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There is a need for groundwater modelling approaches that can incorporate both the complexity of riverbeds and the influence of lateral flows through the river banks in the simulation of river–aquifer interaction. A simple and straight-forward approach is proposed for modelling river–aquifer interaction in gaining rivers based on existing building blocks available in MODFLOW. The river water itself is modelled as constant-head cells, while the riverbed is modelled as one or more separate layers. The Horizontal Flow Barrier (HFB) Package is used to simulate the effect of a river bank on lateral exchange fluxes between river and aquifer. This approach has several advantages over conventional MODFLOW streamflow packages: (1) riverbeds can be modelled as several layers with different hydraulic properties; (2) both vertical and horizontal flow through the riverbed can be modelled; and (3) lateral flow through the river banks can be simulated. The capabilities of the new approach are demonstrated in two applications based on a MODFLOW model of the Aa River, Belgium. Application I demonstrates that the approach can be used to model heterogeneous multi-layered riverbeds. Results show that neglecting this heterogeneity can result in an overestimation of river–aquifer exchange fluxes. Application II shows that the approach can be used to simulate the effect of lateral fluxes through river banks. It demonstrates that lateral fluxes can be a major contributor to total river–aquifer exchange fluxes. The proposed approach provides the necessary tools to accurately model river–aquifer interaction for gaining rivers in MODFLOW. [ABSTRACT FROM AUTHOR]

An improved general understanding of riverbed heterogeneity is of importance for all groundwater modeling studies that include river-aquifer interaction processes. Riverbed hydraulic conductivity ( K ) is one of the main factors controlling river-aquifer exchange fluxes. However, the meter-scale spatial variability of riverbed K has not been adequately mapped as of yet. This study aims to fill this void by combining an extensive field measurement campaign focusing on both horizontal and vertical riverbed K with a detailed geostatistical analysis of the meter-scale spatial variability of riverbed K . In total, 220 slug tests and 45 standpipe tests were performed at two test sites along the Belgian Aa River. Omnidirectional and directional variograms (along and across the river) were calculated. Both horizontal and vertical riverbed K vary over several orders of magnitude and show significant meter-scale spatial variation. Horizontal K shows a bimodal distribution. Elongated zones of high horizontal K along the river course are observed at both sections, indicating a link between riverbed structures, depositional environment and flow regime. Vertical K is lognormally distributed and its spatial variability is mainly governed by the presence and thickness of a low permeable organic layer at the top of the riverbed. The absence of this layer in the center of the river leads to high vertical K and is related to scouring of the riverbed by high discharge events. Variograms of both horizontal and vertical K show a clear directional anisotropy with ranges along the river being twice as large as those across the river. [ABSTRACT FROM AUTHOR]

The main goal of this article is to unravel the social distribution of childcare policies: Who benefits from government investment in public childcare? The analysis complements earlier research on the distribution of social policy outcomes and confronts the growing concern over selectivity. By nature, childcare services tend to be used mainly by people in work, i.e. those in higher income brackets. Concern therefore arises about the consequences of increasing childcare budgets for the overall distribution of the benefits of social policy. This relates to the immediate outcome of social policy (net family income), but also to its increasingly central component: labour market participation. Indeed, if childcare actually benefits ‘labour market insiders’ only, one may wonder whether it is effective as an instrument activating mothers with young children. In this contribution, we look into the distributional impact of subsidized childcare for two countries (Flanders/Belgium and Sweden) already reaching the Barcelona targets for under 3s and interpret the results in a European perspective. Although both cases report high coverage rates, we find that Sweden and Flanders have different – even opposite – distributional outcomes. Both examples provide us with valuable lessons on the redistributive nature of ‘new risk policies’ and the effectiveness of childcare as an instrument of labour market activation. [ABSTRACT FROM PUBLISHER]

In the last few decades, measures to reconcile work and family life have risen in mutual interaction with a rising rate of dual earnership. However, dual earnership has (to date) been adopted in a socially uneven way in most European societies. Therefore, one may wonder whether the activation measures have brought about a loss of vertical redistribution in welfare states. We address this question by focusing on the interaction of three measures of family policy and their overall distributional effect in Europe, with the Belgian region of Flanders as the case in point. We develop a fine-grained analysis to reveal the budgetary impact of the variation in use and generosity, and find that today in Flanders the redistributive effect of child benefits is largely undone by subsidized childcare and parental leave benefits. If parents’ employment is to be generalized, this case study suggests that more attention is required regarding the universal use of reconciliation measures. [ABSTRACT FROM PUBLISHER]

We report on quartz Optically Stimulated Luminescence (OSL) dating of the infill of 14 relict sand wedges and composite-wedge pseudomorphs at 5 different sites in Flanders, Belgium. A laboratory dose recovery test indicates that the single-aliquot regenerative-dose (SAR) procedure is suitable for our samples (measured to a given dose ratio 0.980 ± 0.005; n=139). Completeness of resetting of the wedge infill of two samples was confirmed by single-grain analyses. The suite of optical ages indicates that repeated thermal contraction cracking, degradation and infilling with wind-blown sediment appear to have been commonplace in Flanders during the Late Pleniglacial (Oxygen Isotope Stage 2; OIS2); more specifically, around the Last Glacial Maximum (LGM, ∼21 kyr ago) and the transition period between the LGM and the start of the Lateglacial (∼15 kyr ago). Optical dating at one site has revealed two significantly older wedge levels, the younger inset into the older; the younger wedge has an age of 36 ± 4 kyr (Middle Pleniglacial; OIS3), the older wedge 129 ± 11 kyr, which points to formation during the Late Saalian (OIS6). Our OSL ages of the wedges and host sediments bracket formation of the BGB (Beuningen Gravel Bed: a widespread deflation horizon in northwestern Europe) at between ∼15 and 18 kyr; this is in good agreement with previous OSL dating studies. We conclude that optical dating using quartz SAR OSL establishes an absolute chronology for these periglacial phenomena and allows secure palaeoenvironmental reconstructions to be made. [ABSTRACT FROM AUTHOR]