewer network and the system of surface flow paths to be solved simultaneously. The latter is still an unresolved issue because the heterogeneity of runoff formation requires high detailed information and includes a large variety of feature specific rainfall-runoff dynamics. This paper discloses a methodology for considering the variability of building types and the spatial heterogeneity of land surfaces. The former is achieved by developing a specific conceptual rainfall-runoff model and the latter by defining a fully distributed approach for infiltration processes in urban areas with limited storage capacity dependent on OpenStreetMaps (OSM). The model complexity is increased stepwise by adding components to an existing 2D overland flow model. The different steps are defined as modelling levels. The methodology is applied in a German case study. Results highlight that: (a) spatial heterogeneity of urban features has a medium to high impact on the estimated overland flood-depths, (b) the addition of multiple urban features have a higher cumulative effect due to the dynamic effects simulated by the model, (c) connecting the runoff from buildings to the sewer contributes to the non-linear effects observed on the overland flood-depths, and (d) OSM data is useful in identifying pounding areas (for which infiltration plays a decisive role) and permeable natural surface flow paths (which delay the flood propagation).

Landscape Ecotoxicology of Coho Salmon Spawner Mortality in Urban Streams

PubMed Central

Feist, Blake E.; Buhle, Eric R.; Arnold, Paul; Davis, Jay W.; Scholz, Nathaniel L.

2011-01-01

In the Pacific Northwest of the United States, adult coho salmon (Oncorhynchus kisutch) returning from the ocean to spawn in urban basins of the Puget Sound region have been prematurely dying at high rates (up to 90% of the total runs) for more than a decade. The current weight of evidence indicates that coho deaths are caused by toxic chemical contaminants in land-based runoff to urban streams during the fall spawning season. Non-point source pollution in urban landscapes typically originates from discrete urban and residential land use activities. In the present study we conducted a series of spatial analyses to identify correlations between land use and land cover (roadways, impervious surfaces, forests, etc.) and the magnitude of coho mortality in six streams with different drainage basin characteristics. We found that spawner mortality was most closely and positively correlated with the relative proportion of local roads, impervious surfaces, and commercial property within a basin. These and other correlated variables were used to identify unmonitored basins in the greater Seattle metropolitan area where recurrent coho spawner die-offs may be likely. This predictive map indicates a substantial geographic area of vulnerability for the Puget Sound coho population segment, a species of concern under the U.S. Endangered Species Act. Our spatial risk representation has numerous applications for urban growth management, coho conservation, and basin restoration (e.g., avoiding the unintentional creation of ecological traps). Moreover, the approach and tools are transferable to areas supporting coho throughout western North America. PMID:21858112

Highway runoff quality in Ireland.

PubMed

Berhanu Desta, Mesfin; Bruen, Michael; Higgins, Neil; Johnston, Paul

2007-04-01

Highway runoff has been identified as a significant source of contaminants that impact on the receiving aquatic environment. Several studies have been completed documenting the characteristics of highway runoff and its implication to the receiving water in the UK and elsewhere. However, very little information is available for Ireland. The objective of this study was to determine the quality of highway runoff from major Irish roads under the current road drainage design and maintenance practice. Four sites were selected from the M4 and the M7 motorways outside Dublin. Automatic samplers and continuous monitoring devices were deployed to sample and monitor the runoff quality and quantity. More than 42 storm events were sampled and analysed for the heavy metals Cd, Cu, Pb, and Zn, 16 US EPA specified PAHs, volatile organic compounds including MTBE, and a number of conventional pollutants. All samples were analysed based on the Standard Methods. Significant quantities of solids and heavy metals were detected at all sites. PAHs were not detected very often, but when detected the values were different from quantities observed in UK highways. The heavy metal concentrations were strongly related to the total suspended solids concentrations, which has a useful implication for runoff management strategies. No strong relationship was discovered between pollutant concentrations and event characteristics such as rainfall intensity, antecedent dry days (ADD), or rainfall depth (volume). This study has demonstrated that runoff from Irish motorways was not any cleaner than in the UK although the traffic volume at the monitored sites was relatively smaller. This calls for a site specific investigation of highway runoff quality before adopting a given management strategy.

Removal of road deposited sediments by sweeping and its contribution to highway runoff quality in Korea.

PubMed

Kim, D G; Jeong, K; Ko, S O

2014-01-01

Highway runoff is known to be an important non-point source (NPS), increasing the load of pollutants in receiving water. For reducing NPS pollutants in runoff, removal of road deposited sediment (RDS) by sweeping is considered effective. However, the contribution of sweeping to the improvement of runoff quality has not been clearly and quantitatively demonstrated so far. In this study, a field test was carried out on a section of operating highway in Korea to investigate the effectiveness of sweeping on improving the quality of highway runoff. Results showed that the average reduction in the load of RDS by sweeping was 61.10% with a standard deviation of 1.74%. RDS removal efficiency decreased when the sweeping speed increased from 4-8 to 20 km h(-1), the load decreased from 12.5 to 1.25 g m(-2) and particle size decreased from sand to silt/clay size ranges. Runoff was induced by applying a 15 mm h(-1) artificial rainfall to both swept and non-swept sections. Analysis of runoff quality showed that the event mean concentrations of total suspended solid, biological oxygen demand, chemical oxygen demand, nutrients and most of the heavy metals were reduced by 31-87% after sweeping. In addition, field tests for RDS build-up indicated a sweeping frequency of once every four or five days to prevent re-suspension of RDS. The results of this study suggest that sweeping can be the best management practice for effectively reducing RDS on highways and improving the quality of highway runoff.

Evaluation of the effects of Middleton's stormwater-management activities on streamflow and water-quality characteristics of Pheasant Branch, Dane County, Wisconsin 1975-2008

USGS Publications Warehouse

Gebert, Warren A.; Rose, William J.; Garn, Herbert S.

2012-01-01

Few long-term data sets are available for evaluating the effects of urban stormwater-management practices. Over 30 years of data are available for evaluating the effectiveness of such practices by the city of Middleton, Wis. Analysis of streamflow and water-quality data collected on Pheasant Branch, demonstrates the relation between the changes in the watershed to the structural and nonstructural best management practices put in place during 1975-2008. A comparison of the data from Pheasant Branch with streamflow and water-quality data (suspended sediment and total phosphorus) collected at other nearby streams was made to assist in the determination of the possible causes of the changes in Pheasant Branch. Based on 34 years of streamflow data collected at the Pheasant Branch at Middleton streamflow-gaging station, flood peak discharges increased 37 percent for the 2-year flood and 83 percent for the 100-year flood. A comparison of data for the same period from an adjacent rural stream, Black Earth at Black Earth had a 43 percent increase in the 2-year flood peak discharge and a 140-percent increase in the 100-year flood peak discharge. Because the flood peak discharges on Pheasant Branch have not increased as much as Black Earth Creek it appears that the stormwater management practices have been successful in mitigating the effects of urbanization. Generally urbanization results in increased flood peak discharges. The overall increase in flood peak discharges seen in both streams probably is the result of the substantial increase in precipitation during the study period. Average annual runoff in Pheasant Branch has also been increasing due to increasing average annual precipitation and urbanization. The stormwater-management practices in Middleton have been successful in decreasing the suspended-sediment and total phosphorus loads to Lake Mendota from the Pheasant Branch watershed. These loads decreased in spite of increased annual runoff and flood peaks, which are often expected to produce higher sediment and phosphorus loads. The biggest decreases in sediment and phosphorus loads occurred after 2001 when a large detention pond, the Confluence Pond, began operation. Since 2001, the annual suspended-sediment load has decreased from 2,650 tons per year to 1,450 tons per year for a 45-percent decrease. The annual total phosphorus load has decreased from 12,200 pounds per year to 6,300 pounds per year for a 48-percent decrease. A comparison of Pheasant Branch at Middleton with two other streams, Spring Harbor Storm Sewer and Yahara River at Windsor, that drain into Lake Mendota shows that suspended-sediment and total phosphorus load decreases were greatest at Pheasant Branch at Middleton. Prior to the construction of the Confluence Pond, annual suspended-sediment yield and total phosphorus yield from Pheasant Branch watershed was the largest of the three watersheds. After 2001, suspended-sediment yield was greatest at Spring Harbor Storm Sewer, and lowest at Yahara at Windsor; annual total phosphorus yield was greater at Yahara River at Windsor than that of Pheasant Branch. The stormwater-quality plan for Middleton shows that the city has met the present State of Wisconsin Administrative Code chap. NR216/NR151 requirements of reducing total suspended solids by 20 percent for the developed area in Middleton. In addition, the city already has met the 40-percent reduction in total suspended solids required by 2013. Snow and ice melt runoff from road surfaces and parking lots following winter storms can effect water quality because the runoff contains varying amounts of road salt. To evaluate the effect of road deicing on stream water quality in Pheasant Branch, specific conductance and chloride were monitored during two winter seasons. The maximum estimated concentration of chloride during the monitoring period was 931 milligrams per liter, which exceeded the U.S. Environmental Protection Agency acute criterion of 860 milligrams per liter. Chloride concentrations exceeded the U.S. Environmental Protection Agency chronic criterion of 230 milligrams per liter for at least 10 days during February and March 2007 and for 45 days during the 2007-8 winter seasons. The total sodium chloride load for the monitoring period was 1,720 tons and the largest sodium chloride load occurred in March and April of each year.

Quantifying the benefits of urban forest systems as a component of the green infrastructure stormwater treatment network

Treesearch

Eric Kuehler; Jon Hathaway; Andrew Tirpak

2017-01-01

The use of green infrastructure for reducing stormwater runoff is increasingly common. One under‐studied component of the green infrastructure network is the urban forest system. Trees can play an important role as the “first line of defense” for restoring more natural hydrologic regimes in urban watersheds by intercepting rainfall, delaying runoff, infiltrating, and...

Encapsulating urban traffic rhythms into road networks.

PubMed

Wang, Junjie; Wei, Dong; He, Kun; Gong, Hang; Wang, Pu

2014-02-20

Using road GIS (geographical information systems) data and travel demand data for two U.S. urban areas, the dynamical driver sources of each road segment were located. A method to target road clusters closely related to urban traffic congestion was then developed to improve road network efficiency. The targeted road clusters show different spatial distributions at different times of a day, indicating that our method can encapsulate dynamical travel demand information into the road networks. As a proof of concept, when we lowered the speed limit or increased the capacity of road segments in the targeted road clusters, we found that both the number of congested roads and extra travel time were effectively reduced. In addition, the proposed modeling framework provided new insights on the optimization of transport efficiency in any infrastructure network with a specific supply and demand distribution.

Encapsulating Urban Traffic Rhythms into Road Networks

PubMed Central

Wang, Junjie; Wei, Dong; He, Kun; Gong, Hang; Wang, Pu

2014-01-01

Using road GIS (geographical information systems) data and travel demand data for two U.S. urban areas, the dynamical driver sources of each road segment were located. A method to target road clusters closely related to urban traffic congestion was then developed to improve road network efficiency. The targeted road clusters show different spatial distributions at different times of a day, indicating that our method can encapsulate dynamical travel demand information into the road networks. As a proof of concept, when we lowered the speed limit or increased the capacity of road segments in the targeted road clusters, we found that both the number of congested roads and extra travel time were effectively reduced. In addition, the proposed modeling framework provided new insights on the optimization of transport efficiency in any infrastructure network with a specific supply and demand distribution. PMID:24553203

Characteristics of the event mean concentration (EMC) from rainfall runoff on an urban highway.

PubMed

Lee, Ju Young; Kim, Hyoungjun; Kim, Youngjin; Han, Moo Young

2011-04-01

The purpose of this study was to investigate the characterization of the event mean concentration (EMC) of runoff during heavy precipitation events on highways. Highway runoff quality data were collected from the 7th highway, in South Korea during 2007-2009. The samples were analyzed for runoff quantity and quality parameters such as COD(cr), TSS, TPHs, TKN, NO₃, TP, PO₄ and six heavy metals, e.g., As, Cu, Cd, Ni, Pb and Zn. Analysis of resulting hydrographs and pollutant graphs indicates that the peak of the pollutant concentrations in runoff occurs 20 min after the first rainfall runoff occurrence. The first flush effect depends on the preceding dry period and the rainfall intensity. The results of this study can be used as a reference for water quality management of urban highways. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Factor Analysis of Traffic Safety in Urban Roads Based on FTA-LEC

NASA Astrophysics Data System (ADS)

Shuicheng, TIAN; Xingbo, YANG; Xiaoqing, SHEN; Detao, ZHANG

2018-05-01

In order to reduce the number and the loss of urban road traffic accidents in our country, improve the safety of road traffic, a statistical analysis of the research report on major road traffic accidents in 2016 was conducted. The risk factors affecting urban road traffic in China were analyzed by using FTA to find the basic hidden events. Secondly, the risk value of the identified hidden danger events were calculated and classified into four levels I, II, III and IV through the LEC evaluation method. Finally, the graded results of risk factors are verified through a case of specific accidents in Beijing. The results show that: the case verified the scientificalness and effectiveness of hazard classification and provided guidance for urban road traffic management.

Construction of road network vulnerability evaluation index based on general travel cost

NASA Astrophysics Data System (ADS)

Leng, Jun-qiang; Zhai, Jing; Li, Qian-wen; Zhao, Lin

2018-03-01

With the development of China's economy and the continuous improvement of her urban road network, the vulnerability of the urban road network has attracted increasing attention. Based on general travel cost, this work constructs the vulnerability evaluation index for the urban road network, and evaluates the vulnerability of the urban road network from the perspective of user generalised travel cost. Firstly, the generalised travel cost model is constructed based on vehicle cost, travel time, and traveller comfort. Then, the network efficiency index is selected as an evaluation index of vulnerability: the network efficiency index is composed of the traffic volume and the generalised travel cost, which are obtained from the equilibrium state of the network. In addition, the research analyses the influence of traffic capacity decrease, road section attribute value, and location of road section, on vulnerability. Finally, the vulnerability index is used to analyse the local area network of Harbin and verify its applicability.

EVALUATION OF RETENTION POND AND CONSTRUCTED WETLAND BMPS FOR TREATING PARTICULATE-BOUND HEAVY METALS IN URBAN STORMWATER RUNOFF

EPA Science Inventory

Urban stormwater discharge during wet-weather flows is a major contributor to the pollution of many receiving waters. Heavy metals are of particular interest in stormwater runoff due to their toxicity, ubiquitousness, and their inability to degrade in the environment. The sources...

Using Rapid Indicators for Enterococcus to assess the Risk of Illness after Exposure to Urban Runoff Contaminated Marine Water

EPA Science Inventory

BACKGROUND: Traditional fecal indicator bacteria (FIB) measurement is too slow (>18 h) for timely swimmer warnings. OBJECTIVES: Assess relationship of rapid indicator methods (qPCR) to illness at a marine beach impacted by urban runoff. METHODS: We measured baseline and two...

First flush of storm runoff pollution from an urban catchment in China.

PubMed

Li, Li-Qing; Yin, Cheng-Qing; He, Qing-Ci; Kong, Ling-Li

2007-01-01

Storm runoff pollution process was investigated in an urban catchment with an area of 1.3 km2 in Wuhan City of China. The results indicate that the pollutant concentration peaks preceded the flow peaks in all of 8 monitored storm events. The intervals between pollution peak and flow peak were shorter in the rain events with higher intensity in the initial period than those with lower intensity. The fractions of pollution load transported by the first 30% of runoff volume (FF30) were 52.2%-72.1% for total suspended solids (TSS), 53.0%-65.3% for chemical oxygen demand (COD), 40.4%-50.6% for total nitrogen (TN), and 45.8%-63.2% for total phosphorus (TP), respectively. Runoff pollution was positively related to non-raining days before the rainfall. Intercepting the first 30% of runoff volume can remove 62.4% of TSS load, 59.4% of COD load, 46.8% of TN load, and 54.1% of TP load, respectively, according to all the storm events. It is suggested that controlling the first flush is a critical measure in reduction of urban stormwater pollution.

Run-Off Road Collision Avoidance Countermeasures Using IVHS Countermeasures Task 1 Vol. 2 Support Volume

DOT National Transportation Integrated Search

1994-10-28

The Run-Off-Road Collision Avoidance Using IVHS Countermeasures program is to address the single vehicle crash problem through application of technology to prevent and/or reduce the severity of these crashes. This report contains a summary of data us...

Differentiating littering, urban runoff and marine transport as sources of marine debris in coastal and estuarine environments

PubMed Central

Willis, Kathryn; Denise Hardesty, Britta; Kriwoken, Lorne; Wilcox, Chris

2017-01-01

Marine debris is a burgeoning global issue with economic, ecological and aesthetic impacts. While there are many studies now addressing this topic, the influence of urbanisation factors such as local population density, stormwater drains and roads on the distribution of coastal litter remains poorly understood. To address this knowledge gap, we carried out standardized surveys at 224 transect surveys at 67 sites in two estuaries and along the open coast in Tasmania, Australia. We explored the relative support for three hypotheses regarding the sources of the debris; direct deposition by beachgoers, transport from surrounding areas via storm water drains and coastal runoff, and onshore transport from the marine system. We found strong support for all three mechanisms, however, onshore transport from the marine reservoir was the most important mechanism. Overall, the three models together explained 45.8 percent of the variation in our observations. Our results also suggest that most debris released into the marine environment is deposited locally, which may be the answer to where all the missing plastic is in the ocean. Furthermore, local interventions are likely to be most effective in reducing land-based inputs into the ocean. PMID:28281667

Differentiating littering, urban runoff and marine transport as sources of marine debris in coastal and estuarine environments

NASA Astrophysics Data System (ADS)

Willis, Kathryn; Denise Hardesty, Britta; Kriwoken, Lorne; Wilcox, Chris

2017-03-01

Marine debris is a burgeoning global issue with economic, ecological and aesthetic impacts. While there are many studies now addressing this topic, the influence of urbanisation factors such as local population density, stormwater drains and roads on the distribution of coastal litter remains poorly understood. To address this knowledge gap, we carried out standardized surveys at 224 transect surveys at 67 sites in two estuaries and along the open coast in Tasmania, Australia. We explored the relative support for three hypotheses regarding the sources of the debris; direct deposition by beachgoers, transport from surrounding areas via storm water drains and coastal runoff, and onshore transport from the marine system. We found strong support for all three mechanisms, however, onshore transport from the marine reservoir was the most important mechanism. Overall, the three models together explained 45.8 percent of the variation in our observations. Our results also suggest that most debris released into the marine environment is deposited locally, which may be the answer to where all the missing plastic is in the ocean. Furthermore, local interventions are likely to be most effective in reducing land-based inputs into the ocean.

Urban runoff treatment using nano-sized iron oxide coated sand with and without magnetic field applying

PubMed Central

2013-01-01

Increase of impervious surfaces in urban area followed with increases in runoff volume and peak flow, leads to increase in urban storm water pollution. The polluted runoff has many adverse impacts on human life and environment. For that reason, the aim of this study was to investigate the efficiency of nano iron oxide coated sand with and without magnetic field in treatment of urban runoff. In present work, synthetic urban runoff was treated in continuous separate columns system which was filled with nano iron oxide coated sand with and without magnetic field. Several experimental parameters such as heavy metals, turbidity, pH, nitrate and phosphate were controlled for investigate of system efficiency. The prepared column materials were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDXA) instruments. SEM and EDXA analyses proved that the sand has been coated with nano iron oxide (Fe3O4) successfully. The results of SEM and EDXA instruments well demonstrate the formation of nano iron oxide (Fe3O4) on sand particle. Removal efficiency without magnetic field for turbidity; Pb, Zn, Cd and PO4 were observed to be 90.8%, 73.3%, 75.8%, 85.6% and 67.5%, respectively. When magnetic field was applied, the removal efficiency for turbidity, Pb, Zn, Cd and PO4 was increased to 95.7%, 89.5%, 79.9%, 91.5% and 75.6% respectively. In addition, it was observed that coated sand and magnetic field was not able to remove NO3 ions. Statistical analyses of data indicated that there was a significant difference between removals of pollutants in two tested columns. Results of this study well demonstrate the efficiency of nanosized iron oxide-coated sand in treatment of urban runoff quality; upon 75% of pollutants could be removed. In addition, in the case of magnetic field system efficiency can be improved significantly. PMID:24360061

Estimation of the possible flood discharge and volume of stormwater for designing water storage.

PubMed

Kirzhner, Felix; Kadmon, Avri

2011-01-01

The shortage of good-quality water resources is an important issue in arid and semiarid zones. Stormwater-harvesting systems that are capable of delivering good-quality wastewater for non-potable uses while taking into account environmental and health requirements must be developed. For this reason, the availability of water resources of marginal quality, like stormwater, can be a significant contribution to the water supply. Current stormwater management practices in the world require the creation of control systems that monitor quality and quantity of the water and the development of stormwater basins to store increased runoff volumes. Public health and safety considerations should be considered. Urban and suburban development, with the creation of buildings and roads and innumerable related activities, turns rain and snow into unwitting agents of damage to our nation's waterways. This urban and suburban runoff, legally known as stormwater, is one of the most significant sources of water pollution in the world. Based on various factors like water quality, runoff flow rate and speed, and the topography involved, stormwater can be directed into basins, purification plants, or to the sea. Accurate floodplain maps are the key to better floodplain management. The aim of this work is to use geographic information systems (GIS) to monitor and control the effect of stormwater. The graphic and mapping capabilities of GIS provide strong tools for conveying information and forecasts of different storm-water flow and buildup scenarios. Analyses of hydrologic processes, rainfall simulations, and spatial patterns of water resources were performed with GIS, which means, based on integrated data set, the flow of the water was introduced into the GIS. Two cases in Israel were analyzed--the Hula Project (the Jordan River floods over the peat soil area) and the Kishon River floodplains as it existed in the Yizrael Valley.

Green Infrastructure and Watershed-Scale Hydrology in a Mixed Land Cover System

NASA Astrophysics Data System (ADS)

Hoghooghi, N.; Golden, H. E.; Bledsoe, B. P.

2017-12-01

Urbanization results in replacement of pervious areas (e.g., vegetation, topsoil) with impervious surfaces such as roads, roofs, and parking lots, which cause reductions in interception, evapotranspiration, and infiltration, and increases in surface runoff (overland flow) and pollutant loads and concentrations. Research on the effectiveness of different Green Infrastructure (GI), or Low Impact Development (LID), practices to reduce these negative impacts on stream flow and water quality has been mostly focused at the local scale (e.g., plots, small catchments). However, limited research has considered the broader-scale effects of LID, such as how LID practices influence water quantity, nutrient removal, and aquatic ecosystems at watershed scales, particularly in mixed land cover and land use systems. We use the Visualizing Ecosystem Land Management Assessments (VELMA) model to evaluate the effects of different LID practices on daily and long-term watershed-scale hydrology, including infiltration surface runoff. We focus on Shayler Crossing (SHC) watershed, a mixed land cover (61% urban, 24% agriculture, 15% forest) subwatershed of the East Fork Little Miami River watershed, Ohio, United States, with a drainage area of 0.94 km2. The model was calibrated to daily stream flow at the outlet of SHC watershed from 2009 to 2010 and was applied to evaluate diverse distributions (at 25% to 100% implementation levels) and types (e.g., pervious pavement and rain gardens) of LID across the watershed. Results show reduced surface water runoff and higher rates of infiltration concomitant with increasing LID implementation levels; however, this response varies between different LID practices. The highest magnitude response in streamflow at the watershed outlet is evident when a combination of LID practices is applied. The combined scenarios elucidate that the diverse watershed-scale hydrological responses of LID practices depend primarily on the type and extent of the implemented practices. Our work provides a key advancement toward improving current understanding of the effectiveness and efficiencies of LID approaches in mixed land cover watersheds.

Modeling flood reduction effects of low impact development at a watershed scale.

PubMed

Ahiablame, Laurent; Shakya, Ranish

2016-04-15

Low impact development (LID) is a land development approach that seeks to mimic a site's pre-development hydrology. This study is a case study that assessed flood reduction capabilities of large-scale adoption of LID practices in an urban watershed in central Illinois using the Personal Computer Storm Water Management Model (PCSWMM). Two flood metrics based on runoff discharge were developed to determine action flood (43 m(3)/s) and major flood (95 m(3)/s). Four land use scenarios for urban growth were evaluated to determine the impacts of urbanization on runoff and flooding. Flood attenuation effects of porous pavement, rain barrel, and rain garden at various application levels were also evaluated as retrofitting technologies in the study watershed over a period of 30 years. Simulation results indicated that increase in urban land use from 50 to 94% between 1992 and 2030 increased average annual runoff and flood events by more than 30%, suggesting that urbanization without sound management would increase flood risks. The various implementation levels of the three LID practices resulted in 3-47% runoff reduction in the study watershed. Flood flow events that include action floods and major floods were also reduced by 0-40%, indicating that LID practices can be used to mitigate flood risk in urban watersheds. The study provides an insight into flood management with LID practices in existing urban areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inter-event variability in urban stormwater runoff response associated with hydrologic connectivity

NASA Astrophysics Data System (ADS)

Hondula, K. L.

2015-12-01

Urbanization alters the magnitude and composition of hydrologic and biogeochemical fluxes from watersheds, with subsequent deleterious consequences for receiving waters. Projected changes in storm characteristics such as rainfall intensity and event size are predicted to amplify these impacts and render current regulations inadequate for protecting surface water quality. As stormwater management practices (BMPs) are increasingly being relied upon to reduce excess nutrient pollution in runoff from residential development, empirical investigation of their performance across a range of conditions is warranted. Despite substantial investment in urban and suburban BMPs, significant knowledge gaps exist in understanding how landscape structure and precipitation event characteristics influence the amount of stormwater runoff and associated nutrient loads from these complex catchments. Increasing infiltration of stormwater before it enters the sewer network (source control) is hypothesized to better mimic natural hydrologic and biogeochemical fluxes compared to more centralized BMPs at sewer outlets such as wet and dry ponds. Rainfall and runoff quality and quantity were monitored in four small (1-5 ha) residential catchments in Maryland to test the efficacy of infiltration-based stormwater management practices in comparison to end-of-pipe BMPs. Results indicated that reduced hydrologic connectivity associated with infiltration-based practices affected the relationship between the magnitude of rainfall events and water yield , but only for small precipitation events: compared to end-of-pipe BMPs, source control was associated with both lower runoff ratios and lower nutrient export per area for a given rainfall event size. We found variability in stormwater runoff responses (water yield, quality, and nutrient loads) was associated with precipitation event size, antecedent rainfall, and hydrologic connectivity as quantified by a modified directional connectivity index. Accounting for the interactive effects of landscape structure and precipitation event characteristics can reduce the uncertainty surrounding stormwater runoff responses in complex urban watersheds.

Runoff Characterization and Variations at McMurdo Station, Antarctica

DTIC Science & Technology

2014-05-13

Boulevard Arlington, VA 22230 Laura Elliot and Corey Chan Antarctic Support Contract 7400 S. Tucson Way Centennial , CO 08112 Michael Diamond...then along the road and down Hut Point Road. Sub-basin 2 has the largest area and encompasses the majority of the snowfield and the depression above

On Flood Frequency in Urban Areas under Changing Conditions and Implications on Stormwater Infrastructure Planning and Design

NASA Astrophysics Data System (ADS)

Norouzi, A.; Habibi, H.; Nazari, B.; Noh, S.; Seo, D. J.; Zhang, Y.

2016-12-01

With urbanization and climate change, many areas in the US and abroad face increasing threats of flash flooding. Due to nonstationarities arising from changes in land cover and climate, however, it is not readily possible to project how such changes may modify flood frequency. In this work, we describe a simple spatial stochastic model for rainfall-to-areal runoff in urban areas, evaluate climatological mean and variance of mean areal runoff (MAR) over a range of catchment scale, translate them into runoff frequency, which is used as a proxy for flood frequency, and assess its sensitivity to precipitation, imperviousness and soil, and their changes as a function of catchment scale and magnitude of precipitation. The findings indicate that, due to large sensitivity of frequency of MAR to multiple hydrometeorological and physiographic factors, estimation of flood frequency for urban catchments is inherently more uncertain. The approach used in this work is useful in developing bounds for flood frequencies in urban areas under nonstationary conditions arising from urbanization and climate change.

An integrated material metabolism model for stocks of urban road system in Beijing, China.

PubMed

Guo, Zhen; Hu, Dan; Zhang, Fuhua; Huang, Guolong; Xiao, Qiang

2014-02-01

Rapid urbanization has greatly altered the urban metabolism of material and energy. As a significant part of the infrastructure, urban roads are being rapidly developed worldwide. Quantitative analysis of metabolic processes on urban road systems, especially the scale, composition and spatial distribution of their stocks, could help to assess the resource appropriation and potential environmental impacts, as well as improve urban metabolism models. In this paper, an integrated model, which covered all types of roads, intersection structures and ancillary facilities, was built for calculating the material stocks of urban road systems. Based on a bottom-up method, the total stocks were disassembled into a number of stock parts rather than obtained by input-output data, which provided an approach promoting data availability and inner structure understanding. The combination with GIS enabled the model to tackle the complex structures of road networks and avoid double counting. In the case study of Beijing, the following results are shown: 1) The total stocks for the entire road system reached 159 million tons, of which nearly 80% was stored in roads, and 20% in ancillary facilities. 2) Macadam was the largest stock (111 million tons), while stone mastic asphalt, polyurethane plastics, and atactic polypropylene accounted for smaller components of the overall system. 3) The stock per unit area of pedestrian overcrossing was higher than that of the other stock units in the entire system, and its steel stocks reached 0.49 t/m(2), which was 10 times as high as that in interchanges. 4) The high stock areas were mainly distributed in ring-shaped and radial expressways, as well as in major interchanges. 5) Expressways and arterials were excessively emphasized, while minor roads were relatively ignored. However, the variation of cross-sectional thickness in branches and neighborhood roads will have a significant impact on the scale of material stocks in the entire road system. © 2013.

Development of cloud-operating platform for detention facility design

NASA Astrophysics Data System (ADS)

Tun Lee, Kwan; Hung, Meng-Chiu; Tseng, Wei-Fan; Chan, Yi-Ping

2017-04-01

In the past 20 years, the population of Taiwan has accumulated in urban areas. The land development has changed the hydrological environment and resulted in the increase of surface runoff and shortened the time to peak discharge. The change of runoff characteristics increases the flood risk and reduces resilient ability of the city during flood. Considering that engineering measures may not be easy to implement in populated cities, detention facilities set on building basements have been proposed to compromise the increase of surface runoff resulting from development activities. In this study, a web-based operational platform has been developed to integrate the GIS technologies, hydrological analyses, as well as relevant regulations for the design of detention facilities. The design procedure embedded in the system includes a prior selection of type and size of the detention facility, integrated hydrological analysis for the developing site, and inspection of relevant regulations. After login the platform, designers can access the system database to retrieve road maps, land use coverages, and storm sewer information. Once the type, size, inlet, and outlet of the detention facility are assigned, the system can acquire the rainfall intensity-duration-frequency information from adjacent rain gauges to perform hydrological analyses for the developing site. The increase of the runoff volume due to the development and the reduction of the outflow peak through the construction of the detention facility can be estimated. The outflow peak at the target site is then checked with relevant regulations to confirm the suitability of the detention facility design. The proposed web-based platform can provide a concise layout of the detention facility and the drainageway of the developing site on a graphical interface. The design information can also be delivered directly through a web link to authorities for inspecting to simplify the complex administrative procedures.

Aquatic toxicity of airfield-pavement deicer materials and implications for airport runoff.

