The Pathways Catchment Management Tool (CMT) is being developed for environmental managers intere... more The Pathways Catchment Management Tool (CMT) is being developed for environmental managers interested in water quality modelling and critical source area identification. The CMT is a Geographical Information System (GIS) based application that helps decision makers manage water at catchment scale by predicting fluxes of water and contaminants separately through all of the hydrological pathways and identifying critical source areas (CSAs). This management tool integrates a considerable amount of national datasets and research from a broad range of disciplines into an annual GIS model and a dynamic water quality model to simulate fluxes of water, sediment and nutrients entering a river along various flow paths. Three levels of user interaction are facilitated in the interface to match the complexity of the available information and analysis required, and the user’s level of experience. In Level 1 of the tool, users can view national data sets, delineate a catchment of interest and gen...
The redundancy and ill-conditioned nature of model identification and parameter estimation make i... more The redundancy and ill-conditioned nature of model identification and parameter estimation make it difficult to identify a hydrological model that can correctly split the flow dynamics and associated contaminant transport and transformation between each of its conceptual pathways. The Pathways project, funded by the Irish EPA, combines insights from conceptual catchment modelling and detailed fieldwork investigations to inform an integrated water management tool. Within this project, a user-friendly GIS application is being developed for environmental managers interested in water quality modelling using the Pathways Computational Engine (PACE) model. This variable structure water quality model can be used to investigate hydrological and contaminant processes at sub-catchment scale and to incorporate expert knowledge relating to flow pathways and contaminant transport along these pathways. In this paper, parameter identification issues related to the hydrological model are discussed ...
Increasing pressures on water quality due to intensification of agriculture have raised demands f... more Increasing pressures on water quality due to intensification of agriculture have raised demands for environmental modeling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately represented for water quality simulations to be meaningful. In particular, the relative contribution of groundwater and surface runoff to rivers is of interest, as increasing nitrate concentrations are linked to higher groundwater discharges. These requirements for hydrological modeling of groundwater contribution to rivers initiated this assessment of internal flow path partitioning in conceptual hydrological models. In this study, a variance based sensitivity analysis method was used to investigate parameter sensitivities and flow partitioning of three conceptual hydrological models simulating 31 Irish catchments. We compared two established con...
International Environmental Modelling & Software Society (iEMSs) 8th International Congress on En... more International Environmental Modelling & Software Society (iEMSs) 8th International Congress on Environmental Modelling and Software, Toulouse, France, 10-14 July 2016
LUWQ 2019: International Interdisciplinary Conference on Land Use and Water Quality. Agriculture ... more LUWQ 2019: International Interdisciplinary Conference on Land Use and Water Quality. Agriculture and the Environment. Aarhus, Denmark, 3-6 June 2019
International Association of Hydrogeologists (IAH) (Irish Group) Conference, 25-26 April 2017, Tu... more International Association of Hydrogeologists (IAH) (Irish Group) Conference, 25-26 April 2017, Tullamore, Offaly, Ireland
Distributed or semi-distributed models are usually cascades of lumped models, each with an identi... more Distributed or semi-distributed models are usually cascades of lumped models, each with an identical structure. This, classical, approach has a number of drawbacks; (i) each lumped model must be sufficiently general and thus complex to cope with the range of hydrological situations possible and (ii) it precludes debate and discussion between scientists about the most appropriate model conceptualisation and in particular it precludes using different conceptualisations in different areas to adapt the model to different hydrologic regimes, perhaps even in the same catchment. Both of these lead to distributed models that are unnecessarily complex and over-parameterised with consequent implications for parameter estimation. The rigid, fixed, structure also adds to the difficulty in modelling specific pollution mitigation measures at scales smaller than the catchment model. A hydrological model that has a flexible and variable structure has been developed to address these issues. Based on...
