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Vonk, M.A. (author), Collenteur, Raoul A. (author), Panday, Sorab (author), Schaars, Frans (author), Bakker, M. (author)The performance of time series models is assessed using synthetic head series simulated with a numerical model that solves Richards' equation for variably saturated flow. Heads were simulated in a homogeneous unconfined aquifer between two parallel canals; measured daily precipitation and potential evaporation are specified at the land...journal article 2024
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Houben, Georg J. (author), Collins, Sarah (author), Bakker, M. (author), Daffner, Thomas (author), Triller, Falk (author), Kacimov, Anvar (author)Horizontal wells play an often overlooked role in hydrogeology and aquifer remediation but can be an interesting option for many applications. This study reviews the constructional and hydraulic aspects that distinguish them from vertical wells. Flow patterns towards them are much more complicated than those for vertical wells, which makes their...journal article 2022
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Steffelbauer, D.B. (author), Riva, R.E.M. (author), Timmermans, Jos (author), Kwakkel, J.H. (author), Bakker, M. (author)Global mean sea-level rise (SLR) has accelerated since 1900 from less than 2 mm yr-1 during most of the century to more than 3 mm yr-1 since 1993. Decision-makers in coastal countries, however, require information on SLR at the regional scale, where detection of an acceleration in SLR is difficult, because the long-term sea-level signal is...journal article 2022
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Urgilez Vinueza, A.R. (author), Handwerger, Alexander L. (author), Bakker, M. (author), Bogaard, T.A. (author)Slow-moving landslides move downslope at velocities that range from mm year<sup>−1</sup> to m year<sup>−1</sup>. Such deformations can be measured using satellite-based synthetic aperture radar interferometry (InSAR). We developed a new method to systematically detect and quantify accelerations and decelerations of slowly deforming areas...journal article 2022
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- Bakker, M. (author), Haitjema, Henk M. (author), Strack, Otto D.L. (author) journal article 2022
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Brakenhoff, Davíd A. (author), Vonk, M.A. (author), Collenteur, Raoul A. (author), Van Baar, Marco (author), Bakker, M. (author)In 2018–2020, meteorological droughts over Northwestern Europe caused severe declines in groundwater heads with significant damage to groundwater-dependent ecosystems and agriculture. The response of the groundwater system to different hydrological stresses is valuable information for decision-makers. In this paper, a reproducible, data-driven...journal article 2022
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Duijff, R. (author), Bloemendal, Martin (author), Bakker, M. (author)Aquifer thermal energy storage (ATES) is an energy efficient technique to provide heating and cooling to buildings by storage of warm and cold water in aquifers. In regions with large demand for ATES, ATES adoption has lead to congestion problems in aquifers. The recovery of thermal energy stored in aquifers can be increased by reducing the...journal article 2021
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Collenteur, Raoul A. (author), Bakker, M. (author), Klammler, Gernot (author), Birk, Steffen (author)The estimation of groundwater recharge is of paramount importance to assess the sustainability of groundwater use in aquifers around the world. Estimation of the recharge flux, however, remains notoriously difficult. In this study the application of nonlinear transfer function noise (TFN) models using impulse response functions is explored to...journal article 2021
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des Tombe, B.F. (author), Schilperoort, B. (author), Bakker, M. (author)Distributed temperature sensing (DTS) systems can be used to estimate the temperature along optic fibers of several kilometers at a sub-meter interval. DTS systems function by shooting laser pulses through a fiber and measuring its backscatter intensity at two distinct wavelengths in the Raman spectrum. The scattering-loss coefficients for...journal article 2020
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Urgilez Vinueza, A.R. (author), Robles, Jessica (author), Bakker, M. (author), Guzman, Pablo (author), Bogaard, T.A. (author)The high landslide risk potential along the steep hillslopes of the Eastern Andes in Ecuador provides challenges for hazard mitigation, especially in areas with hydropower dams and reservoirs. The objective of this study was to characterize, understand, and quantify the mechanisms driving the motions of the Guarumales landslide. This 1.5 km...journal article 2020
