Roads and railways are founded on earthwork structures such as embankments, which can be suscepti... more Roads and railways are founded on earthwork structures such as embankments, which can be susceptible to slope instability and failure, with serious economic and safety implications. Existing approaches to earthwork condition appraisal are labour-intensive and hazardous. While the increasing availability of high resolution geospatial data offers improved opportunities for remote and efficient slope stability assessment, there remains a gap between the availability of such data, and the subsequent extraction of intelligent information. In this research, high resolution lidar data and multispectral aerial imagery are supporting the extraction of the key stability controls of slope gradient, aspect, soil moisture and vegetation type. The influence of these parameters has been established through numerical modelling under existing and future climate scenarios, enabling stability to be quantified and mapped in a spatially continuous manner. The research has been applied to a test site located at Haltwhistle in northern England. Results highlight the challenges associated with establishing a suitable spatial resolution for parameter extraction and risk assessment in a GIS environment, with degradation in resolution from 20 to 0.5 points / m 2 required in order to overcome micro-topographic effects. A topographic wetness index (TWI), derived from the lidar DTM, was used to characterise soil moisture across the test site. Initial concerns over whether the restricted lidar coverage would be sufficient to capture broader-scale flow routing were allayed following investigations using a larger-scale DTM, which was found to produce results which were in good agreement with the lidar-derived TWI.
Numerical modelling has been undertaken to help improve understanding of a deep geothermal system... more Numerical modelling has been undertaken to help improve understanding of a deep geothermal system being considered for development in the vicinity of Eastgate (Weardale, County Durham, UK). A parsimonious numerical modelling approach is used, which allows the possibility to develop a workable formal framework, rigorously testing evolving concepts against data as they become available. The approach used and results presented in this study are valuable as a contribution to a wider understanding of deep geothermal systems. This modelling approach is novel in that it utilises the mass transport code MT3DMS as a surrogate representation for heat transport in mid-enthalpy geothermal systems. A three-dimensional heat transport model was built, based on a relatively simple conceptual model. Results of simulation runs of a geothermal production scenario have positive implications for a working geothermal system at Eastgate. The Eastgate Geothermal Field has significant exploitation potential for combined heat and power purposes; it is anticipated that this site could support several tens of megawatts of heat production for direct use and many megawatts of electrical power using a binary power plant.
Physically based spatially distributed (PBSD) river basin models have been available for over 10 ... more Physically based spatially distributed (PBSD) river basin models have been available for over 10 years. One of their strengths lies in the way the surface and subsurface are represented as coupled parts of a whole, giving ground-water flows that are controlled by such factors as realistic surface saturation and infiltration, and surface conditions that are controlled by realistic groundwater levels,
Modelling the impact of afforestation or deforestation on water resources is complex due to facto... more Modelling the impact of afforestation or deforestation on water resources is complex due to factors such as the microclimate, the soils, the underlying geology, the presence of macropores, the species, their age and density. Parameters used in modelling the different processes are traditionally determined individually from laborious measurements. In this study the only input data required are time series precipitation
Proceedings of the ICE - Engineering Sustainability, 2009
A unique facility for engineering and biological research has been established with the aim of im... more A unique facility for engineering and biological research has been established with the aim of improving fundamental understanding of the effects of climate change on slopes. This paper describes the building and monitoring of a full-scale embankment representative of UK infrastructure, the planting and monitoring of representative vegetation, and the construction of a system of sprinklers and covers to control climate. A summary of the results of the first experiments simulating predicted the future UK climate and the response of the embankment is also presented. The information that has begun to be gathered is providing data related to the failure modes anticipated as a result of climate change and hence on the sustainability of UK infrastructure slopes.
Proceedings of the ICE - Engineering Sustainability, 2009
The UK biological and engineering impacts of climate change on slopes (Bionics) project was funde... more The UK biological and engineering impacts of climate change on slopes (Bionics) project was funded to bring together key stakeholders and academics to research advanced procedures for maintaining serviceability and safety of strategic embankments and cuttings in addition to advancing the science base. This paper summarises some of the evidence that suggests climate change will have an effect on the behaviour of infrastructure slopes and their management, and provides an overview of future climate scenarios for the UK. It also ...