PubMed

Corsi, Steven R; Geis, Steven W; Bowman, George; Failey, Greg G; Rutter, Troy D

2009-01-01

Concentrations of airfield-pavement deicer materials (PDM) in a study of airport runoff often exceeded levels of concern regarding aquatic toxicity. Toxicity tests on Vibrio fischeri, Pimephales promelas, Ceriodaphnia dubia, and Pseudokirchneriella subcapitata (commonly known as Selenastrum capricornutum) were performed with potassium acetate (K-Ac) PDM, sodium formate (Na-For) PDM, and with freezing-point depressants (K-Ac and Na-For). Results indicate that toxicity in PDM is driven by the freezing-point depressants in all tests except the Vibrio fisheri test for Na-For PDM which is influenced by an additive. Acute toxicity end points for different organisms ranged from 298 to 6560 mg/L (as acetate) for K-Ac PDM and from 1780 to 4130 mg/L (as formate) for Na-For PDM. Chronic toxicity end points ranged from 19.9 to 336 mg/L (as acetate) for K-Ac PDM and from 584 to 1670 mg/L (as formate) for Na-For PDM. Sample results from outfalls at General Mitchell International Airport in Milwaukee, WI (GMIA) indicated that 40% of samples had concentrations greater thanthe aquatic-life benchmarkfor K-Ac PDM. K-Ac has replaced urea during the 1990s as the most widely used PDM at GMIA and in the United States. Results of ammonia samples from airport outfalls during periods when urea-based PDM was used at GMIA indicated that 41% of samples had concentrations exceeding the U.S. Environmental Protection Agency (USEPA) 1-h water-quality criterion. The USEPA 1-h water-quality criterion for chloride was exceeded in 68% of samples collected in the receiving stream, a result of road-salt runoff from urban influence near the airport. Results demonstrate that PDM must be considered to comprehensively evaluate the impact of chemical deicers on aquatic toxicity in water containing airport runoff.

Urban runoff (URO) process for MODFLOW 2005: simulation of sub-grid scale urban hydrologic processes in Broward County, FL

USGS Publications Warehouse

Decker, Jeremy D.; Hughes, J.D.

2013-01-01

Climate change and sea-level rise could cause substantial changes in urban runoff and flooding in low-lying coast landscapes. A major challenge for local government officials and decision makers is to translate the potential global effects of climate change into actionable and cost-effective adaptation and mitigation strategies at county and municipal scales. A MODFLOW process is used to represent sub-grid scale hydrology in urban settings to help address these issues. Coupled interception, surface water, depression, and unsaturated zone storage are represented. A two-dimensional diffusive wave approximation is used to represent overland flow. Three different options for representing infiltration and recharge are presented. Additional features include structure, barrier, and culvert flow between adjacent cells, specified stage boundaries, critical flow boundaries, source/sink surface-water terms, and the bi-directional runoff to MODFLOW Surface-Water Routing process. Some abilities of the Urban RunOff (URO) process are demonstrated with a synthetic problem using four land uses and varying cell coverages. Precipitation from a hypothetical storm was applied and cell by cell surface-water depth, groundwater level, infiltration rate, and groundwater recharge rate are shown. Results indicate the URO process has the ability to produce time-varying, water-content dependent infiltration and leakage, and successfully interacts with MODFLOW.

Modeling the Hydrologic Effects of Large-Scale Green Infrastructure Projects with GIS

NASA Astrophysics Data System (ADS)

Bado, R. A.; Fekete, B. M.; Khanbilvardi, R.

2015-12-01

Impervious surfaces in urban areas generate excess runoff, which in turn causes flooding, combined sewer overflows, and degradation of adjacent surface waters. Municipal environmental protection agencies have shown a growing interest in mitigating these effects with 'green' infrastructure practices that partially restore the perviousness and water holding capacity of urban centers. Assessment of the performance of current and future green infrastructure projects is hindered by the lack of adequate hydrological modeling tools; conventional techniques fail to account for the complex flow pathways of urban environments, and detailed analyses are difficult to prepare for the very large domains in which green infrastructure projects are implemented. Currently, no standard toolset exists that can rapidly and conveniently predict runoff, consequent inundations, and sewer overflows at a city-wide scale. We demonstrate how streamlined modeling techniques can be used with open-source GIS software to efficiently model runoff in large urban catchments. Hydraulic parameters and flow paths through city blocks, roadways, and sewer drains are automatically generated from GIS layers, and ultimately urban flow simulations can be executed for a variety of rainfall conditions. With this methodology, users can understand the implications of large-scale land use changes and green/gray storm water retention systems on hydraulic loading, peak flow rates, and runoff volumes.

Solutions to Improve Road Circulation in the Pitesti City Based on Analysis-Diagnostics of Road Traffic

NASA Astrophysics Data System (ADS)

Vîlcan, A.; Neagu, E.; Badarau Suster, H.; Boroiu, A. A.

2017-10-01

Road traffic congestion has become a daily phenomenon in the central area of Pitesti in the peak traffic periods. In order to achieve the mobility plan of Pitesti, an important stage is the diagnostic analysis of the road traffic. For this purpose, the urban road network was formalized through a graph containing the most important 40 intersections and traffic measurements were made at all these intersections and on the main roads connecting the peri-urban area. The data obtained by traffic macrosimulation confirmed the overloading of the street network during peak traffic hours and the analyzes made for various road traffic organization scenarios have shown that there are sustainable solutions for urban mobility only if the road network is fundamentally reconfigured (a belt outside the city and a median ring). Thus, the necessity of realizing the road passage in the Prundu neighbourhood and the finishing of the city belt by realizing the “detour West” of the city is argued. The importance of the work is that it brings scientific arguments for the realization of these road infrastructure projects, integrated in the urban mobility plan, which will base the development strategy of the Pitesti municipality.

Investigation of phyco-remediation of road salt run-off with marine microalgae Nannochloropsis gaditana.

PubMed

Devasya, Roopa; Bassi, Amarjeet

2017-11-15

Phyco-remediation is an environmental-friendly method, which involves the application of beneficial microalgae to treat wastewater-containing pollutants for a diverse range of conditions. Several industrial processes generate hyper saline wastewater, which is a significant challenge for conventional wastewater treatment, and the disposal of saline waters also has a negative impact on the environment. Road salt run-off is one such saline wastewater stream not currently treated and one that contributes significantly to negatively impacting receiving bodies of water. In this study, Nannochloropsis microalgae were able to assimilate >95% of the nitrates within 8 days in road salt concentrations ranging from 2.6% to 4.4% under phototrophic cultivation mode. Biomass yields of 1-2 g/l of culture were obtained with the maximum lipid of 22% (g/g) biomass in the road salt media. The crude road salt media provided all the essential micronutrients needed for algal cultivation. The fatty acid composition analysis of the obtained lipid composed of C16 and C18 over 45% of FAME are suitable for biofuel. This study has established that the use of road salt containing nitrate and phosphate nutrients will support the growth of marine micro algae for remediation of a waste water system that are the concern at winter-prevalent regions.

Modelling the impact of retention-detention units on sewer surcharge and peak and annual runoff reduction.

PubMed

Locatelli, Luca; Gabriel, Søren; Mark, Ole; Mikkelsen, Peter Steen; Arnbjerg-Nielsen, Karsten; Taylor, Heidi; Bockhorn, Britta; Larsen, Hauge; Kjølby, Morten Just; Blicher, Anne Steensen; Binning, Philip John

2015-01-01

Stormwater management using water sensitive urban design is expected to be part of future drainage systems. This paper aims to model the combination of local retention units, such as soakaways, with subsurface detention units. Soakaways are employed to reduce (by storage and infiltration) peak and volume stormwater runoff; however, large retention volumes are required for a significant peak reduction. Peak runoff can therefore be handled by combining detention units with soakaways. This paper models the impact of retrofitting retention-detention units for an existing urbanized catchment in Denmark. The impact of retrofitting a retention-detention unit of 3.3 m³/100 m² (volume/impervious area) was simulated for a small catchment in Copenhagen using MIKE URBAN. The retention-detention unit was shown to prevent flooding from the sewer for a 10-year rainfall event. Statistical analysis of continuous simulations covering 22 years showed that annual stormwater runoff was reduced by 68-87%, and that the retention volume was on average 53% full at the beginning of rain events. The effect of different retention-detention volume combinations was simulated, and results showed that allocating 20-40% of a soakaway volume to detention would significantly increase peak runoff reduction with a small reduction in the annual runoff.

Predictability of Road Traffic and Congestion in Urban Areas

PubMed Central

Wang, Jingyuan; Mao, Yu; Li, Jing; Xiong, Zhang; Wang, Wen-Xu

2015-01-01

Mitigating traffic congestion on urban roads, with paramount importance in urban development and reduction of energy consumption and air pollution, depends on our ability to foresee road usage and traffic conditions pertaining to the collective behavior of drivers, raising a significant question: to what degree is road traffic predictable in urban areas? Here we rely on the precise records of daily vehicle mobility based on GPS positioning device installed in taxis to uncover the potential daily predictability of urban traffic patterns. Using the mapping from the degree of congestion on roads into a time series of symbols and measuring its entropy, we find a relatively high daily predictability of traffic conditions despite the absence of any priori knowledge of drivers' origins and destinations and quite different travel patterns between weekdays and weekends. Moreover, we find a counterintuitive dependence of the predictability on travel speed: the road segment associated with intermediate average travel speed is most difficult to be predicted. We also explore the possibility of recovering the traffic condition of an inaccessible segment from its adjacent segments with respect to limited observability. The highly predictable traffic patterns in spite of the heterogeneity of drivers' behaviors and the variability of their origins and destinations enables development of accurate predictive models for eventually devising practical strategies to mitigate urban road congestion. PMID:25849534

Influence of landscape mosaic on streamflow of a peri-urban catchment under Mediterranean climate

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Walsh, Rory; Ferreira, António

2017-04-01

Peri-urban areas tend to be characterized by patchy landscape mosaics of different land-uses. Although the impact of land-use changes on catchment hydrology have been widely investigated, the impact of mixed land-use patterns on the streamflow of peri-urban areas is still poorly understood. This study aims to (i) explore and quantify streamflow delivery from sub-catchments characterized by distinct landscape mosaics; (ii) assess the impact of different urbanization styles on hydrograph properties; and (iii) explore the influence of urbanization type on flow connectivity and stream discharge. The study was carried out in Ribeira dos Covões, a small (6.2km2) peri-urban catchment in central Portugal. The climate is Mediterranean, with a mean annual rainfall of 892mm. Catchment geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). Soils developed on sandstone are generally deep (>3m) Fluvisols and Podsols, whereas on limestone the Leptic Cambisols are typically shallow (<0.4m). Forest is the dominant land-use (56%), but urban areas cover an extensive area (40%), whereas agricultural land has declined to a very small area (4%). The urban area comprises contrasting urban styles, notably older discontinuous urban areas with buildings separated by gardens of low population density (<25 inhabitants km-2), and recent well-defined continuous urban cores dominated by apartment blocks and of high population density (9900 inhabitants km-2). The study uses hydrological data recorded over three hydrological years, starting in November 2010, in a monitoring network comprising eight streamflow gauging stations (instrumented with water level recorders) and five rainfall gauges. The gauging stations provide information on the discharge response to rainstorms of the catchment outlet and upstream sub-catchments of different size, urban pattern (in terms of percentage urban land-use and impervious area, distance to the stream network, and storm water management), and lithology (either sandstone or limestone). Annual storm runoff coefficients were lowest (13.7%) in catchments dominated by forest (>80%) and greatest (17.3-17.6%) in the most urbanized sub-catchments (49-53% urban). Impervious area seems to control streamflow particularly during dry periods. Winter runoff (streamflow per unit area) was 2-4 times higher than summer runoff in highly urbanized areas, but was 21-fold higher in winter than in summer in the least urbanized sub-catchment, indicating greater flow connectivity in winter, enhanced by increased soil moisture. Lithology also played an important role on hydrology, with sandstone sub-catchments exhibiting greater annual baseflow index values (23-46%) than found in limestone ones (<5%). For sub-catchments underlain by both lithologies, linear relationships were found between storm runoff coefficients and percentage urban and percentage impervious area, but with greater runoff responses in the sandstone ones. Nevertheless, linear regression lines for both lithologies get close to each other when the extent of urban areas reached about 50%. The proximity of urban areas to the stream network and whether urban storm runoff is directly piped to the stream network were important parameters influencing peak flows and response time. Landscape mosaics that include land-use patches of high soil permeability tend to provide locations of surface water retention and enhanced infiltration, thereby breaking flow connectivity between hillslope urban surfaces and the stream network. This kind of spatial pattern should be considered for urban planning, in order to minimize flood hazards.

Nilsson's Power Model connecting speed and road trauma: applicability by road type and alternative models for urban roads.

PubMed

Cameron, M H; Elvik, R

2010-11-01

Nilsson (1981) proposed power relationships connecting changes in traffic speeds with changes in road crashes at various levels of injury severity. Increases in fatal crashes are related to the 4(th) power of the increase in mean speed, increases in serious casualty crashes (those involving death or serious injury) according to the 3(rd) power, and increases in casualty crashes (those involving death or any injury) according to the 2(nd) power. Increases in numbers of crash victims at cumulative levels of injury severity are related to the crash increases plus higher powers predicting the number of victims per crash. These relationships are frequently applied in OECD countries to estimate road trauma reductions resulting from expected speed reductions. The relationships were empirically derived based on speed changes resulting from a large number of rural speed limit changes in Sweden during 1967-1972. Nilsson (2004) noted that there had been very few urban speed limit changes studied to test his power model. This paper aims to test the assumption that the model is equally applicable in all road environments. It was found that the road environment is an important moderator of Nilsson's power model. While Nilsson's model appears satisfactory for rural highways and freeways, the model does not appear to be directly applicable to traffic speed changes on urban arterial roads. The evidence of monotonically increasing powers applicable to changes in road trauma at increasing injury severity levels with changes in mean speed is weak. The estimated power applicable to serious casualties on urban arterial roads was significantly less than that on rural highways, which was also significantly less than that on freeways. Alternative models linking the parameters of speed distributions with road trauma are reviewed and some conclusions reached for their use on urban roads instead of Nilsson's model. Further research is needed on the relationships between serious road trauma and urban speeds. 2010 Elsevier Ltd. All rights reserved.

Characterizations of the first flush in storm water runoff from an urban roadway.

PubMed

Lee, B C; Matsui, S; Shimizu, Y; Matsuda, T

2005-07-01

Storm water runoff from urban roadways contains anthropogenic pollutants, which are mainly generated from traffic-related activities. The purpose of this study was to evaluate the characteristics of pollutants from the roadway runoff as well as first flush effects. Storm water runoff was sampled during five storm events from the experimental site in Otsu, Shiga, Japan. From the hydrographs and pollutographs for the roadway runoff, the concentration of pollutants increased with increasing runoff flow in the low flow rate event, but did not significantly increase in the high flow rate event. Moreover, according to the analysis of cumulative pollutant mass versus runoff volume curves from five storm events, the first 50% of the runoff volume transported 62% of TOC and Mo, 60% of SS, 59% of Fe, Mn and Cu, 58% of Ni, 57% of Cd and Pb, 56% of Al, 55% of Zn, and 54% of Cr, as the mean values. The first 30% and 80% of the runoff volume also transported 34-43% mass of the pollutants and 82-88% mass of the pollutants, respectively. This study for storm water runoff may also provide useful information to correctly design treatment facilities, such as detention tanks and ponds, filtration and adsorption systems.

Priority pollutants in urban stormwater: part 1 - case of separate storm sewers.

PubMed

Zgheib, Sally; Moilleron, Régis; Chebbo, Ghassan

2012-12-15

Organic and mineral pollutants have become part of today's urban environment. During a rain event, stormwater quality as well as the corresponding contaminant loads is affected by both atmospheric deposition and the various types of impervious surfaces (roads, rooftops, parking lots etc.) on which runoff occurs. This study provides results on stormwater pollution in Paris and its suburbs from three separate storm sewers (n=20 samples). These results show that the stormwater had been contaminated by 55 chemical substances out of the 88 investigated. A particular attention was given to stormwater particle contamination. Concentrations are provided for: metals, PAHs, PCBs, organotins, alkylphenols, phthalates, pesticides, and VOCs. Our findings are among the first available in the literature since the relevant analyses were all conducted on both the particulate (P) and dissolved (D) phases. For most substances, particles from the three storm sewers were more heavily contaminated than dredged sediments and settleable particles from the Seine River. As a consequence of this finding, the release of untreated stormwater discharges may impact the receiving waters and contribute to sediment contamination. Copyright © 2011 Elsevier Ltd. All rights reserved.

Integration of UAV photogrammetry and SPH modelling of fluids to study runoff on real terrains.

PubMed

Barreiro, Anxo; Domínguez, Jose M; C Crespo, Alejandro J; González-Jorge, Higinio; Roca, David; Gómez-Gesteira, Moncho

2014-01-01

Roads can experience runoff problems due to the intense rain discharge associated to severe storms. Two advanced tools are combined to analyse the interaction of complex water flows with real terrains. UAV (Unmanned Aerial Vehicle) photogrammetry is employed to obtain accurate topographic information on small areas, typically on the order of a few hectares. The Smoothed Particle Hydrodynamics (SPH) technique is applied by means of the DualSPHysics model to compute the trajectory of the water flow during extreme rain events. The use of engineering solutions to palliate flood events is also analysed. The study case simulates how the collected water can flow into a close road and how precautionary measures can be effective to drain water under extreme conditions. The amount of water arriving at the road is calculated under different protection scenarios and the efficiency of a ditch is observed to decrease when sedimentation reduces its depth.

Integration of UAV Photogrammetry and SPH Modelling of Fluids to Study Runoff on Real Terrains

PubMed Central

Barreiro, Anxo; Domínguez, Jose M.; C. Crespo, Alejandro J.; González-Jorge, Higinio; Roca, David; Gómez-Gesteira, Moncho

2014-01-01

Roads can experience runoff problems due to the intense rain discharge associated to severe storms. Two advanced tools are combined to analyse the interaction of complex water flows with real terrains. UAV (Unmanned Aerial Vehicle) photogrammetry is employed to obtain accurate topographic information on small areas, typically on the order of a few hectares. The Smoothed Particle Hydrodynamics (SPH) technique is applied by means of the DualSPHysics model to compute the trajectory of the water flow during extreme rain events. The use of engineering solutions to palliate flood events is also analysed. The study case simulates how the collected water can flow into a close road and how precautionary measures can be effective to drain water under extreme conditions. The amount of water arriving at the road is calculated under different protection scenarios and the efficiency of a ditch is observed to decrease when sedimentation reduces its depth. PMID:25372035

Urban Stream Ecology

EPA Science Inventory

Urban watersheds characteristically have high impervious surface cover, resulting in high surface runoff and low infiltration following storms. In response, urban streams experience “flashy” stormflows, reduced baseflows, bank erosion, channel widening, and sedimentation. Urban ...

CADDIS Volume 2. Sources, Stressors and Responses: Urbanization - Temperature

EPA Pesticide Factsheets

water temperature changes associated with urbanization, heated surface runoff associated with urbanization, how temperature changes associated with urbanization can affect stream biota, interactive effects of urbanizaiton and climate change.

Key factors affecting urban runoff pollution under cold climatic conditions

NASA Astrophysics Data System (ADS)

Valtanen, Marjo; Sillanpää, Nora; Setälä, Heikki

2015-10-01

Urban runoff contains various pollutants and has the potential of deteriorating the quality of aquatic ecosystems. In this study our objective is to shed light on the factors that control the runoff water quality in urbanized catchments. The effects of runoff event characteristics, land use type and catchment imperviousness on event mass loads (EML) and event mean concentrations (EMC) were studied during warm and cold periods in three study catchments (6.1, 6.5 and 12.6 ha in size) in the city of Lahti, Finland. Runoff and rainfall were measured continuously for two years at each catchment. Runoff samples were taken for total nutrients (tot-P and tot-N), total suspended solids (TSS), heavy metals (Zn, Cr, Al, Co, Ni, Cu, Pb, Mn) and total organic carbon (TOC). Stepwise multiple linear regression analysis (SMLR) was used to identify general relationships between the following variables: event water quality, runoff event characteristics and catchment characteristics. In general, the studied variables explained 50-90% of the EMLs but only 30-60% of the EMCs, with runoff duration having an important role in most of the SMLR models. Mean runoff intensity or peak flow was also often included in the runoff quality models. Yet, the importance (being the first, second or third best) and role (negative or positive impact) of the explanatory variables varied between the cold and warm period. Land use type often explained cold period concentrations, but imperviousness alone explained EMCs weakly. As for EMLs, the influence of imperviousness and/or land use was season and pollutant dependent. The study suggests that pollutant loads can be - throughout the year - adequately predicted by runoff characteristics given that seasonal differences are taken into account. Although pollutant concentrations were sensitive to variation in seasonal and catchment conditions as well, the accurate estimation of EMCs would require a more complete set of explanatory factors than used in this study.

High Resolution Flash Flood Forecasting Using a Wireless Sensor Network in the Dallas-Fort Worth Metroplex

NASA Astrophysics Data System (ADS)

Bartos, M. D.; Kerkez, B.; Noh, S.; Seo, D. J.

2017-12-01

In this study, we develop and evaluate a high resolution urban flash flood monitoring system using a wireless sensor network (WSN), a real-time rainfall-runoff model, and spatially-explicit radar rainfall predictions. Flooding is the leading cause of natural disaster fatalities in the US, with flash flooding in particular responsible for a majority of flooding deaths. While many riverine flood models have been operationalized into early warning systems, there is currently no model that is capable of reliably predicting flash floods in urban areas. Urban flash floods are particularly difficult to model due to a lack of rainfall and runoff data at appropriate scales. To address this problem, we develop a wide-area flood-monitoring wireless sensor network for the Dallas-Fort Worth metroplex, and use this network to characterize rainfall-runoff response over multiple heterogeneous catchments. First, we deploy a network of 22 wireless sensor nodes to collect real-time stream stage measurements over catchments ranging from 2-80 km2 in size. Next, we characterize the rainfall-runoff response of each catchment by combining stream stage data with gage and radar-based precipitation measurements. Finally, we demonstrate the potential for real-time flash flood prediction by joining the derived rainfall-runoff models with real-time radar rainfall predictions. We find that runoff response is highly heterogeneous among catchments, with large variabilities in runoff response detected even among nearby gages. However, when spatially-explicit rainfall fields are included, spatial variability in runoff response is largely captured. This result highlights the importance of increased spatial coverage for flash flood prediction.

Stormwater Volume Control to Prevent Increases in Lake Flooding and Dam Failure Risk

NASA Astrophysics Data System (ADS)

Potter, K. W.

2017-12-01

Urban expansion is not often considered a major factor contributing to dam failure. But if urbanization occurs without mitigation of the hydrologic impacts, the risk of dam failure will increase. Of particular concern are increases in the volume of storm runoff resulting from increases in the extent of impervious surfaces. Storm runoff volumes are not regulated for much the U.S, and where they are, the required control is commonly less than 100%. Unmitigated increases in runoff volume due to urbanization can pose a risk to dams. A recent technical advisory committee of Dane County has recommended that the county require 100% control of stormwater volumes for new developments. The primary motivation was to prevent increases in the water levels in the Yahara Lakes, slowly draining lakes that are highly sensitive to runoff volume. The recommendations included the use of "volume trading" to achieve efficient compliance. Such recommendations should be considered for other slowly draining lakes, including those created by artificial structures.

Surface models for coupled modelling of runoff and sewer flow in urban areas.

PubMed

Ettrich, N; Steiner, K; Thomas, M; Rothe, R

2005-01-01

Traditional methods fail for the purpose of simulating the complete flow process in urban areas as a consequence of heavy rainfall and as required by the European Standard EN-752 since the bi-directional coupling between sewer and surface is not properly handled. The new methodology, developed in the EUREKA-project RisUrSim, solves this problem by carrying out the runoff on the basis of shallow water equations solved on high-resolution surface grids. Exchange nodes between the sewer and the surface, like inlets and manholes, are located in the computational grid and water leaving the sewer in case of surcharge is further distributed on the surface. Dense topographical information is needed to build a model suitable for hydrodynamic runoff calculations; in urban areas, in addition, many line-shaped elements like houses, curbs, etc. guide the runoff of water and require polygonal input. Airborne data collection methods offer a great chance to economically gather densely sampled input data.

TREATMENT OF HEAVY METALS IN STORMWATER RUNOFF USING WET POND AND WETLAND MESOCOSMS

EPA Science Inventory

Urban stormwater runoff is being recognized as a major source of pollutants to receiving waters and a number of recent investigations have evaluated stormwater runoff quality and best management practices to minimize pollutant input to receiving waters. Particle-bound contaminant...

Storm Water Management Model Reference Manual Volume I, Hydrology

EPA Science Inventory

SWMM is a dynamic rainfall-runoff simulation model used for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas. The runoff component of SWMM operates on a collection of subcatchment areas that receive precipitation and gene...

Storm Water Management Model Reference Manual Volume II – Hydraulics

EPA Science Inventory

SWMM is a dynamic rainfall-runoff simulation model used for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas. The runoff component of SWMM operates on a collection of subcatchment areas that receive precipitation and gene...

Limited Influence of Urban Stormwater Runoff on Salt Marsh Platform and Marsh Creek Oxygen Dynamics in Coastal Georgia.

PubMed

Savidge, William B; Brink, Jonathan; Blanton, Jackson O

2016-12-01

Oxygen concentrations and oxygen utilization rates were monitored continuously for 23 months on marsh platforms and in small tidal creeks at two sites in coastal Georgia, USA, that receive urban stormwater runoff via an extensive network of drainage canals. These data were compared to nearby control sites that receive no significant surface runoff. Overall, rainfall and runoff per se were not associated with differences in the oxygen dynamics among the different locations. Because of the large tidal range and long tidal excursions in coastal Georgia, localized inputs of stormwater runoff are rapidly mixed with large volumes of ambient water. Oxygen concentrations in tidal creeks and on flooded marsh platforms were driven primarily by balances of respiration and photosynthesis in the surrounding regional network of marshes and open estuarine waters. Local respiration, while measurable, was of relatively minor importance in determining oxygen concentrations in tidal floodwaters. Water residence time on the marshes could explain differences in oxygen concentration between the runoff-influenced and control sites.

Limited Influence of Urban Stormwater Runoff on Salt Marsh Platform and Marsh Creek Oxygen Dynamics in Coastal Georgia

NASA Astrophysics Data System (ADS)

Savidge, William B.; Brink, Jonathan; Blanton, Jackson O.

2016-12-01

Oxygen concentrations and oxygen utilization rates were monitored continuously for 23 months on marsh platforms and in small tidal creeks at two sites in coastal Georgia, USA, that receive urban stormwater runoff via an extensive network of drainage canals. These data were compared to nearby control sites that receive no significant surface runoff. Overall, rainfall and runoff per se were not associated with differences in the oxygen dynamics among the different locations. Because of the large tidal range and long tidal excursions in coastal Georgia, localized inputs of stormwater runoff are rapidly mixed with large volumes of ambient water. Oxygen concentrations in tidal creeks and on flooded marsh platforms were driven primarily by balances of respiration and photosynthesis in the surrounding regional network of marshes and open estuarine waters. Local respiration, while measurable, was of relatively minor importance in determining oxygen concentrations in tidal floodwaters. Water residence time on the marshes could explain differences in oxygen concentration between the runoff-influenced and control sites.

Water-quality assessment of stormwater runoff from a heavily used urban highway bridge in Miami, Florida

USGS Publications Warehouse

McKenzie, Donald J.; Irwin, G.A.

1983-01-01

Runoff from a heavily-traveled, 1.43-acre bridge section of Interstate-95 in Miami, Florida, was comprehensively monitored for both quality and quantity during five selected storms between November 1979 and May 1981. For most water-quality parameters, 6 to 11 samples were collected during each of the 5 runoff events. Concentrations of most parameters in the runoff were quite variable both during individual storm events and among the five storm events; however, the ranges in parameter concentration were about the same magnitude report for numerous other highway and urban drainages. Data were normalized to estimate the average, discharge-weighted parameter loads per storm per acre of bridge surface and results suggested that the most significant factor influencing stormwater loads was parameter concentration. Rainfall intensity and runoff volume, however, influenced rates of loading. The total number of antecedent dry days and traffic volume did not appear to be conspicously related to either runoff concentrations or loads. (USGS)

Influence of time of concentration on variation of runoff from a small urbanized watershed

Treesearch

Devendra Amatya; Agnieszka Cupak; Andrzej Walega

2015-01-01

The main objective of the paper is to estimate the influence of time of concentration (TC) on maximum flow in an urbanized watershed. The calculations of maximum flow have been carried out using the Rational method, Technical Release 55 (TR55) procedure based on NRCS (National Resources Conservation Services) guidelines, and NRCS-UH rainfall-runoff model. Similarly,...

Effects of combined-sewer overflows and urban runoff on the water quality of Fall Creek, Indianapolis, Indiana

USGS Publications Warehouse

Martin, Jeffrey D.

1995-01-01

Concentrations of dissolved oxygen measured at the station in the middle of the combined-sewer overflows were less than the Indiana minimum ambient water-quality standard of 4.0 milligrams per liter during all storms. Concentrations of ammonia, oxygen demand, copper, lead, zinc, and fecal coliform bacteria at the stations downstream from the combined-sewer overflows were much higher in storm runoff than in base flow. Increased concentrations of oxygen demand in runoff probably were caused by combined-sewer overflows, urban runoff, and the resuspension of organic material deposited on the streambed. Some of the increased concentrations of lead, zinc, and probably copper can be attributed to the discharge and resuspension of filter backwash

Using Automatic Control Approach In Detention Storages For Storm Water Management In An Urban Watershed

NASA Astrophysics Data System (ADS)

Goyal, A.; Yadav, H.; Tyagi, H.; Gosain, A. K.; Khosa, R.

2017-12-01

Increased imperviousness due to rapid urbanization have changed the urban hydrological cycle. As watersheds are urbanized, infiltration and groundwater recharge have decreased, surface runoff hydrograph shows higher peak indicating large volumes of surface runoff in lesser time durations. The ultimate panacea is to reduce the peak of hydrograph or increase the retention time of surface flow. SWMM is widely used hydrologic and hydraulic software which helps to simulate the urban storm water management with the provision to apply different techniques to prevent flooding. A model was setup to simulate the surface runoff and channel flow in a small urban catchment. It provides the temporal and spatial information of flooding in a catchment. Incorporating the detention storages in the drainage network helps achieve reduced flooding. Detention storages provided with predefined algorithms were for controlling the pluvial flooding in urban watersheds. The algorithm based on control theory, automated the functioning of detention storages ensuring that the storages become active on occurrence of flood in the storm water drains and shuts down when flooding is over. Detention storages can be implemented either at source or at several downstream control points. The proposed piece of work helps to mitigate the wastage of rainfall water, achieve desirable groundwater and attain a controlled urban storm water management system.

Applicability of models to estimate traffic noise for urban roads.