Increasing pressures on water quality due to intensification of agriculture have increased the ne... more Increasing pressures on water quality due to intensification of agriculture have increased the need for environmental modelling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately represented for water quality simulations to be meaningful. In particular, the relative contribution of groundwater and surface runoff to rivers is of interest, as, for example, higher nitrate concentrations in surface waters are strongly linked to catchments with proportionately larger groundwater contributions to the river. In this study, uncertainty analysis was used to investigate parameter sensitivities and flow partitioning of three conceptual hydrological models simulating 31 Irish catchments. We compared two established conceptual hydrological models (NAM and SMARG) and a new model (SMART), produced especially for water quality modell...
8th International Congress on Environmental Modelling and Software in Toulouse, France, 10-14 Jul... more 8th International Congress on Environmental Modelling and Software in Toulouse, France, 10-14 July 2016
International Association of Hydrogeologists (IAH) (Irish Group) Sustaining Ireland’s Water Futur... more International Association of Hydrogeologists (IAH) (Irish Group) Sustaining Ireland’s Water Future: The Role of Groundwater, Tullamore, Co. Offaly, Ireland, 12-13 April 2016
Nutrient enrichment and eutrophication can increase when urbanisation and intensification of agri... more Nutrient enrichment and eutrophication can increase when urbanisation and intensification of agriculture production occurs without accompanying mitigation measures to offset impacts from land use transitions. The identification of measures to protect or restore water quality is a challenging exercise, particularly in the context of increasing population and urbanisation. Hence, decision-makers need adequate tools to better understand and evaluate the effects of policy interventions on water management and quality control in urban regions. A model integration method was developed to assess future scenarios of urban development on water quality using land use model Monitoring Land Use/Cover Dynamics and nutrient emission model Source Load Apportionment Model. A case study application investigated how projected changes in urban land use in the most populated region of Ireland, the Greater Dublin Region, impact on water quality. Results for all scenarios indicate increasing losses to wa...
The Science of the total environment, Jan 15, 2018
Natural organic matter poses an increasing challenge to water managers because of its potential a... more Natural organic matter poses an increasing challenge to water managers because of its potential adverse impacts on water treatment and distribution, and subsequently human health. Projections were made of impacts of climate change on dissolved organic carbon (DOC) in the primarily agricultural Boyne catchment which is used as a potable water supply in Ireland. The results indicated that excluding a potential rise in extreme precipitation, future projected loads are not dissimilar to those observed under current conditions. This is because projected increases in DOC concentrations are offset by corresponding decreases in precipitation and hence river flow. However, the results presented assume no changes in land use and highlight the predicted increase in DOC loads from abstracted waters at water treatment plants.
Increasing pressures on water quality due to intensification of agriculture have increased the ne... more Increasing pressures on water quality due to intensification of agriculture have increased the need for environmental modelling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately represented for water quality simulations to be meaningful. In particular, the relative contribution of groundwater and surface runoff to rivers is of interest, as, for example, higher nitrate concentrations in surface waters are strongly linked to catchments with proportionately larger groundwater contributions to the river. In this study, uncertainty analysis was used to investigate parameter sensitivities and flow partitioning of three conceptual hydrological models simulating 31 Irish catchments. We compared two established conceptual hydrological models (NAM and SMARG) and a new model (SMART), produced especially for water quality modelling. In addition to the criteria that assess streamflow simulations, a ratio of average groundwater contribution to total streamflow was calculated for all simulations over the 16 year study period. As measured time-series of groundwater contributions to streamflow are not available at catchment scale, the groundwater ratios were evaluated against average annual indices of base flow (from the OPW) and estimates of deep groundwater flow (from the Geological Survey of Ireland) for each catchment. The exploration of sensitivities of internal flow path partitioning was a specific focus to assist in evaluating model performances. Results highlight that model structure has a strong impact on simulated groundwater flow path contributions. Sensitivities to the internal pathways in the models are not reflected in the usual (flood forecasting) performance criteria results. This demonstrates that simulated groundwater contribution should be constrained by independent data to ensure results within realistic bounds if such models are to be used in the broader environmental sustainability decision making context.
