Groundwater impact assessment of infiltration structures for urban drainage control (original) (raw)
Related papers
Quantifying Mass Fluxes from Urban Drainage Systems to the Urban Soil-Aquifer System (11 pp)
Journal of Soils and Sediments, 2007
of the forward modeling exercises. This paper concentrates on the city of Rastatt (SW-Germany) as one of four case studies in the AISWURS project. Using the AISUWRS model chain, mass fluxes of boron to the soil-aquifer system in the range of 0.44 mg/m²/a were calculated. As the boron mass fluxes predominantly originate from leaky sewer systems, the result corresponds reasonably well to the uncertainty range that was calculated for sewer leakage with the Monte Carlo method for the entire city area which is 0.01 mg/m²/a to 4.26 mg/m²/a, with a median mass flux of 0.36 mg/m²/a. On the other hand, chloride fluxes to the soil-aquifer systems were estimated by the AISUWRS model chain to be 7.5 g/m²/a while the Monte Carlo approach predicted an input of 0.071 g/m²/a from sewers. This reflects the additional inputs to infiltration areas from road salting, fertilizer application and runoff from impermeable surfaces. According to these calculations, in the Rastatt case study sewer leakage is not a major source for chloride input into the soil-aquifer system.
MDPI AG, Basel, Switzerland, 2017
A rise in the shallow unconfined groundwater at a site in Australia is causing water logging of the underground facility in the affected area. Realizing this problem, a study was conducted to identify the source of water that is causing the rise and to develop an implementation and operation plan of the mitigation (dewatering system). Modelling was undertaken using MODFLOW-SURFACT code, within the framework of Visual MODFLOW, to assess the spatial and temporal groundwater level at the site. The study undertaken incorporates compilation and assessment of available data, including a list of factual information reviewed, development of a conceptual groundwater model for the site and modelling of the pre and post development conditions. The outcomes of the assessment indicate water level rises due to the construction of the embankment are likely less than 0.12 m and changes in land, such as affected area burial, may change aquifer characteristics more significantly than the embankment. It is concluded that the elevated groundwater levels in the affected area are most likely a result of above average rainfall since 2007 and long term cumulative land use changes. The embankment construction is just one of many land use changes that have occurred both within and surrounding the affected area and likely only a minor contributor to the elevated water levels. Greater contribution may be attributed to redirection of the natural flow paths the railway culvert weir reducing the overland flow gradient and ongoing changes (burial) within the affected area and including the embankment. The model findings gives answers on what factors may be/are causing/contributing to, the higher than usual groundwater levels in the study area. A combination of drainage and/or pumping (dewatering system) is suggested as a solution to overcome the problem of rising groundwater levels at the site. Further, the model output can aid in assessing mitigation options, including horizontal drainage networks and pumping to control for the rising water table conditions in the area, depending on the level of treatment and pathogenic criteria.
Field Evaluation Of Infiltration Models
2018
Infiltration has a great importance in the watershed management and prediction of flood. Infiltration is defined as a physical phenomenon, in which water penetrates into the soil from surface sources such as precipitation, snowfall, irrigation etc. Information of infiltration is necessary in hydrologic design, watershed management, irrigation, and agriculture. It is, therefore, necessary to have a detailed understanding of infiltration characteristics for a given land use complex. Infiltration is a vital component process of the hydrologic cycle. It is one of the main abstractions accounted for in the rainfall-runoff modeling. In the hydrological process, infiltration divids the water into two parts surface flow and groundwater flow. Soils of different types have different infiltration characteristics. Infiltration rates are affected by a number of factors of which antecedent soil moisture texture of the soil, density and behaviour of the soil. Knowledge of infiltration is essential...
