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Uncertainty In Quali-Quantitative Response Of A Natural Catchment On A Daily Basis, A. Candela, G. Aronica, G. Viviani
Uncertainty In Quali-Quantitative Response Of A Natural Catchment On A Daily Basis, A. Candela, G. Aronica, G. Viviani
International Congress on Environmental Modelling and Software
Water quality impacts due to non-point source pollution can be significant particularly in environmentally sensitive areas. They may, however, be difficult to quantify, since the magnitude is heavily influenced by climatic, geomorphologic, lithologic and pedologic characteristics. A conceptual model for continuous daily simulation is proposed to reproduce the quali-quantitative response of a Sicilian catchment. Short-term water quality monitoring is necessary to assess the hydrological response of catchments characterised by hot dry summers and rainfalls with short duration and high intensity. The quantitative sub-model comprises two modules: a non linear loss model, to transform total rainfall in effective rainfall, which involves …
Application Of A Gis-Based Simulation Tool To Analyze And Communicate Uncertainties In Future Water Availability In The Amudarya River Delta, Maja Schlüter, Nadja Rüger
Application Of A Gis-Based Simulation Tool To Analyze And Communicate Uncertainties In Future Water Availability In The Amudarya River Delta, Maja Schlüter, Nadja Rüger
International Congress on Environmental Modelling and Software
Simulation and decision support tools facilitate a process of reasoning about potential future development paths of a system, e.g. a river system, under alternative management strategies. Joint scenario development and analysis with river basin authorities and stakeholders can inform and structure discussions on management goals and major uncertainties affecting river basin management in future. Tools can support the determination of strategies that balance water allocation between multiple users, such as irrigation and the environment, and measures to cope with uncertainties. The GIS-based simulation tool TUGAI has been developed to facilitate exploration of alternative water management strategies for the degraded Amudarya …
Unit Hydrographs And Regionalisation Of United Kingdom River Flows: Comments On Some Estimation Uncertainties, I. G. Littlewood
Unit Hydrographs And Regionalisation Of United Kingdom River Flows: Comments On Some Estimation Uncertainties, I. G. Littlewood
International Congress on Environmental Modelling and Software
Two types of unit hydrograph (UH) are discussed, with an emphasis on uncertainties. The paper reviews the 1-parameter triangular unit hydrograph (UH) employed to assist with systematic design flood hydrograph estimation for ungauged United Kingdom catchments. A 6-parameter rainfall-runoff model that incorporates a 3-parameter UH is also discussed. The precision and accuracy of characteristic decay times for dominant quick and slow response UHs, derived from the 6-parameter model, are examined in the context of uncertainty in flow regime regionalisation. On the basis that, as argued in the paper, the full potential of the 3- parameter UH has yet to be …
Dealing With Unidentifiable Sources Of Uncertainty Within Environmental Models, Ann Van Griensven, T. Meixner
Dealing With Unidentifiable Sources Of Uncertainty Within Environmental Models, Ann Van Griensven, T. Meixner
International Congress on Environmental Modelling and Software
Sources of Uncertainty Global Assessment using Split SamplES (SUNGLASSES) is a method for assessing model global uncertainty to aid in the development of integrated models. The method is complementary to the commonly investigated input and parameter uncertainty, as it accounts for errors that may arise due to unknown or unassessable sources of uncertainty, such as model hypothesis errors, simplifications, scaling effects or the lack of the observation period to represent long-term variability and fluctuations in the system. Such sources are typically dominant for most environmental models and they undermine the reliability of environmental models. The SUNGLASSES algorithm directly estimates the …
Uncertainties In Lca Of Plant-Growth Regulators And Implications On Decision-Making, Georg Geisler, Stefanie Hellweg, Konrad Hungerbühler
Uncertainties In Lca Of Plant-Growth Regulators And Implications On Decision-Making, Georg Geisler, Stefanie Hellweg, Konrad Hungerbühler
International Congress on Environmental Modelling and Software