The Pathways Catchment Management Tool (CMT) is being developed for environmental managers intere... more The Pathways Catchment Management Tool (CMT) is being developed for environmental managers interested in water quality modelling and critical source area identification. The CMT is a Geographical Information System (GIS) based application that helps decision makers manage water at catchment scale by predicting fluxes of water and contaminants separately through all of the hydrological pathways and identifying critical source areas (CSAs). This management tool integrates a considerable amount of national datasets and research from a broad range of disciplines into an annual GIS model and a dynamic water quality model to simulate fluxes of water, sediment and nutrients entering a river along various flow paths. Three levels of user interaction are facilitated in the interface to match the complexity of the available information and analysis required, and the user’s level of experience. In Level 1 of the tool, users can view national data sets, delineate a catchment of interest and gen...
The redundancy and ill-conditioned nature of model identification and parameter estimation make i... more The redundancy and ill-conditioned nature of model identification and parameter estimation make it difficult to identify a hydrological model that can correctly split the flow dynamics and associated contaminant transport and transformation between each of its conceptual pathways. The Pathways project, funded by the Irish EPA, combines insights from conceptual catchment modelling and detailed fieldwork investigations to inform an integrated water management tool. Within this project, a user-friendly GIS application is being developed for environmental managers interested in water quality modelling using the Pathways Computational Engine (PACE) model. This variable structure water quality model can be used to investigate hydrological and contaminant processes at sub-catchment scale and to incorporate expert knowledge relating to flow pathways and contaminant transport along these pathways. In this paper, parameter identification issues related to the hydrological model are discussed ...
Increasing pressures on water quality due to intensification of agriculture have raised demands f... more Increasing pressures on water quality due to intensification of agriculture have raised demands for environmental modeling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately represented for water quality simulations to be meaningful. In particular, the relative contribution of groundwater and surface runoff to rivers is of interest, as increasing nitrate concentrations are linked to higher groundwater discharges. These requirements for hydrological modeling of groundwater contribution to rivers initiated this assessment of internal flow path partitioning in conceptual hydrological models. In this study, a variance based sensitivity analysis method was used to investigate parameter sensitivities and flow partitioning of three conceptual hydrological models simulating 31 Irish catchments. We compared two established con...
International Environmental Modelling & Software Society (iEMSs) 8th International Congress on En... more International Environmental Modelling & Software Society (iEMSs) 8th International Congress on Environmental Modelling and Software, Toulouse, France, 10-14 July 2016
LUWQ 2019: International Interdisciplinary Conference on Land Use and Water Quality. Agriculture ... more LUWQ 2019: International Interdisciplinary Conference on Land Use and Water Quality. Agriculture and the Environment. Aarhus, Denmark, 3-6 June 2019
International Association of Hydrogeologists (IAH) (Irish Group) Conference, 25-26 April 2017, Tu... more International Association of Hydrogeologists (IAH) (Irish Group) Conference, 25-26 April 2017, Tullamore, Offaly, Ireland
Distributed or semi-distributed models are usually cascades of lumped models, each with an identi... more Distributed or semi-distributed models are usually cascades of lumped models, each with an identical structure. This, classical, approach has a number of drawbacks; (i) each lumped model must be sufficiently general and thus complex to cope with the range of hydrological situations possible and (ii) it precludes debate and discussion between scientists about the most appropriate model conceptualisation and in particular it precludes using different conceptualisations in different areas to adapt the model to different hydrologic regimes, perhaps even in the same catchment. Both of these lead to distributed models that are unnecessarily complex and over-parameterised with consequent implications for parameter estimation. The rigid, fixed, structure also adds to the difficulty in modelling specific pollution mitigation measures at scales smaller than the catchment model. A hydrological model that has a flexible and variable structure has been developed to address these issues. Based on...
Increasing pressures on water quality due to intensification of agriculture have increased the ne... more Increasing pressures on water quality due to intensification of agriculture have increased the need for environmental modelling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately represented for water quality simulations to be meaningful. In particular, the relative contribution of groundwater and surface runoff to rivers is of interest, as, for example, higher nitrate concentrations in surface waters are strongly linked to catchments with proportionately larger groundwater contributions to the river. In this study, uncertainty analysis was used to investigate parameter sensitivities and flow partitioning of three conceptual hydrological models simulating 31 Irish catchments. We compared two established conceptual hydrological models (NAM and SMARG) and a new model (SMART), produced especially for water quality modell...
