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Don Mcfarlane - One of the best experts on this subject based on the ideXlab platform.
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projected risks to Groundwater dependent terrestrial vegetation caused by changing climate and Groundwater abstraction in the central perth basin western australia
Hydrological Processes, 2014Co-Authors: Olga Barron, Riasat Ali, Warrick Dawes, Geoff Hodgson, Raymond H Froend, Phil Davies, Don McfarlaneAbstract:The effect of potential climate change on Groundwater-dependent vegetation largely depends on the nature of the climate change (drying or wetting) and the level of current ecosystem dependence on Groundwater resources. In south-western Australia, climate projections suggest a high likelihood of a warmer and drier climate. The paper examines the potential environmental impacts by 2030 at the regional scale on Groundwater-dependent terrestrial vegetation (GDTV) adapted to various watertable depths, on the basis of the combined consideration of Groundwater modelling results and the framework for GDTV risk assessment. The methodology was tested for the historical period from 1984 to 2007, allowing validation of the Groundwater model results' applicability to such an assessment. Climate change effects on GDTV were evaluated using nine global climate Models under three greenhouse gas emission scenarios by applying the climate projections to Groundwater Models. It was estimated that under dry climate scenarios, GDTV is likely to be under high and severe risk over more than 20% of its current habitat area. The risk is also likely to be higher under an increase in Groundwater abstraction above current volumes. The significance of climate change risk varied across the region, depending on both the intensity of the change in water regime and the sensitivity of the GDTV to such change. Greater effects were projected for terrestrial vegetation dependent on deeper Groundwater (6–10 m). Copyright © 2013 John Wiley & Sons, Ltd.
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potential climate change impacts on the water balance of regional unconfined aquifer systems in south western australia
Hydrology and Earth System Sciences, 2012Co-Authors: Riasat Ali, Don Mcfarlane, Sunil Varma, Warrick Dawes, Irina Emelyanova, Geoff HodgsonAbstract:This study assesses climate change impacts on water balance components of the regional unconfined aquifer systems in south-western Australia, an area that has experienced a marked decline in rainfall since the mid 1970s and is expected to experience further decline due to global warming. Compared with the historical period of 1975 to 2007, reductions in the mean annual rainfall of between 15 and 18 percent are expected under a dry variant of the 2030 climate which will reduce recharge rates by between 33 and 49 percent relative to that under the historical period climate. Relative to the historical climate, reductions of up to 50 percent in Groundwater discharge to the ocean and drainage systems are also expected. Sea-water intrusion is likely in the Peel-Harvey Area under the dry future climate and net leakage to confined systems is projected to decrease by up to 35 percent which will cause reduction in pressures in confined systems under current abstraction. The percentage of net annual recharge consumed by Groundwater storage, and ocean and drainage discharges is expected to decrease and percentage of net annual recharge consumed by pumping and net leakage to confined systems to increase under median and dry future climates. Climate change is likely to significantly impact various water balance components of the regional unconfined aquifer systems of south-western Australia. We assess the quantitative climate change impact on the different components (the amounts) using the most widely used GCMs in combination with dynamically linked recharge and physically distributed Groundwater Models.
Warrick Dawes - One of the best experts on this subject based on the ideXlab platform.
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projected risks to Groundwater dependent terrestrial vegetation caused by changing climate and Groundwater abstraction in the central perth basin western australia
Hydrological Processes, 2014Co-Authors: Olga Barron, Riasat Ali, Warrick Dawes, Geoff Hodgson, Raymond H Froend, Phil Davies, Don McfarlaneAbstract:The effect of potential climate change on Groundwater-dependent vegetation largely depends on the nature of the climate change (drying or wetting) and the level of current ecosystem dependence on Groundwater resources. In south-western Australia, climate projections suggest a high likelihood of a warmer and drier climate. The paper examines the potential environmental impacts by 2030 at the regional scale on Groundwater-dependent terrestrial vegetation (GDTV) adapted to various watertable depths, on the basis of the combined consideration of Groundwater modelling results and the framework for GDTV risk assessment. The methodology was tested for the historical period from 1984 to 2007, allowing validation of the Groundwater model results' applicability to such an assessment. Climate change effects on GDTV were evaluated using nine global climate Models under three greenhouse gas emission scenarios by applying the climate projections to Groundwater Models. It was estimated that under dry climate scenarios, GDTV is likely to be under high and severe risk over more than 20% of its current habitat area. The risk is also likely to be higher under an increase in Groundwater abstraction above current volumes. The significance of climate change risk varied across the region, depending on both the intensity of the change in water regime and the sensitivity of the GDTV to such change. Greater effects were projected for terrestrial vegetation dependent on deeper Groundwater (6–10 m). Copyright © 2013 John Wiley & Sons, Ltd.