PubMed

Melo, Ricardo A; Pimentel, Roberto L; Lacerda, Diego M; Silva, Wekisley M

2015-01-01

Traffic noise is a highly relevant environmental impact in cities. Models to estimate traffic noise, in turn, can be useful tools to guide mitigation measures. In this paper, the applicability of models to estimate noise levels produced by a continuous flow of vehicles on urban roads is investigated. The aim is to identify which models are more appropriate to estimate traffic noise in urban areas since several models available were conceived to estimate noise from highway traffic. First, measurements of traffic noise, vehicle count and speed were carried out in five arterial urban roads of a brazilian city. Together with geometric measurements of width of lanes and distance from noise meter to lanes, these data were input in several models to estimate traffic noise. The predicted noise levels were then compared to the respective measured counterparts for each road investigated. In addition, a chart showing mean differences in noise between estimations and measurements is presented, to evaluate the overall performance of the models. Measured Leq values varied from 69 to 79 dB(A) for traffic flows varying from 1618 to 5220 vehicles/h. Mean noise level differences between estimations and measurements for all urban roads investigated ranged from -3.5 to 5.5 dB(A). According to the results, deficiencies of some models are discussed while other models are identified as applicable to noise estimations on urban roads in a condition of continuous flow. Key issues to apply such models to urban roads are highlighted.

Hierarchical graph-based segmentation for extracting road networks from high-resolution satellite images

NASA Astrophysics Data System (ADS)

Alshehhi, Rasha; Marpu, Prashanth Reddy

2017-04-01

Extraction of road networks in urban areas from remotely sensed imagery plays an important role in many urban applications (e.g. road navigation, geometric correction of urban remote sensing images, updating geographic information systems, etc.). It is normally difficult to accurately differentiate road from its background due to the complex geometry of the buildings and the acquisition geometry of the sensor. In this paper, we present a new method for extracting roads from high-resolution imagery based on hierarchical graph-based image segmentation. The proposed method consists of: 1. Extracting features (e.g., using Gabor and morphological filtering) to enhance the contrast between road and non-road pixels, 2. Graph-based segmentation consisting of (i) Constructing a graph representation of the image based on initial segmentation and (ii) Hierarchical merging and splitting of image segments based on color and shape features, and 3. Post-processing to remove irregularities in the extracted road segments. Experiments are conducted on three challenging datasets of high-resolution images to demonstrate the proposed method and compare with other similar approaches. The results demonstrate the validity and superior performance of the proposed method for road extraction in urban areas.

Pesticides on residential outdoor surfaces: environmental impacts and aquatic toxicity.

PubMed

Jiang, Weiying; Luo, Yuzhou; Conkle, Jeremy L; Li, Juying; Gan, Jay

2016-07-01

Pesticides are routinely applied to residential impervious outdoor surfaces for structural pest control. This residential usage has been linked to the occurrence of toxic levels of pesticides in urban water bodies. It is believed that run-off water transports particles that have sorbed hydrophobic pesticides. However, concentrations of particle-bound pesticides have not been directly measured on impervious surfaces, and the role of these particles as a source of contamination is unknown. Pesticides were detected in 99.4% of samples, with >75% of samples containing at least five pesticides. Assuming all particles were transferred with run-off, the run-off amount of pesticide during each rainfall would be >5 mg. We also used the US EPA Storm Water Management Model and estimated that 43 and 65% of the pesticides would be washed off during two rainfall events, with run-off concentrations ranging from 10.0 to 54.6 ng L(-1) and from 13.3 to 109.1 ng L(-1) respectively. The model-predicted pesticide run-off concentrations were similar to the levels monitored in urban run-off and sediments. Most (78%) particle samples contained aggregate toxicities above the Hyalella azteca LC50 . The results suggest that loose particles on residential impervious surfaces are not only carriers but also an important source of hydrophobic pesticides in urban run-off and contribute to downstream aquatic toxicities. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Soil bioretention protects juvenile salmon and their prey from the toxic impacts of urban stormwater runoff.

PubMed

McIntyre, J K; Davis, J W; Hinman, C; Macneale, K H; Anulacion, B F; Scholz, N L; Stark, J D

2015-08-01

Green stormwater infrastructure (GSI), or low impact development, encompasses a diverse and expanding portfolio of strategies to reduce the impacts of stormwater runoff on natural systems. Benchmarks for GSI success are usually framed in terms of hydrology and water chemistry, with reduced flow and loadings of toxic chemical contaminants as primary metrics. Despite the central goal of protecting aquatic species abundance and diversity, the effectiveness of GSI treatments in maintaining diverse assemblages of sensitive aquatic taxa has not been widely evaluated. In the present study we characterized the baseline toxicity of untreated urban runoff from a highway in Seattle, WA, across six storm events. For all storms, first flush runoff was toxic to the daphniid Ceriodaphnia dubia, causing up to 100% mortality or impairing reproduction among survivors. We then evaluated whether soil media used in bioretention, a conventional GSI method, could reduce or eliminate toxicity to juvenile coho salmon (Oncorhynchus kisutch) as well as their macroinvertebrate prey, including cultured C. dubia and wild-collected mayfly nymphs (Baetis spp.). Untreated highway runoff was generally lethal to salmon and invertebrates, and this acute mortality was eliminated when the runoff was filtered through soil media in bioretention columns. Soil treatment also protected against sublethal reproductive toxicity in C. dubia. Thus, a relatively inexpensive GSI technology can be highly effective at reversing the acutely lethal and sublethal effects of urban runoff on multiple aquatic species. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ecotoxicological impact of highway runoff using brown trout (Salmo trutta L.) as an indicator model.

PubMed

Meland, Sondre; Salbu, Brit; Rosseland, Bjørn Olav

2010-03-01

The ecotoxicological impact of highway runoff on brown trout (Salmo trutta L.) was studied in an in situ experiment consisting of four 24 h simulated runoff episodes. Fish were maintained in 5 tanks and exposed to highway runoff from a sedimentation pond close to E6 outside the city of Oslo, Norway. The tanks had the following contaminant loadings during the episodes: stream water (control), pond inlet, pond outlet, pond inlet + stream water and pond outlet + stream water. Opposite to road salt and compared to earlier findings, the first two episodes had rather low concentrations of trace metals, hydrocarbons and polycyclic aromatic hydrocarbons. A heavy rainfall before episode 3 increased the concentrations of all the contaminants except road salt which was diluted. In addition, lowered oxygen levels led to hypoxic conditions. Overall the fish exposed to highway runoff had, compared to the control fish, higher concentrations of trace metals in gills and liver, increased activity of the antioxidant defense system represented by superoxide dismutase, catalase and metallothionein, problems with the regulation of plasma Cl and Na, as well as increased levels of blood glucose and pCO(2). Finally, this seemed to affect the metabolism of the fish through reduced condition factor. The observed effects were likely caused by multiple stressors and not by a single contaminant. The sedimentation pond clearly reduced the toxicity of the highway runoff. But even in the least polluted exposure tank (pond outlet + stream water) signs of physiological disturbances were evident.

Urban Stormwater Runoff: A New Class of Environmental Flow Problem

PubMed Central

Walsh, Christopher J.; Fletcher, Tim D.; Burns, Matthew J.

2012-01-01

Environmental flow assessment frameworks have begun to consider changes to flow regimes resulting from land-use change. Urban stormwater runoff, which degrades streams through altered volume, pattern and quality of flow, presents a problem that challenges dominant approaches to stormwater and water resource management, and to environmental flow assessment. We used evidence of ecological response to different stormwater drainage systems to develop methods for input to environmental flow assessment. We identified the nature of hydrologic change resulting from conventional urban stormwater runoff, and the mechanisms by which such hydrologic change is prevented in streams where ecological condition has been protected. We also quantified the increase in total volume resulting from urban stormwater runoff, by comparing annual streamflow volumes from undeveloped catchments with the volumes that would run off impervious surfaces under the same rainfall regimes. In catchments with as little as 5–10% total imperviousness, conventional stormwater drainage, associated with poor in-stream ecological condition, reduces contributions to baseflows and increases the frequency and magnitude of storm flows, but in similarly impervious catchments in which streams retain good ecological condition, informal drainage to forested hillslopes, without a direct piped discharge to the stream, results in little such hydrologic change. In urbanized catchments, dispersed urban stormwater retention measures can potentially protect urban stream ecosystems by mimicking the hydrologic effects of informal drainage, if sufficient water is harvested and kept out of the stream, and if discharged water is treated to a suitable quality. Urban stormwater is a new class of environmental flow problem: one that requires reduction of a large excess volume of water to maintain riverine ecological integrity. It is the best type of problem, because solving it provides an opportunity to solve other problems such as the provision of water for human use. PMID:23029257

Fundamental concepts and research priorities for advancing the science of urban stormwater hydrology and flood management

NASA Astrophysics Data System (ADS)

Nytch, C. J.; Meléndez-Ackerman, E. J.; Vivoni, E. R.; Grove, J. M.; Ortiz, J.

2016-12-01

In cities, hydrologic processes are drastically altered by human interventions. Modification of land cover and the enhancement of hydraulic efficiency have been documented as root causes of augmented stormwater runoff in urban watersheds, contributing to higher magnitude discharge events that pose flood risks for human communities. Climate change is expected to accelerate the hydrologic cycle, leading to more extreme events and increased flood risk. We present a synthesis of the physical and conceptual components and processes that govern urban stormwater runoff, and highlight key areas for future research. There is limited understanding about the fine-scale spatio-temporal relationships between gray, green, brown, and blue land cover features, the underlying social-ecological mechanisms responsible for their distribution, and the resulting effects on runoff dynamics. Horizontal and vertical complexity of urban morphological features and connectivity with the network of stormwater management infrastructure leads to heterogeneous and non-linear runoff responses that confound efforts for accurately predicting flood hazards. Quantitative analysis is needed to understand how urban drainage network structure varies across stream orders, and illuminate the landscape-scale patterns that potentially serve as organizing principles for generating hydrologic processes across diverse socio-bio-climatic domains and scales. Field-based and modeling studies are also needed to quantify the individual hydrologic capacities of urban structural elements and their cumulative effects at the watershed scale, particularly in developing regions. Integrated, transdisciplinary, multi-scalar approaches to framing and investigating complex socio-eco-techno-hydrologic systems are essential for advancing the science of urban stormwater hydrology, and developing resilient, multifunctional management solutions appropriate to the challenges of urban flooding in the twenty-first century.

An integrated modeling approach for estimating hydrologic responses to future urbanization and climate changes in a mixed-use midwestern watershed.

PubMed

Sunde, Michael G; He, Hong S; Hubbart, Jason A; Urban, Michael A

2018-08-15

Future urban development and climatic changes are likely to affect hydrologic regimes in many watersheds. Quantifying potential water regime changes caused by these stressors is therefore crucial for enabling decision makers to develop viable environmental management strategies. This study presents an approach that integrates mid-21st century impervious surface growth estimates derived from the Imperviousness Change Analysis Tool with downscaled climate model projections and a hydrologic model Soil and Water Assessment Tool to characterize potential water regime changes in a mixed-use watershed in central Missouri, USA. Results for the climate change only scenario showed annual streamflow and runoff decreases (-10.7% and -9.2%) and evapotranspiration increases (+6.8%), while results from the urbanization only scenario showed streamflow and runoff increases (+3.8% and +9.3%) and evapotranspiration decreases (-2.4%). Results for the combined impacts scenario suggested that climatic changes could have a larger impact than urbanization on annual streamflow, (overall decrease of -6.1%), and could largely negate surface runoff increases caused by urbanization. For the same scenario, climatic changes exerted a stronger influence on annual evapotranspiration than urbanization (+3.9%). Seasonal results indicated that the relative influences of urbanization and climatic changes vary seasonally. Climatic changes most greatly influenced streamflow and runoff during winter and summer, and evapotranspiration during summer. During some seasons the directional change for hydrologic processes matched for both stressors. This work presented a practicable approach for investigating the relative influences of mid-21st century urbanization and climatic changes on the hydrology of a representative mixed-use watershed, adding to a limited body of research on this topic. This was done using a transferrable approach that can be adapted for watersheds in other regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

High-quality observation of surface imperviousness for urban runoff modelling using UAV imagery

NASA Astrophysics Data System (ADS)

Tokarczyk, P.; Leitao, J. P.; Rieckermann, J.; Schindler, K.; Blumensaat, F.

2015-10-01

Modelling rainfall-runoff in urban areas is increasingly applied to support flood risk assessment, particularly against the background of a changing climate and an increasing urbanization. These models typically rely on high-quality data for rainfall and surface characteristics of the catchment area as model input. While recent research in urban drainage has been focusing on providing spatially detailed rainfall data, the technological advances in remote sensing that ease the acquisition of detailed land-use information are less prominently discussed within the community. The relevance of such methods increases as in many parts of the globe, accurate land-use information is generally lacking, because detailed image data are often unavailable. Modern unmanned aerial vehicles (UAVs) allow one to acquire high-resolution images on a local level at comparably lower cost, performing on-demand repetitive measurements and obtaining a degree of detail tailored for the purpose of the study. In this study, we investigate for the first time the possibility of deriving high-resolution imperviousness maps for urban areas from UAV imagery and of using this information as input for urban drainage models. To do so, an automatic processing pipeline with a modern classification method is proposed and evaluated in a state-of-the-art urban drainage modelling exercise. In a real-life case study (Lucerne, Switzerland), we compare imperviousness maps generated using a fixed-wing consumer micro-UAV and standard large-format aerial images acquired by the Swiss national mapping agency (swisstopo). After assessing their overall accuracy, we perform an end-to-end comparison, in which they are used as an input for an urban drainage model. Then, we evaluate the influence which different image data sources and their processing methods have on hydrological and hydraulic model performance. We analyse the surface runoff of the 307 individual subcatchments regarding relevant attributes, such as peak runoff and runoff volume. Finally, we evaluate the model's channel flow prediction performance through a cross-comparison with reference flow measured at the catchment outlet. We show that imperviousness maps generated from UAV images processed with modern classification methods achieve an accuracy comparable to standard, off-the-shelf aerial imagery. In the examined case study, we find that the different imperviousness maps only have a limited influence on predicted surface runoff and pipe flows, when traditional workflows are used. We expect that they will have a substantial influence when more detailed modelling approaches are employed to characterize land use and to predict surface runoff. We conclude that UAV imagery represents a valuable alternative data source for urban drainage model applications due to the possibility of flexibly acquiring up-to-date aerial images at a quality compared with off-the-shelf image products and a competitive price at the same time. We believe that in the future, urban drainage models representing a higher degree of spatial detail will fully benefit from the strengths of UAV imagery.

Sustainable oil and grease removal from synthetic stormwater runoff using bench-scale bioretention studies.

PubMed

Hong, Eunyoung; Seagren, Eric A; Davis, Allen P

2006-02-01

One of the principal components of the contaminant load in urban stormwater runoff is oil and grease (O&G) pollution, resulting from vehicle emissions. A mulch layer was used as a contaminant trap to remove O&G (dissolved and particulate-associated naphthalene, dissolved toluene, and dissolved motor oil hydrocarbons) from a synthetic runoff during a bench-scale infiltration study. Approximately 80 to 95% removal of all contaminants from synthetic runoff was found via sorption and filtration. Subsequently, approximately 90% of the sorbed naphthalene, toluene, oil, and particulate-associated naphthalene was biodegraded within approximately 3, 4, 8, and 2 days after the event, respectively, based on decreases in contaminant concentrations coupled with increases of microbial populations. These results indicate the effectiveness and sustainability of placing a thin layer of mulch on the surface of a bioretention facility for reducing O&G pollution from urban stormwater runoff.

Road traffic injuries in Colombia.

PubMed

Rodríguez, Deysi Yasmin; Fernández, Francisco José; Acero Velásquez, Hugo

2003-01-01

Road traffic injuries are a leading public health problem in Colombia. Pedestrians are the most vulnerable road users, especially in the main urban centers of Bogotá, Medellin and Cali. Data analyzed in this report include official statistics from the National Police and the National Institute of Legal Medicine and Forensic Sciences for 1996-2000, and results of a study conducted at the National University of Colombia in 2000. Methods from the Highway Capacity Manual were used for determining physical and technical variables, and a Geographical Information System tool was used for the location and spatial analysis of the road traffic crashes. Pedestrians accounted for close to 32% of injuries and 40% of the deaths from road traffic crashes. The problem of road traffic crashes existed predominately in urban areas. In the main urban centers, pedestrians constituted nearly 68% of road traffic crash victims. The high level of risky road use behaviors demonstrated by pedestrians and drivers, and inadequate infrastructure for safe mobility of pedestrians in some sections of the road network were the main contributing factors. Major improvements were achieved in Bogotá following enhancements to the municipal transport system and other policies introduced since 1995. In conclusion, policies and programs for improving road safety, in particular pedestrian safety, and strengthening urban planning are top priority.

Storm Water Management Model Reference Manual Volume III – Water Quality

EPA Science Inventory

SWMM is a dynamic rainfall-runoff simulation model used for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas. The runoff component of SWMM operates on a collection of subcatchment areas that receive precipitation and gene...

Reducing urban diffuse pollution and surface water flooding using retrofit street trees

NASA Astrophysics Data System (ADS)

Rothwell, James; Stringer, Pete; Causer, Katherine; Ryan, Matt; Mangan, Steve; Appleton, Ian; Savage, Mike

2016-04-01

Nature-based solutions for the management of urban stormwater have been growing in popularity, but there is a lack of empirical performance data for field-scale installations, especially in a UK context. To address this deficiency, a novel retrofit street tree demonstration project was commissioned in the City of Salford, near Manchester (UK). Three fifteen year-old London Plane trees were planted within a large roadside tree trench on an urban residential street. The DeepRoot Silvia Cell modular suspended pavement system was used to maximise soil volume, avoid compaction and support large tree growth. Road runoff is directed to the tree trench via AKO Slot Kerbs. Water is then distributed evenly throughout the whole system via a perforated pipe. Excess water is conveyed out of the system via an underdrain, which is subsequently connected to the sewer network. The tree trench is lined with an impermeable membrane. Access chambers are positioned on the inflow and outflow of the tree trench to facilitate hydrological and water quality monitoring. Installation was completed in autumn 2015 and monitoring will be conducted over a three year period. This paper will provide an overview of the installation process and present initial results on the pollutant removal performance and hydrological functioning of the system.

Objects Grouping for Segmentation of Roads Network in High Resolution Images of Urban Areas

NASA Astrophysics Data System (ADS)

Maboudi, M.; Amini, J.; Hahn, M.

2016-06-01

Updated road databases are required for many purposes such as urban planning, disaster management, car navigation, route planning, traffic management and emergency handling. In the last decade, the improvement in spatial resolution of VHR civilian satellite sensors - as the main source of large scale mapping applications - was so considerable that GSD has become finer than size of common urban objects of interest such as building, trees and road parts. This technological advancement pushed the development of "Object-based Image Analysis (OBIA)" as an alternative to pixel-based image analysis methods. Segmentation as one of the main stages of OBIA provides the image objects on which most of the following processes will be applied. Therefore, the success of an OBIA approach is strongly affected by the segmentation quality. In this paper, we propose a purpose-dependent refinement strategy in order to group road segments in urban areas using maximal similarity based region merging. For investigations with the proposed method, we use high resolution images of some urban sites. The promising results suggest that the proposed approach is applicable in grouping of road segments in urban areas.

Predicting urban stormwater runoff with quantitative precipitation estimates from commercial microwave links

NASA Astrophysics Data System (ADS)

Pastorek, Jaroslav; Fencl, Martin; Stránský, David; Rieckermann, Jörg; Bareš, Vojtěch

2017-04-01

Reliable and representative rainfall data are crucial for urban runoff modelling. However, traditional precipitation measurement devices often fail to provide sufficient information about the spatial variability of rainfall, especially when heavy storm events (determining design of urban stormwater systems) are considered. Commercial microwave links (CMLs), typically very dense in urban areas, allow for indirect precipitation detection with desired spatial and temporal resolution. Fencl et al. (2016) recognised the high bias in quantitative precipitation estimates (QPEs) from CMLs which significantly limits their usability and, in order to reduce the bias, suggested a novel method for adjusting the QPEs to existing rain gauge networks. Studies evaluating the potential of CMLs for rainfall detection so far focused primarily on direct comparison of the QPEs from CMLs to ground observations. In contrast, this investigation evaluates the suitability of these innovative rainfall data for stormwater runoff modelling on a case study of a small ungauged (in long-term perspective) urban catchment in Prague-Letňany, Czech Republic (Fencl et al., 2016). We compare the runoff measured at the outlet from the catchment with the outputs of a rainfall-runoff model operated using (i) CML data adjusted by distant rain gauges, (ii) rainfall data from the distant gauges alone and (iii) data from a single temporary rain gauge located directly in the catchment, as it is common practice in drainage engineering. Uncertainties of the simulated runoff are analysed using the Bayesian method for uncertainty evaluation incorporating a statistical bias description as formulated by Del Giudice et al. (2013). Our results show that adjusted CML data are able to yield reliable runoff modelling results, primarily for rainfall events with convective character. Performance statistics, most significantly the timing of maximal discharge, reach better (less uncertain) values with the adjusted CML data than with the distant rain gauges. When the relative error of the volume discharged during the maximum flow period is concerned, the adjusted CMLs perform even better than the rain gauge in the catchment. This seem to be very promising, especially for urban catchments with sparse rain gauge networks. References: Del Giudice, D., Honti, M., Scheidegger, A., Albert, C., Reichert, P., and Rieckermann, J. 2013. Improving uncertainty estimation in urban hydrological modeling by statistically describing bias. Hydrology and Earth System Sciences 17, 4209-4225. Fencl, M., Dohnal, M., Rieckermann, J., and Bareš, V. 2016. Gauge-Adjusted Rainfall Estimates from Commercial Microwave Links, Hydrology and Earth System Sciences Discussions, doi:10.5194/hess-2016- 397, in review. Acknowledgements to the Czech Science Foundation projects No. 14-22978S and No. 17-16389S.

Impacts of Changing Climate, Hydrology and Land Use on the Stormwater Runoff of Urbanizing Central Florida

NASA Astrophysics Data System (ADS)

Huq, E.; Abdul-Aziz, O. I.

2017-12-01

We computed the historical and future storm runoff scenarios for the Shingle Creek Basin, including the growing urban centers of central Florida (e.g., City of Orlando). Storm Water Management Model (SWMM 5.1) of US EPA was used to develop a mechanistic hydrologic model for the basin by incorporating components of urban hydrology, hydroclimatological variables, and land use/cover features. The model was calibrated and validated with historical streamflow of 2004-2013 near the outlet of the Shingle Creek. The calibrated model was used to compute the sensitivities of stormwater budget to reference changes in hydroclimatological variables (rainfall and evapotranspiration) and land use/cover features (imperviousness, roughness). Basin stormwater budgets for the historical (2010s = 2004-2013) and future periods (2050s = 2030-2059; 2080s = 2070-2099) were also computed based on downscaled climatic projections of 20 GCMs-RCMs representing the coupled model intercomparison project (CMIP5), and anticipated changes in land use/cover. The sensitivity analyses indicated the dominant drivers of urban runoff in the basin. Comparative assessment of the historical and future stormwater runoff scenarios helped to locate basin areas that would be at a higher risk of future stormwater flooding. Importance of the study lies in providing valuable guidelines for managing stormwater flooding in central Florida and similar growing urban centers around the world.

Developing a stochastic conflict resolution model for urban runoff quality management: Application of info-gap and bargaining theories

NASA Astrophysics Data System (ADS)

Ghodsi, Seyed Hamed; Kerachian, Reza; Estalaki, Siamak Malakpour; Nikoo, Mohammad Reza; Zahmatkesh, Zahra

2016-02-01

In this paper, two deterministic and stochastic multilateral, multi-issue, non-cooperative bargaining methodologies are proposed for urban runoff quality management. In the proposed methodologies, a calibrated Storm Water Management Model (SWMM) is used to simulate stormwater runoff quantity and quality for different urban stormwater runoff management scenarios, which have been defined considering several Low Impact Development (LID) techniques. In the deterministic methodology, the best management scenario, representing location and area of LID controls, is identified using the bargaining model. In the stochastic methodology, uncertainties of some key parameters of SWMM are analyzed using the info-gap theory. For each water quality management scenario, robustness and opportuneness criteria are determined based on utility functions of different stakeholders. Then, to find the best solution, the bargaining model is performed considering a combination of robustness and opportuneness criteria for each scenario based on utility function of each stakeholder. The results of applying the proposed methodology in the Velenjak urban watershed located in the northeastern part of Tehran, the capital city of Iran, illustrate its practical utility for conflict resolution in urban water quantity and quality management. It is shown that the solution obtained using the deterministic model cannot outperform the result of the stochastic model considering the robustness and opportuneness criteria. Therefore, it can be concluded that the stochastic model, which incorporates the main uncertainties, could provide more reliable results.

Application of Shuffled Frog Leaping Algorithm and Genetic Algorithm for the Optimization of Urban Stormwater Drainage

NASA Astrophysics Data System (ADS)

Kumar, S.; Kaushal, D. R.; Gosain, A. K.

2017-12-01

Urban hydrology will have an increasing role to play in the sustainability of human settlements. Expansion of urban areas brings significant changes in physical characteristics of landuse. Problems with administration of urban flooding have their roots in concentration of population within a relatively small area. As watersheds are urbanized, infiltration decreases, pattern of surface runoff is changed generating high peak flows, large runoff volumes from urban areas. Conceptual rainfall-runoff models have become a foremost tool for predicting surface runoff and flood forecasting. Manual calibration is often time consuming and tedious because of the involved subjectivity, which makes automatic approach more preferable. The calibration of parameters usually includes numerous criteria for evaluating the performances with respect to the observed data. Moreover, derivation of objective function assosciat6ed with the calibration of model parameters is quite challenging. Various studies dealing with optimization methods has steered the embracement of evolution based optimization algorithms. In this paper, a systematic comparison of two evolutionary approaches to multi-objective optimization namely shuffled frog leaping algorithm (SFLA) and genetic algorithms (GA) is done. SFLA is a cooperative search metaphor, stimulated by natural memetics based on the population while, GA is based on principle of survival of the fittest and natural evolution. SFLA and GA has been employed for optimizing the major parameters i.e. width, imperviousness, Manning's coefficient and depression storage for the highly urbanized catchment of Delhi, India. The study summarizes the auto-tuning of a widely used storm water management model (SWMM), by internal coupling of SWMM with SFLA and GA separately. The values of statistical parameters such as, Nash-Sutcliffe efficiency (NSE) and Percent Bias (PBIAS) were found to lie within the acceptable limit, indicating reasonably good model performance. Overall, this study proved promising for assessing risk in urban drainage systems and should prove useful to improve integrity of the urban system, its reliability and provides guidance for inundation preparedness.Keywords: Hydrologic model, SWMM, Urbanization, SFLA and GA.

Total pollution effect of urban surface runoff.

PubMed

Luo, Hongbing; Luo, Lin; Huang, Gu; Liu, Ping; Li, Jingxian; Hu, Sheng; Wang, Fuxiang; Xu, Rui; Huang, Xiaoxue

2009-01-01

For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD (chemical oxygen demand), TSS (total suspend solid), TP (total phosphorus), TN (total nitrogen) and BOD (biochemical oxygen demand). The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters: rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 (mass first flush ratio) and FF30 (first 30% of runoff volume) can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs (best management practices) facilities.

Runoff of pyrethroid insecticides from concrete surfaces following simulated and natural rainfalls.

PubMed

Jiang, Weiying; Haver, Darren; Rust, Michael; Gan, Jay

2012-03-01

Intensive residential use of insecticides has resulted in their ubiquitous presence as contaminants in urban surface streams. For pest eradication, urban hard surfaces such as concrete are often directly treated with pesticides, and wind/water can also carry pesticides onto hard surfaces from surrounding areas. This study expanded on previous bench-scale studies by considering pesticide runoff caused by irrigation under dry weather conditions and rain during the wet season, and evaluated the effects of pesticide residence time on concrete, single versus recurring precipitations, precipitation intensity, and concrete surface conditions, on pesticide transferability to runoff water. Runoff from concrete 1 d after pesticide treatment contained high levels of bifenthrin (82 μg/L) and permethrin (5143 μg/L for cis and 5518 μg/L for trans), indicating the importance of preventing water contact on concrete after pesticide treatments. Although the runoff transferability quickly decreased as the pesticide residence time on concrete increased, detectable residues were still found in runoff water after 3 months (89 d) exposure to hot and dry summer conditions. ANOVA analysis showed that precipitation intensities and concrete surface conditions (i.e., acid wash, silicone seal, stamping, and addition of microsilica) did not significantly affect the pesticide transferability to runoff. For concrete slabs subjected to natural rainfalls during the winter wet season, pesticide levels in the runoff decreased as the time interval between pesticide application and the rain event increased. However, bifenthrin and permethrin were still detected at 0.15-0.17 and 0.75-1.15 μg/L in the rain runoff after 7 months (221 d) from the initial treatment. In addition, pesticide concentrations showed no decrease between the two rainfall events, suggesting that concrete surfaces contaminated by pesticides may act as a reservoir for pesticide residues, leading to sustained urban runoff contamination. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of distributed and centralized stormwater best management practices and land cover on urban stream hydrology at the catchment scale

NASA Astrophysics Data System (ADS)

Loperfido, J. V.; Noe, Gregory B.; Jarnagin, S. Taylor; Hogan, Dianna M.

2014-11-01

Urban stormwater runoff remains an important issue that causes local and regional-scale water quantity and quality issues. Stormwater best management practices (BMPs) have been widely used to mitigate runoff issues, traditionally in a centralized manner; however, problems associated with urban hydrology have remained. An emerging trend is implementation of BMPs in a distributed manner (multi-BMP treatment trains located on the landscape and integrated with urban design), but little catchment-scale performance of these systems have been reported to date. Here, stream hydrologic data (March, 2011-September, 2012) are evaluated in four catchments located in the Chesapeake Bay watershed: one utilizing distributed stormwater BMPs, two utilizing centralized stormwater BMPs, and a forested catchment serving as a reference. Among urban catchments with similar land cover, geology and BMP design standards (i.e. 100-year event), but contrasting placement of stormwater BMPs, distributed BMPs resulted in: significantly greater estimated baseflow, a higher minimum precipitation threshold for stream response and maximum discharge increases, better maximum discharge control for small precipitation events, and reduced runoff volume during an extreme (1000-year) precipitation event compared to centralized BMPs. For all catchments, greater forest land cover and less impervious cover appeared to be more important drivers than stormwater BMP spatial pattern, and caused lower total, stormflow, and baseflow runoff volume; lower maximum discharge during typical precipitation events; and lower runoff volume during an extreme precipitation event. Analysis of hydrologic field data in this study suggests that both the spatial distribution of stormwater BMPs and land cover are important for management of urban stormwater runoff. In particular, catchment-wide application of distributed BMPs improved stream hydrology compared to centralized BMPs, but not enough to fully replicate forested catchment stream hydrology. Integrated planning of stormwater management, protected riparian buffers and forest land cover with suburban development in the distributed-BMP catchment enabled multi-purpose use of land that provided esthetic value and green-space, community gathering points, and wildlife habitat in addition to hydrologic stormwater treatment.

Effects of distributed and centralized stormwater best management practices and land cover on urban stream hydrology at the catchment scale

USGS Publications Warehouse

Loperfido, John V.; Noe, Gregory B.; Jarnagin, S. Taylor; Hogan, Dianna M.