Performance of two prevalent infiltration models for disturbed urban soils
Hydrology Research, 2017
Estimating infiltration losses is very important for calculating runoff and recharge. However, the accuracy of contemporary infiltration models for disturbed urban soils may not be adequate, potentially compromising calculations based upon them. The objective of this study was to assess the performance of the two most prevalent infiltration models, Horton and Green–Ampt, for applications in urban soils. The data were measured by the US Environmental Protection Agency in a large city for soils with various characteristics of texture, structure, age, compactness, and dryness/wetness. The results indicate both models performed better in predicting infiltration rates for clayey rather than sandy soils, for new rather than old soils, and for wet rather than dry soils. For the clayey soils, both models performed better for the noncompact than compact soils. The opposite was true for sandy soils. Overall, neither infiltration model performed well for most soils, with the sole exception of ...
Stormwater infiltration trenches: a conceptual modelling approach
Water Science & Technology, 2009
In recent years, limitations linked to traditional urban drainage schemes have been pointed out and new approaches are developing introducing more natural methods for retaining and/or disposing of stormwater. These mitigation measures are generally called Best Management Practices or Sustainable Urban Drainage System and they include practices such as infiltration and storage tanks in order to reduce the peak flow and retain part of the polluting components.
Evaluation of some infiltration models and hydraulic parameters
Spanish Journal of Agricultural Research, 2010
The evaluation of infiltration characteristics and some parameters of infiltration models such as sorptivity and final steady infiltration rate in soils are important in agriculture. The aim of this study was to evaluate some of the most common models used to estimate final soil infiltration rate. The equality of final infiltration rate with saturated hydraulic conductivity (K s ) was also tested. Moreover, values of the estimated sorptivity from the Philip's model were compared to estimates by selected pedotransfer functions (PTFs). The infiltration experiments used the doublering method on soils with two different land uses in the Taleghan watershed of Tehran province, Iran, from September to October, 2007. The infiltration models of Kostiakov-Lewis, Philip two-term and Horton were fitted to observed infiltration data. Some parameters of the models and the coefficient of determination goodness of fit were estimated using MATLAB software. The results showed that, based on comparing measured and model-estimated infiltration rate using root mean squared error (RMSE), Horton's model gave the best prediction of final infiltration rate in the experimental area. Laboratory measured K s values gave significant differences and higher values than estimated final infiltration rates from the selected models. The estimated final infiltration rate was not equal to laboratory measured K s values in the study area. Moreover, the estimated sorptivity factor by Philip's model was significantly different to those estimated by selected PTFs. It is suggested that the applicability of PTFs is limited to specific, similar conditions.
Journal of Water and Wastewater, 2022
Separate sewer networks are designed and built to collect foul sewage from buildings and convey it to wastewater treatment plants (WWTPs). However, due to some holes and cracks on the pipes or unsealed pipe joints, a volume of ground or subsurface water that is placed in saturated or unsaturated zones intrudes sewers and WWTPs. In a condition that the wastewater level in the sewer stands higher than the groundwater level, wastewater leaks into the soil and groundwater and this phenomenon is called sewer exfiltration. Moreover, during a rain event, a part of the precipitation gets into the sewer system through the illicit connection of the yard drains and roof downspouts to the building’s lateral, and this part of the flow is called rainfall-derived inflow and infiltration (RDII). In this research, infiltration, exfiltration, and RDII were evaluated in a 16-month period to show the range of inflow and infiltration in the sewer network under the service of the South Tehran WWTP. Results show that the infiltration constitutes the major volume of the total inflow and infiltration. But the RDII leads to more operational problems due to its nature as an intense flow. After calculating the range of inflow and infiltration, results show that the average infiltration rate that entered the WWTP in the year 2014 was 0.0175 L/s/ha that is much less than the values mentioned in Criterion No. 118. Furthermore, total inflow and infiltration in five hours of the study period crossed the upper limit of the inflow and infiltration range (0.6 L/s/ha) in Criterion No. 118 that shows the high percentage of illicit connections in Tehran and a high volume of rainfall that enters the sewer network. Accordingly, the inflow and infiltration range in the Criterion No. 118 seems to be an unsound range and it needs some revisions.