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potential climate change impacts on the water balance of regional unconfined aquifer systems in south western australia
Hydrology and Earth System Sciences, 2012Co-Authors: Riasat Ali, Don Mcfarlane, Sunil Varma, Warrick Dawes, Irina Emelyanova, Geoff HodgsonAbstract:This study assesses climate change impacts on water balance components of the regional unconfined aquifer systems in south-western Australia, an area that has experienced a marked decline in rainfall since the mid 1970s and is expected to experience further decline due to global warming. Compared with the historical period of 1975 to 2007, reductions in the mean annual rainfall of between 15 and 18 percent are expected under a dry variant of the 2030 climate which will reduce recharge rates by between 33 and 49 percent relative to that under the historical period climate. Relative to the historical climate, reductions of up to 50 percent in Groundwater discharge to the ocean and drainage systems are also expected. Sea-water intrusion is likely in the Peel-Harvey Area under the dry future climate and net leakage to confined systems is projected to decrease by up to 35 percent which will cause reduction in pressures in confined systems under current abstraction. The percentage of net annual recharge consumed by Groundwater storage, and ocean and drainage discharges is expected to decrease and percentage of net annual recharge consumed by pumping and net leakage to confined systems to increase under median and dry future climates. Climate change is likely to significantly impact various water balance components of the regional unconfined aquifer systems of south-western Australia. We assess the quantitative climate change impact on the different components (the amounts) using the most widely used GCMs in combination with dynamically linked recharge and physically distributed Groundwater Models.
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a sub grid representation of Groundwater discharge using a one dimensional Groundwater model
Hydrological Processes, 2003Co-Authors: Cuan Petheram, Warrick Dawes, R B Grayson, Andrew Bradford, G R WalkerAbstract:Simple Models of Groundwater flow have limited capability of representing spatial waterlogging/salinization due to the mismatch in scale between model cell size/process conceptualization and actual process scale. This paper presents a method for utilizing increasingly available high-resolution digital elevation data to develop a sub-grid parameterization for Groundwater discharge and surface waterlogging. This enables simple Groundwater Models to represent the actual area of waterlogging/salinization better. The approach utilizes a ‘zero-piezometric surface’ (i.e. a planar surface that passes through the lowest point of each element in a Groundwater model). The difference in elevation between the zero-piezometric surface and a high-resolution digital elevation model (DEM) provides a distribution of depth to the zero-piezometric surface (at the DEM scale) for each element in the model. Traditional methods for evaluating surface discharge can then be applied at the DEM cell scale to the distribution of depth to zero-piezometric surface to derive a relationship between depth to piezometric surface and net recharge/discharge, for each element in the model. A simple one dimensional Groundwater flow model, FLOWTUBE, is used to demonstrate the approach. Copyright © 2003 John Wiley & Sons, Ltd.
Geoff Hodgson - One of the best experts on this subject based on the ideXlab platform.
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projected risks to Groundwater dependent terrestrial vegetation caused by changing climate and Groundwater abstraction in the central perth basin western australia
Hydrological Processes, 2014Co-Authors: Olga Barron, Riasat Ali, Warrick Dawes, Geoff Hodgson, Raymond H Froend, Phil Davies, Don McfarlaneAbstract:The effect of potential climate change on Groundwater-dependent vegetation largely depends on the nature of the climate change (drying or wetting) and the level of current ecosystem dependence on Groundwater resources. In south-western Australia, climate projections suggest a high likelihood of a warmer and drier climate. The paper examines the potential environmental impacts by 2030 at the regional scale on Groundwater-dependent terrestrial vegetation (GDTV) adapted to various watertable depths, on the basis of the combined consideration of Groundwater modelling results and the framework for GDTV risk assessment. The methodology was tested for the historical period from 1984 to 2007, allowing validation of the Groundwater model results' applicability to such an assessment. Climate change effects on GDTV were evaluated using nine global climate Models under three greenhouse gas emission scenarios by applying the climate projections to Groundwater Models. It was estimated that under dry climate scenarios, GDTV is likely to be under high and severe risk over more than 20% of its current habitat area. The risk is also likely to be higher under an increase in Groundwater abstraction above current volumes. The significance of climate change risk varied across the region, depending on both the intensity of the change in water regime and the sensitivity of the GDTV to such change. Greater effects were projected for terrestrial vegetation dependent on deeper Groundwater (6–10 m). Copyright © 2013 John Wiley & Sons, Ltd.
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potential climate change impacts on the water balance of regional unconfined aquifer systems in south western australia
Hydrology and Earth System Sciences, 2012Co-Authors: Riasat Ali, Don Mcfarlane, Sunil Varma, Warrick Dawes, Irina Emelyanova, Geoff HodgsonAbstract:This study assesses climate change impacts on water balance components of the regional unconfined aquifer systems in south-western Australia, an area that has experienced a marked decline in rainfall since the mid 1970s and is expected to experience further decline due to global warming. Compared with the historical period of 1975 to 2007, reductions in the mean annual rainfall of between 15 and 18 percent are expected under a dry variant of the 2030 climate which will reduce recharge rates by between 33 and 49 percent relative to that under the historical period climate. Relative to the historical climate, reductions of up to 50 percent in Groundwater discharge to the ocean and drainage systems are also expected. Sea-water intrusion is likely in the Peel-Harvey Area under the dry future climate and net leakage to confined systems is projected to decrease by up to 35 percent which will cause reduction in pressures in confined systems under current abstraction. The percentage of net annual recharge consumed by Groundwater storage, and ocean and drainage discharges is expected to decrease and percentage of net annual recharge consumed by pumping and net leakage to confined systems to increase under median and dry future climates. Climate change is likely to significantly impact various water balance components of the regional unconfined aquifer systems of south-western Australia. We assess the quantitative climate change impact on the different components (the amounts) using the most widely used GCMs in combination with dynamically linked recharge and physically distributed Groundwater Models.
