Search results for "Drainage System"

The impact of beaver dam removal on the chemical properties of water in drainage ditches in peatland forests

2020

Despite near-extinction in the nineteenth century, after efficient restoration measures the population of Eurasian beaver (Castor fiber L.) in Latvia currently is viable and growing. While the ecol...

Évaluation du colmatage de tranchées d'infiltration selon le type de sol : analyse à long terme

2010

In recent years, limitations linked to traditional urban drainage schemes have been pointed out and new approaches were developed introducing more natural methods for retaining and/or disposing of stormwater. Such practices include infiltration and storage tanks in order to reduce the peak flow and retain part of the polluting components. The impact of such practices on stormwater quantity and quality is not easily assessable because of the complexity of physical and chemical processes involved. In such cases, integrated urban drainage models may play a relevant role providing tools for long term analysis of infiltration structures efficiency. In this study, the effect of the clogging pheno…

Long Term Efficiency Analysis of Infiltration Trenches Subjected to Clogging

2018

Abstract: In recent years, limitations linked to traditional urban drainage schemes have been pointed out and new approaches were developed introducing more natural methods for retaining and/or disposing of stormwater. Such practices include infiltration and storage tanks in order to reduce the peak flow and retain part of the polluting components. The impact of such practices on stormwater quantity and quality is not easily assessable because of the complexity of physical and chemical processes involved. In such cases, integrated urban drainage models may play a relevant role providing tools for long term analysis. In this study, the effect of the clogging phenomenon has been assessed by m…

Effects of climate change on the urban drainage system of Palermo

Questa ricerca mira a studiare la risposta al cambiamento climatico di un sistema di drenaggio urbano. Riconosciuto dal mondo scientifico come un delle più grandi sfide del XXI secolo, il cambiamento climatico rischia di mettere alla prova i centri abitati: più frequenti precipitazioni, alluvioni e ondate di calore saranno i problemi più impegnativi che le città dovranno affrontare. Ciò potrebbe comportare serie conseguenze per le infrastrutture urbane come i sistemi di trasporto e le reti di drenaggio. Nello specifico, in caso di forti precipitazioni e alluvioni il pericolo è che i sistemi di drenaggio esistenti si rivelino inadeguati. In questo caso le strade vengono sommerse dall'acqua c…

Uncertainty estimation of a complex water quality model: The influence of Box–Cox transformation on Bayesian approaches and comparison with a non-Bay…

2012

Abstract In urban drainage modelling, uncertainty analysis is of undoubted necessity. However, uncertainty analysis in urban water-quality modelling is still in its infancy and only few studies have been carried out. Therefore, several methodological aspects still need to be experienced and clarified especially regarding water quality modelling. The use of the Bayesian approach for uncertainty analysis has been stimulated by its rigorous theoretical framework and by the possibility of evaluating the impact of new knowledge on the modelling predictions. Nevertheless, the Bayesian approach relies on some restrictive hypotheses that are not present in less formal methods like the Generalised L…

Assessment of data and parameter uncertainties in integrated water-quality model

2011

In integrated urban drainage water quality models, due to the fact that integrated approaches are basically a cascade of sub-models (simulating sewer system, wastewater treatment plant and receiving water body), uncertainty produced in one sub-model propagates to the following ones depending on the model structure, the estimation of parameters and the availability and uncertainty of measurements in the different parts of the system. Uncertainty basically propagates throughout a chain of models in which simulation output from upstream models is transferred to the downstream ones as input. The overall uncertainty can differ from the simple sum of uncertainties generated in each sub-model, dep…

Identifiability analysis for receiving water body quality modelling

2009

In urban drainage, new computational possibilities have supported the development of new integrated approaches aimed at joint water quantity and quality analysis of the whole urban drainage system. Although the benefit of an integrated approach has been widely demonstrated, to date, several aspects prevent its applicability such as scarce availability of field data if compared with model complexity. These aspects sometimes prevent the correct estimation of parameters thus leading to large uncertainty in modelling response. This is a typical parameter identifiability problem that is discussed in the present paper evaluating the effect of identifiability procedures in increasing operator conf…

Modelling of E. colidistribution in coastal areas subjected to combined sewer overflows

2013

Rivers, lakes and the sea were the natural receivers of raw urban waste and storm waters for a long time but the low sustainability of such practice, the increase of population and a renewed environmental sensibility increased researcher interest in the analysis and mitigation of the impact of urban waters on receiving water bodies (RWB). In Europe, the integrated modelling of drainage systems and RWB has been promoted as a promising approach for implementing the Water Framework Directive. A particular interest is given to the fate of pathogens and especially of Escherichia coli, in all the cases in which an interaction between population and the RWB is foreseen. The present paper aims to p…

Assessing physical surrogates for biodiversity: Do tributary and stream type classifications reflect macroinvertebrate assemblage diversity in runnin…

2006

Landscape classifications are increasingly being used in conservation planning and biodiversity management, although there is a dearth of studies actually showing concordant patterns between such classifications and biodiversity. We studied the utility of tributary and stream type classifications in accounting for the variability of invertebrate biodiversity in a boreal drainage system. We found that only weak, although significant, differences existed between the studied three tributaries and four stream types in macroinvertebrate assemblage structure, species distributions, and taxonomic richness. Further, the classification strengths, calculated as mean within-group-similarity minus mean…

Proglacial sediment dynamics from daily to seasonal scales in a glaciated Alpine catchment (Bossons glacier, Mont Blanc massif, France)

2018

The sediment yields of Alpine catchments are commonly determined from streamload measurements made some distance downstream from glaciers. However, this approach indiscriminately integrates erosion processes occurring in both the glacial and proglacial areas. A specific method is required to ascertain the respective inputs from (i) subglacial and supraglacial sediments, (ii) proglacial hillslopes and (iii) proglacial alluvial areas or sandurs. This issue is addressed here by combining high‐resolution monitoring (2 min) of suspended sediment concentrations at different locations within a catchment with discharge gauging and precipitation data. This methodological framework is applied to two …