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Newmarket, New Zealand

Whiteman M.I.,UK Environment Agency | Maginness C.H.,AMEC Environment and Infrastructure | Maginness C.H.,Pattle Delamore Partners Ltd | Farrell R.P.,UK Environment Agency | And 2 more authors.
Geological Society Special Publication

The National Groundwater Modelling System (NGMS) is a map-based, client-server system for holding groundwater models and supporting documentation. Models can be run, new 'what-if' scenarios created, and time series and spatial data rapidly viewed and exported. Use of the system will result in greater standardization of data formats, model codes and methods used by the Environment Agency without stifling technological progress. NGMS enables a wider audience of water resource staff to access groundwater models. The system is being used to improve representation of groundwater in Catchment Abstraction Management Strategies and to forecast the potential impacts of climate change upon water resources. However, the day-to-day, operational use of groundwater models by the Environment Agency remains a challenge that requires engagement with other specialists (e.g. hydrologists and IT systems specialists). Considerable effort is required to roll out the system, train people and adapt operational decision-making processes to bring NGMS into regular and safe use. Source

Whiteman M.I.,UK Environment Agency | Seymour K.J.,UK Environment Agency | Van Wonderen J.J.,Mott MacDonald Ltd. | Maginness C.H.,AMEC Environment and Infrastructure | And 5 more authors.
Geological Society Special Publication

Over the last 10 years there has been a unique regulator-led programme involving extensive development of regional groundwater models across England and Wales for water resources purposes by the Environment Agency for England and Wales. Eight regionally managed programmes are underpinned by a framework, which has allowed a coordinated national approach. The main uses of the models are for catchment abstraction management and licensing. Models have also assisted in monitoring network design, investigating groundwater quality and implementing groundwater source protection zones. A five-yearly review of the programmes recognized the importance of benefit realization and stakeholder involvement as well as technical good practice. The programme already delivered provides a solid foundation for supporting the management decisions required in areas such as climate change mitigation and integrated catchment management using appropriate tools at a time of rapid organization change and financial uncertainty. © The Geological Society of London 2012. Source

Murphy L.U.,University of Canterbury | Cochrane T.A.,University of Canterbury | O'Sullivan A.,University of Canterbury | O'Sullivan A.,Pattle Delamore Partners Ltd
Science of the Total Environment

Atmospheric pollutants deposited on impermeable surfaces can be an important source of pollutants to stormwater runoff; however, modelling atmospheric pollutant loads in runoff has rarely been done, because of the challenges and uncertainties in monitoring their contribution. To overcome this, impermeable concrete boards (≈1m2) were deployed for 11months in different locations within an urban area (industrial, residential and airside) throughout Christchurch, New Zealand, to capture spatially distributed atmospheric deposition loads in runoff over varying meteorological conditions. Runoff was analysed for total and dissolved Cu, Zn, Pb, and total suspended solids (TSS). Mixed-effect regression models were developed to simulate atmospheric pollutant loads in stormwater runoff. In addition, the models were used to explain the influence of different meteorological characteristics (e.g. antecedent dry days and rain depth) on pollutant build-up and wash-off dynamics. The models predicted approximately 53% to 69% of the variation in pollutant loads and were successful in predicting pollutant-load trends over time which can be useful for general stormwater planning processes. Results from the models illustrated the importance of antecedent dry days on pollutant build-up. Furthermore, results indicated that peak rainfall intensity and rain duration had a significant relationship with TSS and total Pb, whereas, rain depth had a significant relationship with total Cu and total Zn. This suggested that the pollutant speciation phase plays an important role in surface wash-off. Rain intensity and duration had a greater influence when the pollutants were predominantly in their particulate phase. Conversely, rain depth exerted a greater influence when a high fraction of the pollutants were predominantly in their dissolved phase. For all pollutants, the models were represented by a log-arctan relationship for pollutant build-up and a log-log relationship for pollutant wash-off. The modelling approach enables the site-specific relationships between individual pollutants and rainfall characteristics to be investigated. © 2014 Elsevier B.V. Source

Murphy L.U.,University of Canterbury | Cochrane T.A.,University of Canterbury | O'Sullivan A.,Pattle Delamore Partners Ltd
Water, Air, and Soil Pollution

Abstract From a storm water management perspective, not all pavements are equivalent. Pavement type can impose a strong influence on pollutant wash-off dynamics. Pollutant loads from pavement wash-off are affected by the pavements' physical and chemical composition. However, there is a dearth of information regarding how pavement type influences atmospherically deposited pollutant loads in storm water. Therefore, experimental impermeable and permeable asphalt and concrete boards were deployed in a residential area in Christchurch, New Zealand, to quantify the influence of pavement type on storm water pollutant dynamics. Each pavement type had four replicate systems elevated 500 mm from the ground at a 4° slope. Wash-off from the pavements was collected and analysed for total suspended solids and metals (Cu, Pb, and Zn) from June to August 2014. Results show that Cu and Zn loads were lower from the concrete pavements than the asphalt pavements because the carbonates and hydroxides within the concrete adsorbed Cu and Zn. Run-off from the impermeable asphalt had the highest loads of Zn, which was attributed to Zn leaching from the asphalt. Infiltrate from permeable asphalt provided little/no retention of Cu and Zn, due to the low pH of the infiltrate causing Cu and Zn to partition into the dissolved phase and leach through the pavement. Total suspended solid (TSS) and Pb loads were the highest in run-off from the impermeable concrete, which was attributed to the smooth surface enabling particulates to be easily mobilised. TSS and Pb loads were the lowest from the permeable pavement due to the permeable material filtering out particulates. © Springer International Publishing Switzerland 2015. Source

Soley R.W.N.,AMEC Environment and Infrastructure Inc. | Matthews A.,UK Environment Agency | Ross D.,Atkins Boreas | Maginness C.H.,AMEC Environment and Infrastructure Inc. | And 4 more authors.
Geological Society Special Publication

Regional groundwater resource models are often built to improve confidence in predicted groundwater abstraction impacts on river flows and groundwater levels. By explicitly representing the aquifer system geometry, properties and boundaries, together with transient recharge and abstraction pressures, such models provide a robust platform to support abstraction impact assessment, alongside evidence from field data and investigations. Regulatory drivers include the European Union Habitats and Water Framework Directives and other abstraction licensing decisions. This paper presents examples of the spatial and temporal patterns of groundwater abstraction impacts predicted by several models. A variety of presentation formats are used to illustrate the simulated flow impacts of abstractions both individually, and in combination with other surface water abstractions and discharges. Model predictions from a range of abstraction, aquifer, and river settings are often more complex than would be suggested by simpler tools and approaches. In many cases, absolute low-flow impacts are less than long-term groundwater abstraction rates. The 'real world' hydrogeological mechanisms behind these impact patterns are discussed. The paper also recommends a protocol for using regional models to assess individual licensed groundwater abstraction impacts across the full range of historic climate conditions (typically, as monitored since 1970) and in the context of other operational artificial influences. Source

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