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Bradley, C.E. (author), Randall, J.A.D. (author), Abobeih, M.H.M.A. (author), Berrevoets, R.C. (author), Degen, M.J. (author), Bakker, M. (author), Markham, M. (author), Twitchen, D. J. (author), Taminiau, T.H. (author)Spins associated with single defects in solids provide promising qubits for quantum-information processing and quantum networks. Recent experiments have demonstrated long coherence times, high-fidelity operations, and long-range entanglement. However, control has so far been limited to a few qubits, with entangled states of three spins...journal article 2019
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Bakker, M. (author), Schaars, Frans (author)Time series analysis is a data-driven approach to analyze time series of heads measured in an observation well. Time series models are commonly much simpler and give much better fits than regular groundwater models. Time series analysis with response functions gives insight into why heads vary, while such insight is difficult to gain with black...journal article 2019
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des Tombe, B.F. (author), Bakker, M. (author), Smits, F.J.C. (author), Schaars, Frans (author), van der Made, Kees Jan (author)An approach is presented to determine groundwater flow in unconsolidated aquifers with a heat pulse response test using a heating cable and a fiber-optic cable. The cables are installed together using direct push so that the cables are in direct contact with the aquifer. The temperature response is measured for multiple days along the fiber...journal article 2019
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Bakker, M. (author)A new analytic solution is presented for tidal propagation in multilayer coastal aquifers consisting of an arbitrary number of layers. The solution is derived using matrix calculus and may be applied to simulate tidal propagation in systems where aquifer layers are separated by leaky layers of low permeability or in stratified aquifers. The head...journal article 2019
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Obergfell, C.C.A. (author), Bakker, M. (author), Maas, C. (author)A new method is presented to estimate average diffuse aquifer recharge of water table aquifers in temperate climates using time series analysis of water table level fluctuations. An accurate estimate of the recharge caused by rainfall requires an accurate estimate of the influence of evaporation. In temperate climates, evaporation imprints a...journal article 2019
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Obergfell, C.C.A. (author), Bakker, M. (author), Maas, C. (author)Time series analysis is applied to identify and analyze a transition in the groundwater regime in the aquifer below the sand ridge of Salland in the Netherlands, where groundwater regime refers to the range of head variations throughout the seasons. Standard time series analysis revealed a discrepancy between modeled and observed heads in...journal article 2019
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Collenteur, R.A. (author), Bakker, M. (author), Caljé, Ruben (author), Klop, Stijn A. (author), Schaars, Frans (author)Time series analysis is an increasingly popular method to analyze heads measured in an observation well. Common applications include the quantification of the effect of different stresses (rainfall, pumping, etc.), and the detection of trends and outliers. Pastas is a new and open source Python package for the analysis of hydrogeological time...journal article 2019
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des Tombe, B.F. (author), Bakker, M. (author), Schaars, Frans (author), van der Made, Kees Jan (author)An approach is presented to determine the seasonal variations in travel time in a bank filtration system using a passive heat tracer test. The temperature in the aquifer varies seasonally because of temperature variations of the infiltrating surface water and at the soil surface. Temperature was measured with distributed temperature sensing...journal article 2018
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Post, Vincent E.A. (author), Essink, Gualbert Oude (author), Szymkiewicz, Adam (author), Bakker, M. (author), Houben, Georg (author), Custodio, Emilio (author), Voss, Clifford (author)The Salt Water Intrusion Meetings, or SWIMs, are a series of meetings that focus on seawater intrusion in coastal aquifers and other salinisation processes. 2018 marks the 50th year of the SWIM and the 25th biennial meeting. The SWIM proceedings record half a century of research progress on site characterisation, geophysical and geochemical...journal article 2018
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van der Spek, J.E. (author), Bakker, M. (author)The influence of the length of the calibration period and observation frequency on the predictive uncertainty in time series modeling of groundwater dynamics is investigated. Studied series are from deltaic regions with predominantly shallow groundwater tables in a temperate maritime climate where heads vary due to precipitation and...journal article 2017