2014-01-01

Urban stormwater runoff remains an important issue that causes local and regional-scale water quantity and quality issues. Stormwater best management practices (BMPs) have been widely used to mitigate runoff issues, traditionally in a centralized manner; however, problems associated with urban hydrology have remained. An emerging trend is implementation of BMPs in a distributed manner (multi-BMP treatment trains located on the landscape and integrated with urban design), but little catchment-scale performance of these systems have been reported to date. Here, stream hydrologic data (March, 2011–September, 2012) are evaluated in four catchments located in the Chesapeake Bay watershed: one utilizing distributed stormwater BMPs, two utilizing centralized stormwater BMPs, and a forested catchment serving as a reference. Among urban catchments with similar land cover, geology and BMP design standards (i.e. 100-year event), but contrasting placement of stormwater BMPs, distributed BMPs resulted in: significantly greater estimated baseflow, a higher minimum precipitation threshold for stream response and maximum discharge increases, better maximum discharge control for small precipitation events, and reduced runoff volume during an extreme (1000-year) precipitation event compared to centralized BMPs. For all catchments, greater forest land cover and less impervious cover appeared to be more important drivers than stormwater BMP spatial pattern, and caused lower total, stormflow, and baseflow runoff volume; lower maximum discharge during typical precipitation events; and lower runoff volume during an extreme precipitation event. Analysis of hydrologic field data in this study suggests that both the spatial distribution of stormwater BMPs and land cover are important for management of urban stormwater runoff. In particular, catchment-wide application of distributed BMPs improved stream hydrology compared to centralized BMPs, but not enough to fully replicate forested catchment stream hydrology. Integrated planning of stormwater management, protected riparian buffers and forest land cover with suburban development in the distributed-BMP catchment enabled multi-purpose use of land that provided esthetic value and green-space, community gathering points, and wildlife habitat in addition to hydrologic stormwater treatment.

Conceptual models of the formation of acid-rock drainage at road cuts in Tennessee

USGS Publications Warehouse

Bradley, Michael W.; Worland, Scott; Byl, Tom

2015-01-01

Pyrite and other minerals containing sulfur and trace metals occur in several rock formations throughout Middle and East Tennessee. Pyrite (FeS2) weathers in the presence of oxygen and water to form iron hydroxides and sulfuric acid. The weathering and interaction of the acid on the rocks and other minerals at road cuts can result in drainage with low pH (< 4) and high concentrations of trace metals. Acid-rock drainage can cause environmental problems and damage transportation infrastructure. The formation and remediation of acid-drainage from roads cuts has not been researched as thoroughly as acid-mine drainage. The U.S Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to better understand the geologic, hydrologic, and biogeochemical factors that control acid formation at road cuts. Road cuts with the potential for acid-rock drainage were identifed and evaluated in Middle and East Tennessee. The pyrite-bearing formations evaluated were the Chattanooga Shale (Devonian black shale), the Fentress Formation (coal-bearing), and the Precambrian Anakeesta Formation and similar Precambrian rocks. Conceptual models of the formation and transport of acid-rock drainage (ARD) from road cuts were developed based on the results of a literature review, site reconnaissance, and the initial rock and water sampling. The formation of ARD requires a combination of hydrologic, geochemical, and microbial interactions which affect drainage from the site, acidity of the water, and trace metal concentrations. The basic modes of ARD formation from road cuts are; 1 - seeps and springs from pyrite-bearing formations and 2 - runoff over the face of a road cut in a pyrite-bearing formation. Depending on site conditions at road cuts, the basic modes of ARD formation can be altered and the additional modes of ARD formation are; 3 - runoff over and through piles of pyrite-bearing material, either from construction or breakdown material weathered from shale, and 4 - the deposition of secondary-sulfate minerals can store trace metals and, during rainfall, result in increased acidity and higher concentrations of trace metals in storm runoff. Understanding the factors that control ARD formation and transport are key to addressing the problems associated with the movement of ARD from the road cuts to the environment. The investigation will provide the Tennessee Department of Transportation with a regional characterization of ARD and provide insights into the geochemical and biochemical attributes for the control and remediation of ARD from road cuts.

Evaluation of core cultivation practices to reduce ecological risk of pesticides in runoff from turf

USDA-ARS?s Scientific Manuscript database

Pesticides associated with the turfgrass industry have been detected in storm runoff and surface waters of urban watersheds; raising concern of their potential environmental effects and a desire to reduce their transport to non-target locations. Runoff studies were conducted to compare the effective...

Laboratory Simulation of Urban Runoff and Estimation of Runoff Hydrographs with Experimental Curve Numbers Implemented in USEPA SWMM

EPA Science Inventory

The prognostic capabilities of a lumped hydrologic modeling approach may be complicated by routing and connectivity among infiltrative and impervious surfaces. We used artificial rainfall to generate runoff from impervious and bare soil boxes arranged in series to simulate differ...

Development and integration of sub-hourly rainfall-runoff modeling capability within a watershed model

USDA-ARS?s Scientific Manuscript database

Increasing urbanization changes runoff patterns to be flashy and instantaneous with decreased base flow. A model with the ability to simulate sub-daily rainfall–runoff processes and continuous simulation capability is required to realistically capture the long-term flow and water quality trends in w...

Comparison of the physical and chemical characteristics of fine road dust at different urban sites.

PubMed

Lee, Kwang Yul; Batmunkh, Tsatsral; Joo, Hung Soo; Park, Kihong

2018-04-18

The size distribution and chemical components of a fine fraction (<2.5 μm) of road dust collected at urban sites in Korea (Gwangju) and Mongolia (Ulaanbaatar) where distinct urban characteristics exist were measured. A clear bimodal size distribution was observed for the resuspended fine road dust at the urban sites in Korea. The first mode peaked at 100-110 nm, and the second peak was observed at 435-570 nm. Ultrafine mode (~30 nm) was found for the fine road dust at the Mongolia site, which was significantly affected by residential coal/biomass burning. The contribution of the water-soluble ions to the fine road dust was higher at the sites in Mongolia (15.8-16.8%) than at those in Korea (1.2-4.8%). Sulfate and chloride were the most dominant ionic species for the fine road dust in Mongolia. As (arsenic) was also much higher for the Mongolian road dust than the others. The sulfate, chloride, and As mainly come from coal burning activity, suggesting that coal and biomass combustion in Mongolia during the heating season should affect the size and chemical components of the fine road dust. Cu (copper) and Zn (zinc), carbonaceous particles (organic carbon [OC] and elemental carbon [EC]) increased at sites in Korea, suggesting that the fine road dust at these sites was significantly affected by the high volume of traffic (engine emission and brake/tire wear). Our results suggest that chemical profiles for road dust specific to certain sites should be applied to more accurately apportion road dust source contributing to the ambient particulate matter. Size and chemical characteristics of fine road dust at sites having distinct urban characteristics were examined. Residential coal and biomass burning and traffic affected physiochemical properties of the fine road dust. Different road dust profiles at different sites should be needed to determine the ambient PM2.5 sources more accurately.

Precipitation and runoff water quality from an urban parking lot and implications for tree growth

Treesearch

C. H. Pham; H. G. Halverson; G. M. Heisler

1978-01-01

The water quality of precipitation and runoff from a large parking lot in New Brunswick, New Jersey was studied during the early growing season, from March to June 1976. Precipitation and runoff from 10 storms were analyzed. The runoff was higher in all constituents considered except for P, Pb, and Cu. Compared with published values for natural waters, sewage effluent...

Urban stormwater runoff study at Davenport, Iowa

USGS Publications Warehouse

Schaap, Bryan D.

1995-01-01

Urban storm water runoff is being investigated as a nonpoint source of pollution across the country as urban areas with populations over 100,000 conduct studies designed to meet U.S. Environmental Protection Agency guidelines for National Pollutant Discharge Elimination System permits for their stormwater discharges. From 1991 through 1994, the City of Davenport, Iowa (fig. 1), and the U.S. Geological Survey cooperatively conducted a study designed to meet technical conditions of the permit application and to develop the criteria for ongoing monitoring during the term of the permit. 

Spatial Patterns of Road-Induced Backwater Sediment Storage Across A Rural to Urban Gradient

NASA Astrophysics Data System (ADS)

Copeland, M.; Bain, D.

2017-12-01

Road networks dominate many landscapes and often interact with stream networks to alter basin sediment dynamics. Currently, conceptual models of catchment-scale sediment fluxes remain at a coarse scale (i.e., the entire catchment) and are unable to resolve important human-driven sediment storage processes. The spatio-temporal complexity of the interactions between road networks and streams has made it challenging to infer the fine-scale impacts of road crossings on fluvial systems. Here, road crossings in multiple drainage networks and the associated backwater sediment accumulations are examined along a rural to urban gradient around Pittsburgh, PA. Preliminary results indicate that upstream drainage area, channel slope, and human activities control stream crossing type and therefore drive associated sediment accumulation, particularly in urban headwater channels. The data indicate that the combination of land use intensity and infrastructure age influences the volume of sediment trapped in road-induced backwaters. Clarification of the coupled human, road-building, and natural stream adjustments will allow for more effective treatments of fluvial impacts, such as the "urban stream syndrome."

National Program for Inspection of Non-Federal Dams. Arm Brook Multiple Purpose Dam (MA 00604) Connecticut River Basin, Westfield, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1978-08-01

based on the stimated "Probable Maximum Flood" for the region (greatest easonably possible storm runoff ), or fractions thereof. ecause of the...mechanism could have been general flooding of the outlet work due to runoff from storm water. The 1972 SCS report does mention that the inspection...Westfield William F. Warren, SCS ARM BROOK SITE Beach Area 0 0 Problems: Gullies are being washed in the beach by runoff from the road and especially

Spatiotemporal responses of dengue fever transmission to the road network in an urban area.

PubMed

Li, Qiaoxuan; Cao, Wei; Ren, Hongyan; Ji, Zhonglin; Jiang, Huixian

2018-07-01

Urbanization is one of the important factors leading to the spread of dengue fever. Recently, some studies found that the road network as an urbanization factor affects the distribution and spread of dengue epidemic, but the study of relationship between the distribution of dengue epidemic and road network is limited, especially in highly urbanized areas. This study explores the temporal and spatial spread characteristics of dengue fever in the distribution of road network by observing a dengue epidemic in the southern Chinese cities. Geographic information technology is used to extract the spatial location of cases and explore the temporal and spatial changes of dengue epidemic and its spatial relationship with road network. The results showed that there was a significant "severe" period in the temporal change of dengue epidemic situation, and the cases were mainly concentrated in the vicinity of narrow roads, the spread of the epidemic mainly along the high-density road network area. These results show that high-density road network is an important factor to the direction and scale of dengue epidemic. This information may be helpful to the development of related epidemic prevention and control strategies. Copyright © 2018. Published by Elsevier B.V.

Relative importance of impervious area, drainage density, width function, and subsurface storm drainage on flood runoff from an urbanized catchment

NASA Astrophysics Data System (ADS)

Ogden, Fred L.; Raj Pradhan, Nawa; Downer, Charles W.; Zahner, Jon A.

2011-12-01

The literature contains contradictory conclusions regarding the relative effects of urbanization on peak flood flows due to increases in impervious area, drainage density and width function, and the addition of subsurface storm drains. We used data from an urbanized catchment, the 14.3 km2 Dead Run watershed near Baltimore, Maryland, USA, and the physics-based gridded surface/subsurface hydrologic analysis (GSSHA) model to examine the relative effect of each of these factors on flood peaks, runoff volumes, and runoff production efficiencies. GSSHA was used because the model explicitly includes the spatial variability of land-surface and hydrodynamic parameters, including subsurface storm drains. Results indicate that increases in drainage density, particularly increases in density from low values, produce significant increases in the flood peaks. For a fixed land-use and rainfall input, the flood magnitude approaches an upper limit regardless of the increase in the channel drainage density. Changes in imperviousness can have a significant effect on flood peaks for both moderately extreme and extreme storms. For an extreme rainfall event with a recurrence interval in excess of 100 years, imperviousness is relatively unimportant in terms of runoff efficiency and volume, but can affect the peak flow depending on rainfall rate. Changes to the width function affect flood peaks much more than runoff efficiency, primarily in the case of lower density drainage networks with less impermeable area. Storm drains increase flood peaks, but are overwhelmed during extreme rainfall events when they have a negligible effect. Runoff in urbanized watersheds with considerable impervious area shows a marked sensitivity to rainfall rate. This sensitivity explains some of the contradictory findings in the literature.

A simple metric to predict stream water quality from storm runoff in an urban watershed.

PubMed

Easton, Zachary M; Sullivan, Patrick J; Walter, M Todd; Fuka, Daniel R; Petrovic, A Martin; Steenhuis, Tammo S

2010-01-01

The contribution of runoff from various land uses to stream channels in a watershed is often speculated and used to underpin many model predictions. However, these contributions, often based on little or no measurements in the watershed, fail to appropriately consider the influence of the hydrologic location of a particular landscape unit in relation to the stream network. A simple model was developed to predict storm runoff and the phosphorus (P) status of a perennial stream in an urban watershed in New York State using the covariance structure of runoff from different landscape units in the watershed to predict runoff in time. One hundred and twenty-seven storm events were divided into parameterization (n = 85) and forecasting (n = 42) data sets. Runoff, dissolved P (DP), and total P (TP) were measured at nine sites distributed among three land uses (high maintenance, unmaintained, wooded), three positions in the watershed (near the outlet, midwatershed, upper watershed), and in the stream at the watershed outlet. The autocorrelation among runoff and P concentrations from the watershed landscape units (n = 9) and the covariance between measurements from the landscape units and measurements from the stream were calculated and used to predict the stream response. Models, validated using leave-one-out cross-validation and a forecasting method, were able to correctly capture temporal trends in streamflow and stream P chemistry (Nash-Sutcliffe efficiencies, 0.49-0.88). The analysis suggests that the covariance structure was consistent for all models, indicating that the physical processes governing runoff and P loss from these landscape units were stationary in time and that landscapes located in hydraulically active areas have a direct hydraulic link to the stream. This methodology provides insight into the impact of various urban landscape units on stream water quantity and quality.

Mineral Adsorbents for Removal of Metals in Urban Runoff

NASA Astrophysics Data System (ADS)

Bjorklund, Karin; Li, Loretta

2014-05-01

The aim of this research was to determine the capacity of four different soil minerals to adsorb metals frequently detected in urban runoff. These are low-cost, natural and commercially available soil minerals. Contaminated surface runoff from urban areas is a major cause of concern for water quality and aquatic ecosystems worldwide. Pollution in urban areas is generated by a wide array of non-point sources, including vehicular transportation and building materials. Some of the most frequently detected pollutants in urban runoff are metals. Exhaust gases, tire wear and brake linings are major sources of such metals as Pb, Zn and Cu, while impregnated wood, plastics and galvanized surfaces may release As, Cd, Cr and Zn. Many metals have toxic effects on aquatic plants and animals, depending on metal speciation and bioavailability. The removal efficiency of pollutants in stormwater depends on treatment practices and on the properties the pollutant. The distribution of metals in urban runoff has shown, for example, that Pb is predominantly particle-associated, whereas Zn and Cd are present mainly in dissolved form. Many metals are also attached to colloids, which may act as carriers for contaminants, thereby facilitating their transport through conventional water treatment processes. Filtration of stormwater is one of the most promising techniques for removal of particulates, colloidal and truly dissolved pollutants, provided that effective filtration and adsorption media are used. Filtration and infiltration are used in a wide array of stormwater treatment methods e.g. porous paving, infiltration drains and rain gardens. Several soil minerals were investigated for their potential as stormwater filter materials. Laboratory batch tests were conducted to determine the adsorption capacity of these minerals. A synthetic stormwater was tested, with spiked concentrations corresponding to levels reported in urban runoff, ranging from 50-1,500 µg/L for Zn; 5-250 µg/L for Cu, 2-20 µg/L for Cd and 10-150 µg/L for Ni and Pb. Humic acids were used to imitate natural stormwater contaminated with natural organic matter. The adsorption kinetics was also investigated through a sequence (10-120 min) of batch tests. By studying the capacity of a range of sorbents in batch tests under identical conditions, the most promising sorbent can be identified. The research is ongoing. Preliminary results will be presented.

Preserving ecosystem services in urban regions: challenges for planning and best practice examples from Switzerland.

PubMed

Tobias, Silvia

2013-04-01

This article presents a literature review that explores the challenges for planning in urban regions in connection with the preservation of ecosystem services. It further presents some best practice examples for meeting these challenges. The demand for the provision of ecosystem services within urban regions changed during the transition from a largely agrarian society to an industrial society and, most recently, to a service society. Although in the past, provisioning services such as food production or the provision of raw material were decisive for urban development, today cultural services, e.g., clear views or nearby recreation areas, have become increasingly important. According to the literature, soil sealing is the greatest threat urbanization poses toward ecosystem services, as it compromises all of them. Spatially extensive cities with a high building density particularly inhibit regulating services like the regulation of temperature or water surface runoff. Conversely, scattered settlement patterns may lead to very small remnants of open space that cannot reasonably serve as natural habitat, agricultural land, or recreation area. The challenges for planning in urban regions are: 1) specifying regulations that define outer limits to the development of each settlement unit, 2) comprehensive planning with focal points for development, and limiting access and development at other places, and 3) compensating for new soil sealing by restoring nearby sealed areas. The article presents 3 best-practice examples that support these principles: designating areas with a particular soil quality that should not be built over, offering incentives for corporate planning in urban regions, and restoring a country road in connection with a motorway construction. Copyright © 2013 SETAC.

Preserving Ecosystem Services in Urban Regions: Challenges for Planning and Best Practice Examples from Switzerland

PubMed Central

Tobias, Silvia

2013-01-01

This article presents a literature review that explores the challenges for planning in urban regions in connection with the preservation of ecosystem services. It further presents some best practice examples for meeting these challenges. The demand for the provision of ecosystem services within urban regions changed during the transition from a largely agrarian society to an industrial society and, most recently, to a service society. Although in the past, provisioning services such as food production or the provision of raw material were decisive for urban development, today cultural services, e.g., clear views or nearby recreation areas, have become increasingly important. According to the literature, soil sealing is the greatest threat urbanization poses toward ecosystem services, as it compromises all of them. Spatially extensive cities with a high building density particularly inhibit regulating services like the regulation of temperature or water surface runoff. Conversely, scattered settlement patterns may lead to very small remnants of open space that cannot reasonably serve as natural habitat, agricultural land, or recreation area. The challenges for planning in urban regions are: 1) specifying regulations that define outer limits to the development of each settlement unit, 2) comprehensive planning with focal points for development, and limiting access and development at other places, and 3) compensating for new soil sealing by restoring nearby sealed areas. The article presents 3 best-practice examples that support these principles: designating areas with a particular soil quality that should not be built over, offering incentives for corporate planning in urban regions, and restoring a country road in connection with a motorway construction. Integr Environ Assess Manag 2013; 9: 243–251. © 2013 SETAC PMID:23307283

Surface Erosion Control Techniques on Newly Constructed Forest Roads

Treesearch

Johnny M. Grace; John Wilhoit; Robert Rummer; Bryce Stokes

1999-01-01

A newly constructed forest road was treated with three erosion control treatments: wood excelsior erosion mat, native grass species, and exotic grass species. The study evaluates treatment methods on the basis of sediment reduction and runoff volume reduction compared to no treatment. The erosion mat treatment was most effective in mitigating erosion losses with a 98...

High spatial-temporal resolution and integrated surface and subsurface precipitation-runoff modelling for a small stormwater catchment

NASA Astrophysics Data System (ADS)

Hailegeorgis, Teklu T.; Alfredsen, Knut

2018-02-01

Reliable runoff estimation is important for design of water infrastructure and flood risk management in urban catchments. We developed a spatially distributed Precipitation-Runoff (P-R) model that explicitly represents the land cover information, performs integrated modelling of surface and subsurface components of the urban precipitation water cycle and flow routing. We conducted parameter calibration and validation for a small (21.255 ha) stormwater catchment in Trondheim City during Summer-Autumn events and season, and snow-influenced Winter-Spring seasons at high spatial and temporal resolutions of respectively 5 m × 5 m grid size and 2 min. The calibration resulted in good performance measures (Nash-Sutcliffe efficiency, NSE = 0.65-0.94) and acceptable validation NSE for the seasonal and snow-influenced periods. The infiltration excess surface runoff dominates the peak flows while the contribution of subsurface flow to the sewer pipes also augments the peak flows. Based on the total volumes of simulated flow in sewer pipes (Qsim) and precipitation (P) during the calibration periods, the Qsim/P ranges from 21.44% for an event to 56.50% for the Winter-Spring season, which are in close agreement with the observed volumes (Qobs/P). The lowest percentage of precipitation volume that is transformed to the total simulated runoff in the catchment (QT) is 79.77%. Computation of evapotranspiration (ET) indicated that the ET/P is less than 3% for the events and snow-influenced seasons while it is about 18% for the Summer-Autumn season. The subsurface flow contribution to the sewer pipes are markedly higher than the total surface runoff volume for some events and the Summer-Autumn season. The peakiest flow rates correspond to the Winter-Spring season. Therefore, urban runoff simulation for design and management purposes should include two-way interactions between the subsurface runoff and flow in sewer pipes, and snow-influenced seasons. The developed urban P-R model is useful for better computation of runoff generated from different land cover, for assessments of stormwater management techniques (e.g. the Low Impact Development or LID) and the impacts of land cover and climate change. There are some simplifications or limitations such as the runoff routing does not involve detailed sewer hydraulics, effects of leakages from water supply systems and faulty/illegal connections from sanitary sewer are not considered, the model cannot identify actual locations of the interactions between the subsurface runoff and sewer pipes and lacks parsimony.

Urban snow indicates pollution originating from road traffic.

PubMed

Kuoppamäki, Kirsi; Setälä, Heikki; Rantalainen, Anna-Lea; Kotze, D Johan

2014-12-01

Traffic is a major source of pollutants in cities. In this well-replicated study we analysed a broad array of contaminants in snowpacks along roads of different traffic intensities. The majority of pollutants showed a similar pattern with respect to traffic intensity: pH and conductivity as well as concentrations of PAHs, total suspended solids, phosphorus and most heavy metals were higher next to high intensity roads compared to low intensity roads. These pollutant levels also decreased considerably up to 5 m distance from the roads. Furthermore, apart from nitrogen, these variables increased in concentration from control sites in urban forest patches to road bank sites next to roads of low, intermediate and high traffic intensities. The deposition pattern of various traffic-derived pollutants--whether gaseous or particle-bound--was the same. Such information can be useful for the purposes of managing pollutants in urban areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effects of de-icing in Helsinki urban streams, southern Finland.

PubMed

Ruth, O

2003-01-01

The environmental effects of road salt have been studied in Finland mainly in order to monitor and reduce groundwater contamination. In urban areas the road salt used for road maintenance in winter ends up in the storm water drains and receiving water bodies. We report here on water samples taken in 1998-1999 from three urban streams with catchments varying in area 1.7 to 24.4 km2 in different parts of the City of Helsinki. Despite efforts to reduce the amount of road salt, high concentrations were found in the urban stream water. Sudden variations in water quality were very marked during the spring flood period, with sodium and chloride concentrations varying over nine-fold within one day. Some 35-50% of the salt used on the roads in Helsinki passes into natural streams and from there into the sea. The significant positive correlation between NaCl and dissolved zinc in stream water was observed. The results show that it is important to monitor water quality, especially at the beginning of the spring flood period, when road salt and other contaminant levels are markedly high in urban streams.

Flood reduction as an ecosystem service of constructed wetlands for combined sewer overflow

NASA Astrophysics Data System (ADS)

Rizzo, A.; Bresciani, R.; Masi, F.; Boano, F.; Revelli, R.; Ridolfi, L.

2018-05-01

Urban runoff negatively impacts the receiving streams and different solutions have been proposed in literature to limit the effect of urbanization on the water balance. These solutions suggest to manage urban runoff in order to switch from a post-development river hydrograph (high peak and short duration) back again to a pre-development hydrograph (low peak and high duration). Combined sewer overflows (CSOs) represent severe pollutant sources for receiving streams due to the combination of first flush of roads and sewers and black water conveyed by combined sewer systems. Constructed wetlands for CSO treatment (CSO-CWs) are adopted with increasing frequency for reducing pollutant inputs to streams. Moreover, these systems exhibit the characteristic to behave similarly to ponds, wetlands, and bioretention systems that provide flood mitigation by decreasing the intensity of peak flows. This work aims to show the additional ecosystem service provided by CSO-CWs in term of limitation of the hydraulic impact of CSO on stream hydrograph. A mathematical model is developed to simulate the hydraulic behavior of a real case study situated in Gorla Maggiore (Italy), which includes vertical flow subsurface beds (VF) as first stage and a free water surface bed (FWS) as second stage. The model simulates the unsaturated flow within VF and the accumulation of water on the top of VF and within FWS. Results show a satisfactory lamination performance of the system for both single and up to 5 consecutive flood events, with a peak flow reduction ranging from 52.7% to 95.4%. Withdrawn of flow rate from the river in order to cope with long dry period does not significantly affect the lamination performances. The considered CSO-CW exhibits an excellent lamination efficiency also during more intense floods events, with a peak flow reduction of 86.2% for a CSO event with return period of 10 years. The flow rate frequency density function determined by the CSO-CW is more shifted towards lower values compared to untreated CSOs. These results indicate that CSO-CWs work properly in terms of reduction of CSO urbanization impact on stream hydrology.

Relationship between road traffic noisescape and urban form in Hong Kong.

PubMed

Lam, Kin-Che; Ma, Weichun; Chan, Pak Kin; Hui, Wing Chi; Chung, King Lam; Chung, Yi-tak Teresa; Wong, Chun Yin; Lin, Hui

2013-12-01

This paper reports on a study which explored the possible relationship between road traffic noisescape and urban form in Hong Kong. A total of 212 residential complexes from 11 contrasting urban forms were sampled, and their noise levels assessed both at dwelling and neighbourhood scales by noise mapping. Its findings indicate that residential complexes with different urban forms have significantly different noisescape attributes. There is a strong correlation between the noise characteristics and morphological indicators at the dwelling scale. A less obstreperous noisescape is associated with urban forms with lower road and building densities, and with building arrangements which provide self-noise screening. These findings suggest that urban form is an influential determinant of the noisescape in the urban environment, and they point to the need to rethink the conventional approach to managing the urban acoustic environment.

Impacts of urbanization on nitrogen cycling and aerosol, surface and groundwater transport in semi-arid regions

NASA Astrophysics Data System (ADS)

Lohse, K. A.; Gallo, E.; Carlson, M.; Riha, K. M.; Brooks, P. D.; McIntosh, J. C.; Sorooshian, A.; Michalski, G. M.; Meixner, T.

2011-12-01

Semi-arid regions are experiencing disproportionate increases in human population and land transformation worldwide, taxing limited water resources and altering nitrogen (N) biogeochemistry. How the redistribution of water and N by urbanization affects semi-arid ecosystems and downstream water quality (e.g. drinking water) is unclear. Understanding these interactions and their feedbacks will be critical for developing science-based management strategies to sustain these limited resources. This is especially true in the US where some of the fastest growing urban areas are in semi-arid ecosystems, where N and water cycles are accelerated, and intimately coupled, and where runoff from urban ecosystems is actively managed to augment a limited water supply to the growing human population. Here we synthesize several ongoing studies from the Tucson Basin in Arizona and examine how increasing urban land cover is altering rainfall-runoff relationships, groundwater recharge, water quality, and long range transport of atmospheric N. Studies across 5 catchments varying in impervious land cover showed that only the least impervious catchment responded to antecedent moisture conditions while hydrologic responses were not statistically related to antecedent rainfall conditions at more impervious sites. Regression models indicated that rainfall depth, imperviousness, and their combined effect control discharge and runoff ratios (p < 0.01, r2 = 0.91 and 0.75, respectively). In contrast, runoff quality was not predictably related to imperviousness or catchment size. Rather, rainfall depth and duration, time since antecedent rainfall, and stream channel characteristics and infrastructure controlled runoff chemistry. Groundwater studies showed nonpoint source contamination of CFCs and associated nitrate in areas of rapid recharge along ephemeral channels. Aerosol measurements indicate that both long-range transport of N and N emissions from Tucson are being transported and deposited at high elevation in areas that recharge regional groundwater. Combined, our findings suggest that urbanization in semi-arid regions results in tradeoffs in the redistribution of water and N that have important implications for water management and sustaining water quality.

Optimizing low impact development (LID) for stormwater runoff treatment in urban area, Korea: Experimental and modeling approach.

PubMed

Baek, Sang-Soo; Choi, Dong-Ho; Jung, Jae-Woon; Lee, Hyung-Jin; Lee, Hyuk; Yoon, Kwang-Sik; Cho, Kyung Hwa

2015-12-01

Currently, continued urbanization and development result in an increase of impervious areas and surface runoff including pollutants. Also one of the greatest issues in pollutant emissions is the first flush effect (FFE), which implies a greater discharge rate of pollutant mass in the early part in the storm. Low impact development (LID) practices have been mentioned as a promising strategy to control urban stormwater runoff and pollution in the urban ecosystem. However, this requires many experimental and modeling efforts to test LID characteristics and propose an adequate guideline for optimizing LID management. In this study, we propose a novel methodology to optimize the sizes of different types of LID by conducting intensive stormwater monitoring and numerical modeling in a commercial site in Korea. The methodology proposed optimizes LID size in an attempt to moderate FFE on a receiving waterbody. Thereby, the main objective of the optimization is to minimize mass first flush (MFF), which is an indicator for quantifying FFE. The optimal sizes of 6 different LIDs ranged from 1.2 mm to 3.0 mm in terms of runoff depths, which significantly moderate the FFE. We hope that the new proposed methodology can be instructive for establishing LID strategies to mitigate FFE. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of particle size distribution on the design of urban stormwater control measures

USGS Publications Warehouse

Selbig, William R.; Fienen, Michael N.; Horwatich, Judy A.; Bannerman, Roger T.

2016-01-01

An urban pollutant loading model was used to demonstrate how incorrect assumptions on the particle size distribution (PSD) in urban runoff can alter the design characteristics of stormwater control measures (SCMs) used to remove solids in stormwater. Field-measured PSD, although highly variable, is generally coarser than the widely-accepted PSD characterized by the Nationwide Urban Runoff Program (NURP). PSDs can be predicted based on environmental surrogate data. There were no appreciable differences in predicted PSD when grouped by season. Model simulations of a wet detention pond and catch basin showed a much smaller surface area is needed to achieve the same level of solids removal using the median value of field-measured PSD as compared to NURP PSD. Therefore, SCMs that used the NURP PSD in the design process could be unnecessarily oversized. The median of measured PSDs, although more site-specific than NURP PSDs, could still misrepresent the efficiency of an SCM because it may not adequately capture the variability of individual runoff events. Future pollutant loading models may account for this variability through regression with environmental surrogates, but until then, without proper site characterization, the adoption of a single PSD to represent all runoff conditions may result in SCMs that are under- or over-sized, rendering them ineffective or unnecessarily costly.

Evaluation of Green Infrastructure on Peak Flow Mitigation Focusing on the Connectivity of Impervious Areas

NASA Astrophysics Data System (ADS)

Seo, Y.; Hwang, J.; Kwon, Y.

2017-12-01

The existence of impervious areas is one of the most distinguishing characteristics of urban catchments. It decreases infiltration and increases direct runoff in urban catchments. The recent introduction of green infrastructure in urban catchments for the purpose of sustainable development contributes to the decrease of the directly connected impervious areas (DCIA) by isolating existing impervious areas and consequently, to the flood risk mitigation. This study coupled the width function-based instantaneous hydrograph (WFIUH), which is able to handle the spatial distribution of the impervious areas, with the concept of the DCIA to assess the impact of decreasing DCIA on the shape of direct runoff hydrographs. Using several scenarios for typical green infrastructure and corresponding changes of DCIA in a test catchment, this study evaluated the effect of green infrastructure on the shape of the resulting direct runoff hydrographs and peak flows. The results showed that the changes in the DCIA immediately affects the shape of the direct runoff hydrograph and decreases peak flows depending on spatial implementation scenarios. The quantitative assessment of the spatial distribution of impervious areas and also the changes to the DCIA suggests effective and well-planned green infrastructure can be introduced in urban environments for flood risk management.

