2nd MINEO Workshop - Orléans, 11-13 December 2002 MINEO Hydrology, Hydrogeology and Transport Modelling Principal investigators : Stuart Marsh and Stephane.

2nd MINEO Workshop - Orléans, 11-13 December 2002

MINEO MINEO

Hydrology, Hydrogeology and Transport Modelling

Principal investigators : Stuart Marsh and Stephane Chevrel

Collaborating organisation 1 : British Geological Survey

Collaborating organisation 2 : BRGM


IntroductionIntroduction

• MINEO’s remote sensing workflow gives MINEO’s remote sensing workflow gives two major outputs for subsequent use:two major outputs for subsequent use:– terrain models via stereo aerial photographyterrain models via stereo aerial photography

– contamination maps from hyperspectral datacontamination maps from hyperspectral data

• This talk describes their use in modelling:This talk describes their use in modelling:– pollution run-off and dispersal pathwayspollution run-off and dispersal pathways

– drainage contamination mapsdrainage contamination maps

– groundwater vulnerability mapsgroundwater vulnerability maps

– groundwater flow modelsgroundwater flow models

– transport network analysistransport network analysis

• Both GIS & numerical modelling are usedBoth GIS & numerical modelling are used


Pollution Run-offPollution Run-off

Drainage ContamDrainage Contam

Groundwater VulnGroundwater Vuln

Groundwater FlowGroundwater Flow

Transport NetworkTransport Network

ConclusionsConclusions


Mapping run-off pollution dispersal Mapping run-off pollution dispersal pathwayspathways

• Application of flow-accumulation Application of flow-accumulation algorithm to DEMs enables : algorithm to DEMs enables : – modelling downstream run-off from source(s) modelling downstream run-off from source(s)

of pollution (points or areas) of pollution (points or areas)

– mapping surface pollution dispersal pathwaysmapping surface pollution dispersal pathways

• Shows how run-off transported pollution Shows how run-off transported pollution gathers into the main drainage system gathers into the main drainage system and can pollute the hydrographic and can pollute the hydrographic network downstreamnetwork downstream









Mapping run-off pollution dispersal Mapping run-off pollution dispersal pathwayspathways


Production of potential drainage Production of potential drainage contamination mapcontamination map

• Application of this technique at a regional Application of this technique at a regional scale enablesscale enables– mapping the sensitivity of the drainage mapping the sensitivity of the drainage

system to pollutionsystem to pollution

– identification of areas most likely to be identification of areas most likely to be affected by pollutionaffected by pollution

• can be used in the performance ofcan be used in the performance of– risk analysis and managementrisk analysis and management

– prioritisation of detailed investigations and prioritisation of detailed investigations and clean-up activities, remediation studiesclean-up activities, remediation studies

– assessment of the impact of planned polluting assessment of the impact of planned polluting activitiesactivities










Uncontaminated DrainageUncontaminated Drainage

Polluted Run-offPolluted Run-off

Contaminated DrainageContaminated Drainage










Uncontaminated DrainageUncontaminated Drainage

Polluted Run-offPolluted Run-off

Contaminated DrainageContaminated Drainage

Polluted areasPolluted areas









Groundwater vulnerability mapGroundwater vulnerability map

• Results of a multi-criteria GIS analysisResults of a multi-criteria GIS analysis

• performed from an extensive set of GIS-layersperformed from an extensive set of GIS-layers– geology (permability)geology (permability)

– soils and land-use (holding capacity),soils and land-use (holding capacity),

– thickness of the vadoze zone, thickness of the vadoze zone,

– characteristics of the aquifer (transmissivity) , characteristics of the aquifer (transmissivity) ,

– topography (slopes)topography (slopes)

– potential evapo-transpirationpotential evapo-transpiration

– etc...etc...

