Search results for "Catchment"

Catchment size and contribution of the largest daily events to suspended sediment load on a continental scale

2013

Abstract The classic approach defines an extreme event as a rare event identified by magnitude–frequency analysis and quantified by its deviation from a central value. They are key to understand geomorphological dynamics, since they are responsible for a considerable amount of work and “time compression”. Time compression means that most of the geomorphic work (particularly sediment transport) is produced in very short temporal intervals (i.e. in few events). Moreover, it is well known from magnitude–frequency analyses that events not necessarily extreme by magnitude could be responsible for a large amount of geomorphic work. To analyse the time compression of geomorphological processes, a …

Catchment scale modeling approach for a holistic urban water quality management

2008

Urban water quality modelling: a parsimonious holistic approach for a complex real case study

2010

In the past three decades, scientific research has focused on the preservation of water resources, and in particular, on the polluting impact of urban areas on natural water bodies. One approach to this research has involved the development of tools to describe the phenomena that take place on the urban catchment during both wet and dry periods. Research has demonstrated the importance of the integrated analysis of all the transformation phases that characterise the delivery and treatment of urban water pollutants from source to outfall. With this aim, numerous integrated urban drainage models have been developed to analyse the fate of pollution from urban catchments to the final receiving …

Improving child maltreatment detection systems: a large-scale case study involving health, social services, and school professionals.

2003

Abstract Objectives: The purpose of this 5-year study was to improve detection in two consecutive phases: (a) To close the gap between the number of identified cases and the actual number of cases of child abuse by increasing detection; and (b) To increase the possibility of a broader spectrum of detection. Method: The Balearic Islands (one of the Autonomous Communities of Spain, with 161,287 children under 18 years old) was selected as the study area. Phase 1: front-line professionals (181) from all the health and social services agencies were trained in detection. Phase 2, school professionals (251) from all schools in the territory were also trained. The independent factor was the interv…

[Clinical audit of patients admitted to hospital in Spain due to exacerbation of COPD (AUDIPOC study): method and organisation].

2010

There is little information regarding the clinical management of hospital inpatients diagnosed with exacerbation of Chronic Obstructive Pulmonary Disease (COPD). AUDIPOC is a clinical audit dealing with the clinical management of COPD in Spain.To examine the adequacy and validity of the instruments used to measure the variables proposed by AUDIPOC Spain (Preliminary Study) and to verify the viability of AUDIPOC in a complex environment with hospitals of different sizes, resources, and organizational layout (Pilot Study).The Preliminary Study took place in 4 hospitals and studied 213 cases. The Pilot Study took place in 30 hospitals of 6 Autonomous Communities (i.e. Regions) and studied 1203…

Daily streamlow prediction with uncertainty in ephemeral catchments using the GLUE methodology

2009

Abstract The Generalised Likelihood Uncertainty Estimation (GLUE) approach is presented here as a tool for estimating the predictive uncertainty of a rainfall–runoff model. The GLUE methodology allows to recognise the possible equifinality of different parameter sets and assesses the likelihood of a parameters set being acceptable simulator when model predictions are compared to observed field data. The results of the GLUE methodology depend greatly on the choice of the likelihood measure and on the choice of the threshold which determines if a parameters set is behavioural or not. Moreover the sampling size has a strong influence on the uncertainty assessment of the response of a rainfall–…

Short communication: Driftwood provides reliable chronological markers in Arctic coastal deposits

2021

Originating from the boreal forest and often transported over large distances, driftwood characterizes many Arctic coastlines. Here we present a combined assessment of radiocarbon (14C) and dendrochronological (ring width) age estimates of driftwood samples to constrain the progradation of two Holocene beach-ridge systems near the Lena Delta in the Siberian Arctic (Laptev Sea). Our data show that the 14C ages obtained on syndepositional driftwood from beach deposits yield surprisingly coherent chronologies for the coastal evolution of the field sites. The dendrochronological analysis of wood from modern drift lines revealed the origin and recent delivery of the wood from the Lena River catc…

Streamwater responses to reduced nitrogen deposition at four small upland catchments in Norway

2020

AbstractReduced emissions of nitrogen (N) in Europe have resulted in decreasing atmospheric deposition since 1990. Long-term data (1988–2017) from four small Norwegian catchments located along gradients in N deposition, rainfall, and organic carbon (C) show different responses to 25–30% reductions in N deposition during the same period. At three sites the decreased N deposition caused reduced leaching of nitrate to surface water, whereas the westernmost site showed no decrease, probably due to thin soils with low C:N ratio, poor vegetation cover and high precipitation. The loss of total N to streamwater constituted 30–50% of the N deposition. Losses via denitrification are unknown but assum…

Stormwater infiltration trenches: a conceptual modelling approach.

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. The introduction of such practices in urban drainage systems entails an upgrade of existing modelling frameworks in order to evaluate their efficiency in mitigating the impact of urban drainage systems on receiving water bodies. While s…

The way forward : Can connectivity be useful to design better measuring and modelling schemes for water and sediment dynamics?

2018

For many years, scientists have tried to understand, describe and quantify water and sediment fluxes, with associated substances like pollutants, at multiple scales. In the past two decades, a new concept called connectivity has been used by Earth Scientists as a means to describe and quantify the influences on the fluxes of water and sediment on different scales: aggregate, pedon, location on the slope, slope, watershed, and basin. A better understanding of connectivity can enhance our comprehension of landscape processes and provide a basis for the development of better measurement and modelling approaches, further leading to a better potential for implementing this concept as a managemen…