Evaluation of the impacts of groundwater abstractions on surface water systems is 17 a necessary ... more Evaluation of the impacts of groundwater abstractions on surface water systems is 17 a necessary task in integrated water resources management. A range of hydrological, 18 hydrogeological, and geomorphological factors influence the complex processes of 19 interaction between groundwater and rivers. This paper presents an approach which uses 20 the Lambourne catchment over a Chalk aquifer was used successfully to test the 16 modeling tool. This modeling approach provides a general methodology for rapid 17 simulations of complex hydrogeological systems which preserves the physical 18 consistency between multiple and diverse model outputs. 19 20
ABSTRACT A rapid assessment method for evaluating the impacts of groundwater abstraction on river... more ABSTRACT A rapid assessment method for evaluating the impacts of groundwater abstraction on river flow depletion has been developed and tested. A hybrid approach was taken, in which a neural network model was used to mimic the results from numerical simulations of interactions between groundwater and rivers using the SHETRAN integrated catchment modelling system. The use of a numerical model ensures self-consistent relationships between input and output data which have a physical basis and are smooth and free of noise. The model simulations required large number of input parameters and several types of time series and spatial output data representing river flow depletions and groundwater drawdown. An orthogonal array technique was used to select parameter values from the multi-dimensional parameter space, providing an efficient design for the neural network training as the datasets are reasonably independent. The efficiency of the neural network model was also improved by a data reduction approach involving fitting curves to the outputs from the numerical model without significant loss of information. It was found that the use of these techniques were essential to develop a feasible method of providing rapid access to the results of detailed process-based simulations using neural networks.
IEEE Transactions on Geoscience and Remote Sensing, 2000
Earthworks such as embankments and cuttings are integral to road and rail networks but can be pro... more Earthworks such as embankments and cuttings are integral to road and rail networks but can be prone to instability, necessitating rigorous and continual monitoring. To date, the potential of remote sensing for earthwork hazard assessment has been largely overlooked. However, techniques such as airborne laser scanning (ALS) are now ripe for addressing these challenges. This research presents the development of a novel hazard assessment strategy, combining high-resolution remote sensing with a numerical modeling approach. The research was implemented at a railway test site located in northern England, U.K.; ALS data and multispectral aerial imagery facilitated the determination of key slope stability variables, which were then used to parameterize a coupled hydrological-geotechnical model, in order to simulate slope behavior under current and future climates. A software toolset was developed to integrate the core elements of the methodology and determine resultant slope failure hazard which could then be mapped and queried within a geographical information system environment. Results indicate that the earthworks are largely stable, which is in broad agreement with the management company's slope hazard grading data, and in terms of morphological analysis, the remote methodology was able to correctly identify 99% of earthworks classed as embankments and 100% of cuttings. The developed approach provides an effective and practicable method for remotely quantifying slope failure hazard at fine spatial scales (0.5 m) and for prioritizing and reducing on-site inspection.
ABSTRACT The Système Hydrologique Europeén (SHE) modelling system and physically-based distribute... more ABSTRACT The Système Hydrologique Europeén (SHE) modelling system and physically-based distributed modelling (PBDM) were discussed in Refsgaard et al.'s Système Hydrologique Europeén (SHE): review and perspectives after 30 years development in distributed physically-based hydrological modelling (Hydrology Research 41, pp. 355–377). The opportunity is taken here to correct some oversights and potentially misleading perspectives in that paper and mount a more robust defence of PBDM.
This study emphasizes the importance of rainstorm events in mobilizing carbon at the soil-stream ... more This study emphasizes the importance of rainstorm events in mobilizing carbon at the soil-stream interface from tropical rainforests. Half-hourly geochemical/isotopic records over a 13.5 h period from a 20 km 2 tropical rainforest headwater in Guyana show an order of magnitude increase in dissolved organic carbon (DOC) concentration in less than 30 mins (10.6-114 mg/L). The composition of DOC varies significantly and includes optically invisible dissolved organic matter (iDOM) that accounts for a large proportion (4-89%) of the total DOC, quantified using size exclusion chromatography (SEC). SEC suggests that iDOM is comprised of low molecular weight organic moieties, which are likely sourced from fresh leaf litter and/or topsoil, as shown in soils from the surrounding environment. Although poorly constrained at present, the presence of iDOM further downstream during the wet season suggests that this organic matter fraction may represent an unquantified source of riverine CO 2 outgassing in tropical headwaters, requiring further consideration.
