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The development of low-cost impedance spectroscopy devices is limited by the capabilities of low-cost hardware. Impedance spectroscopy requires high accuracy over a large bandwidth and dynamic range for most applications. In this paper, back-end signal processing solutions are examined and implemented to improve both the bandwidth and dynamic range of a typical low-cost impedance analyser without modifying the hardware. The bandwidth is improved by undersampling the input waveforms and reconstructing the signals based on the known frequency information. The bandwidth can be increased by multiple orders of magnitude and the limiting factor of the system becomes amplifier bandwidth and the Analog-to-Digital Converter (ADC) sample-and-hold circuit. Despite allowing signals to become orders of magnitude larger than the ADC range, the original signal can be reconstructed based on the measured saturated signal. This saturation technique more than doubles the dynamic range for any given accuracy requirement.

The adverse health effects of the presence of lead in wastewater streams are well documented, with conventional methods of lead recovery and removal suffering from disadvantages such as high energy costs, the production of toxic sludge, and low lead selectivity. Klebsiella pneumoniae and Paraclostridium bifermentans have been identified as potential lead-precipitating species for use in a lead recovery bioreactor. Electrical impedance spectroscopy (EIS) on a low-cost device is used to determine the potential for the probe-free and label-free monitoring of cell growth in a bioreactor containing these bacteria. A complex polynomial is fit for several reactive equivalent circuit components. A direct correlation is found between the extracted supercapacitance and the plated colony-forming unit count during the exponential growth phase, and a qualitative correlation is found between all elements of the measured reactance outside the exponential growth phase. Strong evidence is found that Pb(II) ions act as an anaerobic respiration co-substrate for both cells observed, with changes in plated count qualitatively mirrored in the Pb(II) concentration. Guidance is given on the implementation of EIS devices for continuous impedance monitoring.

This paper addresses the process towards the integration of subsurface knowledge into urban planning for three cities – Rotterdam, Glasgow and Oslo – participating in the European Cooperation in Science and Technology (COST) Action TU1206 Sub-Urban. These cities each have unique challenges in managing conflicts and opportunities in the subsurface in the planning process. The COST Sub-Urban Action has enabled a unique interaction between subsurface specialists and urban planners across over 20 European cities, and has laid the foundations for a new understanding between experts who develop subsurface knowledge and those who can benefit most from it – urban planners and decision makers. Common challenges identified include: improving planning policies, enhancing the level of awareness of the subsurface in city development and the modification of legislation to include the subsurface. The paper provides a review of the current status of subsurface planning in the three cities, each of whom are aiming to adapt their urban planning practice and legislation in light of emerging subsurface knowledge, and the current major knowledge gaps. In our opinion, there are two main routes to raise awareness that lead to improved understanding and the use of subsurface information in urban planning processes: (1) the development of a subsurface policy and (2) providing subsurface information. These measures should enable subsurface knowledge to be widely disseminated in order to manage risks and opportunities, and maximise the economic, social and environmental benefits of the urban subsurface and its services on which cities depend.

Monitoring of the archaeological deposits at the World Heritage Site Bryggen in Bergen has been ongoing since 2001. In latter years a large-scale project of mitigation works has been carried out, resulting in the creation of a water-management system aimed at raising groundwater-levels and increasing soil moisture content in areas with poor preservation conditions. Oxygen is a key parameter in the decay of archaeological material in the unsaturated zone, and the monitoring at Bryggen includes in situ monitoring of oxygen concentrations and comparison to soil moisture content, temperature, groundwater-level, precipitation and soil reactivity. This is used to document where and when decay takes place and to estimate “how wet is wet enough” in order to reduce the oxygen diffusion and the decay rate to an acceptable level. The results show that even small changes in the soil moisture can have a large impact on the oxygen dynamics in the ground.

