THE ROLE OF ANTHROPOGENIC HYDROLOGY ON THE TRANSPORT, PARTITIONING AND SOLID-PHASE DISTRIBUTION OF HEAVY METALS IN URBAN STORM WATER – IMPLICATIONS FOR TREATMENT

An estimate of diffuse sources of heavy metals (Hg, Cd, Cu, Zn, Pb, Cr, Ni) in the Rhine catchment stressed the urban storm water discharges in the German part and drainage flow in the Dutch part as the most important pathways. Additional sources are erosion and, to a far lesser extent, atmospheric deposition on open water areas. All other pathways were of minor importance. Meanwhile, after reduction of the point sources by between 72-95%, the diffuse sources dominate the total emissions. For several metals the anthropogenic diffuse sources amounted to 40-80%, the point sources to 15-40% and the geogeneous sources to 5-40%. The estimated inputs sufficiently agreed with the loads of the river Rhine. For the estimation, mean values were used for the water masses and the substance concentrations of the different hydrological pathways. It is recommended to undertake further studies on diffuse sources of heavy metals in urban areas and on the possibilities to improve urban storm water management. The calculation methods and the recommendations of the International Commission for the Protection of the Rhine (ICPR) are explained in detail.

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Solid-phase distribution of heavy metals as affected by single reagent extraction in dredged sediment derived surface soils

Chemical Speciation and Bioavailability ◽

10.1080/09542299.1996.11083265 ◽

1996 ◽

Vol 8 (1-2) ◽

pp. 37-43 ◽

Cited By ~ 9

Author(s):

S.P. Singh ◽

F.M.G. Tack ◽

M.G. Verloo

Keyword(s):

Heavy Metals ◽

Phase Distribution ◽

Solid Phase ◽

Dredged Sediment ◽

Surface Soils

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Evaluating a Sewershed Urban Storm Water Model for Variability in Parameter Sensitivity and Resolution Effects

10.31224/osf.io/u5tsz ◽

2020 ◽

Author(s):

Zhaokai Dong ◽

Daniel Bain ◽

Murat Akcakaya ◽

Carla Ng

Keyword(s):

Pipe Flow ◽

Peak Flow ◽

Model Performance ◽

Parameter Sensitivity ◽

Geometric Parameters ◽

Storm Water ◽

Parameter Estimates ◽

Kappa Statistics ◽

Thiessen Polygon ◽

Urban Storm

A high-quality parameter set is essential for reliable stormwater models. Model performance can be improved by optimizing initial parameter estimates. Parameter sensitivity analysis is a robust way to distinguish the influence of parameters on model output and efficiently target the most important parameters to modify. This study evaluates efficient construction of a sewershed model using relatively low-resolution (e.g., 30 meter DEM) data and explores model sensitivity to parameters and regional characteristics using the EPA’s Storm Water Management Model (SWMM). A SWMM model was developed for a sewershed in the City of Pittsburgh, where stormwater management is a critical concern. We assumed uniform or log-normal distributions for parameters and used Monte Carlo simulations to explore and rank the influence of parameters on predicted surface runoff, peak flow, maximum pipe flow and model performance, as measured using the Nash–Sutcliffe efficiency metric. By using the Thiessen polygon approach for sub-catchment delineations, we substantially simplified the parameterization of the areas and hydraulic parameters. Despite this simplification, our approach provided good agreement with monitored pipe flow (Nash–Sutcliffe efficiency: 0.41 – 0.85). Total runoff and peak flow were very sensitive to the model discretization. The size of the polygons (modeled subcatchment areas) and imperviousness had the most influence on both outputs. The imperviousness, infiltration and Manning’s roughness (in the pervious area) contributed strongly to the Nash-Sutcliffe efficiency (70%), as did pipe geometric parameters (92%). Parameter rank sets were compared by using kappa statistics between any two model elements to identify generalities. Within our relatively large (9.7 km^2) sewershed, optimizing parameters for the highly impervious (>50%) areas and larger pipes lower in the network contributed most to improving Nash–Sutcliffe efficiency. The geometric parameters influence the water quantity distribution and flow conveyance, while imperviousness determines the subcatchment subdivision and influences surface water generation. Application of the Thiessen polygon approach can simplify the construction of large-scale urban storm water models, but the model is sensitive to the sewer network configuration and care must be taken in parameterizing areas (polygons) with heterogenous land uses.

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