Question: How can long-term monitoring of hydrological and ecological parameters support manageme... more Question: How can long-term monitoring of hydrological and ecological parameters support management strategies aimed towards wetland restoration and re-creation in a complex hydrological system? Location: Newham Bog National Nature Reserve, Northumberland, UK, a site with a long history of active management, and recorded as drought-sensitive over the last 100 years. Methods: Water level readings are correlated with longer-term hydrological databases, and these data related to vegetation data collected intermittently over a 12 year period. Two analyses are undertaken: (1) a composite DCA analysis of 1993 and 2002 survey data to assess plant community transitions within the wetland and over time, and (2) analysis of recent vegetation data to explore wider vegetation gradients. This allows (3) communities to be classified using NVC classes and (4) integrated with revised Ellenberg F-values. Results: Drought impact and subsequent hydrological recovery over a 22-year period are quantified. Vegetation data display strong moisture and successional gradients. Analysis shows a shift from grassland communities toward mire communities across much of the site. Conclusion: The site is regionally unique in that it has a detailed long-term monitoring record. Hydrological data and vegetation survey have allowed the impact of the most recent 'groundwater' drought (1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997) to be quantified. This information on system resilience, combined with eco-hydrological analyses of plant community-water regime/quality relationships, provide a basis for recommendations concerning conservation and restoration.
Roads and railways are founded on earthwork structures such as embankments, which can be suscepti... more Roads and railways are founded on earthwork structures such as embankments, which can be susceptible to slope instability and failure, with serious economic and safety implications. Existing approaches to earthwork condition appraisal are labour-intensive and hazardous. While the increasing availability of high resolution geospatial data offers improved opportunities for remote and efficient slope stability assessment, there remains a gap between the availability of such data, and the subsequent extraction of intelligent information. In this research, high resolution lidar data and multispectral aerial imagery are supporting the extraction of the key stability controls of slope gradient, aspect, soil moisture and vegetation type. The influence of these parameters has been established through numerical modelling under existing and future climate scenarios, enabling stability to be quantified and mapped in a spatially continuous manner. The research has been applied to a test site located at Haltwhistle in northern England. Results highlight the challenges associated with establishing a suitable spatial resolution for parameter extraction and risk assessment in a GIS environment, with degradation in resolution from 20 to 0.5 points / m 2 required in order to overcome micro-topographic effects. A topographic wetness index (TWI), derived from the lidar DTM, was used to characterise soil moisture across the test site. Initial concerns over whether the restricted lidar coverage would be sufficient to capture broader-scale flow routing were allayed following investigations using a larger-scale DTM, which was found to produce results which were in good agreement with the lidar-derived TWI.
Numerical modelling has been undertaken to help improve understanding of a deep geothermal system... more Numerical modelling has been undertaken to help improve understanding of a deep geothermal system being considered for development in the vicinity of Eastgate (Weardale, County Durham, UK). A parsimonious numerical modelling approach is used, which allows the possibility to develop a workable formal framework, rigorously testing evolving concepts against data as they become available. The approach used and results presented in this study are valuable as a contribution to a wider understanding of deep geothermal systems. This modelling approach is novel in that it utilises the mass transport code MT3DMS as a surrogate representation for heat transport in mid-enthalpy geothermal systems. A three-dimensional heat transport model was built, based on a relatively simple conceptual model. Results of simulation runs of a geothermal production scenario have positive implications for a working geothermal system at Eastgate. The Eastgate Geothermal Field has significant exploitation potential for combined heat and power purposes; it is anticipated that this site could support several tens of megawatts of heat production for direct use and many megawatts of electrical power using a binary power plant.
Physically based spatially distributed (PBSD) river basin models have been available for over 10 ... more Physically based spatially distributed (PBSD) river basin models have been available for over 10 years. One of their strengths lies in the way the surface and subsurface are represented as coupled parts of a whole, giving ground-water flows that are controlled by such factors as realistic surface saturation and infiltration, and surface conditions that are controlled by realistic groundwater levels,
Modelling the impact of afforestation or deforestation on water resources is complex due to facto... more Modelling the impact of afforestation or deforestation on water resources is complex due to factors such as the microclimate, the soils, the underlying geology, the presence of macropores, the species, their age and density. Parameters used in modelling the different processes are traditionally determined individually from laborious measurements. In this study the only input data required are time series precipitation
Proceedings of the ICE - Engineering Sustainability, 2009
A unique facility for engineering and biological research has been established with the aim of im... more A unique facility for engineering and biological research has been established with the aim of improving fundamental understanding of the effects of climate change on slopes. This paper describes the building and monitoring of a full-scale embankment representative of UK infrastructure, the planting and monitoring of representative vegetation, and the construction of a system of sprinklers and covers to control climate. A summary of the results of the first experiments simulating predicted the future UK climate and the response of the embankment is also presented. The information that has begun to be gathered is providing data related to the failure modes anticipated as a result of climate change and hence on the sustainability of UK infrastructure slopes.