Uncertainty assessment in LCA enables the evaluation of the significance of results, which is important for providing sound decision-support. In this work, an LCA was performed on two plant-growth regulators considering various sources of uncertainty: In the LCI, uncertainties of imprecise measurements of elementary flows, temporal and spatial variation, and different production processes were assessed. In the characterisation phase, the uncertainties of substance properties and the composition of sum-parameters were considered. These uncertainties were expressed as probability distributions and assessed via stochastic modelling (Monte-Carlo Simulation). For most LCI- and LCIA-data, generic uncertainty ranges were used. Uncertainties due to assumptions on …
A Regional Methodology For Deriving Flood Frequency Curves (Ffc) In Partially Gauged Catchments With Uncertain Knowledge Of Soil Moisture Conditions, G. Aronica, A. Candela
A Regional Methodology For Deriving Flood Frequency Curves (Ffc) In Partially Gauged Catchments With Uncertain Knowledge Of Soil Moisture Conditions, G. Aronica, A. Candela
International Congress on Environmental Modelling and Software
In this paper a Monte Carlo procedure for deriving frequency distributions of extreme dischargesstarting from a simplified description of rainfall and surface runoff processes and using regional data ispresented. The procedure is based on two modules: a stochastic rainfall generator module and a catchmentresponse module. In the rainfall generator module the rainfall storm, i.e. the maximum rainfall depth for afixed duration, is assumed to follow the Two Components Extreme Value (TCEV) distribution whoseparameters have been estimated at regional scale for Sicily. The catchment response has been modelled byusing the Soil Conservation Service – Curve Number for the total-effective rainfall transformation …
An Implemented Approach For Estimating Uncertainties For Toxicological Impact Characterisation, R. Rosenbaum, D. W. Pennington, O. Jolliet
An Implemented Approach For Estimating Uncertainties For Toxicological Impact Characterisation, R. Rosenbaum, D. W. Pennington, O. Jolliet
International Congress on Environmental Modelling and Software
One approach accounting for parameter and model uncertainty is implemented in the LCIA (lifecycle impact assessment) method IMPACT 2002. The uncertainty is estimated for intermediate results fromthe chemical fate, human intake fraction, and two toxicological effect modules. Overall uncertainty estimatesare then arithmetically calculated. Results are presented for impact contributions in the contexts of aquaticecosystems and human health. The approach of Hofstetter (1998) was adapted for estimating the uncertaintyrelated to chemical fate and human intake fractions. A fundamental problem when estimating uncertainties for1000’s of substances consists of the lack of uncertainty distributions for all of the input data and the need …
Implications Of Complexity And Uncertainty For Integrated Modelling And Impact Assessment In River Basins, Valentina Krysanova, Fred Hattermann, Frank Wechsung
Implications Of Complexity And Uncertainty For Integrated Modelling And Impact Assessment In River Basins, Valentina Krysanova, Fred Hattermann, Frank Wechsung
International Congress on Environmental Modelling and Software
The paper focuses on implications of uncertainty in climate change impact assessment at the river basin and regional scales. The study was performed using the process-based ecohydrological spatially distributed model SWIM (Soil and Water Integrated Model). The model integrates hydrological processes, vegetation/crop growth, erosion and nutrient dynamics in river basins. It was developed from the SWAT and MATSALU models for climate and land use change impact assessment. The study area is the German part of the Elbe River basin (about 100.000 km2). It is representative for semi-humid landscapes in Europe, where water availability during the summer season is the limiting …
An Integrated Approach For The Management Of Uncertainty In Decision Making Supported By Lca-Based Environmental Performance Information, L. Basson, J. G. Petrie
An Integrated Approach For The Management Of Uncertainty In Decision Making Supported By Lca-Based Environmental Performance Information, L. Basson, J. G. Petrie
International Congress on Environmental Modelling and Software
This paper presents an approach for the integrated consideration of both technical and valuation uncertainties during decision making supported by LCA-type environmental performance information. Key elements of this approach include “distinguishability analysis” to determine whether the uncertainty in the performance information is likely to make it impossible to distinguish between the activities under consideration, and the use of a multivariate statistical analysis approach, called principal components analysis (PCA), which facilitates the rapid analysis of large numbers of parallel sets of results, and enables the identification of choices that lead to similar and/or opposite evaluations of activities. The integrated approach for …