8th International Congress on Environmental Modelling and Software in Toulouse, France, 10-14 Jul... more 8th International Congress on Environmental Modelling and Software in Toulouse, France, 10-14 July 2016
International Association of Hydrogeologists (IAH) (Irish Group) Sustaining Ireland’s Water Futur... more International Association of Hydrogeologists (IAH) (Irish Group) Sustaining Ireland’s Water Future: The Role of Groundwater, Tullamore, Co. Offaly, Ireland, 12-13 April 2016
Nutrient enrichment and eutrophication can increase when urbanisation and intensification of agri... more Nutrient enrichment and eutrophication can increase when urbanisation and intensification of agriculture production occurs without accompanying mitigation measures to offset impacts from land use transitions. The identification of measures to protect or restore water quality is a challenging exercise, particularly in the context of increasing population and urbanisation. Hence, decision-makers need adequate tools to better understand and evaluate the effects of policy interventions on water management and quality control in urban regions. A model integration method was developed to assess future scenarios of urban development on water quality using land use model Monitoring Land Use/Cover Dynamics and nutrient emission model Source Load Apportionment Model. A case study application investigated how projected changes in urban land use in the most populated region of Ireland, the Greater Dublin Region, impact on water quality. Results for all scenarios indicate increasing losses to wa...
The Science of the total environment, Jan 15, 2018
Natural organic matter poses an increasing challenge to water managers because of its potential a... more Natural organic matter poses an increasing challenge to water managers because of its potential adverse impacts on water treatment and distribution, and subsequently human health. Projections were made of impacts of climate change on dissolved organic carbon (DOC) in the primarily agricultural Boyne catchment which is used as a potable water supply in Ireland. The results indicated that excluding a potential rise in extreme precipitation, future projected loads are not dissimilar to those observed under current conditions. This is because projected increases in DOC concentrations are offset by corresponding decreases in precipitation and hence river flow. However, the results presented assume no changes in land use and highlight the predicted increase in DOC loads from abstracted waters at water treatment plants.
Increasing pressures on water quality due to intensification of agriculture have increased the ne... more Increasing pressures on water quality due to intensification of agriculture have increased the need for environmental modelling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately represented for water quality simulations to be meaningful. In particular, the relative contribution of groundwater and surface runoff to rivers is of interest, as, for example, higher nitrate concentrations in surface waters are strongly linked to catchments with proportionately larger groundwater contributions to the river. In this study, uncertainty analysis was used to investigate parameter sensitivities and flow partitioning of three conceptual hydrological models simulating 31 Irish catchments. We compared two established conceptual hydrological models (NAM and SMARG) and a new model (SMART), produced especially for water quality modelling. In addition to the criteria that assess streamflow simulations, a ratio of average groundwater contribution to total streamflow was calculated for all simulations over the 16 year study period. As measured time-series of groundwater contributions to streamflow are not available at catchment scale, the groundwater ratios were evaluated against average annual indices of base flow (from the OPW) and estimates of deep groundwater flow (from the Geological Survey of Ireland) for each catchment. The exploration of sensitivities of internal flow path partitioning was a specific focus to assist in evaluating model performances. Results highlight that model structure has a strong impact on simulated groundwater flow path contributions. Sensitivities to the internal pathways in the models are not reflected in the usual (flood forecasting) performance criteria results. This demonstrates that simulated groundwater contribution should be constrained by independent data to ensure results within realistic bounds if such models are to be used in the broader environmental sustainability decision making context.
The CatchmentTools Project (2014-2016) is developing data analysis tools and models for assessing... more The CatchmentTools Project (2014-2016) is developing data analysis tools and models for assessing nutrients in Irish catchments to support catchment scientists and managers to (1) characterise catchments and (2) implement measures. This work builds on the STRIVE Pathways Project findings by continuing the development of the Catchment Tools.
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