W-SAHARA Stochastic analysis of well head protection and risk assessment
| Country: EU Projects
| Start Date:
Project Type: RTD
| Contract Number: EVK1-CT-1999-00041
| Organisation Type:
Contaminated land-->Risk assessment-->Receptor: Water
Contaminated land-->Risk assessment-->Tools and procedures
Groundwater protection-->Groundwater processes-->Contaminant hydrology
Groundwater protection-->Groundwater processes-->Groundwater processes overview
Water and sanitation-->Water supply
| Project objectives:
Objectives include: (a) development of a methodology for the quantification of the concept of vulnerability of groundwater drinking wells, in a probabilistic
framework; (b) application of this strategy to a specific situation and a selected site and simulation of the impact of the obtained solution in decision-making
policies; (c) definition of the philosophy of risk assessment for well fields in a stochastic context and (d) production of guidelines for drinking water companies
and Environmental Agencies on how to reduce uncertainty on heads/fluxes prediction by geological field investigations and monitoring of groundwater heads/concentrations.
We will attack the problem on different fronts: (a) theoretical/conceptual; (b) laboratory and field scale; (c) deterministic and stochastic model development
of synthetic and real-world cases. Numerical Monte Carlo (MC) techniques will be employed, addressing issues such as (a) development of efficient algorithms
for MC simulations of catchments in 3D using alternative methods of particle tracking and Kolmogorov backward equation; (b) clarification of conditioning
formalisms, through analysis of the importance of conditioning data in order to reduce the uncertainty of well catchments; (c) adoption and development of
inverse methods that can use a variety of data types to decrease uncertainty about aquifer properties and wellhead regions of influence. Algorithms for optimum
unbiased prediction (together with corresponding prediction errors) of head and fluxes leading to identification of well catchments will be developed according
to the novel nonlocal formalism of groundwater flow moment equations. Laboratory and field data will be collected and analysed. A traditional deterministic
model will be applied to a selected field situation and results will be evaluated in light of probabilistic concepts. Our new numerical schemes and methodologies
will be demonstrated in selected practical situations.
Wellhead protection zones serve as an effective protection of groundwater against pollution byregulating human activities in areas around drinking wells.
The major problem that drinking water companies are facing is the definition of a reliable strategy for the quantification of the risk associated to drinking
well fields. Traditional deterministic models inherently offer predictions of undetermined quality. We propose to develop efficient scholastic computational
methods for flow and well catchment predictions in aquifers of random heterogeneity, conditioned on available measurements, including a quantification
of the concept of risk associated with such predictions. We will perform field and laboratory experiments, demonstrate our methodology through application
to selected field data and offer guidelines on how to reduce uncertainty by geological investigations and monitoring of groundwater heads/concentrations.
| Achieved Objectives:
The code SicWin (Stocastich IsoChrones) has been developed within the Project W-SAHaRA (Stochastic Analysis of Well-Head Protection and Risk Assessment,
supported by the EU within the Fifth Framework, Key Action Water. It simulates pumping of a single well in a uniform base flow and the related spatial distribution
of isochrones of an ideal solute. The well is fully penetrating a confined aquifer of given thickness and infinite extent. Aquifer hydraulic conductivity
is simulated as a random constant, whose value can be drawn from either a Uniform or a Log-normal probability distribution, chosen by the user.
| Product Descriptions:
W-SAHaRA aimed to develop guidelines for predicting the extent of drinking wells protection region in natural heterogeneous formations and assessing the
associated prediction errors in a probabilistic framewrok.
The following producst are available:
- Software producted by the consortium (SicWin)
- publication list
- A review of stochastic methods for well capture zone determination
- Downloadable Summaries for different Workpackages
| Additional Information:
| Project Resources:
Software produced by the Consortium
Stochastic determination of well capture zones conditioned on regular grids of transmissivity measurements
A review of stochastic methods for well capture zone determination
Summary: Nonlocal Flow Algorithms
Comparison between Nonlocal Equations and Monte Carlo simulations
Summary: Nonlocal Travel Time Concepts
Summary: MC Algorithms
Summary: Analysis of Key Parameters
Summary: Laboratory Experiments
Summary: Field Experiments
Deterministic Model of Real World Fields
| Funding Programme(s):
EC Framework Programme 5
| Link to Organisations:
Prof Paul Bardos
Who does what?
Professor Paul Bardos
Who does what?