A Review Of Approaches To Treat Uncertainty In Lca, Reinout Heijungs, Mark A. J. Huijbregts
A Review Of Approaches To Treat Uncertainty In Lca, Reinout Heijungs, Mark A. J. Huijbregts
International Congress on Environmental Modelling and Software
It is important to know to what extent the outcome of an LCA is affected by various types ofuncertainty, such as parameter, scenario and model uncertainty. These types may occur in the goal andscope definition, the inventory analysis and the impact assessment of an LCA. Information on the uncertaintyof the model outcomes provides useful information to assess the reliability of LCA-based decisionsand to guide future research towards reducing uncertainty. This paper reviews several approaches to treatdifferent types of uncertainty in LCA. It will discuss the typology of uncertainty that may be encountered inLCA, the qualitative and quantitative techniques that are …
A Tool For Evaluating Risk To Surface Water Quality Status, Neil Mcintyre
A Tool For Evaluating Risk To Surface Water Quality Status, Neil Mcintyre
International Congress on Environmental Modelling and Software
Water quality Risk Analysis Tool (WaterRAT) is recently developed software for supportingsurface water quality management. The software contains a library of river and lake quality models, aiming togive flexibility over specification of model scope, complexity and scale. Various sources of uncertainty canbe included in the analysis, including uncertainty in boundary conditions, initial conditions, parameters,model structure and management objectives. Water quality can then be modelled allowing for these sources ofuncertainty. Important data uncertainties can be indicated, and so data collection programmes can be suitablyrefined. In this paper, the motivation for the WaterRAT tool and the methods it employs are presented, itsfeatures …
Implications Of Uncertainty And Variability In The Life Cycle Assessment Of Pig Farming Systems, C. Basset-Mens, H.M.G. Van Der Werf, P. Durand, Ph Leterme
Implications Of Uncertainty And Variability In The Life Cycle Assessment Of Pig Farming Systems, C. Basset-Mens, H.M.G. Van Der Werf, P. Durand, Ph Leterme
International Congress on Environmental Modelling and Software
In a case study of pig production systems we propose a simple quantification of the uncertainty of LCA results (intra-system variability) and we explored inter-system variability in order to produce more robust LCA outcomes. Our quantification of the uncertainty took into account the variability of technical performance (crop yield, feed efficiency) and of emission factors (for NH3, N2O and NO3) and the influence of the functional unit (FU) (kg of pig versus hectare used). For farming systems, the inter-system variability was investigated through differentiating by the production mode (conventional, quality label, organic (AB)), and farmer practices (Good Agricultural Practice (GAP) …
Decision Making Under Uncertainty In A Decision Support System For The Red River, Inge A. T. De Kort, Martijn J. Booij
Decision Making Under Uncertainty In A Decision Support System For The Red River, Inge A. T. De Kort, Martijn J. Booij
International Congress on Environmental Modelling and Software
Decision support systems (DSSs) are increasingly being used in water management for the evaluation of impacts of policy measures under different scenarios. The exact impacts generally are unknown and surrounded with considerable uncertainties. These uncertainties stem from natural randomness, uncertainty in data, models and parameters, and uncertainty about measures and scenarios. It may therefore be difficult to make a selection of measures relevant for a particular water management problem. In order to support policy makers to make a strategic selection between different measures in a DSS while taking uncertainty into account, a methodology for the ranking of measures has been …
Floodplain Risk Analysis Using Flood Probability And Annual Exceedance Probability Maps, Christopher M. Smemoe
Floodplain Risk Analysis Using Flood Probability And Annual Exceedance Probability Maps, Christopher M. Smemoe
Theses and Dissertations
This research presents two approaches to determining the effects of natural variability and model uncertainty on the extents of computed floodplain boundaries. The first approach represents the floodplain boundary as a spatial map of flood probabilities -- with values between 0 and 100%. Instead of representing the floodplain boundary at a certain recurrence interval as a single line, this approach creates a spatial map that shows the probability of flooding at each point in the floodplain. This flood probability map is a useful tool for visualizing the uncertainty of a floodplain boundary. However, engineers are still required to determine a …