The World Heritage Site of Bryggen in Bergen, Norway, has experienced significant degradation of archaeological deposits as a consequence of changes in the soil water and groundwater balance after urban redevelopment adjacent to the heritage site. Additionally, groundwater temperatures below the heritage site were found to be significantly higher closer to the redeveloped area. One of the main mitigation measures taken to reduce the degradation of the archaeology has been the construction of a hydrological barrier along the sheet piling that divides the redeveloped area and the historic site. A shallow subsurface infiltration system was designed to achieve groundwater levels and flow conditions that are optimal for the preservation of archaeological remains directly along the sheet pile, while reducing drainage and subsidence also further upstream. Monitoring of groundwater level and temperatures after implementation of the hydrological barrier shows that groundwater levels and flow conditions have improved with respect to optimal preservation conditions, and groundwater temperatures have generally been reduced by up to 2 °C.

City growth threatens sustainable development of cities. Over the past decades increased urbanization has created more pressure - not only on the suburban outskirts - but also in the inner core of the cities, putting important environmental issues such as water management and cultural heritage under stress. Cultural heritage, either standing monuments or archaeological remains, is internationally recognized as an important legacy of our history. The European Convention on the Protection of the Archaeological Heritage incorporates concepts and ideas that have become accepted practice in Europe. Conservation and enhancement of archaeological heritage is one of the goals of urban planning policies. One of the key objectives of the European policy is to protect, preferably in-situ, archaeological remains buried in the soil or seabed and to incorporate archaeological heritage into spatial planning policies. Conflicts with prior uses and unappreciated impacts on other subsurface resources, amongst them archaeological heritage, make use of underground space in cities suboptimal. In terms of ecosystem services, the subsurface environment acts either as a carrier of archaeological heritage in situ (stewardship) or supports above-ground cultural heritage. Often, it’s not enough to protect the heritage site or monument itself: new developments outside a specific protected area can lead to changes in groundwater level, and cause serious damage to heritage buildings and archaeological deposits. This paper presents good practices in cultural heritage management and the use of subsurface knowledge in urban areas.

The European COST Sub-Urban Action (TU1206) has had the fundamental aim of closing the knowledge gap between subsurface experts and potential users of subsurface knowledge - urban decision- makers, practitioners and researchers. The Action assembled a network involving >30 countries, 23 actively participating cities, researchers, practitioners and urban decision-makers, and brought together the fragmented research and good practice across Europe in sustainable urban sub-surface use. Development of national exemplars has been encouraged, and good practice identified to inspire others, using a lighthouse-follower approach to cascade knowledge and good practice across Europe and further afield. Experts from both sides of the knowledge gap were brought together to assess and synthesise the state-of-the-art in lighthouse cities with respect to urban sub-surface knowledge, understanding, and use of that knowledge. This was achieved in 19 City Studies, with findings encapsulated in an over-view report “Out of Sight - Out of Mind”. Expert sub-groups then identified good practice in subsurface data and knowledge locally, nationally, and Europe-wide. These are highlighted in the synthesis report “Opening up the subsurface for the cities of tomorrow”, and expanded on in seven topic review reports. These also identified key gaps in knowledge, and its use. A new concept, GEOCIM is proposed for City Quarter to Conurbation scales, combining subsurface and above-ground models. These enable: a.) holistic urban planning ; b.) identifying subsurface opportunities ; and c.) saving costs by reducing uncertainty in ground conditions. Finally, the Action’s reports and outputs were integrated within an online toolbox, and will be further outlined in the Final Report of the Action, to be made available on the Action’s website. The Sub-Urban Toolbox promotes and disseminates the good practice, and decision-support tools: a.) to help better inform and empower city decision- and policy-makers about the sub-surface and the vital importance of its early-stage consideration ; and b.) accelerate uptake amongst sub-surface experts of sub-surface modelling workflows. Users with different backgrounds and needs, require different access to, and appropriate translations of, the Sub-Urban Toolbox. Therefore different entry points are provided for sub-surface technical experts, and urban planners, and decision- and policy-makers. As the critical mass of city decision- and policy-makers that is better aware of the sub-surface and its sustainable use expands, the potential for higher level policy consideration of the subsurface grows, and a wider range of impacts will become achievable