Estimating spatially and temporally varying recharge and runoff from precipitation and urban irrigation in the Los Angeles Basin, California

USGS Publications Warehouse

Hevesi, Joseph A.; Johnson, Tyler D.

2016-10-17

A daily precipitation-runoff model, referred to as the Los Angeles Basin watershed model (LABWM), was used to estimate recharge and runoff for a 5,047 square kilometer study area that included the greater Los Angeles area and all surface-water drainages potentially contributing recharge to a 1,450 square kilometer groundwater-study area underlying the greater Los Angeles area, referred to as the Los Angeles groundwater-study area. The recharge estimates for the Los Angeles groundwater-study area included spatially distributed recharge in response to the infiltration of precipitation, runoff, and urban irrigation, as well as mountain-front recharge from surface-water drainages bordering the groundwater-study area. The recharge and runoff estimates incorporated a new method for estimating urban irrigation, consisting of residential and commercial landscape watering, based on land use and the percentage of pervious land area.The LABWM used a 201.17-meter gridded discretization of the study area to represent spatially distributed climate and watershed characteristics affecting the surface and shallow sub-surface hydrology for the Los Angeles groundwater study area. Climate data from a local network of 201 monitoring sites and published maps of 30-year-average monthly precipitation and maximum and minimum air temperature were used to develop the climate inputs for the LABWM. Published maps of land use, land cover, soils, vegetation, and surficial geology were used to represent the physical characteristics of the LABWM area. The LABWM was calibrated to available streamflow records at six streamflow-gaging stations.Model results for a 100-year target-simulation period, from water years 1915 through 2014, were used to quantify and evaluate the spatial and temporal variability of water-budget components, including evapotranspiration (ET), recharge, and runoff. The largest outflow of water from the LABWM was ET; the 100-year average ET rate of 362 millimeters per year (mm/yr) accounted for 66 percent of the combined water inflow of 551 mm/yr, including 488 mm/yr from precipitation and 63 mm/yr from urban irrigation. The simulated ET rate varied from a minimum of 0 mm/yr for impervious areas to high values of more than 1,000 mm/yr for many areas, including the south-facing slopes of the San Gabriel Mountains, stream channels underlain by permeable soils and thick root zones, and pervious locations receiving inflows both from urban irrigation and surface water. Runoff was the next largest outflow, averaging 145 mm/yr for the 100-year period, or 26 percent of the combined precipitation and urban-irrigation inflow. Recharge averaged 45 mm/yr, or about 8 percent of the combined inflow from precipitation and urban irrigation.Simulation results indicated that recharge in response to urban irrigation was an important component of spatially distributed recharge, contributing an average of 56 percent of the total recharge to the eight LABWM subdomains containing the Los Angeles groundwater study area. The 100‑year average recharge rate for the eight subdomains was 41 mm/yr, or 8,473 hectare-meters per year (ha-m/yr), with urban irrigation included in the simulation compared to a recharge rate of 18 mm/yr, or 3,741 ha-m/yr, with urban irrigation excluded. In contrast to recharge, the effect of urban irrigation on runoff was slight; runoff was 72,667 ha-m/yr with urban irrigation included compared to 72,618 ha-m/yr with urban irrigation excluded, an increase of only 48 ha-m/yr (about 0.1 percent).Simulation results also indicated that potential recharge from hilly drainages outside of, but bordering and tributary to, the lower-lying area of the Los Angeles groundwater study area, in this study referred to as mountain-front recharge, could provide an important contribution to the total recharge for the groundwater basins. The time-averaged recharge rate was similar to the combined direct and mountain-front recharge components estimated in a previous study and used as input for a calibrated groundwater model. The annual (water year) recharge estimates simulated in this study, however, indicated much greater year-to-year variability, which was dependent on year-to-year variability in the magnitude and distribution of daily precipitation, compared to the previous estimates.

Evaluation of an Infiltration Model with Microchannels

NASA Astrophysics Data System (ADS)

Garcia-Serrana, M.; Gulliver, J. S.; Nieber, J. L.

2015-12-01

This research goal is to develop and demonstrate the means by which roadside drainage ditches and filter strips can be assigned the appropriate volume reduction credits by infiltration. These vegetated surfaces convey stormwater, infiltrate runoff, and filter and/or settle solids, and are often placed along roads and other impermeable surfaces. Infiltration rates are typically calculated by assuming that water flows as sheet flow over the slope. However, for most intensities water flow occurs in narrow and shallow micro-channels and concentrates in depressions. This channelization reduces the fraction of the soil surface covered with the water coming from the road. The non-uniform distribution of water along a hillslope directly affects infiltration. First, laboratory and field experiments have been conducted to characterize the spatial pattern of flow for stormwater runoff entering onto the surface of a sloped surface in a drainage ditch. In the laboratory experiments different micro-topographies were tested over bare sandy loam soil: a smooth surface, and three and five parallel rills. All the surfaces experienced erosion; the initially smooth surface developed a system of channels over time that increased runoff generation. On average, the initially smooth surfaces infiltrated 10% more volume than the initially rilled surfaces. The field experiments were performed in the side slope of established roadside drainage ditches. Three rates of runoff from a road surface into the swale slope were tested, representing runoff from 1, 2, and 10-year storm events. The average percentage of input runoff water infiltrated in the 32 experiments was 67%, with a 21% standard deviation. Multiple measurements of saturated hydraulic conductivity were conducted to account for its spatial variability. Second, a rate-based coupled infiltration and overland model has been designed that calculates stormwater infiltration efficiency of swales. The Green-Ampt-Mein-Larson assumptions were implemented to calculate infiltration along with a kinematic wave model for overland flow that accounts for short-circuiting of flow. Additionally, a sensitivity analysis on the parameters implemented in the model has been performed. Finally, the field experiments results have been used to quantify the validity of the coupled model.

Time series models for prediction the total and dissolved heavy metals concentration in road runoff and soil solution of roadside embankments

NASA Astrophysics Data System (ADS)

Aljoumani, Basem; Kluge, Björn; sanchez, Josep; Wessolek, Gerd

2017-04-01

Highways and main roads are potential sources of contamination for the surrounding environment. High traffic rates result in elevated heavy metal concentrations in road runoff, soil and water seepage, which has attracted much attention in the recent past. Prediction of heavy metals transfer near the roadside into deeper soil layers are very important to prevent the groundwater pollution. This study was carried out on data of a number of lysimeters which were installed along the A115 highway (Germany) with a mean daily traffic of 90.000 vehicles per day. Three polyethylene (PE) lysimeters were installed at the A115 highway. They have the following dimensions: length 150 cm, width 100 cm, height 60 cm. The lysimeters were filled with different soil materials, which were recently used for embankment construction in Germany. With the obtained data, we will develop a time series analysis model to predict total and dissolved metal concentration in road runoff and in soil solution of the roadside embankments. The time series consisted of monthly measurements of heavy metals and was transformed to a stationary situation. Subsequently, the transformed data will be used to conduct analyses in the time domain in order to obtain the parameters of a seasonal autoregressive integrated moving average (ARIMA) model. Four phase approaches for identifying and fitting ARIMA models will be used: identification, parameter estimation, diagnostic checking, and forecasting. An automatic selection criterion, such as the Akaike information criterion, will use to enhance this flexible approach to model building

Urban stormwater capture curve using three-parameter mixed exponential probability density function and NRCS runoff curve number method.

PubMed

Kim, Sangdan; Han, Suhee

2010-01-01

Most related literature regarding designing urban non-point-source management systems assumes that precipitation event-depths follow the 1-parameter exponential probability density function to reduce the mathematical complexity of the derivation process. However, the method of expressing the rainfall is the most important factor for analyzing stormwater; thus, a better mathematical expression, which represents the probability distribution of rainfall depths, is suggested in this study. Also, the rainfall-runoff calculation procedure required for deriving a stormwater-capture curve is altered by the U.S. Natural Resources Conservation Service (Washington, D.C.) (NRCS) runoff curve number method to consider the nonlinearity of the rainfall-runoff relation and, at the same time, obtain a more verifiable and representative curve for design when applying it to urban drainage areas with complicated land-use characteristics, such as occurs in Korea. The result of developing the stormwater-capture curve from the rainfall data in Busan, Korea, confirms that the methodology suggested in this study provides a better solution than the pre-existing one.

Loading estimates of lead, copper, cadmium, and zinc in urban runoff from specific sources.

PubMed

Davis, A P; Shokouhian, M; Ni, S

2001-08-01

Urban stormwater runoff is being recognized as a substantial source of pollutants to receiving waters. A number of investigators have found significant levels of metals in runoff from urban areas, especially in highway runoff. As an initiatory study, this work estimates lead, copper, cadmium, and zinc loadings from various sources in a developed area utilizing information available in the literature, in conjunction with controlled experimental and sampling investigations. Specific sources examined include building siding and roofs; automobile brakes, tires, and oil leakage; and wet and dry atmospheric deposition. Important sources identified are building siding for all four metals, vehicle brake emissions for copper and tire wear for zinc. Atmospheric deposition is an important source for cadmium, copper, and lead. Loadings and source distributions depend on building and automobile density assumptions and the type of materials present in the area examined. Identified important sources are targeted for future comprehensive mechanistic studies. Improved information on the metal release and distributions from the specific sources, along with detailed characterization of watershed areas will allow refinements in the predictions.

2015/2016 Urban Waters Small Grants Request for Proposals

EPA Pesticide Factsheets

The 2015/2016 Urban Waters Small Grants Request for Proposals: Proposed projects will address urban runoff pollution through diverse partnerships that produce multiple community benefits, with emphasis on underserved communities.

Toward an operational tool to simulate green roof hydrological impact at the basin scale: a new version of the distributed rainfall-runoff model Multi-Hydro.

PubMed

Versini, Pierre-Antoine; Gires, Auguste; Tchinguirinskaia, Ioulia; Schertzer, Daniel

2016-10-01

Currently widespread in new urban projects, green roofs have shown a positive impact on urban runoff at the building scale: decrease and slow-down of the peak discharge, and decrease of runoff volume. The present work aims to study their possible impact at the catchment scale, more compatible with stormwater management issues. For this purpose, a specific module dedicated to simulating the hydrological behaviour of a green roof has been developed in the distributed rainfall-runoff model (Multi-Hydro). It has been applied on a French urban catchment where most of the building roofs are flat and assumed to accept the implementation of a green roof. Catchment responses to several rainfall events covering a wide range of meteorological situations have been simulated. The simulation results show green roofs can significantly reduce runoff volume and the magnitude of peak discharge (up to 80%) depending on the rainfall event and initial saturation of the substrate. Additional tests have been made to assess the susceptibility of this response regarding both spatial distributions of green roofs and precipitation. It appears that the total area of greened roofs is more important than their locations. On the other hand, peak discharge reduction seems to be clearly dependent on spatial distribution of precipitation.

δ(15)N and δ(18)O Reveal the Sources of Nitrate-Nitrogen in Urban Residential Stormwater Runoff.

PubMed

Yang, Yun-Ya; Toor, Gurpal S

2016-03-15

Nitrogen (N) sources are widely distributed in the complex urban environment. High-resolution data elucidating N sources in the residential catchments are not available. We used stable isotopes of N and oxygen (O) of nitrate (δ(18)O-NO3(-) and δ(15)N-NO3(-)) along with δ(18)O and hydrogen (δD) of water (H2O) to understand the sources and transformations of N in residential stormwater runoff. Stormwater runoff samples were collected over 25 stormwater events at 5 min intervals using an autosampler installed at the residential catchment outlet pipe that drained 31 low-density homes with a total drainage area of 0.11 km(2). Bayesian mixing model results indicated that atmospheric deposition (range 43-71%) and chemical N fertilizers (range <1-49%) were the dominant NO3-N sources in the stormwater runoff and that there was a continuum of source changes during the stormwater events. Further, the NO3-N transport in the stormwater runoff from the residential catchment was driven by mixing of multiple sources and biotic (i.e., nitrification) processes. This work suggests that a better understanding of N transport and sources is needed to reduce N export and improve water quality in urban water systems.

The U.S. Geological Survey and City of Atlanta water-quality and water-quantity monitoring network

USGS Publications Warehouse

Horowitz, Arthur J.; Hughes, W. Brian

2006-01-01

Population growth and urbanization affect the landscape, and the quality and quantity of water in nearby rivers and streams, as well as downstream receiving waters (Ellis, 1999). Typical impacts include: (1) disruption of the hydrologic cycle through increases in the extent of impervious surfaces (e.g., roads, roofs, sidewalks) that increase the velocity and volume of surface-water runoff; (2) increased chemical loads to local and downstream receiving waters from industrial sources, nonpoint-source runoff, leaking sewer systems, and sewer overflows; (3) direct or indirect soil contamination from industrial sources, power-generating facilities, and landfills; and (4) reduction in the quantity and quality of aquatic habitats. The City of Atlanta's monitoring network consists of 21 long-term sites. Eleven of these are 'fully instrumented' to provide real-time data on water temperature, pH, specific conductance, dissolved oxygen, turbidity (intended as a surrogate for suspended sediment concentration), water level (gage height, intended as a surrogate for discharge), and precipitation. Data are transmitted hourly and are available on a public Web site (http://ga.water.usgs.gov/). Two sites only measure water level and rainfall as an aid to stormwater monitoring. The eight remaining sites are used to assess water quality.

Trace element carriers in combined sewer during dry and wet weather: an electron microscope investigation.

PubMed

El Samrani, A G; Lartiges, B S; Ghanbaja, J; Yvon, J; Kohler, A

2004-04-01

The nature of trace element carriers contained in sewage and combined sewer overflow (CSO) was investigated by TEM-EDX-Electron diffraction and SEM-EDX. During dry weather, chalcophile elements were found to accumulate in sewer sediments as early diagenetic sulfide phases. The sulfurization of some metal alloys was also evidenced. Other heavy metal carriers detected in sewage include metal alloys, some iron oxihydroxide phases and neoformed phosphate minerals such as anapaite. During rain events, the detailed characterization of individual mineral species allowed to differentiate the contributions from various specific sources. Metal plating particles, barite from automobile brake, or rare earth oxides from catalytic exhaust pipes, originate from road runoff, whereas PbSn alloys and lead carbonates are attributed to zinc-works from roofs and paint from building siding. Soil contribution can be traced by the presence of clay minerals, iron oxihydroxides, zircons and rare earth phosphates. However, the most abundant heavy metal carriers in CSO samples were the sulfide particles eroded from sewer sediments. The evolution of relative abundances of trace element carriers during a single storm event, suggests that the pollution due to the "first flush" effect principally results from the sewer stock of sulfides and previously deposited metal alloys, rather than from urban surface runoff.

Urban Greening Bay Area

EPA Pesticide Factsheets

Information about the San Francisco Bay Water Quality Project (SFBWQP) Urban Greening Bay Area, a large-scale effort to re-envision urban landscapes to include green infrastructure (GI) making communities more livable and reducing stormwater runoff.

Nonpoint Source: Urban Areas

EPA Pesticide Factsheets

Urbanization increases the variety and amount of pollutants carried into our nation's waters. Pavement and compacted landscapes do not allow rain and snow melt to soak into the ground. List of typical pollutants from Urban runoff.

A multi-stakeholder framework for urban runoff quality management: Application of social choice and bargaining techniques.

PubMed

Ghodsi, Seyed Hamed; Kerachian, Reza; Zahmatkesh, Zahra

2016-04-15

In this paper, an integrated framework is proposed for urban runoff management. To control and improve runoff quality and quantity, Low Impact Development (LID) practices are utilized. In order to determine the LIDs' areas and locations, the Non-dominated Sorting Genetic Algorithm-II (NSGA-II), which considers three objective functions of minimizing runoff volume, runoff pollution and implementation cost of LIDs, is utilized. In this framework, the Storm Water Management Model (SWMM) is used for stream flow simulation. The non-dominated solutions provided by the NSGA-II are considered as management scenarios. To select the most preferred scenario, interactions among the main stakeholders in the study area with conflicting utilities are incorporated by utilizing bargaining models including a non-cooperative game, Nash model and social choice procedures of Borda count and approval voting. Moreover, a new social choice procedure, named pairwise voting method, is proposed and applied. Based on each conflict resolution approach, a scenario is identified as the ideal solution providing the LIDs' areas, locations and implementation cost. The proposed framework is applied for urban water quality and quantity management in the northern part of Tehran metropolitan city, Iran. Results show that the proposed pairwise voting method tends to select a scenario with a higher percentage of reduction in TSS (Total Suspended Solid) load and runoff volume, in comparison with the Borda count and approval voting methods. Besides, the Nash method presents a management scenario with the highest cost for LIDs' implementation and the maximum values for percentage of runoff volume reduction and TSS removal. The results also signify that selection of an appropriate management scenario by stakeholders in the study area depends on the available financial resources and the relative importance of runoff quality improvement in comparison with reducing the runoff volume. Copyright © 2016 Elsevier B.V. All rights reserved.

Performance of compost filtration practice for green infrastructure stormwater applications.

PubMed

Faucette, Britt; Cardoso, Fatima; Mulbry, Walter; Millner, Pat

2013-09-01

Urban storm water runoff poses a substantial threat of pollution to receiving surface waters. Green infrastructure, low impact development, green building ordinances, National Pollutant Discharge Elimination System (NPDES) storm water permit compliance, and Total Maximum Daily Load (TMDL) implementation strategies have become national priorities; however, designers need more sustainable, low-cost solutions to meet these goals and guidelines. The objective of this study was to determine the multiple-event removal efficiency and capacity of compost filter socks (FS) and filter socks with natural sorbents (NS) to remove soluble phosphorus, ammonium-nitrogen, nitrate-nitrogen, E. coli, Enterococcus, and oil from urban storm water runoff. Treatments were exposed to simulated storm water pollutant concentrations consistent with urban runoff originating from impervious surfaces, such as parking lots and roadways. Treatments were exposed to a maximum of 25 runoff events, or when removal efficiencies were < or = 25%, whichever occurred first. Experiments were conducted in triplicate. The filter socks with natural sorbents removed significantly greater soluble phosphorus than the filter socks alone, removing a total of 237 mg/linear m over eight runoff events, or an average of 34%. The filter socks with natural sorbents removed 54% of ammonium-nitrogen over 25 runoff events, or 533 mg/linear m, and only 11% of nitrate-nitrogen, or 228 mg/linear m. The filter socks and filter socks with natural sorbents both removed 99% of oil over 25 runoff events, or a total load of 38,486 mg/linear m. Over 25 runoff events the filter socks with natural sorbents removed E. coli and Enteroccocus at 85% and 65%, or a total load of 3.14 CFUs x 10(8)/ linear m and 1.5 CFUs x 10(9)/linear m, respectively; both were significantly greater than treatment by filter socks alone. Based on these experiments, this technique can be used to reduce soluble pollutants from storm water over multiple runoff events.

Regression Techniques for Determining the Effective Impervious Area in Southern California Watersheds

NASA Astrophysics Data System (ADS)

Sultana, R.; Mroczek, M.; Dallman, S.; Sengupta, A.; Stein, E. D.

2016-12-01

The portion of the Total Impervious Area (TIA) that is hydraulically connected to the storm drainage network is called the Effective Impervious Area (EIA). The remaining fraction of impervious area, called the non-effective impervious area, drains onto pervious surfaces which do not contribute to runoff for smaller events. Using the TIA instead of EIA in models and calculations can lead to overestimates of runoff volumes peak discharges and oversizing of drainage system since it is assumed all impervious areas produce urban runoff that is directly connected to storm drains. This makes EIA a better predictor of actual runoff from urban catchments for hydraulic design of storm drain systems and modeling non-point source pollution. Compared to TIA, determining the EIA is considerably more difficult to calculate since it cannot be found by using remote sensing techniques, readily available EIA datasets, or aerial imagery interpretation alone. For this study, EIA percentages were calculated by two successive regression methods for five watersheds (with areas of 8.38 - 158mi2) located in Southern California using rainfall-runoff event data for the years 2004 - 2007. Runoff generated from the smaller storm events are considered to be emanating only from the effective impervious areas. Therefore, larger events that were considered to have runoff from both impervious and pervious surfaces were successively removed in the regression methods using a criterion of (1) 1mm and (2) a max (2 , 1mm) above the regression line. MSE is calculated from actual runoff and runoff predicted by the regression. Analysis of standard deviations showed that criterion of max (2 , 1mm) better fit the regression line and is the preferred method in predicting the EIA percentage. The estimated EIAs have shown to be approximately 78% to 43% of the TIA which shows use of EIA instead of TIA can have significant impact on the cost building urban hydraulic systems and stormwater capture devices.

Main Road Extraction from ZY-3 Grayscale Imagery Based on Directional Mathematical Morphology and VGI Prior Knowledge in Urban Areas

PubMed Central

Liu, Bo; Wu, Huayi; Wang, Yandong; Liu, Wenming

2015-01-01

Main road features extracted from remotely sensed imagery play an important role in many civilian and military applications, such as updating Geographic Information System (GIS) databases, urban structure analysis, spatial data matching and road navigation. Current methods for road feature extraction from high-resolution imagery are typically based on threshold value segmentation. It is difficult however, to completely separate road features from the background. We present a new method for extracting main roads from high-resolution grayscale imagery based on directional mathematical morphology and prior knowledge obtained from the Volunteered Geographic Information found in the OpenStreetMap. The two salient steps in this strategy are: (1) using directional mathematical morphology to enhance the contrast between roads and non-roads; (2) using OpenStreetMap roads as prior knowledge to segment the remotely sensed imagery. Experiments were conducted on two ZiYuan-3 images and one QuickBird high-resolution grayscale image to compare our proposed method to other commonly used techniques for road feature extraction. The results demonstrated the validity and better performance of the proposed method for urban main road feature extraction. PMID:26397832

Safety analysis of urban arterials at the meso level.

PubMed

Li, Jia; Wang, Xuesong

2017-11-01

Urban arterials form the main structure of street networks. They typically have multiple lanes, high traffic volume, and high crash frequency. Classical crash prediction models investigate the relationship between arterial characteristics and traffic safety by treating road segments and intersections as isolated units. This micro-level analysis does not work when examining urban arterial crashes because signal spacing is typically short for urban arterials, and there are interactions between intersections and road segments that classical models do not accommodate. Signal spacing also has safety effects on both intersections and road segments that classical models cannot fully account for because they allocate crashes separately to intersections and road segments. In addition, classical models do not consider the impact on arterial safety of the immediately surrounding street network pattern. This study proposes a new modeling methodology that will offer an integrated treatment of intersections and road segments by combining signalized intersections and their adjacent road segments into a single unit based on road geometric design characteristics and operational conditions. These are called meso-level units because they offer an analytical approach between micro and macro. The safety effects of signal spacing and street network pattern were estimated for this study based on 118 meso-level units obtained from 21 urban arterials in Shanghai, and were examined using CAR (conditional auto regressive) models that corrected for spatial correlation among the units within individual arterials. Results showed shorter arterial signal spacing was associated with higher total and PDO (property damage only) crashes, while arterials with a greater number of parallel roads were associated with lower total, PDO, and injury crashes. The findings from this study can be used in the traffic safety planning, design, and management of urban arterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Installation of stormwater management and treatment demonstration facility.

DOT National Transportation Integrated Search

2013-06-01

Roadway runoff contributes large amounts of suspended solids/sediment, heavy metals, petroleum : hydrocarbons, deicing chemicals, bacteria and other constituents to receiving waterways. The EPA : National Urban Runoff Program (NURP) indicated that le...

Quantitative analysis on the urban flood mitigation effect by the extensive green roof system.

PubMed

Lee, J Y; Moon, H J; Kim, T I; Kim, H W; Han, M Y

2013-10-01

Extensive green-roof systems are expected to have a synergetic effect in mitigating urban runoff, decreasing temperature and supplying water to a building. Mitigation of runoff through rainwater retention requires the effective design of a green-roof catchment. This study identified how to improve building runoff mitigation through quantitative analysis of an extensive green-roof system. Quantitative analysis of green-roof runoff characteristics indicated that the extensive green roof has a high water-retaining capacity response to rainfall of less than 20 mm/h. As the rainfall intensity increased, the water-retaining capacity decreased. The catchment efficiency of an extensive green roof ranged from 0.44 to 0.52, indicating reduced runoff comparing with efficiency of 0.9 for a concrete roof. Therefore, extensive green roofs are an effective storm water best-management practice and the proposed parameters can be applied to an algorithm for rainwater-harvesting tank design. © 2013 Elsevier Ltd. All rights reserved.

An investigation of wash-off controlling parameters at urban and commercial monitoring sites.

PubMed

Berretta, C; Gnecco, I; Lanza, L G; La Barbera, P

2007-01-01

The relationship between the parameters of the wash-off function and the controlling hydrologic variables are investigated in this paper, assuming that the pollutant generation process basically depends on the watershed rainfall-runoff response characteristics. Data collected during an intense monitoring program carried out by the Department of Environmental Engineering of the University of Genova (Italy) within a residential area, an auto dismantler facility, a tourism terminal and a urban waste truck depot are used to this aim. The observed runoff events are classified into different TSS mass delivery processes and the occurrence of the first flush phenomenon is also investigated. The correlation between the mathematical parameters describing the exponential process and the hydrological parameters of the corresponding rainfall-runoff event is analysed: runoff parameters and in particular the maximum flow discharge over the time of concentration of the drainage network are proposed as the controlling factor for the total mass of pollutant that is made available for wash-off during each runoff event.

Cluster categorization of urban roads to optimize their noise monitoring.

PubMed

Zambon, G; Benocci, R; Brambilla, G

2016-01-01

Road traffic in urban areas is recognized to be associated with urban mobility and public health, and it is often the main source of noise pollution. Lately, noise maps have been considered a powerful tool to estimate the population exposure to environmental noise, but they need to be validated by measured noise data. The project Dynamic Acoustic Mapping (DYNAMAP), co-funded in the framework of the LIFE 2013 program, is aimed to develop a statistically based method to optimize the choice and the number of monitoring sites and to automate the noise mapping update using the data retrieved from a low-cost monitoring network. Indeed, the first objective should improve the spatial sampling based on the legislative road classification, as this classification is mainly based on the geometrical characteristics of the road, rather than its noise emission. The present paper describes the statistical approach of the methodology under development and the results of its preliminary application to a limited sample of roads in the city of Milan. The resulting categorization of roads, based on clustering the 24-h hourly L Aeqh, looks promising to optimize the spatial sampling of noise monitoring toward a description of the noise pollution due to complex urban road networks more efficient than that based on the legislative road classification.

Prevalence and regional correlates of road traffic injury among Chinese urban residents: A 21-city population-based study.

PubMed

Rockett, Ian R H; Jiang, Shuhan; Yang, Qian; Yang, Tingzhong; Yang, Xiaozhao Y; Peng, Sihui; Yu, Lingwei

2017-08-18

This study estimated the prevalence of road traffic injury among Chinese urban residents and examined individual and regional-level correlates. A cross-sectional multistage process was used to sample residents from 21 selected cities in China. Survey respondents reported their history of road traffic injury in the past 12 months through a community survey. Multilevel, multivariable logistic regression analysis was used to identify injury correlates. Based on a retrospective 12-month reporting window, road traffic injury prevalence among urban residents was 13.2%. Prevalence of road traffic injury, by type, was 8.7, 8.7, 8.5, and 7.7% in the automobile, bicycle, motorcycle, and pedestrian categories, respectively. Multilevel analysis showed that prevalence of road traffic injury was positively associated with minority status, income, and mental health disorder score at the individual level. Regionally, road traffic injury was associated with geographic location of residence and prevalence of mental health disorders. Both individual and regional-level variables were associated with road traffic injury among Chinese urban residents, a finding whose implications transcend wholesale imported generic solutions. This descriptive research demonstrates an urgent need for longitudinal studies across China on risk and protective factors, in order to inform injury etiology, surveillance, prevention, treatment, and evaluation.

The Evaluation of Screening Process and Local Bureaucracy in Determining the Priority of Urban Roads Maintenance and Rehabilitation

NASA Astrophysics Data System (ADS)

Hendhratmoyo, Andri; Syafi'i; Pungky Pramesti, Florentina

2017-11-01

Due to the limited budget of urban roads maintenance and rehabilitation, its prioritizationis inevitable. Many models have been developed to solve these problems. That is the reason why the purpose of this study was to evaluate the screening process in the decision making of the urban roads maintenance and rehabilitation priority. The prioritization that have to be taken into account on the effect of important criteria are road condition, traffic volume, budget processing and land use. 30 stakeholders were asked to fill in the questionnaires. The object of this case study are 188 urban roads sections at Ponorogo in order to examine the priorities. The researchers collected the data from Surface Distress Index (SDI), traffic volume, budget processing and land use of these road sections. Based on analysis, the weights of the criteria were: road condition (W1) = 0,411; traffic volume (W2) = 0,122; budget processing (W3) = 0,363 and land use (W4) = 0,105. The result of this study by the comparison of the index values of the alternatives priorities, Nyi Ageng Serang Street, was revealed to have the highest priority over the other streets regarding of maintenance and rehabilitation activities.

Effects of roads and well pads on erosion in the Largo Canyon watershed, New Mexico, 2001-02

USGS Publications Warehouse

Matherne, Anne Marie

2006-01-01

Largo Canyon, located in the San Juan Basin of northwestern New Mexico, is one of the longest dry washes in the world. Oil and gas production in the San Juan Basin, which began in the 1940's, required the development of an extensive network of dirt roads to service the oil and gas wells in the Navajo Reservoir area. Presently, there are about eight wells per square mile, and the density of oil and gas wells is expected to increase. Potential environmental effects on landscape stability that may result from the additional roads and well pads have not been documented. In 2001, the U.S. Geological Survey began a study in cooperation with the Bureau of Land Management to evaluate the effects of roads and well pads associated with oil and gas operations on the erosion potential of Bureau of Land Management lands in the Largo Canyon watershed. The effects of roads and well pads on erosion were quantified by installing sediment dams (dams) and by surveying transects across roads and well pads. Data from 26 dams were used in the analysis. Dams were installed at 43 sites: 21 on hillsides upslope from roads or pads to measure erosion from hillslopes, 11 at the downslope edges of roads to measure erosion from roads, and 11 at the downslope edges of well pads to measure erosion from well pads. Pairs of survey transects were established at nine well pads and two road locations. Sediment-accumulation data for 26 dams, recorded at 17 measurement intervals, indicate that average erosion rates at the dams significantly correlate to size of the contributing area. The average erosion rate normalized by drainage area was 0.001 foot per year below roads, 0.003 foot per year on hillslopes, and 0.011 foot per year below well pads. Results of a two-sample t-test indicate that there was no significant difference in average erosion rates for dams located on hillslopes and below roads, whereas average erosion rates were significantly greater for dams below well pads than for dams on hillslopes and dams below roads. The average erosion rates estimated from the data collected during this study most likely represent minimum erosion rates. Sediment-accumulation data for measurement intervals and for dams that were breached during 2002, resulting from the large volume of runoff generated by high-intensity storms, were not used to compute erosion rates. For this reason, the higher range of erosion rates is underrepresented and the results of this study are biased toward the lower end of the range of erosion rates. Measurements along road transects generally indicate that sediment is eroded from the top of road berms and redeposited at the base of the berms and may be transported downslope along the road. Measurements along well-pad transects generally indicate that sediment eroded from hillslopes is transported over the surface of the well pad and down the well-pad edges. Based on field observations, roads aligned parallel to topographic contours facilitate erosional processes in two ways: (1) roads cut across and collect runoff from previously established drainages and (2) roads, where they are cut into hillsides or into the land surface, provide focal points for the initiation of erosion. Roads aligned across topographic contours can serve as conduits to channel runoff but do not constitute a large percentage of the road network.

