scholarly journals Zn and Pb emissions from roofing materials – modelling and mass balance attempt at the scale of a small urban catchment

2011 ◽  
Vol 63 (11) ◽  
pp. 2590-2597 ◽  
Author(s):  
M. C. Gromaire ◽  
P. Robert-Sainte ◽  
A. Bressy ◽  
M. Saad ◽  
B. De Gouvello ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Assessment Tools ◽  
Test Bed ◽  
Catchment Scale ◽  
Sewer System ◽  
Urban Catchment ◽  
Surface Areas ◽  
Total Runoff ◽  
Materials Modelling ◽  
Roofing Materials

Many studies have shown that roofing materials are an important source of metals in urban runoff. Today, in the context of the European Water Directive (2000/60 CE), the quantification of these emissions is necessary, and thus the development of assessment tools is needed. This study focuses on a small urban catchment (drained by a separative sewer system). Atmospheric fallout, road runoff, roof runoff and total runoff at the outlet of the catchment were sampled. The aim is (1) to verify the contribution of roofing materials to metallic flows of Zn and Pb at the catchment scale and (2) to try to model emissions using some models previously developed at the test-bed scale. These models have to be tested at different spatial scales. Results obtained confirm the strong contribution of roofing materials to Zn and Pb flows at the catchment scale. For Zn, models tested were successfully transposed and validated at the roof and the catchment scales, permitting a good quantification of Zn emissions. For Pb, the use of the models highlights some difficulties, especially concerning the identification and the quantification of lead surface areas implemented.

Quantification of sewer system infiltration using δ18O hydrograph separation

2009 ◽  
Vol 60 (3) ◽  
pp. 727-735 ◽  
Author(s):  
V. Prigiobbe ◽  
M. Giulianelli
Keyword(s):  
Sampling Strategy ◽  
Infiltration Rate ◽  
Hydrograph Separation ◽  
Catchment Scale ◽  
Sewer System ◽  
Urban Catchment ◽  
Sewer Systems ◽  
Conservative Tracer ◽  
Effective Water ◽  
Sewer Networks

The infiltration of parasitical water into two sewer systems in Rome (Italy) was quantified during a dry weather period. Infiltration was estimated using the hydrograph separation method with two water components and δ18O as a conservative tracer. The two water components were groundwater, the possible source of parasitical water within the sewer, and drinking water discharged into the sewer system. This method was applied at an urban catchment scale in order to test the effective water-tightness of two different sewer networks. The sampling strategy was based on an uncertainty analysis and the errors have been propagated using Monte Carlo random sampling. Our field applications showed that the method can be applied easily and quickly, but the error in the estimated infiltration rate can be up to 20%. The estimated infiltration into the recent sewer in Torraccia is 14% and can be considered negligible given the precision of the method, while the old sewer in Infernetto has an estimated infiltration of 50%.

Origins and characteristics of urban wet weather pollution in combined sewer systems: the experimental urban catchment “Le Marais” in Paris

1998 ◽  
Vol 37 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Marie-Christine Gromaire-Mertz ◽  
Ghassan Chebbo ◽  
Mohamed Saad
Keyword(s):  
Waste Water ◽  
Sewer System ◽  
Urban Catchment ◽  
Rainfall Events ◽  
Sources Of Pollution ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Wet Weather ◽  
Wet Weather Flow ◽  
Different Sources

An experimental urban catchment has been created in the centre of Paris, in order to obtain a description of the pollution of urban wet weather flows at different levels of the combined sewer system, and to estimate the contribution of runoff, waste water and sewer sediments to this pollution. Twenty-two rainfall events were studied from May to October 1996. Dry weather flow was monitored for one week. Roof, street and yard runoff, total flow at the catchment outlet and waste water were analysed for SS, VSS, COD and BOD5, on both total and dissolved fraction. Results show an evolution in the characteristics of wet weather flow from up to downstream: concentrations increase from the catchment entry to the outlet, as well as the proportion of particle-bound pollutants and the part of organic matter. A first evaluation of the different sources of pollution establishes that a major part of wet weather flow pollution originates from inside the combined sewer, probably through erosion of sewer sediments.

