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Abstract: This paper describes a method to estimate changes in impervious surface fraction from widely available medium resolution remote sensing data. The potential of the impervious surface fraction data for hydrological modeling is illustrated by a case study for the Kleine Nete catchment, Belgium. Impervious surface fraction data for the Kleine Nete were simulated based on a Landsat TM image acquired in 1986 and a Landsat ETM+ of 2003. The paper assesses the impact of change in impervious surface cover between 1986 and 2003 on the vertical water balance and groundwater system. The results show that impervious surface fractions can be obtained from medium resolution remote sensing data with reasonable accuracy, the mean average error is around 18% and the bias close to zero for both the recent and historical image. Comparing the impervious surface fractions of 1986 and 2003 indicates that most urbanization occurred by densification of existing urban areas. The average impervious fraction of the urban cells increases from 25.4% to 29.2% between 1986 and 2003. Urban runoff increases by 9.5% between 1986 and 2003 due to the increase in impervious surfaces, while the evapotranspiration and recharge in urban areas decrease by 1.5% and 1.6% respectively. For the study area a land-use class based parameterization method underestimates groundwater recharge and head decreases in the most dense urban area and overestimates those in some of the smaller urban centers. [Copyright &y& Elsevier]

Abstract: This paper illustrates the potential of a decision-support system developed for Belgium by a consortium of universities and a private firm, in the framework of a public call made by the Ministry of the Interior. The system is designed to provide the Belgian emergency management administration with a complete decision-aid tool for the location of fire stations. The originality of the project is that it includes a risk-modeling approach developed at a national scale. This analysis involves a multiscale GIS that includes a thorough representation of the physical, human and economic spatial realities, a risk-modeling approach, an adequate optimal location and allocation model (taking into account both queuing and staffing problems). The final result is an interactive operational tool for defining locations, equipment allocations, staffing, response times, the cost/efficiency trade-off, etc. This flexible tool can be used in an assessment as well as a prospective context. It has been used to draw a national reorganization plan for fire stations that started being implemented in 2010. [Copyright &y& Elsevier]

Abstract: This paper examines the effects of two traffic management measures, speed limit reduction and coordinated traffic lights, in an area of Antwerp, Belgium. An integrated model is deployed that combines the microscopic traffic simulation model Paramics with the CO2 and NO X emission model VERSIT+. On the one hand, reductions in CO2 and NO X emissions of about 25% were found if speed limits are lowered from 50 to 30km/h in the residential part of the case study area. On the other hand, reductions in the order of 10% can be expected from the implementation of a green wave signal coordination scheme along an urban arterial road. [Copyright &y& Elsevier]

Abstract: A recurring topic in discussions on the implementation of carbon capture and storage are the uncertainties in the estimations of the storage potential. Many regions worldwide and also in Europe are indeed insufficiently explored for providing estimates that are sufficiently reliable for such purposes. In this paper we present a method through which reliable and quantitative estimates can be obtained for very poorly explored regions. This new approach is based on well-proven economic principles and expert input, which are combined with a semi-generic storage model. Evaluation of the Belgian storage potential results in an estimation of 15 Mt/y (95% C.I.: 3 to 35 Mt/y) when expressed as an annual injection rate, or 620Mt (95% C.I.: 150 to 1400 Mt) when expressed as the total storage capacity. This estimation is that of the actual, practical storage potential, rather than a theoretical overestimation which is obtained by other methods. The reliability of the method is theoretically and empirically verified. [Copyright &y& Elsevier]

Abstract: It is well known that urban expansion has a severe impact on the surface water balance by transforming vegetated covers into sealed surfaces. This transformation causes changing fluxes of evapotranspiration, surface runoff and groundwater recharge. In order to estimate the impact of land cover changes on the surface hydrology, hydrological models are often coupled with different types of land cover change models. It is, however, not clear to what extent spatially-explicit urban expansion scenarios provide an added value in comparison with non-spatial urban expansion models at different scale levels. The objective of this paper is to acquire a better insight in the importance of scale effects involved in the coupling of urban expansion scenarios and hydrological models. The relative importance of using different projections of both (i) quantity and (ii) spatial patterns of urban expansion was analysed at four different scale levels. The highly urbanised Flanders–Brussels region was taken as an example application. Twelve different urban expansion scenarios for 2025 and 2050 were developed and subsequently used as an input in a spatially-distributed water balance model. The results obtained suggest that at the level of the Flanders–Brussels region, an accurate estimation of the quantity of urban expansion should get priority over an accurate projection of the spatial patterns. However, the importance of using accurate projections of the spatial pattern of urban expansion increases systematically at local scale levels. A uniform strategy for coupling urban expansion models and hydrological models thus seems inappropriate. These findings are highly relevant for water management and spatial planning policymakers that typically operate at different administrative levels. [Copyright &y& Elsevier]

Abstract: Most literature in landscape perception and preference has focused on aesthetic preference by (groups of) people. Factors that could influence the aesthetic preference, such as landscape dimensions and observer''s background characteristics, are far less examined. This may be due to the increasing complexity of the dataset, when variation both in landscape attributes and respondents’ characteristics is to be included in the models. The complex multivariate analysis models that emerge require more sophisticated statistical analysis. Also, the conclusions that result from the traditional analysis sound like, e.g. experts show lower preferences than nonexperts, which is rather deterministic and leaves no room for fuzziness. Latent class analysis provides an opportunity to include fuzziness, by only probabilistically assigning respondents in a latent class in function of the respondent''s characteristics. The present paper explores the use of latent class analysis to determine individual differences in the importance appended to several landscape dimensions for landscape aesthetic preference. A questionnaire survey was executed in a spatially stratified sample amongst inhabitants of the city of Ghent (Flanders, Belgium). Latent preference classes are identified of which the cases vary in the level of importance attached to landscape characteristics for aesthetic preference. Care and disturbance appear to have larger effect on preference than naturalness and urbanisation. The effect of care and disturbance on landscape aesthetic preference also most significantly distinguishes between the latent preference classes. The importance of openness for aesthetics is small and not significantly dependent on the individual background of the observer. Respondents’ characteristics that affect the probability of belonging to a latent preference class are environmental behaviour and attitude, actual living environment, age class, education level, and organisation membership. Understanding the basis for differences in landscape preference may respond to tastes and aspirations of the general public, putting landscape planning in the broader context of society. [Copyright &y& Elsevier]