A comparative study of health risk of potentially toxic metals in urban and suburban road dust in the most populated city of China

NASA Astrophysics Data System (ADS)

Shi, Guitao; Chen, Zhenlou; Bi, Chunjuan; Wang, Li; Teng, Jiyan; Li, Yuansheng; Xu, Shiyuan

2011-01-01

Urban and suburban road dust samples were collected in the most populated city of China, Shanghai. Size fractions of dust particles were analyzed; metal levels of the dust were also measured. Human exposure to individual toxic metals through road dust was assessed for both children and adults. The results showed that dust particles from urban and suburban road were presented similar size distribution pattern, with most particles in the range of 100-400 μm. Urban road dust consisted of higher proportions of inhalable, thoracic and respirable particles with increased risk of adverse effects to human. In general, mean grain sizes of urban road dust were smaller than suburban dust. Total organic carbon contents and levels of Pb, Cd, Cu, Zn, Ni, Cr in urban dust were higher than those of suburban dust. But the concentrations of As and Hg from suburban dust were higher, indicting a different main source. The exposure pathway which resulted in the highest level of risk for human exposed to road dust was ingestion of this material, which was followed by dermal contact. Except for some locations, risk values of both cancer and non-cancer obtained in this study were in the receivable range on the whole. Children had greater health risks than adults. The overall risks of non-cancer in urban area were higher than those in suburban area, but the values of cancer in the two areas were comparable. As for the aggregate noncarcinogenic risk, Pb was of most concern regarding the potential occurrence of health impacts. Of the three carcinogenic metals As, Cr and Cd, the only mean risk higher than 10 -6 was Cr, accounting for a great percentage (95%) of the overall risk of cancer. Hence, potentially adverse health effects arising from Pb and Cr in road dust should arouse wide concern.

Spatial and temporal variations in toxicity in a marsh receiving urban runoff

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katznelson, R.; Jewell, W.T.; Anderson, S.L.

1993-06-01

This project is composed of two sections. The first section describes dry weather toxicity surveys to evaluate the distribution of toxicity in the waters of San Francisco Bay and adjacent wetland habitat, and the second is a series of wet weather toxicity studies with emphasis on a marsh receiving urban runoff. The dry weather studies are reported in the appendices, while the wet weather work comprises the main report.

Comparison of sediments and organisms in identifying sources of biologically available trace metal contamination

USGS Publications Warehouse

Thomson, E.A.; Luoma, S.N.; Johansson, C.E.; Cain, D.J.

1984-01-01

Sediments and an indicator organism (Macoma balthica, a deposit-feeding bivalve) were used to assess the relative importance of secondary sewage, urban runoff, a landfill containing metal-enriched ash wastes and a yacht harbor in contributing to Ag, Cu and Zn enrichment in South San Francisco Bay. Spatial gradients in sediments and organisms showed Cu and Ag enrichment originated from sewage discharge, whereas Zn enrichment originated from both sewage and urban runoff. Elevated concentrations of Cu in the sediments of the yacht harbor resulted from a high abundance of fine particles. The biological availability of Cu, Ag and Zn did not coincide with metal enrichment in sediments. The availability of Cu and Ag was greatest nearest the sewage outfall and greater in winter and spring than in summer. The availability of Zn in urban runoff appeared to be lower than the availability of Zn associated with sewage.

Evaluation of statistical distributions to analyze the pollution of Cd and Pb in urban runoff.

PubMed

Toranjian, Amin; Marofi, Safar

2017-05-01

Heavy metal pollution in urban runoff causes severe environmental damage. Identification of these pollutants and their statistical analysis is necessary to provide management guidelines. In this study, 45 continuous probability distribution functions were selected to fit the Cd and Pb data in the runoff events of an urban area during October 2014-May 2015. The sampling was conducted from the outlet of the city basin during seven precipitation events. For evaluation and ranking of the functions, we used the goodness of fit Kolmogorov-Smirnov and Anderson-Darling tests. The results of Cd analysis showed that Hyperbolic Secant, Wakeby and Log-Pearson 3 are suitable for frequency analysis of the event mean concentration (EMC), the instantaneous concentration series (ICS) and instantaneous concentration of each event (ICEE), respectively. In addition, the LP3, Wakeby and Generalized Extreme Value functions were chosen for the EMC, ICS and ICEE related to Pb contamination.

Rainfall-Runoff Simulations to Assess the Potential of SuDS for Mitigating Flooding in Highly Urbanized Catchments.

PubMed

Jato-Espino, Daniel; Charlesworth, Susanne M; Bayon, Joseba R; Warwick, Frank

2016-01-21

Sustainable Urban Drainage Systems (SuDS) constitute an alternative to conventional drainage when managing stormwater in cities, reducing the impact of urbanization by decreasing the amount of runoff generated by a rainfall event. This paper shows the potential benefits of installing different types of SuDS in preventing flooding in comparison with the common urban drainage strategies consisting of sewer networks of manholes and pipes. The impact of these systems on urban water was studied using Geographic Information Systems (GIS), which are useful tools when both delineating catchments and parameterizing the elements that define a stormwater drainage system. Taking these GIS-based data as inputs, a series of rainfall-runoff simulations were run in a real catchment located in the city of Donostia (Northern Spain) using stormwater computer models, in order to compare the flow rates and depths produced by a design storm before and after installing SuDS. The proposed methodology overcomes the lack of precision found in former GIS-based stormwater approaches when dealing with the modeling of highly urbanized catchments, while the results demonstrated the usefulness of these systems in reducing the volume of water generated after a rainfall event and their ability to prevent localized flooding and surcharges along the sewer network.

Rainfall–Runoff Simulations to Assess the Potential of SuDS for Mitigating Flooding in Highly Urbanized Catchments

PubMed Central

Jato-Espino, Daniel; Charlesworth, Susanne M.; Bayon, Joseba R.; Warwick, Frank

2016-01-01

Sustainable Urban Drainage Systems (SuDS) constitute an alternative to conventional drainage when managing stormwater in cities, reducing the impact of urbanization by decreasing the amount of runoff generated by a rainfall event. This paper shows the potential benefits of installing different types of SuDS in preventing flooding in comparison with the common urban drainage strategies consisting of sewer networks of manholes and pipes. The impact of these systems on urban water was studied using Geographic Information Systems (GIS), which are useful tools when both delineating catchments and parameterizing the elements that define a stormwater drainage system. Taking these GIS-based data as inputs, a series of rainfall–runoff simulations were run in a real catchment located in the city of Donostia (Northern Spain) using stormwater computer models, in order to compare the flow rates and depths produced by a design storm before and after installing SuDS. The proposed methodology overcomes the lack of precision found in former GIS-based stormwater approaches when dealing with the modeling of highly urbanized catchments, while the results demonstrated the usefulness of these systems in reducing the volume of water generated after a rainfall event and their ability to prevent localized flooding and surcharges along the sewer network. PMID:26805864

Indicators for Assessing Climate Change Resilience Resulting from Emplacement of Green Infrastructure Projects Across an Urban Landscape

NASA Astrophysics Data System (ADS)

Parish, E. S.; Omitaomu, O.; Sylvester, L.; Nugent, P.

2015-12-01

Many U.S. cities are exploring the potential of using green infrastructure (e.g., porous pavements, green roofs, street planters) to reduce urban storm water runoff, which can be both be a nuisance and costly to treat. While tools exist to measure local runoff changes resulting from individual green infrastructure (GI) projects, most municipalities currently have no method of analyzing the collective impact of GI projects on urban stormwater systems under future rainfall scenarios and impervious surface distribution patterns. Using the mid-sized city of Knoxville, Tennessee as a case study, we propose a set of indicators that can be used to monitor and analyze the collective effects of GI emplacement on urban storm water runoff volumes as well as to quantify potential co-benefits of GI projects (e.g., urban heat island reduction, reduced stream scouring) under different climate projection ensembles and population growth scenarios. These indicators are intended to help the city prioritize GI projects as opportunities arise, as well as to track the effectiveness of GI implementation over time. We explore the aggregation of these indicators across different spatial scales (e.g., plot, neighborhood, watershed, city) in order to assess potential changes in climate change resilience resulting from the collective implementation of GI projects across an urban landscape.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hale, Rebecca L.; Turnbull, Laura; Earl, Stevan

Urban watersheds are often sources of nitrogen (N) to downstream systems, contributing to poor water quality. However, it is unknown which components (e.g., land cover and stormwater infrastructure type) of urban watersheds contribute to N export and which may be sites of retention. In this study we investigated which watershed characteristics control N sourcing, biogeochemical processing of nitrate (NO3–) during storms, and the amount of rainfall N that is retained within urban watersheds. We used triple isotopes of NO3– (δ15N, δ18O, and Δ17O) to identify sources and transformations of NO3– during storms from 10 nested arid urban watersheds that variedmore » in stormwater infrastructure type and drainage area. Stormwater infrastructure and land cover—retention basins, pipes, and grass cover—dictated the sourcing of NO3– in runoff. Urban watersheds can be strong sinks or sources of N to stormwater depending on the proportion of rainfall that leaves the watershed as runoff, but we found no evidence that denitrification occurred during storms. Our results suggest that watershed characteristics control the sources and transport of inorganic N in urban stormwater but that retention of inorganic N at the timescale of individual runoff events is controlled by hydrologic, rather than biogeochemical, mechanisms.« less

Long-term stormwater quantity and quality analysis using continuous measurements in a French urban catchment.

PubMed

Sun, Siao; Barraud, Sylvie; Castebrunet, Hélène; Aubin, Jean-Baptiste; Marmonier, Pierre

2015-11-15

The assessment of urban stormwater quantity and quality is important for evaluating and controlling the impact of the stormwater to natural water and environment. This study mainly addresses long-term evolution of stormwater quantity and quality in a French urban catchment using continuous measured data from 2004 to 2011. Storm event-based data series are obtained (716 rainfall events and 521 runoff events are available) from measured continuous time series. The Mann-Kendall test is applied to these event-based data series for trend detection. A lack of trend is found in rainfall and an increasing trend in runoff is detected. As a result, an increasing trend is present in the runoff coefficient, likely due to growing imperviousness of the catchment caused by urbanization. The event mean concentration of the total suspended solid (TSS) in stormwater does not present a trend, whereas the event load of TSS has an increasing tendency, which is attributed to the increasing event runoff volume. Uncertainty analysis suggests that the major uncertainty in trend detection results lies in uncertainty due to available data. A lack of events due to missing data leads to dramatically increased uncertainty in trend detection results. In contrast, measurement uncertainty in time series data plays a trivial role. The intra-event distribution of TSS is studied based on both M(V) curves and pollutant concentrations of absolute runoff volumes. The trend detection test reveals no significant change in intra-event distributions of TSS in the studied catchment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Watershed and land use-based sources of trace metals in urban storm water.

PubMed

Tiefenthaler, Liesl L; Stein, Eric D; Schiff, Kenneth C

2008-02-01

Trace metal contributions in urban storm water are of concern to environmental managers because of their potential impacts on ambient receiving waters. The mechanisms and processes that influence temporal and spatial patterns of trace metal loading in urban storm water, however, are not well understood. The goals of the present study were to quantify trace metal event mean concentration (EMC), flux, and mass loading associated with storm water runoff from representative land uses; to compare EMC, flux, and mass loading associated with storm water runoff from urban (developed) and nonurban (undeveloped) watersheds; and to investigate within-storm and within-season factors that affect trace metal concentration and flux. To achieve these goals, trace metal concentrations were measured in 315 samples over 11 storm events in five southern California, USA, watersheds representing eight different land use types during the 2000 through 2005 storm seasons. In addition, 377 runoff samples were collected from 12 mass emission sites (end of watershed) during 15 different storm events. Mean flux at land use sites ranged from 24 to 1,238, 0.1 to 1,272, and 6 to 33,189 g/km(2) for total copper, total lead, and total zinc, respectively. Storm water runoff from industrial land use sites contained higher EMCs and generated greater flux of trace metals than other land use types. For all storms sampled, the highest metal concentrations occurred during the early phases of storm water runoff, with peak concentrations usually preceding peak flow. Early season storms produced significantly higher metal flux compared with late season storms at both mass emission and land use sites.

Using recorded sound spectra profile as input data for real-time short-term urban road-traffic-flow estimation.

PubMed

Torija, Antonio J; Ruiz, Diego P

2012-10-01

Road traffic has a heavy impact on the urban sound environment, constituting the main source of noise and widely dominating its spectral composition. In this context, our research investigates the use of recorded sound spectra as input data for the development of real-time short-term road traffic flow estimation models. For this, a series of models based on the use of Multilayer Perceptron Neural Networks, multiple linear regression, and the Fisher linear discriminant were implemented to estimate road traffic flow as well as to classify it according to the composition of heavy vehicles and motorcycles/mopeds. In view of the results, the use of the 50-400 Hz and 1-2.5 kHz frequency ranges as input variables in multilayer perceptron-based models successfully estimated urban road traffic flow with an average percentage of explained variance equal to 86%, while the classification of the urban road traffic flow gave an average success rate of 96.1%. Copyright © 2012 Elsevier B.V. All rights reserved.

Diurnal variation of on-road air pollution in an urban street canyon in Seoul

NASA Astrophysics Data System (ADS)

Ho, Woo, Sung; Lee, Seung-Bok; Kim, Kyung Hwan; Bae, Gwi-Nam; Sunwoo, Young; Ma, Young-Il; Han, Dokyoung; Song, Sanghoo

2014-05-01

Motor vehicles are a major source of CO, NOx and particulate matters. Especially, in the surroundings of high-raised buildings, so-called an urban street canyon, air pollution levels increase due to limited dispersion of vehicle emissions. In this study, a mobile laboratory was used to measure diurnal variation of on-road concentrations of air pollutants such as NOx, particle-bound polycyclic aromatic hydrocarbons, black carbon and particle number in the urban street canyon on the Teheran road with eight lanes in Seoul, Korea from 5th to 8th November 2013. Each traveling distance was about 3.3km. Traveling vehicle at the middle of the Teheran road was recorded by video camera, and then the car counting by vehicle types. On road measurements conducted for 3~6 hours per day. Hourly average of air pollutant concentration in morning rush hour more than two times higher than those at the daybreak. We will analyze the correlation between air pollution levels and traffic volume by vehicle types. We will discuss about spatial characteristics of on-road air pollution levels in the urban street canyon.

Spatial variability of characteristics and origins of urban wet weather pollution in combined sewers.

PubMed

Kafi-Benyahia, M; Gromaire, M G; Chebbo, G

2005-01-01

An experimental on-site observatory of urban pollutant loads in combined sewers was created in the centre of Paris to quantify and characterise the dry and wet weather flow in relation to spatial scale. Eight rainfall events were studied from April 2003 to May 2004. Samples were analysed for suspended solids, organic matter, nitrogen and heavy metals. Results confirm the extent of wet weather pollution. They have shown the relative homogeneity of SS and organic matter characteristics from one urban catchment area to another. Two groups of heavy metals were identified. The first one concerns Cu, which has a higher concentration in wet weather flow (WWF) than in dry weather flow (DWF), and runoff. The second includes Cd, Pb and Zn, where higher concentrations were measured in urban runoff than in WWF and DWF. A first evaluation of contribution of wastewater, urban runoff and sewer deposit erosion sources to wet weather pollution was established and has highlighted the contribution of wastewater and sewer deposits to this pollution. However, it has shown that sewer deposit erosion remains an important source of wet weather pollution at different spatial scales.

Analysis of the influence of rainfall variables on urban effluents concentrations and fluxes in wet weather

NASA Astrophysics Data System (ADS)

Gooré Bi, Eustache; Monette, Frédéric; Gasperi, Johnny

2015-04-01

Urban rainfall runoff has been a topic of increasing importance over the past years, a result of both the increase in impervious land area arising from constant urban growth and the effects of climate change on urban drainage. The main goal of the present study is to assess and analyze the correlations between rainfall variables and common indicators of urban water quality, namely event mean concentrations (EMCs) and event fluxes (EFs), in order to identify and explain the impacts of each of the main rainfall variables on the generation process of urban pollutants during wet periods. To perform this analysis, runoff from eight summer rainfall events that resulted in combined sewer overflow (CSO) was sampled simultaneously from two distinct catchment areas in order to quantify discharges at the respective outfalls. Pearson statistical analysis of total suspended solids (TSS), chemical oxygen demand (COD), carbonaceous biochemical oxygen demand at 5 days (CBOD5), total phosphorus (Ptot) and total kedjal nitrogen (N-TKN) showed significant correlations (ρ = 0.05) between dry antecedent time (DAT) and EMCs on one hand, and between total rainfall (TR) and the volume discharged (VD) during EFs, on the other. These results show that individual rainfall variables strongly affect either EMCs or EFs and are good predictors to consider when selecting variables for statistical modeling of urban runoff quality. The results also show that in a combined sewer network, there is a linear relationship between TSS event fluxes and COD, CBOD5, Ptot, and N-TKN event fluxes; this explains 97% of the variability of these pollutants which adsorb onto TSS during wet weather, which therefore act as tracers. Consequently, the technological solution selected for TSS removal will also lead to a reduction of these pollutants. Given the huge volumes involved, urban runoffs contribute substantially to pollutant levels in receiving water bodies, a situation which, in a climate change context, may get much worse as a result of more frequent, shorter, but more intense rainfall events.

Distribution and sources of polychlorinated biphenyls in Woods Inlet, Lake Worth, Fort Worth, Texas, 2003

USGS Publications Warehouse

Besse, Richard E.; Van Metre, Peter C.; Wilson, Jennifer T.

2005-01-01

Woods Inlet is a flooded stream channel on the southern shore of Lake Worth along the western boundary of Air Force Plant 4 in Fort Worth, Texas, where elevated polychlorinated biphenyl (PCB) concentrations in sediment were detected in a previous study. In response, the U.S. Geological Survey, in cooperation with the U.S. Air Force, conducted a study in 2003 to map the extent of elevated PCB concentrations in Woods Inlet and to identify possible sources (or more specifically, source areas) of PCBs in the watershed of Woods Inlet. Three gravity cores (penetration to pre-reservoir sediment at three sites) and 17 box cores (surficial bottom sediment samples) were collected in Woods Inlet. Suspended sediment in stormwater runoff and streambed sediment were sampled in tributaries to Woods Inlet following storms. Assemblages of PCB congeners in surficial inlet sediments and suspended and streambed sediments were analyzed to indicate sources of PCBs in the inlet sediments on the basis of chemical signatures of PCBs. Woods Inlet receives runoff primarily from three tributaries: (1) Gruggs Park Creek, (2) the small unnamed creek that drains a Texas National Guard maintenance facility, called TNG Creek for this report, and (3) Meandering Road Creek. Twenty-seven of 209 possible PCB congeners were analyzed. The sum of the congeners was used as a measure of total PCB. The spatial distribution of total PCB concentrations in the inlet indicates that most PCBs are originating in the Meandering Road Creek watershed. Peak total PCB concentrations in the three gravity cores occurred at depths corresponding to sediment deposition dates of about 1960 for two of the cores and about 1980 for the third core. The magnitudes of peak total PCB concentrations in the gravity cores followed a spatial distribution generally similar to that of surficial bottom sediment concentrations. Total PCB concentrations in suspended and streambed sediment varied greatly between sites and indicated a likely source of PCBs associated with a sampling site that receives runoff from Air Force Plant 4. Three approaches to the analyses of congener assemblages indicate that PCBs in surficial bottom sediment of Woods Inlet primarily enter Lake Worth from Meandering Road Creek and that runoff from Air Force Plant 4 is a source of the PCBs in Meandering Road Creek. Although current (2003) transport of PCBs from Air Force Plant 4 to the creek is occurring, large decreases in PCB concentrations with decreasing age in two cores indicate that PCB loading to the inlet has decreased greatly since the 1960s. Because runoff entering Meandering Road Creek from some parts of Air Force Plant 4 was not measured or sampled in this study, it cannot be said with certainty that the Air Force Plant 4 site sampled is the only source of PCBs to Meandering Road Creek.

Improved Gradation for Rain Garden of Low Impact Development

NASA Astrophysics Data System (ADS)

Lee, Sandra; Chang, Fu-Ming

2016-04-01

With rapid urban and economic development, living standard improves in urban areas but urban ecological environments deteriorate rapidly. Urban waterlogging and flooding have become a serious problem for urban water security. As urbanization continues, sustainability is the key to balance between urban development and healthy environment. Rain garden is recommended to be one of the best ways to reduce urban pollutants. It not only diminishes runoff flooding but also purify water in the urban area. The studies on rain gardens are mainly about how to incorporate rain garden to purify water quality, but lack of researches on runoff control. This project focuses on rain garden under Low Impact Development using indoor laboratory to test and quantify the water holding capacities of two different Taiwan indigenous rain garden plants, Taiwan Cyclosorus and Sour Grass. The results show that the water holding capacity of Sour Grass (10%-37%) is better than that of Taiwan Cyclosorus (6.8%-17.3%). The results could be a helpful reference for Low Impact Development in urban flood prevention and urban planning. Keywords: Low Impact Development; rain garden; indoor laboratory experiments; water holding capacity; porosity

Estimating risks for water-quality exceedances of total-copper from highway and urban runoff under predevelopment and current conditions with the Stochastic Empirical Loading and Dilution Model (SELDM)

USGS Publications Warehouse

Granato, Gregory E.; Jones, Susan C.; Dunn, Christopher N.; Van Weele, Brian

2017-01-01

The stochastic empirical loading and dilution model (SELDM) was used to demonstrate methods for estimating risks for water-quality exceedances of event-mean concentrations (EMCs) of total-copper. Monte Carlo methods were used to simulate stormflow, total-hardness, suspended-sediment, and total-copper EMCs as stochastic variables. These simulations were done for the Charles River Basin upstream of Interstate 495 in Bellingham, Massachusetts. The hydrology and water quality of this site were simulated with SELDM by using data from nearby, hydrologically similar sites. Three simulations were done to assess the potential effects of the highway on receiving-water quality with and without highway-runoff treatment by a structural best-management practice (BMP). In the low-development scenario, total copper in the receiving stream was simulated by using a sediment transport curve, sediment chemistry, and sediment-water partition coefficients. In this scenario, neither the highway runoff nor the BMP effluent caused concentration exceedances in the receiving stream that exceed the once in three-year threshold (about 0.54 percent). In the second scenario, without the highway, runoff from the large urban areas in the basin caused exceedances in the receiving stream in 2.24 percent of runoff events. In the third scenario, which included the effects of the urban runoff, neither the highway runoff nor the BMP effluent increased the percentage of exceedances in the receiving stream. Comparison of the simulated geometric mean EMCs with data collected at a downstream monitoring site indicates that these simulated values are within the 95-percent confidence interval of the geometric mean of the measured EMCs.

Spatial variations of storm runoff pollution and their correlation with land-use in a rapidly urbanizing catchment in China.

PubMed

Qin, Hua-Peng; Khu, Soon-Thiam; Yu, Xiang-Ying

2010-09-15

The composition of land use for a rapidly urbanizing catchment is usually heterogeneous, and this may result in significant spatial variations of storm runoff pollution and increase the difficulties of water quality management. The Shiyan Reservoir catchment, a typical rapidly urbanizing area in China, is chosen as a study area, and temporary monitoring sites were set at the downstream of its 6 sub-catchments to synchronously measure rainfall, runoff and water quality during 4 storm events in 2007 and 2009. Due to relatively low frequency monitoring, the IHACRES and exponential pollutant wash-off simulation models are used to interpolate the measured data to compensate for data insufficiency. Three indicators, event pollutant loads per unit area (EPL), event mean concentration (EMC) and pollutant loads transported by the first 50% of runoff volume (FF50), were used to describe the runoff pollution for different pollutants in each sub-catchment during the storm events, and the correlations between runoff pollution spatial variations and land-use patterns were tested by Spearman's rank correlation analysis. The results indicated that similar spatial variation trends were found for different pollutants (EPL or EMC) in light storm events, which strongly correlate with the proportion of residential land use; however, they have different trends in heavy storm events, which correlate with not only the residential land use, but also agricultural and bare land use. And some pairs of pollutants (such as COD/BOD, NH(3)-N/TN) might have the similar source because they have strong or moderate positive spatial correlation. Moreover, the first flush intensity (FF50) varies with impervious land areas and different interception ratio of initial storm runoff volume should be adopted in different sub-catchments. Copyright 2010 Elsevier B.V. All rights reserved.

Biomarker responses and PAH ratios in fish inhabiting an estuarine urban waterway.

PubMed

Duarte, Rafael Mendonça; Sadauskas-Henrique, Helen; de Almeida-Val, Vera Maria Fonseca; Val, Adalberto Luis; Nice, Helen Elizabeth; Gagnon, Marthe Monique

2017-10-01

Many cities worldwide are established adjacent to estuaries and their catchments resulting in estuarine contamination due to intense anthropogenic activities. The aim of this study was to evaluate if fish living in an estuarine urban waterway were affected by contamination, via the measurement of a suite of biomarkers of fish health. Black bream (Acanthopagrus butcheri) were sampled in a small urban embayment and a suite of biomarkers of fish health measured. These were condition factor (CF), liver somatic index (LSI), gonadosomatic index (GSI), hepatic EROD activity, polycyclic aromatic hydrocarbon (PAH) biliary metabolites, serum sorbitol dehydrogenase (s-SDH) and branchial enzymes cytochrome C oxidase (CCO), and lactate dehydrogenase (LDH) activities. The biomarkers of exposure EROD activity, and pyrene- and B(a)P-type biliary metabolites confirmed current or recent exposure of the fish and that fish were metabolizing contaminants. Relative to a reference site, LSI was higher in fish collected in the urban inlet as was the metabolic enzyme LDH activity. CF, GSI, s-SDH, CCO, and naphthalene-type metabolites were at similar levels in the urban inlet relative to the reference site. PAH biliary metabolite ratios of high-molecular-weight to low-molecular-weight suggest that fish from the urban inlet were exposed to pyrogenic PAHs, likely from legacy contamination and road runoff entering the embayment. Similarly, the sediment PAH ratios and the freshness indices suggested legacy contamination of a pyrogenic source, likely originating from the adjacent historic gasworks site and a degree of contamination of petrogenic nature entering the inlet via storm water discharge. Biomarkers of exposure and effect confirmed that black bream collected in the Claisebrook Cove inlet, Western Australia, are currently exposed to contamination and are experiencing metabolic perturbations not observed in fish collected at a nearby reference site. © 2017 Wiley Periodicals, Inc.

Trace elements and nitrogen content in naturally growing moss Hypnum cupressiforme in urban and peri-urban forests of the Municipality of Ljubljana (Slovenia).

PubMed

Berisha, S; Skudnik, M; Vilhar, U; Sabovljević, M; Zavadlav, S; Jeran, Z

2017-02-01

We monitored trace metals and nitrogen using naturally growing moss Hypnum cupressiforme Hedw. in urban and peri-urban forests of the City Municipality of Ljubljana. The aim of this study was to explore the differences in atmospheric deposition of trace metals and nitrogen between urban and peri-urban forests. Samples were collected at a total of 44 sites in urban forests (forests within the motorway ring road) and peri-urban forests (forests outside the motorway ring road). Mosses collected in urban forests showed increased trace metal concentrations compared to samples collected from peri-urban forests. Higher values were significant for As, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Tl and V. Within the motorway ring road, the notable differences in element concentrations between the two urban forests were significant for Cr, Ni and Mo. Factor analysis showed three groups of elements, highlighting the contribution of traffic emissions, individual heating appliances and the resuspension of contaminated soils and dust as the main sources of trace elements in urban forests.

Enrichment and sources of trace metals in roadside soils in Shanghai, China: A case study of two urban/rural roads.

PubMed

Yan, Geng; Mao, Lingchen; Liu, Shuoxun; Mao, Yu; Ye, Hua; Huang, Tianshu; Li, Feipeng; Chen, Ling

2018-08-01

The road traffic has become one of the main sources of urban pollution and could directly affect roadside soils. To understand the level of contamination and potential sources of trace metals in roadside soils of Shanghai, 10 trace metals (Sb, Cr, Co, Ni, Cu, Cd, Pb, Hg, Mn and Zn) from two urban/rural roads (Hutai Road and Wunign-Caoan Road) were analyzed in this study. Antimony, Ni, Cu, Cd, Pb, Hg and Zn concentrations were higher than that of soil background values of Shanghai, whereas accumulation of Cr, Co and Mn were minimal. Significantly higher Sb, Cd, Pb contents were found in samples from urban areas than those from suburban area, suggesting the impact from urbanization. The concentrations of Sb and Cd in older road (Hutai) were higher than that in younger road (Wunign-Caoan). Multivariate statistical analysis revealed that Sb, Cu, Cd, Pb and Zn were mainly controlled by traffic activities (e.g. brake wear, tire wear, automobile exhaust) with high contamination levels found near traffic-intensive areas; Cr, Co, Ni and Mn derived primarily from soil parent materials; Hg was related to industrial activities. Besides, the enrichment of Sb, Cd, Cu, Pb and Zn showed a decreasing trend with distance to the road edges. According to the enrichment factors (EF s ), 78.5% of Sb, Cu, Cd, Pb and Zn were in moderate or significant pollution, indicating considerable traffic contribution. In particular, recently introduced in automotive technology, accumulation of Sb has been recognized in 42.9% samples of both roads. The accumulation of these traffic-derived metals causes potential negative impact to human health and ecological environment and should be concerned, especially the emerging trace elements like Sb. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of urban stormwater runoff on ground water beneath recharge basins on Long Island, New York

USGS Publications Warehouse

Ku, H.F.; Simmons, D.L.

1986-01-01

Urban stormwater runoff was monitored during 1980-82 to investigate the source, type, quantity, and fate of contaminants routed to the more than 3,000 recharge basins on Long Island and to determine whether this runoff might be a significant source of contamination to the groundwater reservoir. Forty-six storms were monitored at five recharge basins in representative land use areas (strip commercial, shopping-mall parking lot, major highway, low-density residential, and medium-density residential). Runoff:precipitation ratios indicate that all storm runoff is derived from precipitation on impervious surfaces in the drainage area, except during storms of high intensity or long duration, when additional runoff can be derived from precipitation on permeable surfaces. Lead was present in highway runoff in concentrations up to 3300 micrograms/L, and chloride was found in parking lot runoff concentrations up to 1,100 mg/L during winter, when salt is used for deicing. In the five composite stormwater samples and nine groundwater grab samples that were analyzed for 113 EPA-designated ' priority pollutants, ' four constituents were detected in concentrations exceeding New York State guidelines of 50 micrograms/L for an individual organic compound in drinking water: p-chloro-m-cresol (79 micrograms/L); 2 ,4-dimethylphenol (96 micrograms/L); 4-nitrophenol (58 micrograms/L); and methylene chloride (230 micrograms/L in either groundwater or stormwater at the highway basin). One stormwater sample and two groundwater samples exceeded New York State guidelines for total organic compounds in drinking water (100 micrograms/L). The presence of these constituents is attributed to contamination from point sources rather than to the quality of runoff from urban areas. The median number of indicator bacteria in stormwater ranged from 0.1 to 10 billion MPN/100 ml. Fecal coliforms and fecal streptococci increased by 1 to 2 orders of magnitude during the warm season. The use of recharge basins to dispose of storm runoff does not appear to have significant adverse effects on groundwater quality in terms of the chemical and microbiological stormwater constituents studied. (Author 's abstract)

Habitat complexity influences fine scale hydrological processes and the incidence of stormwater runoff in managed urban ecosystems.