scholarly journals Hydromorphologic Sorting of In-Stream Nitrogen Uptake Across Spatial Scales

Ecosystems ◽  
2020 ◽  
Author(s):  
Ute Risse-Buhl ◽  
Christine Anlanger ◽  
Christian Noss ◽  
Andreas Lorke ◽  
Daniel von Schiller ◽  
...  
Keyword(s):  
Spatial Scales ◽  
N Uptake ◽  
High Light ◽  
Environmental Constraints ◽  
Light Conditions ◽  
Catchment Scale ◽  
Biogeochemical Fluxes ◽  
Epilithic Biofilms ◽  
Lower Biomass

AbstractNitrogen (N) uptake is a key process in stream ecosystems that is mediated mainly by benthic microorganisms (biofilms on different substrata) and has implications for the biogeochemical fluxes at catchment scale and beyond. Here, we focused on the drivers of assimilatory N uptake, especially the effects of hydromorphology and other environmental constraints, across three spatial scales: micro, meso and reach. In two seasons (summer and spring), we performed whole-reach 15N-labelled ammonium injection experiments in two montane, gravel-bed stream reaches with riffle–pool sequences. N uptake was highest in epilithic biofilms, thallophytes and roots (min–max range 0.2–545.2 mg N m−2 day−1) and lowest in leaves, wood and fine benthic organic matter (0.05–209.2 mg N m−2 day−1). At the microscale, N uptake of all primary uptake compartments except wood was higher in riffles than in pools. At the mesoscale, hydromorphology determined the distribution of primary uptake compartments, with fast-flowing riffles being dominated by biologically more active compartments and pools being dominated by biologically less active compartments. Despite a lower biomass of primary uptake compartments, mesoscale N uptake was 1.7–3.0 times higher in riffles than in pools. At reach scale, N uptake ranged from 79.6 to 334.1 mg N m−2 day−1. Highest reach-scale N uptake was caused by a bloom of thallopyhtes, mainly filamentous autotrophs, during stable low discharge and high light conditions. Our results reveal the important role of hydromorphologic sorting of primary uptake compartments at mesoscale as a controlling factor for reach-scale N uptake in streams.

scholarly journals Hydrologic-environmental effects of sponge city under different spatial scales

2019 ◽  
Vol 10 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Jiake Li ◽  
Cong Mu ◽  
Chenning Deng ◽  
Menghua Ma
Keyword(s):  
Environmental Effects ◽  
Large Scale ◽  
Peak Flow ◽  
Spatial Scales ◽  
Small Scale ◽  
Pollution Load ◽  
Sponge City ◽  
Medium Scale ◽  
Total Runoff ◽  
Runoff Reduction

Abstract The storm water management models were established at three spatial scales (large, medium, and small) based on a sponge city pilot area in China to explore the hydrological and environmental effects of rainfall conditions and development modes. Results showed the following. (1) Total runoff reduction rates increased from 26.7% to 53.9% for the rainfall event of a 2-year recurrence period as the scale increased. For 5-year and above recurrence periods, total runoff reduction rates were 19.5–49.4%. These rates increased from the small to medium scale and slightly decreased from the medium to large scale. (2) The runoff coefficients were 0.87–0.29, which decreased from the small to medium scale and were basically constant from the medium to large scale. (3) The peak flow reduction rates decreased with increased recurrence periods. The rates increased initially and then decreased at the small scale, whereas the opposite trend occurred at the medium scale. (4) The reduction rates of pollutants were negatively correlated with recurrence periods under the three spatial scales. The pollution load reduction rates were 19.5–54.7%, which increased from the small to medium scale and were basically constant from the medium to large scale.