• Takes into account electrical conductivity Takes into account electrical conductivity (witnessing contamination) in layer-weighting (witnessing contamination) in layer-weighting calculationcalculation









Groundwater vulnerability mapGroundwater vulnerability map

Low Low vulnerabilityvulnerability

High High vulnerabilityvulnerability









Dtm10mgrd0 - 2020 - 5050 - 7070 - 9090 - 120120 - 140140 - 160160 - 190190 - 210210 - 240No Data

M7bnds.shp

5000 0 5000 Meters

Groundwater flow modellingGroundwater flow modelling

• Numerical Modelling used to assess where Numerical Modelling used to assess where groundwater will flow away from mine sitegroundwater will flow away from mine site

• Inputs are the:Inputs are the:– identified contaminated siteidentified contaminated site– digital terrain modeldigital terrain model

• This example:This example:– Cornwall, UKCornwall, UK– Dave Noy’s workDave Noy’s work







ConclusionsConclusionsOuter boundary of finite element mesh Zone of mesh refinement

Mine wastelocation at the United

Downs mine


• Finite element mesh used for modelFinite element mesh used for model– 8605 nodes and 16892 triangular elements8605 nodes and 16892 triangular elements

• 2D unconfined aquifer model2D unconfined aquifer model

– Top surface at DTM, bottom at -100m ODTop surface at DTM, bottom at -100m OD

– No flow around boundary, except where main No flow around boundary, except where main

valley exits model: a fixed head is imposed herevalley exits model: a fixed head is imposed here

– A Uniform infiltration rate of 50cm/yr and an A Uniform infiltration rate of 50cm/yr and an

isotropic, homogeneous hydraulic conductivity isotropic, homogeneous hydraulic conductivity

of 1.0e-6 m/s were usedof 1.0e-6 m/s were used







ConclusionsConclusions Mesh Elevations Calculated Flows


HHeads and flows at the mine waste siteeads and flows at the mine waste site









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Dtm10mgrd0 - 2020 - 5050 - 7070 - 9090 - 120120 - 140140 - 160160 - 190190 - 210210 - 240No Data

Outline6.shp

Solute concentration# 0.01 - 0.03# 0.03 - 0.06# 0.06 - 0.09# 0.09 - 0.13# 0.13 - 0.16# 0.16 - 0.19# 0.19 - 0.22# 0.22 - 0.25# 0.25 - 0.28# 0.28 - 0.32# 0.32 - 0.35# 0.35 - 0.38# 0.38 - 0.41# 0.41 - 0.44# 0.44 - 0.47# 0.47 - 0.51# 0.51 - 0.54# 0.54 - 0.57# 0.57 - 0.6# 0.6 - 0.63

600 0 600 1200 Meters








Solute concentrations overlain on DTMSolute concentrations overlain on DTM


Modelling pollution transport networks: Modelling pollution transport networks: examples from Wheal Jane in the UKexamples from Wheal Jane in the UK• The drainage network can be used to model The drainage network can be used to model

transport from mine to estuarytransport from mine to estuaryIntroductionIntroduction








Modelling other transport networksModelling other transport networks

• HyMap identifies contamination along the HyMap identifies contamination along the roads around the Wheal Jane mine siteroads around the Wheal Jane mine site









• The outputs of the remote sensing study form the The outputs of the remote sensing study form the inputs to subsequent analysisinputs to subsequent analysis

• Complex hyperspectral products need to be Complex hyperspectral products need to be presented in simpler forms for GIS analysispresented in simpler forms for GIS analysis

• GIS is a powerful tool to extend analysis over GIS is a powerful tool to extend analysis over wide areas using multiple datasetwide areas using multiple dataset

• Modelling can be undertaken by complex GIS Modelling can be undertaken by complex GIS and numerical modelling calculations and also and numerical modelling calculations and also using simple visual approachesusing simple visual approaches

• Modelling can often be applied equally at any of Modelling can often be applied equally at any of the sites; it is more generic than remote sensingthe sites; it is more generic than remote sensing

• Results can be fed more easily into management Results can be fed more easily into management information systems than the hyperspectral datainformation systems than the hyperspectral data









2nd MINEO Workshop - Orléans, 11-13 December 2002 MINEO Hydrology, Hydrogeology and Transport Modelling Principal investigators : Stuart Marsh and Stephane.

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