PubMed

Ossola, Alessandro; Hahs, Amy Kristin; Livesley, Stephen John

2015-08-15

Urban ecosystems have traditionally been considered to be pervious features of our cities. Their hydrological properties have largely been investigated at the landscape scale and in comparison with other urban land use types. However, hydrological properties can vary at smaller scales depending upon changes in soil, surface litter and vegetation components. Management practices can directly and indirectly affect each of these components and the overall habitat complexity, ultimately affecting hydrological processes. This study aims to investigate the influence that habitat components and habitat complexity have upon key hydrological processes and the implications for urban habitat management. Using a network of urban parks and remnant nature reserves in Melbourne, Australia, replicate plots representing three types of habitat complexity were established: low-complexity parks, high-complexity parks, and high-complexity remnants. Saturated soil hydraulic conductivity in low-complexity parks was an order of magnitude lower than that measured in the more complex habitat types, due to fewer soil macropores. Conversely, soil water holding capacity in low-complexity parks was significantly higher compared to the two more complex habitat types. Low-complexity parks would generate runoff during modest precipitation events, whereas high-complexity parks and remnants would be able to absorb the vast majority of rainfall events without generating runoff. Litter layers on the soil surface would absorb most of precipitation events in high-complexity parks and high-complexity remnants. To minimize the incidence of stormwater runoff from urban ecosystems, land managers could incrementally increase the complexity of habitat patches, by increasing canopy density and volume, preserving surface litter and maintaining soil macropore structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimation of urban-enhanced infiltration and groundwater recharge, Sierra Vista subbasin, southeast Arizona USA

NASA Astrophysics Data System (ADS)

Stewart, Anne M.

This dissertation reports on the methods and results of a three-phased investigation to estimate the annual volume of ephemeral-channel-focused groundwater recharge attributable to urbanization (urban-enhanced groundwater recharge) in the Sierra Vista subwatershed of southeastern Arizona, USA. Results were used to assess a prior estimate. The first research phase focused on establishment of a study area, installation of a distributed network of runoff gages, gaging for stage, and transforming 2008 stage data into time series of volumetric discharge, using the continuous slope-area method. Stage data were collected for water years 2008 - 2011. The second research phase used 2008 distributed runoff data with NWS DOPPLER RADAR data to optimize a rainfall-runoff computational model, with the aim of identifying optimal site-specific distributed hydraulic conductivity values and model-predicted infiltration. The third research phase used the period-of-record runoff stage data to identify study-area ephemeral flow characteristics and to estimate channel-bed infiltration of flow events. Design-storm modeling was used to identify study-area predevelopment ephemeral flow characteristics, given the same storm event. The difference between infiltration volumes calculated for the two cases was attributed to urbanization. Estimated evapotranspiration was abstracted and the final result was equated with study-area-scale urban-enhanced groundwater recharge. These results were scaled up to the Sierra Vista subwatershed: the urban-enhanced contribution to groundwater recharge is estimated to range between 3270 and 3635 cubic decameters (between 2650 and 2945 acre-feet) per year for the period of study. Evapotranspirational losses were developed from estimates made elsewhere in the subwatershed. This, and other sources of uncertainty in the estimates, are discussed and quantified if possible.

Annual compilation and analysis of hydrologic data for urban studies in the Austin, Texas Metropolitan Area, 1971

USGS Publications Warehouse

Tovar, F.H.

1973-01-01

The U.S. Geological Survey, in cooperation with the Texas Water Development Board, began hydrologic studies in the Austin urban area in 1954. The objectives of this project are as follows: 1. To determine the effects of progressive urbanization on infiltration, rates of peak discharge, and rainfall-runoff relations in the Waller Creek watershed. 2. To provide rainfall-and-runoff data from the rural Wilbarger Creek watershed to be used for comparative purposes in determining the effects of existing and progressive urbanization in the Waller Creek watershed. 3. To provide applied research facilities for studies at the University of Texas at Austin. The purpose of this report is to present rainfall-and-runoff data for the Waller Creek and Wilbarger Creek study areas for the 1971 water year (October 1, 1970, to September 30, 1971). To facilitate the publication and distribution of this report at the earliest feasible time, certain material has been included that does not conform to the formal publication standards of the U.S. Geological Survey.

Rainfall-runoff in the Albuquerque, New Mexico, area: Measurements, analyses and comparisons

USGS Publications Warehouse

Anderson, C.E.; Ward, T.J.; Kelly, T.; ,

2005-01-01

Albuquerque, New Mexico, has experienced significant growth over the last 20 years like many other cities in the Southwestern United States. While the US population grew by 37% between the 1970 and 2000 censuses, the growth for Albuquerque was 83%. More people mean more development and increased problems of managing runoff from urbanizing watersheds. The U.S. Geological Survey (USGS) in cooperation with the Albuquerque Arroyo Metropolitan Flood Control Authority (AMAFCA) and the City of Albuquerque has maintained a rainfall-runoff data collection program since 1976. The data from measured precipitation events can be used to verify hydrologic modeling. In this presentation, data from a representative gaged watershed is analyzed and discussed to set the overall framework for the rainfall-runoff process in the Albuquerque area. Of particular interest are the basic relationships between rainfall and watershed runoff response and an analysis of curve numbers as an indicator of runoff function. In urbanized areas, four land treatment types (natural, irrigated lawns, compacted soil, and impervious) are used to define surface infiltration conditions. Rainfall and runoff gage data are used to compare curve number (CN) and initial abstraction/uniform infiltration (IA/INF) techniques in an Albuquerque watershed. The IA/INF method appears to produce superior results over the CN method for the measured rainfall events.

Quantitative assessment of human health risk posed by polycyclic aromatic hydrocarbons in urban road dust.

PubMed

Ma, Yukun; Liu, An; Egodawatta, Prasanna; McGree, James; Goonetilleke, Ashantha

2017-01-01

Among the numerous pollutants present in urban road dust, polycyclic aromatic hydrocarbons (PAHs) are among the most toxic chemical pollutants and can pose cancer risk to humans. The primary aim of the study was to develop a quantitative model to assess the cancer risk from PAHs in urban road dust based on traffic and land use factors and thereby to characterise the risk posed by PAHs in fine (<150μm) and coarse (>150μm) particles. The risk posed by PAHs was quantified as incremental lifetime cancer risk (ILCR), which was modelled as a function of traffic volume and percentages of different urban land uses. The study outcomes highlighted the fact that cancer risk from PAHs in urban road dust is primarily influenced by PAHs associated with fine solids. Heavy PAHs with 5 to 6 benzene rings, especially dibenzo[a,h]anthracene (D[a]A) and benzo[a]pyrene (B[a]P) in the mixture contribute most to the risk. The quantitative model developed based on traffic and land use factors will contribute to informed decision making in relation to the management of risk posed by PAHs in urban road dust. Copyright © 2016 Elsevier B.V. All rights reserved.

The improved degree of urban road traffic network: A case study of Xiamen, China

NASA Astrophysics Data System (ADS)

Wang, Shiguang; Zheng, Lili; Yu, Dexin

2017-03-01

The complex network theory is applied to the study of urban road traffic network topology, and we constructed a new measure to characterize an urban road network. It is inspiring to quantify the interaction more appropriately between nodes in complex networks, especially in the field of traffic. The measure takes into account properties of lanes (e.g. number of lanes, width, traffic direction). As much, it is a more comprehensive measure in comparison to previous network measures. It can be used to grasp the features of urban street network more clearly. We applied this measure to the road network in Xiamen, China. Based on a standard method from statistical physics, we examined in more detail the distribution of this new measure and found that (1) due to the limitation of space geographic attributes, traditional research conclusions acquired by using the original definition of degree to study the primal approach modeled urban street network are not very persuasive; (2) both of the direction of the network connection and the degree's odd or even classifications need to be analyzed specifically; (3) the improved degree distribution presents obvious hierarchy, and hierarchical values conform to the power-law distribution, and correlation of our new measure shows some significant segmentation of the urban road network.

Streams in the urban heat island: spatial and temporal variability in temperature

USGS Publications Warehouse

Somers, Kayleigh A.; Bernhardt, Emily S.; Grace, James B.; Hassett, Brooke A.; Sudduth, Elizabeth B.; Wang, Siyi; Urban, Dean L.

2013-01-01

Streams draining urban heat islands tend to be hotter than rural and forested streams at baseflow because of warmer urban air and ground temperatures, paved surfaces, and decreased riparian canopy. Urban infrastructure efficiently routes runoff over hot impervious surfaces and through storm drains directly into streams and can lead to rapid, dramatic increases in temperature. Thermal regimes affect habitat quality and biogeochemical processes, and changes can be lethal if temperatures exceed upper tolerance limits of aquatic fauna. In summer 2009, we collected continuous (10-min interval) temperature data in 60 streams spanning a range of development intensity in the Piedmont of North Carolina, USA. The 5 most urbanized streams averaged 21.1°C at baseflow, compared to 19.5°C in the 5 most forested streams. Temperatures in urban streams rose as much as 4°C during a small regional storm, whereas the same storm led to extremely small to no changes in temperature in forested streams. Over a kilometer of stream length, baseflow temperature varied by as much as 10°C in an urban stream and as little as 2°C in a forested stream. We used structural equation modeling to explore how reach- and catchment-scale attributes interact to explain maximum temperatures and magnitudes of storm-flow temperature surges. The best predictive model of baseflow temperatures (R2  =  0.461) included moderately strong pathways directly (extent of development and road density) and indirectly, as mediated by reach-scale factors (canopy closure and stream width), from catchment-scale factors. The strongest influence on storm-flow temperature surges appeared to be % development in the catchment. Reach-scale factors, such as the extent of riparian forest and stream width, had little mitigating influence (R2  =  0.448). Stream temperature is an essential, but overlooked, aspect of the urban stream syndrome and is affected by reach-scale habitat variables, catchment-scale urbanization, and stream thermal regimes.

The Impact of Large Urban Structural Elements on Traffic Flow   a Case Study of Danwei and Xiaoqu in Shanghai

NASA Astrophysics Data System (ADS)

Lyu, H.; Ding, L.; Fan, H.; Meng, L.

2017-09-01

Danwei (working unit) and Xiaoqu (residential community) are two typical and unique structural urban elements in China. The interior roads of Danwei and Xiaoqu are usually not accessible for the public. Recently, there is a call for opening these interior roads to the public to improve road network structure and optimize traffic flow. In this paper we investigate the impact of Danwei and Xiaoqu on their neighbouring traffic quantitatively. By taking into consideration of origins and destinations (ODs) distributions and route selection behaviours (e.g., shortest paths), we propose an extended betweenness centrality to investigate the traffic flow in two scenarios 1) the interior roads of Danwei and Xiaoqu are excluded from urban road network, 2) the interior roads are integrated into road network. A Danwei and a Xiaoqu in Shanghai are used as the study area. The preliminary results show the feasibility of our extended betweenness centrality in investigating the traffic flow patterns and reveal the quantitative changes of the traffic flow after opening interior roads.

Impact of green roofs on stormwater quality in a South Australian urban environment.

PubMed

Razzaghmanesh, M; Beecham, S; Kazemi, F

2014-02-01

Green roofs are an increasingly important component of water sensitive urban design systems and can potentially improve the quality of urban runoff. However, there is evidence that they can occasionally act as a source rather than a sink for pollutants. In this study, the water quality of the outflow from both intensive and extensive green roof systems were studied in the city of Adelaide, South Australia over a period of nine months. The aim was to examine the effects of different green roof configurations on stormwater quality and to compare this with runoff from aluminium and asphalt roofs as control surfaces. The contaminant concentrations in runoff from both intensive and extensive green roofs generally decreased during the study period. A comparison between the two types of green roof showed that except for some events for EC, TDS and chloride, the values of the parameters such as pH, turbidity, nitrate, phosphate and potassium in intensive green roof outflows were higher than in the outflows from the extensive green roofs. These concentrations were compared to local, state, national and international water quality guidelines in order to investigate the potential for outflow runoff from green roofs to be reused for potable and non-potable purposes. The study found that green roof outflow can provide an alternative water source for non-potable purposes such as urban landscape irrigation and toilet flushing. © 2013.

BMP UNIT PROCESS DESIGN, MONITORING, AND PERFORMANCE

EPA Science Inventory

Urbanization results in more impervious areas that cause larger quantities of stormwater runoff. This runoff can contribute significant amounts of pollutants (e.g., litter, oils, microorganisms, sediments, nutrients, organic matter, and heavy metals) to receiving waters. To impro...

EVALUATION OF ECONOMIC INCENTIVES FOR DECENTRALIZED STORMWATER RUNOFF MANAGEMENT

EPA Science Inventory

Impervious surfaces in urban and suburban areas can lead to excess stormwater runoff throughout a watershed, typically resulting in widespread hydrologic and ecological alteration of receiving streams. Decentralized stormwater management may improve stream ecosystems by reducing ...

CHAPTER 17: STORMWATER

EPA Science Inventory

The process of urbanization causes significant changes to the hydrologic regime of catchments through increased impervious areas (roads, roofs, etc) and alterations to the natural drainage network. Some examples of urbanization processes include: increasing surface area of road ...

Understanding congested travel in urban areas

PubMed Central

Çolak, Serdar; Lima, Antonio; González, Marta C.

2016-01-01

Rapid urbanization and increasing demand for transportation burdens urban road infrastructures. The interplay of number of vehicles and available road capacity on their routes determines the level of congestion. Although approaches to modify demand and capacity exist, the possible limits of congestion alleviation by only modifying route choices have not been systematically studied. Here we couple the road networks of five diverse cities with the travel demand profiles in the morning peak hour obtained from billions of mobile phone traces to comprehensively analyse urban traffic. We present that a dimensionless ratio of the road supply to the travel demand explains the percentage of time lost in congestion. Finally, we examine congestion relief under a centralized routing scheme with varying levels of awareness of social good and quantify the benefits to show that moderate levels are enough to achieve significant collective travel time savings. PMID:26978719

Understanding congested travel in urban areas

NASA Astrophysics Data System (ADS)

Çolak, Serdar; Lima, Antonio; González, Marta C.

2016-03-01

Rapid urbanization and increasing demand for transportation burdens urban road infrastructures. The interplay of number of vehicles and available road capacity on their routes determines the level of congestion. Although approaches to modify demand and capacity exist, the possible limits of congestion alleviation by only modifying route choices have not been systematically studied. Here we couple the road networks of five diverse cities with the travel demand profiles in the morning peak hour obtained from billions of mobile phone traces to comprehensively analyse urban traffic. We present that a dimensionless ratio of the road supply to the travel demand explains the percentage of time lost in congestion. Finally, we examine congestion relief under a centralized routing scheme with varying levels of awareness of social good and quantify the benefits to show that moderate levels are enough to achieve significant collective travel time savings.

RNICO: a new simple geometric index for assessing the impact of urban development pattern on peak flows in urban catchments

NASA Astrophysics Data System (ADS)

Kasaee Roodsari, B.; Chandler, D. G.

2016-12-01

Urban sprawl is widespread across the world and the associated hydrologic impacts are increasing in peri-urban catchments due to increased area of impervious. There is a strong agreement on the positive correlation between the fractional impervious area and peak flows in urban catchments. Nevertheless, the effect of land development pattern on peak flows is not well investigated. In this study, a new simple geometric index, Relative Nearness of Imperviousness to the Catchment Outlet (RNICO), is defined to correlate imperviousness distribution of peri-urban catchments to runoff peak flows. Results of applying RNICO to 20 sub-catchments in New York State showed a strong positive correlation (R2>0.97) between RNICO and runoff peak flows for small peri-urban catchments (A< 42 km2) indicating higher flood risk of downstream urbanization. For large catchments (A> 42 km2), no correlation was indicated between RNICO and peak flows. We highlight the necessity of a greater discharge monitoring network at small peri-urban catchments to support local urban flood forecast.

Movement of road salt to a small New Hampshire lake

USGS Publications Warehouse

Rosenberry, D.O.; Bukaveckas, P.A.; Buso, D.C.; Likens, G.E.; Shapiro, A.M.; Winter, T.C.

1999-01-01

Runoff of road salt from an interstate highway in New Hampshire has led to contamination of a lake and a stream that flows into the lake, in spite of the construction of a diversion berm to divert road salt runoff out of the lake drainage basin. Chloride concentration in the stream has increased by over an order of magnitude during the 23 yr since the highway was opened, and chloride concentration in the lake has tripled. Road salt moves to the lake primarily via the contaminated stream, which provides 53% of all the chloride to the lake and only 3% of the total streamflow to the lake. The stream receives discharge of salty water froth leakage through the diversion berm. Uncontaminated ground water dilutes the stream downstream of the berm. However, reversals of gradient during summer months, likely caused by transpiration from deciduous trees, result in flow of contaminated stream water into the adjacent ground water along the lowest 40-m reach of the stream. This contaminated ground water then discharges into the lake along a 70-m-wide segment of lake shore. Road salt is pervasive in the bedrock between the highway and the lake, but was not detected at all of the wells in the glacial overburden. Of the 500 m of shoreline that could receive discharge of saly ground water directly from the highway, only a 50-m-long segment appears to be contaminated.

[Influence of green roof application on water quantity and quality in urban region].

PubMed

Wang, Shu-Min; Li, Xing-Yang; Zhang, Jun-Hua; Yu, Hui; Hao, You-Zhi; Yang, Wan-Yi

2014-07-01

Green roof is widely used in advanced stormwater management as a major measure now. Taking Huxi catchment in Chongqing University as the study area, the relationships between green roof installation with runoff volume and water quality in urban region were investigated. The results showed that roof greening in the urban region contributed to reducing the runoff volume and pollution load. In addition, the spatial distribution and area of green roof also had effects on the runoff water quality. With the conditions that the roof area was 25% of the total watershed area, rainfall duration was 15 min and rainfall intensity was 14.8 mm x h(-1), the peak runoff and total runoff volume were reduced by 5.3% and 31%, the pollution loads of total suspended solid (TSS), total phosphorus (TP) and total nitrogen (TN) decreased by 40.0%, 31.6% and 29.8%, their peak concentrations decreased by 21.0%, 16.0% and -12.2%, and the EMCs (event mean concentrations) were cut down by 13.1%, 0.9% and -1.7%, respectively, when all impervious roofs were greened in the research area. With the increase of roof greening rate, the reduction rates of TSS and TP concentrations increased, while the reduction rate of TN concentration decreased on the whole. Much more improvement could be obtained with the use of green roofs near the outlet of the watershed.

Effects of climate and land cover on hydrology in the southeastern U.S.: Potential impacts on watershed planning

USGS Publications Warehouse

LaFontaine, Jacob H.; Hay, Lauren E.; Viger, Roland; Regan, R. Steve; Markstrom, Steven

2015-01-01

The hydrologic response to statistically downscaled general circulation model simulations of daily surface climate and land cover through 2099 was assessed for the Apalachicola-Chattahoochee-Flint River Basin located in the southeastern United States. Projections of climate, urbanization, vegetation, and surface-depression storage capacity were used as inputs to the Precipitation-Runoff Modeling System to simulate projected impacts on hydrologic response. Surface runoff substantially increased when land cover change was applied. However, once the surface depression storage was added to mitigate the land cover change and increases of surface runoff (due to urbanization), the groundwater flow component then increased. For hydrologic studies that include projections of land cover change (urbanization in particular), any analysis of runoff beyond the change in total runoff should include effects of stormwater management practices as these features affect flow timing and magnitude and may be useful in mitigating land cover change impacts on streamflow. Potential changes in water availability and how biota may respond to changes in flow regime in response to climate and land cover change may prove challenging for managers attempting to balance the needs of future development and the environment. However, these models are still useful for assessing the relative impacts of climate and land cover change and for evaluating tradeoffs when managing to mitigate different stressors.

Groundwater and surface water dynamics of Na and Cl in an urban stream: effects of road salts

EPA Science Inventory

AbstractRoad salts are a growing environmental and health concern in urban watersheds. We examined groundwater (GW) and surface water (SW) dynamics of Na and Cl in an urban stream, Minebank Run (MBR), MD. We observed an increasing salinity trend in this restored stream. Current b...

Modeling salinization and recovery of road salt-impacted lakes in temperate regions based on long-term monitoring of Lake George, New York (USA) and its drainage basin.

PubMed

Sutherland, J W; Norton, S A; Short, J W; Navitsky, C

2018-05-08

Road salt mitigates winter highway icing but accumulates in watershed soils and receiving waters, affecting soil chemistry and physical, biological, and ecological processes. Despite efforts to reduce salt loading in watersheds, accumulated cations and Cl - continue to impact tributaries and lakes, and the recovery process is not well understood. Lake George, New York (USA) is typical of many temperate lakes at risk for elevated Cl - concentrations from winter deicing; the lake salt concentration increased by ~3.4% year -1 since 1980. Here, we evaluated the ionic composition in Finkle Brook, a major watershed draining to Lake George, studied intermittently since 1970 and typical of other salt-impacted Lake George tributaries. Salt loading in the Lake George basin since the 1940s displaced cations from exchange sites in basin soils; these desorbed cations follow a simple ion-exchange model, with lower sodium and higher calcium, magnesium and potassium fluxes in runoff. Reduced salt application in the Finkle Brook watershed during the low-snow winter of 2015-2016 led to a 30-40% decline of Cl - and base cations in the tributary, implying a Cl - soil half-life of 1-2 years. We developed a conceptual model that describes cation behavior in runoff from a watershed that received road salt loading over a long period of time, and then recovery following reduced salt loading. Next, we developed a dynamic model estimating time to steady-state for Cl - in Lake George with road salt loading starting in 1940, calibrating the model with tributary runoff and lake chemistry data from 1970 and 1980, respectively, and forecasting Cl - concentrations in Lake George based on various scenarios of salt loading and soil retention of Cl - . Our Lake George models are readily adaptable to other temperate lakes with drainage basins where road salt is applied during freezing conditions and paved roads cover a portion of the watershed. Copyright © 2018 Elsevier B.V. All rights reserved.

Sediment pathways in a tropical forest: effects of logging roads and skid trails

NASA Astrophysics Data System (ADS)

Sidle, Roy C.; Sasaki, Shozo; Otsuki, Mieko; Noguchi, Shoji; Rahim Nik, Abdul

2004-03-01

Significant erosion occurred from recently constructed forest logging roads and skid trails in a small headwater catchment in Peninsular Malaysia. Soil loss was estimated by measuring dimensions of all significant rills and gullies along the road, as well as by measuring height of preserved soil pedestals in sidecast and fill material and on skid trails. Estimates of surface erosion from logging roads and skid trails were 272 +/- 20 t ha-1 year-1 and 275 +/- 20 t ha-1 year-1 respectively. However, owing to lack of connectivity of skid trails to the stream, much of the sediment mobilized on skid trails was stored either on adjacent hillslopes or the trails themselves, rather than being transported to the stream system, as was the case for the road. Steeper skid trails (>20% gradient) had slightly higher erosion rates (320 +/- 24 t ha-1 year-1) than trails with gentler gradients (245-264 t ha-1 year-1). Some 60% of the soil loss on logging roads comes from erosion of the running surface. Disturbed cut and fill material along the road supplied the remaining 40% of the soil loss from roads. Roads and skid trails had no designed drainage systems; runoff discharged onto the hillslope at 25 major discharge nodes from the logging road (690 m total length) and at 34 nodes from skid trails (2300 m). Sediment pathways were either fully or moderately connected to headwater channels at 64% of the logging road nodes, but at only 26% of the nodes emanating from skid trails. A detailed sediment budget revealed that 78% of the soil loss from the road system (including log landings) was delivered to the stream in the first 16 months after logging began. Most (90%) of the deposition from skid trails occurred below just three discharge nodes. Runoff from and onto skid trails often exacerbated the sediment connectivity to channels. Clearly, sediment discharge from logging roads was more highly connected to the stream than discharge from skid trails. Once in the channel, much of this sediment was temporarily stored in the floodplain and behind woody debris.

Comparative Synthesis of Current and Future Urban Stormwater Runoff Scenarios in Tampa Bay Basin under a Changing Climate

NASA Astrophysics Data System (ADS)

Khan, M.; Abdul-Aziz, O. I.

2016-12-01

Changes in climatic regimes and basin characteristics such as imperviousness, roughness and land use types would lead to potential changes in stormwater budget. In this study we quantified reference sensitivities of stormwater runoff to the potential climatic and land use/cover changes by developing a large-scale, mechanistic rainfall-runoff model for the Tampa Bay Basin of Florida using the US EPA Storm Water Management Model (SWMM 5.1). Key processes of urban hydrology, its dynamic interactions with groundwater and sea level, hydro-climatic variables and land use/cover characteristics were incorporated within the model. The model was calibrated and validated with historical streamflow data. We then computed the historical (1970-2000) and potential 2050s stormwater budgets for the Tampa Bay Basin. Climatic scenario projected by the global climate models (GCMs) and the regional climate models (RCMs), along with sea level and land use/cover projections, were utilized to anticipate the future stormwater budget. The comparative assessment of current and future stormwater scenario will aid a proactive management of stormwater runoff under a changing climate in the Tampa Bay Basin and similar urban basins around the world.

The use of simulated rainfall to study the discharge process and the influence factors of urban surface runoff pollution loads.

PubMed

Qinqin, Li; Qiao, Chen; Jiancai, Deng; Weiping, Hu

2015-01-01

An understanding of the characteristics of pollutants on impervious surfaces is essential to estimate pollution loads and to design methods to minimize the impacts of pollutants on the environment. In this study, simulated rainfall equipment was constructed to investigate the pollutant discharge process and the influence factors of urban surface runoff (USR). The results indicated that concentrations of total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) appeared to be higher in the early period and then decreased gradually with rainfall duration until finally stabilized. The capacity and particle size of surface dust, rainfall intensity and urban surface slopes affected runoff pollution loads to a variable extent. The loads of TP, TN and COD showed a positive relationship with the surface dust capacity, whereas the maximum TSS load appeared when the surface dust was 0.0317 g·cm⁻². Smaller particle sizes (<0.125 mm) of surface dust generated high TN, TP and COD loads. Increases in rainfall intensity and surface slope enhanced the pollution carrying capacity of runoff, leading to higher pollution loads. Knowledge of the influence factors could assist in the management of USR pollution loads.

EPA RESEARCH IN URBAN STORMWATER POLLUTION CONTROL

EPA Science Inventory

This state-of-the-art on the Environmental Protection Agency' s research in urban stormwater and combined sewer overflow pollution control describes the major elements of the Urban Runoff Pollution Control Program. roblem definition, users assistance tools, management alternative...

Modeling the heterogeneous traffic correlations in urban road systems using traffic-enhanced community detection approach

NASA Astrophysics Data System (ADS)

Lu, Feng; Liu, Kang; Duan, Yingying; Cheng, Shifen; Du, Fei

2018-07-01

A better characterization of the traffic influence among urban roads is crucial for traffic control and traffic forecasting. The existence of spatial heterogeneity imposes great influence on modeling the extent and degree of road traffic correlation, which is usually neglected by the traditional distance based method. In this paper, we propose a traffic-enhanced community detection approach to spatially reveal the traffic correlation in city road networks. First, the road network is modeled as a traffic-enhanced dual graph with the closeness between two road segments determined not only by their topological connection, but also by the traffic correlation between them. Then a flow-based community detection algorithm called Infomap is utilized to identify the road segment clusters. Evaluated by Moran's I, Calinski-Harabaz Index and the traffic interpolation application, we find that compared to the distance based method and the community based method, our proposed traffic-enhanced community based method behaves better in capturing the extent of traffic relevance as both the topological structure of the road network and the traffic correlations among urban roads are considered. It can be used in more traffic-related applications, such as traffic forecasting, traffic control and guidance.

Thermal Fluxes and Temperatures in Small Urban Headwater Streams of the BES LTER: Landscape Forest and Impervious Patches and the Importance of Spatial and Temporal Scales

NASA Astrophysics Data System (ADS)

Kim, H.; Belt, K. T.; Welty, C.; Heisler, G.; Pouyat, R. V.; McGuire, M. P.; Stack, W. P.

2006-05-01

Water and material fluxes from urban landscape patches to small streams are modulated by extensive "engineered" drainage networks. Small urban headwater catchments are different in character and function from their larger receiving streams because of their extensive, direct connections to impervious surface cover (ISC) and their sometimes buried nature. They need to be studied as unique functional hydrologic units if impacts on biota are to be fully understood. As part of the Baltimore Ecosystem Study LTER project, continuous water temperature data are being collected at 2-minute intervals at over twenty small catchments representing various mixtures of forest and ISC. Suburban stream sites with greater ISC generally have higher summer water temperatures. Suburban catchments with most of their channel drainage contained within storm drain pipes show subdued diurnal variation and cool temperatures, but with very large spikes in summer runoff events. Conversely, high ISC urban piped streams have elevated "baseline" temperatures that stand well above all the other monitoring sites. There is a pronounced upstream-downstream effect; nested small headwater catchments experience more frequent, larger temperature spikes related to runoff events than downstream sites. Also, runoff-initiated temperature elevations at small stream sites unexpectedly last much longer than the storm runoff hydrographs. These observations suggest that for small headwater catchments, urban landscapes not only induce an ambient, "heat island" effect on stream temperatures, but also introduce thermal disturbance regimes and fluxes that are not trivial to aquatic biota.

Aquatic toxicity of airfield-pavement deicer materials and implications for airport runoff

USGS Publications Warehouse

Corsi, S.R.; Geis, S.W.; Bowman, G.; Failey, G.G.; Rutter, T.D.

2009-01-01

Concentrations of airfield-pavement deicer materials (PDM) in a study of airport runoff often exceeded levels of concern regarding aquatic toxicity. Toxicity tests on Vibrio fischeri, Pimephales promelas, Ceriodaphnia dubia, and Pseudokirchneriella subcapitata (commonly known as Selenastrum capricornutum) were performed with potassium acetate (K-Ac) PDM, sodium formate (Na-For) PDM, and with freezing- point depressants (K-Ac and Na-For). Results indicate that toxicity in PDM is driven by the freezing-point depressants in all tests except the Vibrio fisheri test for Na-For PDM which is influenced by an additive. Acute toxicity end points for different organisms ranged from 298 to 6560 mg/L (as acetate) for K-Ac PDM and from 1780 to 4130 mg/L (as formate) for Na- For PDM. Chronic toxicity end points ranged from 19.9 to 336 mg/L (as acetate) for K-Ac PDM and from 584 to 1670 mg/L (as formate) for Na-For PDM. Sample results from outfalls at General Mitchell International Airport in Milwaukee, Wl (GMIA) indicated that 40% of samples had concentrations greater than the aquatic-life benchmark for K-Ac PDM. K-Ac has replaced urea during the 1990s as the most widely used PDM at GMIA and in the United States. Results of ammonia samples from airport outfalls during periods when urea-based PDM was used at GMIA indicated that41% of samples had concentrations exceeding the U.S. Environmental Protection Agency (USEPA) 1 -h water-quality criterion. The USEPA 1-h water-quality criterion for chloride was exceeded in 68% of samples collected in the receiving stream, a result of road-salt runoff from urban influence near the airport. Results demonstrate that PDM must be considered to comprehensively evaluate the impact of chemical deicers on aquatic toxicity in water containing airport runoff. ?? 2009 American Chemical Society.