Riasat Ali - One of the best experts on this subject based on the ideXlab platform.
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projected risks to Groundwater dependent terrestrial vegetation caused by changing climate and Groundwater abstraction in the central perth basin western australia
Hydrological Processes, 2014Co-Authors: Olga Barron, Riasat Ali, Warrick Dawes, Geoff Hodgson, Raymond H Froend, Phil Davies, Don McfarlaneAbstract:The effect of potential climate change on Groundwater-dependent vegetation largely depends on the nature of the climate change (drying or wetting) and the level of current ecosystem dependence on Groundwater resources. In south-western Australia, climate projections suggest a high likelihood of a warmer and drier climate. The paper examines the potential environmental impacts by 2030 at the regional scale on Groundwater-dependent terrestrial vegetation (GDTV) adapted to various watertable depths, on the basis of the combined consideration of Groundwater modelling results and the framework for GDTV risk assessment. The methodology was tested for the historical period from 1984 to 2007, allowing validation of the Groundwater model results' applicability to such an assessment. Climate change effects on GDTV were evaluated using nine global climate Models under three greenhouse gas emission scenarios by applying the climate projections to Groundwater Models. It was estimated that under dry climate scenarios, GDTV is likely to be under high and severe risk over more than 20% of its current habitat area. The risk is also likely to be higher under an increase in Groundwater abstraction above current volumes. The significance of climate change risk varied across the region, depending on both the intensity of the change in water regime and the sensitivity of the GDTV to such change. Greater effects were projected for terrestrial vegetation dependent on deeper Groundwater (6–10 m). Copyright © 2013 John Wiley & Sons, Ltd.
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potential climate change impacts on the water balance of regional unconfined aquifer systems in south western australia
Hydrology and Earth System Sciences, 2012Co-Authors: Riasat Ali, Don Mcfarlane, Sunil Varma, Warrick Dawes, Irina Emelyanova, Geoff HodgsonAbstract:This study assesses climate change impacts on water balance components of the regional unconfined aquifer systems in south-western Australia, an area that has experienced a marked decline in rainfall since the mid 1970s and is expected to experience further decline due to global warming. Compared with the historical period of 1975 to 2007, reductions in the mean annual rainfall of between 15 and 18 percent are expected under a dry variant of the 2030 climate which will reduce recharge rates by between 33 and 49 percent relative to that under the historical period climate. Relative to the historical climate, reductions of up to 50 percent in Groundwater discharge to the ocean and drainage systems are also expected. Sea-water intrusion is likely in the Peel-Harvey Area under the dry future climate and net leakage to confined systems is projected to decrease by up to 35 percent which will cause reduction in pressures in confined systems under current abstraction. The percentage of net annual recharge consumed by Groundwater storage, and ocean and drainage discharges is expected to decrease and percentage of net annual recharge consumed by pumping and net leakage to confined systems to increase under median and dry future climates. Climate change is likely to significantly impact various water balance components of the regional unconfined aquifer systems of south-western Australia. We assess the quantitative climate change impact on the different components (the amounts) using the most widely used GCMs in combination with dynamically linked recharge and physically distributed Groundwater Models.
T P Clement - One of the best experts on this subject based on the ideXlab platform.
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theoretical analysis of the worthiness of henry and elder problems as benchmarks of density dependent Groundwater flow Models
Advances in Water Resources, 2003Co-Authors: Matthew J Simpson, T P ClementAbstract:Computer Models must be tested to ensure that the mathematical statements and solution schemes accurately represent the physical processes of interest. Because the availability of benchmark problems for testing density-dependent Groundwater Models is limited, one should be careful in using these problems appropriately. Details of a Galerkin finite-element model for the simulation of density-dependent, variably saturated flow processes are presented here. The model is tested using the Henry salt-water intrusion problem and Elder salt convection problem. The quality of these benchmark problems is then evaluated by solving the problems in the standard density-coupled mode and in a new density-uncoupled mode. The differences between the solutions indicate that the Henry salt-water intrusion problem has limited usefulness in benchmarking density-dependent flow Models because the internal flow dynamics are largely determined by the boundary forcing. Alternatively, the Elder salt-convection problem is more suited to the model testing process because the flow patterns are completely determined by the internal balance of pressure and gravity forces.