Proceedings of the ICE - Engineering Sustainability, 2009
The UK biological and engineering impacts of climate change on slopes (Bionics) project was funde... more The UK biological and engineering impacts of climate change on slopes (Bionics) project was funded to bring together key stakeholders and academics to research advanced procedures for maintaining serviceability and safety of strategic embankments and cuttings in addition to advancing the science base. This paper summarises some of the evidence that suggests climate change will have an effect on the behaviour of infrastructure slopes and their management, and provides an overview of future climate scenarios for the UK. It also ...
Evaluation of the impacts of groundwater abstractions on surface water systems is 17 a necessary ... more Evaluation of the impacts of groundwater abstractions on surface water systems is 17 a necessary task in integrated water resources management. A range of hydrological, 18 hydrogeological, and geomorphological factors influence the complex processes of 19 interaction between groundwater and rivers. This paper presents an approach which uses 20 the Lambourne catchment over a Chalk aquifer was used successfully to test the 16 modeling tool. This modeling approach provides a general methodology for rapid 17 simulations of complex hydrogeological systems which preserves the physical 18 consistency between multiple and diverse model outputs. 19 20
ABSTRACT A rapid assessment method for evaluating the impacts of groundwater abstraction on river... more ABSTRACT A rapid assessment method for evaluating the impacts of groundwater abstraction on river flow depletion has been developed and tested. A hybrid approach was taken, in which a neural network model was used to mimic the results from numerical simulations of interactions between groundwater and rivers using the SHETRAN integrated catchment modelling system. The use of a numerical model ensures self-consistent relationships between input and output data which have a physical basis and are smooth and free of noise. The model simulations required large number of input parameters and several types of time series and spatial output data representing river flow depletions and groundwater drawdown. An orthogonal array technique was used to select parameter values from the multi-dimensional parameter space, providing an efficient design for the neural network training as the datasets are reasonably independent. The efficiency of the neural network model was also improved by a data reduction approach involving fitting curves to the outputs from the numerical model without significant loss of information. It was found that the use of these techniques were essential to develop a feasible method of providing rapid access to the results of detailed process-based simulations using neural networks.
IEEE Transactions on Geoscience and Remote Sensing, 2000
Earthworks such as embankments and cuttings are integral to road and rail networks but can be pro... more Earthworks such as embankments and cuttings are integral to road and rail networks but can be prone to instability, necessitating rigorous and continual monitoring. To date, the potential of remote sensing for earthwork hazard assessment has been largely overlooked. However, techniques such as airborne laser scanning (ALS) are now ripe for addressing these challenges. This research presents the development of a novel hazard assessment strategy, combining high-resolution remote sensing with a numerical modeling approach. The research was implemented at a railway test site located in northern England, U.K.; ALS data and multispectral aerial imagery facilitated the determination of key slope stability variables, which were then used to parameterize a coupled hydrological-geotechnical model, in order to simulate slope behavior under current and future climates. A software toolset was developed to integrate the core elements of the methodology and determine resultant slope failure hazard which could then be mapped and queried within a geographical information system environment. Results indicate that the earthworks are largely stable, which is in broad agreement with the management company's slope hazard grading data, and in terms of morphological analysis, the remote methodology was able to correctly identify 99% of earthworks classed as embankments and 100% of cuttings. The developed approach provides an effective and practicable method for remotely quantifying slope failure hazard at fine spatial scales (0.5 m) and for prioritizing and reducing on-site inspection.