Geospatial Estimates of Road Salt Usage Across a Gradient of Urbanizing Watersheds in Southern Ontario:Thesis for Masters in Spatial Analysis (MSA)

NASA Astrophysics Data System (ADS)

Giberson, G. K.; Oswald, C.

2015-12-01

In areas affected by snow, chloride (Cl) salts are widely used as a de-icing agent to improve road conditions. While the improvement in road safety is indisputable, there are environmental consequences to local aquatic ecosystems. In many waterways, Cl concentrations have been increasing since the early 1990s, often exceeding national water quality guidelines. To determine the quantity of Cl that is accumulating in urban and urbanizing watersheds, accurate estimates of road salt usage at the watershed-scale are needed. The complex jurisdictional control over road salt application in southern Ontario lends itself to a geospatial approach for calculating Cl inputs to improve the accuracy of watershed-scale Cl mass balance estimates. This study will develop a geospatial protocol for combining information on road salt applications and road network areas to refine watershed-scale Cl inputs, as well as assess spatiotemporal patterns in road salt application across the southern Ontario study region. The overall objective of this project is to use geospatial methods (predominantly ArcGIS) to develop high-accuracy estimates of road salt usage in urbanizing watersheds in southern Ontario. Specifically, the aims will be to map and summarize the types and areas ("lane-lengths") of roadways in each watershed that have road salt applied to them, to determine the most appropriate source(s) of road salt usage data for each watershed, taking into consideration multiple levels of jurisdiction (e.g. municipal, regional, provincial), to calculate and summarize sub-watershed and watershed-scale road salt usage estimates for multiple years, and to analyze intra-watershed spatiotemporal patterns of road salt usage, especially focusing on impervious surfaces. These analyses will recommend areas of concern exacerbated by high-levels of road salt distribution; recommendations around modifying on-the-ground operations will be the next step in helping to correct these issues.

Rain Gardens: Stormwater Infiltrating Systems

EPA Science Inventory

The hydrological dynamics and changes in stormwater nutrient concentrations within rain gardens were studied by introducing captured stormwater runoff to rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey. The runoff used in these experiments was collected...

REMOVAL OF DISSOLVED POLLUTANTS FROM URBAN STORMWATER RUNOFF

EPA Science Inventory

Stormwater runoff, because of its heavy metals and poly aromatic hydrocarbons (PAHs) content, may be considered toxic for discharge to receiving surface waters without further treatment. A number of structural devices, collectively known as structural best management practices (...

Rooftop Runoff as a Source of Contamination: A Review

EPA Science Inventory

Scientific reports concerning chemical and microbiological contaminant levels of rainwater runoff from rooftop collection in both urban and rural areas are reviewed. This alternative source of water has been documented to often contain substantial amounts of contaminants. Studi...

Encouraging stormwater management using a reverse auction: potential to restore stream ecosystems

EPA Science Inventory

Stormwater runoff is the primary mechanism by which urbanizing landscapes disrupt natural, stream ecosystems. Source control management has been demonstrated as an effective and cost-efficient method for reducing stormwater runoff; however, sufficiently widespread implementation...

Impacts of Urbanization on Groundwater Quality and Recharge in a Semi-arid Alluvial Basin

USDA-ARS?s Scientific Manuscript database

The management of groundwater resources is paramount in semi-arid regions experiencing urban development. In the southwestern United States, enhancing recharge of urban storm runoff has been identified as a strategy for augmenting groundwater resources. An understanding of how urbanization may impac...

Storm water runoff-a source of emerging contaminants in urban streams

NASA Astrophysics Data System (ADS)

Xia, K.; Chen, C.; FitzGerald, K.; Badgley, B.

2016-12-01

Emerging contaminants (ECs) that refers to prescription, over-the-counter, veterinary, and illicit drugs in addition to products intended to have primary effects on the human body, such as sunscreens and insect repellants. Historically municipal wastewater treatment effluent has been considered to be the main source of ECs in aquatic environment. However, recent investigations have suggested urban storm water runoff as an important source of ECs in the environment. The objective of this multi-year study was to investigate the occurrence of a wide range of ECs and the special and temporal change of 4-Nonlyphenol (4-NP), an endocrine disruptor, in a stream solely impacted by the storm water runoff from Blacksburg, VA. Urban land cover has doubled during the past 15 years surrounding this. Water and sediment samples were collected periodically along the stream during a 3-year period and analyzed for 4-NP using a gas chromatography/tandem mass spectrometry and for EC screening using an ultra- performance liquid chromatography/tandem mass spectrometry. In addition, human-associated Bacteroides sp. (HF183) was analyzed to explore possible cross contamination between the sewer system and storm water collection system of the city. Fifteen ECs were detected in water samples from various locations along the stream at estimated levels ranging from low ppt to low ppb. The levels of 4-NP in the storm water sediment samples, ranging from 30-1500 µg/kg (d.w.), positively correlated with the levels of Human-associated Bacteroides sp. (HF183) in the storm water. Our study suggested: 1) collective urban activity and leaky urban sewer systems are significant sources of ECs in storm water runoff that are often untreated or with minimum treatment before flowing into urban streams; and 2) sediment transport and re-suspension can further releases accumulated ECs back into stream water during rain events, resulting in occurrence of ECs downstream and possibly in the receiving river. This study demonstrated that urband storm water runoff could be a significant source, in addition to WWTP effluent, contributing to the widespread occurrence of ECs in aquatic environment.

Coupled 1-D sewer and street networks and 2-D flooding model to rapidly evaluate surface inundation

NASA Astrophysics Data System (ADS)

Kao, Hong-Ming; Hsu, Hao-Ming

2017-04-01

Flash floods have occurred frequently in the urban areas around the world and cause the infrastructure and people living to expose continuously in the high risk level of pluvial flooding. According to historical surveys, the major reasons of severe surface inundations in the urban areas can be attributed to heavy rainfall in the short time and/or drainage system failure. In order to obtain real-time flood forecasting with high accuracy and less uncertainty, an appropriate system for predicting floods is necessary. For the reason, this study coupled 1-D sewer and street networks and 2-D flooding model as an operational modelling system for rapidly evaluating surface inundation. The proposed system is constructed by three significant components: (1) all the rainfall-runoff of a sub-catchment collected via gullies is simulated by the RUNOFF module of the Storm Water Management Model (SWMM); (2) and directly drained to the 1-D sewer and street networks via manholes as inflow discharges to conduct flow routing by using the EXTRAN module of SWMM; (3) after the 1-D simulations, the surcharges from manholes are considered as point sources in 2-D overland flow simulations that are executed by the WASH123D model. It can thus be used for urban flood modelling that reflects the rainfall-runoff processes, and the dynamic flow interactions between the storm sewer system and the ground surface in urban areas. In the present study, we adopted the Huwei Science and Technology Park, located in the south-western part of Taiwan, as the demonstration area because of its high industrial values. The region has an area about 1 km2 with approximately 1 km in both length and width. It is as isolated urban drainage area in which there is a complete sewer system that collects the runoff and drains to the detention pond. Based on the simulated results, the proposed modelling system was found that the simulated floods fit to the survey records because the physical rainfall-runoff phenomena in urban environment were better reflected. Keywords: SWMM, WASH123D, surface inundation, real-time.

Controlling Factors of the Surface Energy and Water Balances in cities located in cold climate regions

NASA Astrophysics Data System (ADS)

Järvi, L.; Grimmond, S. B.; Christen, A.; McFadden, J. P.; Strachan, I. B.

2016-12-01

Urban effects on climate are often pronounced in winter due to large anthropogenic heat releases and differences in snow cover between urban and surrounding rural areas. In this study, we simulate energy and water balances in cities characterized by cold winter climates with snow. Eleven urban sites from Helsinki (Finland), Basel (Switzerland), Montreal (Canada) and Minneapolis (USA) are analysed. The sites were selected based on the availability of either measured turbulent fluxes (from eddy covariance) or surface runoff to be used for model evaluation. The sites vary with respect to land cover fractions, irrigation habits and population densities. For example, the plan area fraction of impervious surface varies from 5% in Minneapolis to 84% in Basel. To simulate urban energy and water balances, we use the Surface Urban Energy and Water balance Scheme (SUEWS) model, which has been designed to minimize the number of required input variables and model parameters. For each site, the model is run in an offline mode using measured hourly meteorological data with a time step of 5-min. As the modelled time periods range from one (Basel) to 7.5 years (Helsinki), a wide range of meteorological conditions occur. Our results show how both evaporation and surface runoff are highly dependent on the fraction of impervious surface cover (r > |0.8|) during snow-free periods. However, high year-to-year variability in simulated evaporation and runoff indicates that climatological factors are also important. In winter, the amount and duration of snow cover become import controlling factor in determining the two components of water balance. The shorter the snow cover period is, the larger the cumulative runoff tends to be. Thus, our results suggest that warmer winters with less snow will increase the stress on drainage systems and modify the urban ecosystem via changes in evaporation and Bowen ratio. Also, our results indicate that simply using the fraction of impervious or pervious surfaces when estimating the surface runoff at different sites is not sufficient, but rather inter-annual variability in climatology also needs to be considered.

Percentage entrainment of constituent loads in urban runoff, south Florida

USGS Publications Warehouse

Miller, R.A.

1985-01-01

Runoff quantity and quality data from four urban basins in south Florida were analyzed to determine the entrainment of total nitrogen, total phosphorus, total carbon, chemical oxygen demand, suspended solids, and total lead within the stormwater runoff. Land use of the homogeneously developed basins are residential (single family), highway, commercial, and apartment (multifamily). A computational procedure was used to calculate, for all storms that had water-quality data, the percentage of constituent load entrainment in specified depths of runoff. The plot of percentage of constituent load entrained as a function of runoff is termed the percentage-entrainment curve. Percentage-entrainment curves were developed for three different source areas of basin runoff: (1) the hydraulically effective impervious area, (2) the contributing area, and (3) the drainage area. With basin runoff expressed in inches over the contributing area, the depth of runoff required to remove 90 percent of the constituent load ranged from about 0.4 inch to about 1.4 inches; and to remove 80 percent, from about 0.3 to 0.9 inch. Analysis of variance, using depth of runoff from the contributing area as the response variable, showed that the factor 'basin' is statistically significant, but that the factor 'constituent' is not statistically significant in the forming of the percentage-entrainment curve. Evidently the sewerage design, whether elongated or concise in plan dictates the shape of the percentage-entrainment curve. The percentage-entrainment curves for all constituents were averaged for each basin and plotted against basin runoff for three source areas of runoff-the hydraulically effective impervious area, the contributing area, and the drainage area. The relative positions of the three curves are directly related to the relative sizes of the three source areas considered. One general percentage-entrainment curve based on runoff from the contributing area was formed by averaging across both constituents and basins. Its coordinates are: 0.25 inch of runoff for 50-percent entrainment, 0.65 inch of runoff for 80-percent entrainment, and 0.95 inch of runoff for 90-percent entrainment. The general percentage-entrainment curve based on runoff from the hydraulically effective impervious area has runoff values of 0.35, 0.95, 1.6 inches, respectively.

A numerical forecast model for road meteorology

NASA Astrophysics Data System (ADS)

Meng, Chunlei

2017-05-01

A fine-scale numerical model for road surface parameters prediction (BJ-ROME) is developed based on the Common Land Model. The model is validated using in situ observation data measured by the ROSA road weather stations of Vaisala Company, Finland. BJ-ROME not only takes into account road surface factors, such as imperviousness, relatively low albedo, high heat capacity, and high heat conductivity, but also considers the influence of urban anthropogenic heat, impervious surface evaporation, and urban land-use/land-cover changes. The forecast time span and the update interval of BJ-ROME in vocational operation are 24 and 3 h, respectively. The validation results indicate that BJ-ROME can successfully simulate the diurnal variation of road surface temperature both under clear-sky and rainfall conditions. BJ-ROME can simulate road water and snow depth well if the artificial removing was considered. Road surface energy balance in rainy days is quite different from that in clear-sky conditions. Road evaporation could not be neglected in road surface water cycle research. The results of sensitivity analysis show solar radiation correction coefficient, asphalt depth, and asphalt heat conductivity are important parameters in road interface temperatures simulation. The prediction results could be used as a reference of maintenance decision support system to mitigate the traffic jam and urban water logging especially in large cities.

Controlled-release Hydrogen Peroxide for On-site Treatment of Organic Pollutants in Urban Storm Runoff

NASA Astrophysics Data System (ADS)

Lee, E.; Sun, S.; Kim, Y.

2011-12-01

Nonpoint source (NPS) pollutants are the remaining cause of the environment problems, significantly impairing the hydrologic and biologic function of urban water systems and human health. Managing the NPS loads to urban aquatic systems remains a challenge because of ubiquitous contaminant sources and large pollutants loads in the first flush. Best management practices (BMPs) exist for reducing the NPS pollutants in urban storm waters, but the remedial efficiencies of these passive schemes are unpredictable. This study aims to develop a controlled-release system as part of an in situ chemical oxidation scheme designed for on-site treatment of organic pollutants in urban runoff. Controlled-release hydrogen peroxide (CR-HP) solids were manufactured by dispersing fine sodium percarbonate granules in paraffin wax matrices. Release kinetics and treatment efficiencies of CR-HP for BTEX and MTBE were investigated through a series of column tests. Release data indicated that the CR-HP could continually release hydrogen peroxide (H2O2) in flowing water at controlled rates over 276-1756 days, and the release rates could be adjusted by changing the mixing ratios of sodium percarbonate and wax matrices. Additional column tests and model calculations demonstrated that CR-HP/UV systems can provide low-cost, target-specific, and persistent source of oxidants for efficient treatment of organic compounds in urban storm runoff.

Study on Construction Technology of Municipal Road and Bridge Concrete

NASA Astrophysics Data System (ADS)

Tang, Fuyong

2018-03-01

With the continuous development of social economy and the accelerating process of urbanization, municipal road and bridge projects have also shown a trend of rapid development. Municipal road and bridge work can fully reflect the economic and cultural development level of cities and is also an important symbol of urban development. As a basic material of construction, concrete is widely used in engineering construction. This article will analyze the municipal road and bridge concrete construction technology, put forward corresponding measures.

Determination of rainfall losses in Virginia : the effects of urbanization.

DOT National Transportation Integrated Search

1983-01-01

The effects of urbanization on the Corps of Engineers' HEC-I rainfall-runoff model parameters were examined. Data on rainfall events and corresponding streamflow hydrographs were gathered for five watersheds in rural and highly urbanized areas in Vir...

Urban Land: Study of Surface Run-off Composition and Its Dynamics

NASA Astrophysics Data System (ADS)

Palagin, E. D.; Gridneva, M. A.; Bykova, P. G.

2017-11-01

The qualitative composition of urban land surface run-off is liable to significant variations. To study surface run-off dynamics, to examine its behaviour and to discover reasons of these variations, it is relevant to use the mathematical apparatus technique of time series analysis. A seasonal decomposition procedure was applied to a temporary series of monthly dynamics with the annual frequency of seasonal variations in connection with a multiplicative model. The results of the quantitative chemical analysis of surface wastewater of the 22nd Partsjezd outlet in Samara for the period of 2004-2016 were used as basic data. As a result of the analysis, a seasonal pattern of variations in the composition of surface run-off in Samara was identified. Seasonal indices upon 15 waste-water quality indicators were defined. BOD (full), suspended materials, mineralization, chlorides, sulphates, ammonium-ion, nitrite-anion, nitrate-anion, phosphates (phosphorus), iron general, copper, zinc, aluminium, petroleum products, synthetic surfactants (anion-active). Based on the seasonal decomposition of the time series data, the contribution of trends, seasonal and accidental components of the variability of the surface run-off indicators was estimated.

Soil erosion on road and railways embankments in the Canyoles river Basin. Eastern Spain.

NASA Astrophysics Data System (ADS)

Cerdà, Artemi; Antonio, Giménez-Morera; Félix Ángel, González-Peñaloza; María, Burguet; Paulo, Pereira; José Reyes, Ruiz

2013-04-01

Mediterranean landscapes are man-made. Its human ecosystems are characterized by a high population density, a long history of human settlement and an intense exchange of goods and people (Cerdà et al., 2010). This was possible due to a dense road network, most of it created during the Roman Empire. Modern roads and railways increased drastically during the last 30 years in the Mediterranean. Spain is a clear example of the acceleration of the road and railway infrastructures (Bel, 2005), especially during the 1960s as the tourism started to become a big issue in this part of the World. The increase in road and railways during the last 30 years resulted in a new transport system in Spain, which is based on high-speed railways and motorways. The characteristic of these infrastructures is that they were built by means of embankments, and little is now about the erosional response of those embankments to rainfall. The objective of this research is to assess the soil losses measured in road and railway embankments. The Canyoles River watershed was selected as an example of a region with a dense and recently developed modern network of roads, motorways and railway. The Canyoles river watershed is the natural path between the Mediterranean coast and Central Spain, the capital of the country and the touristic regions. Two motorways and two railways were built or re-built during the last two years and this paper assesses their impact on soil and water losses. As soil erosion rates are dependent on the high intensity - low frequency rainfall events, rainfall simulation experiments (40 experiments) were conducted (1 m2 plots; 60 minutes duration; 78 mm h-1 intensity) were carried out over plots on 2 railway (n=10 + 10) and motorway (n=10 + 10) research sites in August 2011, under very dry conditions. Soil moisture was below 5 % in the top 2 cm soil layer. The vegetation cover was very low in the two road and two railway embankments as the average cover was 4.2 % ranging from 1 to 7 %. Time to ponding was 135.8 seconds, ranging from 131.1 and 158.7 seconds within four road embankments. Time to runoff was also very quick, with 367 seconds, ranging from 326.9 to 376.9 seconds after the start of the rain. The runoff outlet was reached after 402.08 seconds, ranging from 367.1 to 428.5 seconds. Runoff was 56.25 % of the rainfall, ranging from 54.93 % in the Road1 embankments to 57.08 % on the Railway1 embamkments. Sediment concentration was 41.41 g l-1 in average for the 40 rainfall simulation experiments and ranged from 40.20 to 42.54 g l-1. After 78 mm h-1 (156 liters on the 2m2 plots) of simulated rainfall during one hour, the total runoff collected was 87.75 %, with a very low variability within the four studied embankments an the 40 research plots (9 % variation coefficient). The sediment yield collected during the 25-year return period experiments resulted in 3.67 Kg in average values with again a low spatial variability (18 % variation coefficient). The soil erosion registered in the four-studied road and railway embankments reached a value of 18.25 Mg ha-1 h-1. The results shown above demonstrate that the water and soil losses in the road embankments under intense thunderstorms are very high, which is a general trend in Mediterranean ecosystems due to the climatologically conditions and the lack of restoration and rehabilitation strategies (Cerdà, 2007). The comparison with other research under different land uses show that the soil losses are very high on the road embankments due to the impact of the slope and the bare soil (Bakr et al., 2012) and show higher erosion rates than the unpaved forest roads (Jordán and Martínez Zavala, 2008). Scrublands, meadows, forest, and agriculture land in general show much lower soil losses at the study area (García Orenes et al., 2009). This is why most of the current research is developing strategies to control the soil and water losses (Persyn et al., 2004: Xu et al., 2006; de Oñae et al., 2009). This paper concludes that the soil erosion on road and railways are not sustainable and they are the highest soil losses measured in the study area. Road embankments are triggering land degradation and Desertification processes as less water is available for the soil processes and more soil is lost. Keywords: Road, Railway, Embankments, Erosion, Runoff. Acknowledgements The research projects GL2008-02879/BTE and LEDDRA 243857 supported this research. References Bakr, N., Weindorf, D.C., Zhu, Y., Arceneaux, A.E., & Selim, H.M. 2012. Evaluation of compost/mulch as highway embankment erosion control in Louisiana at the plot-scale Journal of Hydrology, 468-469, 257-267. Bel, G. 2011. Infrastructure and nation building: The regulation and financing of network transportation infrastructures in Spain (1720-2010), Business History, 53:5, 688-705. http://dx.doi.org/10.1080/00076791.2011.599591 Cerdà, A. 2007. Soil water erosion on road enbankments in eastern Spain. Science of the Total Environment, 378, 151-155. Cerdà, A., Hooke, J. Romero-Diaz, A., Montanarella, L., & Lavee, H. 2010. Soil erosion on Mediterranean Type-Ecosystems Land Degradation and Development. Editors. DOI 10.1002/ldr.968. De Oña, J., Osorio, F., & Garcia, P. A. 2009. Assessing the effects of using compost-sludge mixtures to reduce erosion in road embankments. Journal of Hazardous Materials, 164(2-3), 1257-1265. García-Orenes, F., Cerdà, A., Mataix-Solera, J., Guerrero, C., Bodí, M.B., Arcenegui, V., Zornoza, R. & Sempere, J.G. 2009. Effects of agricultural management on surface soil properties and soil-water losses in eastern Spain. Soil and Tillage Research, doi:10.1016/j.still.2009.06.002 Jordán, A., & Martínez-Zavala, L. 2008. Soil loss and runoff rates on unpaved forest roads in southern Spain after simulated rainfall. Forest Ecology and Management, 255 (3-4), 913-919. Persyn, R. A., Glanville, T. D., Richard, T. L., Laflen, J. M., & Dixon, P. M. 2004. Environmental effects of applying composted organics to new highway embankments: Part 1. interrill runoff and erosion. Transactions of the American Society of Agricultural Engineers, 47(2), 463-469. Xu, X., Zhang, K., Kong, Y., Chen, J., & Yu, B. 2006. Effectiveness of erosion control measures along the qinghai-tibet highway, tibetan plateau, china. Transportation Research Part D: Transport and Environment, 11(4), 302-309.

Effects of road salts on groundwater and surface water dynamics of socium and chloride in an urban restored stream

EPA Science Inventory

Road salts are a growing environmental concern in urban watersheds. We examined groundwater (GW) and surface water (SW) dynamics of Na+ and Cl− in Minebank Run (MBR), an urban stream in Maryland, USA. We observed an increasing salinity trend in this restored stream. Current basef...

Concentrations and loads of PCBs, dioxins, PAHs, PBDEs, OC pesticides and pyrethroids during storm and low flow conditions in a small urban semi-arid watershed.

PubMed

Gilbreath, Alicia N; McKee, Lester J

2015-09-01

Urban runoff has been identified in water quality policy documents for San Francisco Bay as a large and potentially controllable source of pollutants. In response, concentrations of suspended sediments and a range of trace organic pollutants were intensively measured in dry weather and storm flow runoff from a 100% urban watershed. Flow in this highly urban watershed responded very quickly to rainfall and varied widely resulting in rapid changes of turbidity, suspended sediments and pollutant concentrations. Concentrations of each organic pollutant class were within similar ranges reported in other studies of urban runoff, however comparison was limited for several of the pollutants given information scarcity. Consistently among PCBs, PBDEs, and PAHs, the more hydrophobic congeners were transported in larger proportions during storm flows relative to low flows. Loads for Water Years 2007-2010 were estimated using regression with turbidity during the monitored months and a flow weighted mean concentration for unmonitored dry season months. More than 91% of the loads for every pollutant measured were transported during storm events, along with 87% of the total discharge. While this dataset fills an important local data gap for highly urban watersheds of San Francisco Bay, the methods, the uniqueness of the analyte list, and the resulting interpretations have applicability for managing pollutant loads in urban watersheds in other parts of the world. Copyright © 2015 Elsevier B.V. All rights reserved.

A video-based real-time adaptive vehicle-counting system for urban roads.

PubMed

Liu, Fei; Zeng, Zhiyuan; Jiang, Rong

2017-01-01

In developing nations, many expanding cities are facing challenges that result from the overwhelming numbers of people and vehicles. Collecting real-time, reliable and precise traffic flow information is crucial for urban traffic management. The main purpose of this paper is to develop an adaptive model that can assess the real-time vehicle counts on urban roads using computer vision technologies. This paper proposes an automatic real-time background update algorithm for vehicle detection and an adaptive pattern for vehicle counting based on the virtual loop and detection line methods. In addition, a new robust detection method is introduced to monitor the real-time traffic congestion state of road section. A prototype system has been developed and installed on an urban road for testing. The results show that the system is robust, with a real-time counting accuracy exceeding 99% in most field scenarios.

A video-based real-time adaptive vehicle-counting system for urban roads

PubMed Central

2017-01-01

In developing nations, many expanding cities are facing challenges that result from the overwhelming numbers of people and vehicles. Collecting real-time, reliable and precise traffic flow information is crucial for urban traffic management. The main purpose of this paper is to develop an adaptive model that can assess the real-time vehicle counts on urban roads using computer vision technologies. This paper proposes an automatic real-time background update algorithm for vehicle detection and an adaptive pattern for vehicle counting based on the virtual loop and detection line methods. In addition, a new robust detection method is introduced to monitor the real-time traffic congestion state of road section. A prototype system has been developed and installed on an urban road for testing. The results show that the system is robust, with a real-time counting accuracy exceeding 99% in most field scenarios. PMID:29135984

Positive effects of afforestation efforts on the health of urban soils

Treesearch

Emily E. Oldfield; Alexander J. Felson; Stephen A. Wood; Richard A. Hallett; Michael S. Strickland; Mark A. Bradford

2014-01-01

Large-scale tree planting projects in cities are increasingly implemented as a strategy to improve the urban environment. Trees provide multiple benefits in cities, including reduction of urban temperatures, improved air quality, mitigation of storm-water run-off, and provision of wildlife habitat. How urban afforestation affects the properties and functions of urban...

Identification of the potential gap areas for the developing green infrastructure in the Urban area using High resolution satellite Imagery

NASA Astrophysics Data System (ADS)

Kanaparthi, M. B.

2017-12-01

In India urban population is growing day by day which is causing air pollution less air quality finally leading to climate change and global warming. To mitigate the effect of the climate change we need to plant more trees in the urban area. The objective of this study is develop a plan to improve the urban Green Infrastructure (GI) to fight against the climate change and global warming. Improving GI is a challenging and difficult task in the urban areas because land unavailability of land, to overcome the problem greenways is a good the solution. Greenway is a linear open space developed along the rivers, canals, roads in the urban areas to form a network of green spaces. Roads are the most common structures in the urban area. The idea is to develop the greenways alongside the road to connecting the different green spaces. Tree crowns will act as culverts to connect the green spaces. This will require the spatial structure of the green space, distribution of trees along the roads and the gap areas along the road where more trees can be planted. This can be achieved with help of high resolution Satellite Imagery and the object extraction techniques. This study was carried in the city Bhimavaram which is located in state Andhra Pradesh. The final outcome of this study is potential gap areas for planting trees in the city.

Urban networks among Chinese cities along "the Belt and Road": A case of web search activity in cyberspace.

PubMed

Zhang, Lu; Du, Hongru; Zhao, Yannan; Wu, Rongwei; Zhang, Xiaolei

2017-01-01

"The Belt and Road" initiative has been expected to facilitate interactions among numerous city centers. This initiative would generate a number of centers, both economic and political, which would facilitate greater interaction. To explore how information flows are merged and the specific opportunities that may be offered, Chinese cities along "the Belt and Road" are selected for a case study. Furthermore, urban networks in cyberspace have been characterized by their infrastructure orientation, which implies that there is a relative dearth of studies focusing on the investigation of urban hierarchies by capturing information flows between Chinese cities along "the Belt and Road". This paper employs Baidu, the main web search engine in China, to examine urban hierarchies. The results show that urban networks become more balanced, shifting from a polycentric to a homogenized pattern. Furthermore, cities in networks tend to have both a hierarchical system and a spatial concentration primarily in regions such as Beijing-Tianjin-Hebei, Yangtze River Delta and the Pearl River Delta region. Urban hierarchy based on web search activity does not follow the existing hierarchical system based on geospatial and economic development in all cases. Moreover, urban networks, under the framework of "the Belt and Road", show several significant corridors and more opportunities for more cities, particularly western cities. Furthermore, factors that may influence web search activity are explored. The results show that web search activity is significantly influenced by the economic gap, geographical proximity and administrative rank of the city.

Effects of urbanization on stream ecosystems along an agriculture-to-urban land-use gradient, Milwaukee to Green Bay, Wisconsin, 2003-2004

USGS Publications Warehouse

Richards, Kevin D.; Scudder, Barbara C.; Fitzpatrick, Faith A.; Steuer, Jeffery J.; Bell, Amanda H.; Peppler, Marie C.; Stewart, Jana S.; Harris, Mitchell A.

2010-01-01

In 2003 and 2004, 30 streams near Milwaukee and Green Bay, Wisconsin, were part of a national study by the U.S. Geological Survey to assess urbanization effects on physical, chemical, and biological characteristics along an agriculture-to-urban land-use gradient. A geographic information system was used to characterize natural landscape features that define the environmental setting and the degree of urbanization within each stream watershed. A combination of land cover, socioeconomic, and infrastructure variables were integrated into a multi-metric urban intensity index, scaled from 0 to 100, and assigned to each stream site to identify a gradient of urbanization within relatively homogeneous environmental settings. The 35 variables used to develop the final urban intensity index characterized the degree of urbanization and included road infrastructure (road area and road traffic index), 100-meter riparian land cover (percentage of impervious surface, shrubland, and agriculture), watershed land cover (percentage of impervious surface, developed/urban land, shrubland, and agriculture), and 26 socioeconomic variables (U.S. Census Bureau, 2001). Characteristics examined as part of this study included: habitat, hydrology, stream temperature, water chemistry (chloride, sulfate, nutrients, dissolved and particulate organic and inorganic carbon, pesticides, and suspended sediment), benthic algae, benthic invertebrates, and fish. Semipermeable membrane devices (SPMDs) were used to assess the potential for bioconcentration of hydrophobic organic contaminants (specifically polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine and pyrethroid insecticides) in biological membranes, such as the gills of fish. Physical habitat measurements reflective of channel enlargement, including bankfull channel size and bank erosion, increased with increasing urbanization within the watershed. In this study, percentage of riffles and streambed substrate size were more strongly related to local geologic setting, slope, watershed topography, and river-engineering practices than to urbanization. Historical local river-engineering features such as channelization, bank stabilization, and grade controls may have confounded relations among habitat characteristics and urbanization. A number of hydrologic-condition metrics (including flashiness and duration of high flow during pre- or post-ice periods) showed strong relations to the urban intensity index. Hydrologic-condition metrics cannot be used alone to predict habitat or geomorphic change. Chloride and SPMD measures of potential toxicity and polycyclic aromatic hydrocarbon concentrations showed the strongest positive correlations to urbanization including increases in road infrastructure, percentage of impervious surface in the watershed, urban land cover, and land-distribution related to urban land cover. This suggests that automobiles and the infrastructure required to support automobiles are a significant source of these compounds in this study area. Chloride in spring and summer showed a significant positive correlation with the urban intensity index; concentrations increased with increasing road infrastructure, urban land cover, and a number of landscape variables related to urbanization. Spring concentrations of sulfate, prometon, and diazinon correlated to fewer urban characteristics than chloride, including increases in road infrastructure, percentage of impervious surface, and urban land cover. Changes in biological communities correlated to the urban intensity index or individual urban-associated variables. Decreased percentages of pollution-sensitive diatoms and diatoms requiring high dissolved-oxygen saturation correlated to increases in the percentage of developed urban land, total impervious surface, stream flashiness, population density, road-area density, and decreases in the percentage of wetland in the watershed. Invertebrate taxa richness and Coleop

Flow Dynamics and Nutrient Reduction in Rain Gardens

EPA Science Inventory

The hydrological dynamics and changes in stormwater nutrient concentrations within rain gardens were studied by introducing captured stormwater runoff to rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey. The runoff used in these experiments was collected...