The shallow subsurface in historic cities often contains extensive archaeological remains, also known as cultural deposits. Preservation conditions for naturally degradable archaeological remains are strongly dependent on the presence or absence of groundwater. One of the main goals at such heritage sites is to establish a stable hydrological environment. Green infrastructural solutions such as Sustainable Urban Drainage Systems (SUDS) can support preservation of cultural deposits. Several cases show that implementation of SUDS can be cost effective at preservation of cultural deposits. These include Motte of Montferland, City mound of Vlaardingen, Weiwerd in Delfzijl, and the Leidse Rijn area. In all cases, the amount of underground infrastructure is minimised to prevent damaging cultural layers. SUDS have been implemented to preserve cultural heritage. The first monitoring results and evaluation of the processes give valuable lessons learned, transnational knowledge exchange is an important element to bring the experiences across boundaries.

Environmental monitoring at the World Heritage Site of Bryggen in Bergen, Norway, has shown damaging settling rates caused by degradation of underlying archaeological deposits. Measurements of piezometric head, oxygen, and soil moisture content, as well as chemical analyses of water and soil samples are key elements of the environmental monitoring.Groundwater monitoring and geochemical analyses reveal a complex and dynamic flow through the natural and anthropogenic stratigraphy. The preservation conditions within the organic archaeological deposits are strongly correlated with oxygen and soil moisture content, that are controlled by the groundwater flow conditions at the site. To quantify decay rates, it is thus essential to understand the wider hydrogeological context of the site. This paper presents recent advancements in quantifying decay rates in the saturated zone at Bryggen. The paper also shows that 3D geo-archaeological modelling can contribute to preservation management by visually combin...

Download for free This CIENS-report sums up the main findings from the project “Cultural Heritage and Water Management in Urban Planning” (Urban WATCH), financed by the Research Council of Norway through the MILJØ2015 programme, and cofunded by the Directorate for Cultural Heritage in Norway (Riksantikvaren) and the Geological Survey of Norway (NGU). The project started up in 2012 and ended in 2015. The report consists of five chapters. After a short introduction (chapter 1), main research results are presented in chapters 2, 3 and 4. Chapter 2 gives a presentation of how authorities in the two largest cities of Norway deal with the challenges associated with water management, cultural heritage and urban planning. Chapter 3 describes how modern urban stormwater management can contribute to improved protection and preservation of archaeological remains. In chapter 4, several issues are being dealt with: Modelling the soil-water balance in unsaturated archaeological deposits. The chapter also raises the question: Should monitoring of oxygen or the redoxpotential be used in standard monitoring programs? The last part of the chapter presents data from an evaluation of the use of the Norwegian standard for environmental monitoring and investigation of archaeological deposits (NS9451:2009). The last chapter (chapter 5) discuss, and sums up, some of the main findings in the report. Associated project Cultural Heritage and Water management in Urban Planning (Urban Watch)

The landscape of many historic cities and the character of their shallow subsurface environments are defined by a legacy of interaction between anthropogenic and geological processes. Anthropogenic deposits and excavations result from processes ranging from archaeological activities to modern urban development. Hence, in heritage cities, any geological investigation should acknowledge the role of past and ongoing human activities, while any archaeological investigation should be conducted with geological processes in mind. In this paper it is shown that 3D geological and anthropogenic models at different scales can provide a holistic system for the management of the subsurface. It provides a framework for the integration of other spatial and process models to help assess the preservation potential for buried heritage. Such an integrated framework model is thus contributing to a decision support system for sustainable urban (re)development and regeneration in cities, while preserving cultural heritage. A collaborative approach is proposed to enhance research and implementation of combined geological and archaeological modelling for sustainable land use planning and heritage preservation, using York and Bryggen as prime examples. This paper presents the status of 3D framework modelling at Bryggen in Norway as an example. © 2011 Natural Environment Research Council.