scholarly journals Extending the Predictability of Hydrometeorological Flood Events Using Radar Rainfall Nowcasting

2006 ◽  
Vol 7 (4) ◽  
pp. 660-677 ◽  
Author(s):  
Enrique R. Vivoni ◽  
Dara Entekhabi ◽  
Rafael L. Bras ◽  
Valeriy Y. Ivanov ◽  
Matthew P. Van Horne ◽  
...  
Keyword(s):  
Lead Time ◽  
Flash Flood ◽  
Spatial Scales ◽  
Surface Characteristics ◽  
Hydrologic Model ◽  
Flood Events ◽  
Catchment Scale ◽  
Radar Rainfall ◽  
Time Operation ◽  
Forecast Lead Time

Abstract The predictability of hydrometeorological flood events is investigated through the combined use of radar nowcasting and distributed hydrologic modeling. Nowcasting of radar-derived rainfall fields can extend the lead time for issuing flood and flash flood forecasts based on a physically based hydrologic model that explicitly accounts for spatial variations in topography, surface characteristics, and meteorological forcing. Through comparisons to discharge observations at multiple gauges (at the basin outlet and interior points), flood predictability is assessed as a function of forecast lead time, catchment scale, and rainfall spatial variability in a simulated real-time operation. The forecast experiments are carried out at temporal and spatial scales relevant for operational hydrologic forecasting. Two modes for temporal coupling of the radar nowcasting and distributed hydrologic models (interpolation and extended-lead forecasting) are proposed and evaluated for flood events within a set of nested basins in Oklahoma. Comparisons of the radar-based forecasts to persistence show the advantages of utilizing radar nowcasting for predicting near-future rainfall during flood event evolution.

scholarly journals A hydrological emulator for global applications – HE v1.0.0

2018 ◽  
Vol 11 (3) ◽  
pp. 1077-1092 ◽  
Author(s):  
Yaling Liu ◽  
Mohamad Hejazi ◽  
Hongyi Li ◽  
Xuesong Zhang ◽  
Guoyong Leng
Keyword(s):  
Spatial Heterogeneity ◽  
Computational Efficiency ◽  
Spatial Scales ◽  
Computational Cost ◽  
Infiltration Capacity ◽  
Vic Model ◽  
Total Runoff ◽  
Computation Efficiency ◽  
Annual Total ◽  
Distributed Scheme

Abstract. While global hydrological models (GHMs) are very useful in exploring water resources and interactions between the Earth and human systems, their use often requires numerous model inputs, complex model calibration, and high computation costs. To overcome these challenges, we construct an efficient open-source and ready-to-use hydrological emulator (HE) that can mimic complex GHMs at a range of spatial scales (e.g., basin, region, globe). More specifically, we construct both a lumped and a distributed scheme of the HE based on the monthly abcd model to explore the tradeoff between computational cost and model fidelity. Model predictability and computational efficiency are evaluated in simulating global runoff from 1971 to 2010 with both the lumped and distributed schemes. The results are compared against the runoff product from the widely used Variable Infiltration Capacity (VIC) model. Our evaluation indicates that the lumped and distributed schemes present comparable results regarding annual total quantity, spatial pattern, and temporal variation of the major water fluxes (e.g., total runoff, evapotranspiration) across the global 235 basins (e.g., correlation coefficient r between the annual total runoff from either of these two schemes and the VIC is  > 0.96), except for several cold (e.g., Arctic, interior Tibet), dry (e.g., North Africa) and mountainous (e.g., Argentina) regions. Compared against the monthly total runoff product from the VIC (aggregated from daily runoff), the global mean Kling–Gupta efficiencies are 0.75 and 0.79 for the lumped and distributed schemes, respectively, with the distributed scheme better capturing spatial heterogeneity. Notably, the computation efficiency of the lumped scheme is 2 orders of magnitude higher than the distributed one and 7 orders more efficient than the VIC model. A case study of uncertainty analysis for the world's 16 basins with top annual streamflow is conducted using 100 000 model simulations, and it demonstrates the lumped scheme's extraordinary advantage in computational efficiency. Our results suggest that the revised lumped abcd model can serve as an efficient and reasonable HE for complex GHMs and is suitable for broad practical use, and the distributed scheme is also an efficient alternative if spatial heterogeneity is of more interest.