Abstract: This paper presents an agent-based approach used to design a Transportation Regulation Support System (TRSS), that reports the network activity in real-time and thus assists the bus network regulators. The objective is to combine the functionalities of the existing information system with the functionalities of a decision support system in order to propose a generic model of a traffic regulation support system. Unlike the other approaches that only deal with a specific task, the original feature of our generic model is that it proposes a global approach to the regulation function under normal conditions (network monitoring, dynamic timetable management) and under disrupted conditions (disturbance assessment and action planning of feasible solutions). Following the introduction, the second section presents the notions of the domain and highlights the main regulation problems. The third section details and motivates our choice of the components of the generic model. Based on our generic model, in the fourth section, we present a TRSS prototype called SATIR (Système Automatique de Traitement des Incidents en Réseau – Automatic System for Network Incident Processing) that we have developed. SATIR has been tested on the Brussels transportation network (STIB). The results are presented in the fifth section. Lastly, we show how using the multi-agent paradigm opens perspectives regarding the development of new functionalities to improve the management of a bus network. [Copyright &y& Elsevier]

Aquatic habitat suitability models have increasingly received attention due to their wide management applications. Ecological expert knowledge has been frequently incorporated in such models to link environmental conditions to the quantitative habitat suitability of aquatic species. Since the formalisation of problem-specific human expert knowledge is often difficult and tedious, data-driven machine learning techniques may be helpful to extract knowledge from ecological datasets. In this paper, both expert knowledge-based and data-driven fuzzy habitat suitability models were developed and the performance of these models was compared. For the data-driven models, a hill-climbing optimisation algorithm was applied to derive ecological knowledge from the available data. Based on the available ecological expert knowledge and on biological samples from the Zwalm river basin (Belgium), habitat suitability models were generated for the mayfly Baetis rhodani (Pictet 1843). Data-driven models appeared to outperform expert knowledge-based models substantially, while a step-forward model selection procedure indicated that physical habitat variables adequately described the mayfly habitat suitability in the studied area. This study has important implications on the application of expert knowledge in ecological studies, especially if this knowledge is extrapolated to other areas. The results suggest that data-driven models can complement expert knowledge-based approaches and hence improve model reliability. [Copyright &y& Elsevier]

Abstract: The objective of this paper is to build a general correction model that takes into account all the different radiocarbon-dilution reactions and resolving the processes that are geochemically “aging” the groundwater in the Neogene Aquifer. For this, δ13C and radiocarbon in groundwater are investigated with their relationship to other chemical components in groundwater. The δ13C values in the Neogene Aquifer are influenced by various geochemical reactions like calcite dissolution, oxidation of organic matter and methanogenesis. Calcite dissolution and CH4 production increase δ13C while the oxidation of organic matter decreases δ13C in the groundwater. The reactions that modify δ13C also influence the 14C activity. Due to the complex geochemical environment, existing correction models are not applicable to this situation. A correction model for initial 14C activity is formulated in which the different C sources that influence 14C activity are taken into account. It is observed that recent dissolved organic matter plays an important role in redox reactions. The corrected 14C ages lie between −0.792 and 6.425ka representing the maximum age. If a part of the organic matter that oxidises is fossil, the determined age will represent an overestimated age. [Copyright &y& Elsevier]

Abstract: A new container dock in the Port of Antwerp, the Deurganckdok, was recently constructed in a location close to the Estuarine Turbidity Maximum (ETM) of the Scheldt River. In order to minimise sedimentation in the new dock, a Current Deflecting Wall (CDW) will be constructed. The aim of this paper is to assess the effect of the CDW on exchange flows and sediment fluxes. Determining this effect requires (1) understanding and reproduction of the sediment dynamics close to the Deurganckdok, and (2) accurate reproduction of the exchange flows between the dock and the Scheldt, and the effect of the CDW thereon. The sediment dynamics close to the Deurganckdok are dominated by a high concentration suspension (near-bed concentrations around 1g/l) which is advected along the dock by the tidal currents. The sediment concentration is limited by the supply of sediment rather than the flow velocity. Most sediment will temporarily settle from suspension around slack tide. Hence, flood and ebb sediment concentrations are comparable, although the ebb and flood velocities are asymmetric. The peak sediment concentration occurs at the left or right bank of the Scheldt River, depending on the clockwise and counter-clockwise residual cross-channel currents. Exchange flows between the dock and the Scheldt are mainly a combination of horizontal eddies and salinity-driven flows, with velocities around 0.4m/s. Most sediment enters the dock in a near-bed horizontal eddy, occurring around HW. The main effect of a CDW is a deflection of this sediment patch towards the river, reducing the sediment influx into the dock. The estimated reduction of siltation by the CDW is 18%. Alternative CDW configurations also reduce sedimentation in the dock, but less than computed with the design CDW. [Copyright &y& Elsevier]