ABSTRACT The Système Hydrologique Europeén (SHE) modelling system and physically-based distribute... more ABSTRACT The Système Hydrologique Europeén (SHE) modelling system and physically-based distributed modelling (PBDM) were discussed in Refsgaard et al.'s Système Hydrologique Europeén (SHE): review and perspectives after 30 years development in distributed physically-based hydrological modelling (Hydrology Research 41, pp. 355–377). The opportunity is taken here to correct some oversights and potentially misleading perspectives in that paper and mount a more robust defence of PBDM.
This study emphasizes the importance of rainstorm events in mobilizing carbon at the soil-stream ... more This study emphasizes the importance of rainstorm events in mobilizing carbon at the soil-stream interface from tropical rainforests. Half-hourly geochemical/isotopic records over a 13.5 h period from a 20 km 2 tropical rainforest headwater in Guyana show an order of magnitude increase in dissolved organic carbon (DOC) concentration in less than 30 mins (10.6-114 mg/L). The composition of DOC varies significantly and includes optically invisible dissolved organic matter (iDOM) that accounts for a large proportion (4-89%) of the total DOC, quantified using size exclusion chromatography (SEC). SEC suggests that iDOM is comprised of low molecular weight organic moieties, which are likely sourced from fresh leaf litter and/or topsoil, as shown in soils from the surrounding environment. Although poorly constrained at present, the presence of iDOM further downstream during the wet season suggests that this organic matter fraction may represent an unquantified source of riverine CO 2 outgassing in tropical headwaters, requiring further consideration.
Question: How can long-term monitoring of hydrological and ecological parameters support manageme... more Question: How can long-term monitoring of hydrological and ecological parameters support management strategies aimed towards wetland restoration and re-creation in a complex hydrological system? Location: Newham Bog National Nature Reserve, Northumberland, UK, a site with a long history of active management, and recorded as drought-sensitive over the last 100 years. Methods: Water level readings are correlated with longer-term hydrological databases, and these data related to vegetation data collected intermittently over a 12 year period. Two analyses are undertaken: (1) a composite DCA analysis of 1993 and 2002 survey data to assess plant community transitions within the wetland and over time, and (2) analysis of recent vegetation data to explore wider vegetation gradients. This allows (3) communities to be classified using NVC classes and (4) integrated with revised Ellenberg F-values. Results: Drought impact and subsequent hydrological recovery over a 22-year period are quantified. Vegetation data display strong moisture and successional gradients. Analysis shows a shift from grassland communities toward mire communities across much of the site. Conclusion: The site is regionally unique in that it has a detailed long-term monitoring record. Hydrological data and vegetation survey have allowed the impact of the most recent 'groundwater' drought (1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997) to be quantified. This information on system resilience, combined with eco-hydrological analyses of plant community-water regime/quality relationships, provide a basis for recommendations concerning conservation and restoration.
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Papers by Geoff Parkin
considered for development in the vicinity of Eastgate (Weardale, County Durham, UK). A parsimonious numerical
modelling approach is used, which allows the possibility to develop a workable formal framework, rigorously testing
evolving concepts against data as they become available. The approach used and results presented in this study are
valuable as a contribution to a wider understanding of deep geothermal systems. This modelling approach is novel in
that it utilises the mass transport code MT3DMS as a surrogate representation for heat transport in mid-enthalpy
geothermal systems. A three-dimensional heat transport model was built, based on a relatively simple conceptual
model. Results of simulation runs of a geothermal production scenario have positive implications for a working
geothermal system at Eastgate. The Eastgate Geothermal Field has significant exploitation potential for combined
heat and power purposes; it is anticipated that this site could support several tens of megawatts of heat production
for direct use and many megawatts of electrical power using a binary power plant.
considered for development in the vicinity of Eastgate (Weardale, County Durham, UK). A parsimonious numerical
modelling approach is used, which allows the possibility to develop a workable formal framework, rigorously testing
evolving concepts against data as they become available. The approach used and results presented in this study are
valuable as a contribution to a wider understanding of deep geothermal systems. This modelling approach is novel in
that it utilises the mass transport code MT3DMS as a surrogate representation for heat transport in mid-enthalpy
geothermal systems. A three-dimensional heat transport model was built, based on a relatively simple conceptual
model. Results of simulation runs of a geothermal production scenario have positive implications for a working
geothermal system at Eastgate. The Eastgate Geothermal Field has significant exploitation potential for combined
heat and power purposes; it is anticipated that this site could support several tens of megawatts of heat production
for direct use and many megawatts of electrical power using a binary power plant.