scholarly journals Comparison of MODIS and SWAT Evapotranspiration over a Complex Terrain at Different Spatial Scales

2017 ◽  
Author(s):  
Olanrewaju O. Abiodun ◽  
Huade Guan ◽  
Vincent E. A. Post ◽  
Okke Batelaan
Keyword(s):  
Complex Terrain ◽  
Spatial Scales ◽  
Swat Model ◽  
South Australia ◽  
Remotely Sensed ◽  
Distributed Model ◽  
Climate Data ◽  
Remotely Sensed Data ◽  
Catchment Scale ◽  
Distributed Hydrological Models

Abstract. In most hydrological systems, evapotranspiration (ET) and precipitation are the largest components of the water balance, which are difficult to estimate, particularly over complex terrain. In recent decades, the advent of remotely-sensed data based ET algorithms and distributed hydrological models has provided improved spatially-upscaled ET estimates. However, information on the performance of these methods at various spatial scales is limited. This study compares the ET from the MODIS remotely sensed ET dataset (MOD16) with the ET estimates from a SWAT hydrological model for the complex terrain of the Sixth Creek Catchment of the Western Mount Lofty Ranges, South Australia. The SWAT model analyses are performed on daily timescales with a 6-year calibration period (2000–2005) and 7-year validation period (2007–2013). Differences in ET estimation between the two methods of up to 48 %, 21 % and 16 % were observed at respectively 1 km2, 5 km2 and 10 km2 spatial resolutions. Land cover differences, mismatches between the two methods and catchment-scale averaging of input climate data in the SWAT semi-distributed model were identified as the principal sources of weaker correlations at higher spatial resolution.

scholarly journals Assessing the long-term hydrologic response to wildfires in mountainous regions

2017 ◽  
Author(s):  
Aaron Havel ◽  
Ali Tasdighi ◽  
Mazdak Arabi
Keyword(s):  
Assessment Tool ◽  
Spatial Scales ◽  
Swat Model ◽  
Hydrologic Response ◽  
Mountainous Regions ◽  
Total Runoff ◽  
Streamflow Statistics ◽  
Flow Duration Curves ◽  
Hydrologic Responses

Abstract. This study aims to understand the long-term hydrologic responses to wildfires in mountainous regions at various spatial scales. The Soil and Water Assessment Tool (SWAT) was used to evaluate hydrologic response of the upper Cache la Poudre watershed in Colorado to the 2012 High Park and Hewlett wildfire events. A baseline SWAT model was established to simulate the hydrology of the study area between the years 2000 and 2014. The effects of wildfires on land cover were accounted for in the model using the SWAT land use update module. The wildfire effects on curve numbers were determined comparing the probability distribution of curve numbers after calibrating the model for pre and post wildfire conditions. Daily calibration and testing of the model produced very good results. No-wildfire and wildfire scenarios were created and compared to quantify changes in average annual total runoff volume, water budgets, and full streamflow statistics at different spatial scales. At the watershed scale, wildfire conditions showed little impact on the hydrologic responses. However, a runoff increase up to 75 percent was observed between the scenarios in sub-watersheds with high burn intensity. Generally, higher surface runoff and decreased subsurface flow were observed under post-wildfire conditions. Flow-duration curves developed for burned sub-basins using full streamflow statistics showed that less frequent streamflows become greater in magnitude. A strong (R2 > 0.8) and significant (p 

Sign in / Sign up

Export Citation Format

Share Document