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The importance of relativistic effects on two-photon absorption spectra in metal halide perovskites

Wei, Z. (author), Guo, Dengyang (author), Thieme, J. (author), Katan, Claudine (author), Caselli, V.M. (author), Even, Jacky (author), Savenije, T.J. (author)

Despite intense research into the optoelectronic properties of metal halide perovskites (MHPs), sub-bandgap absorption in MHPs remains largely unexplored. Here we recorded two-photon absorption spectra of MHPs using the time-resolved microwave conductivity technique. A two-step upward trend is observed in the two-photon absorption spectrum...

journal article 2019

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Global phosphorus recovery from wastewater for agricultural reuse

Kok, D.D. (author), Pande, S. (author), van Lier, J.B. (author), Ortigara, Angela R.C. (author), Savenije, Hubert (author), Uhlenbrook, S. (author)

Phosphorus is a nutrient necessary for the development of crops and is thus commonly applied as fertilizer to sustain agricultural production. It occurs naturally, in indefinite quantities of uncertain quality in phosphate rock formations, but also accumulates in urban and livestock wastewater wherefrom it is often lost as a pollutant....

journal article 2018

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Partially replacing Pb²⁺ by Mn²⁺ in hybrid metal halide perovskites: Structural and electronic properties

Bartesaghi, D. (author), Ray, Aniruddha (author), Jiang, Junke (author), Bouwer, Ricardo K.M. (author), Tao, S. (author), Savenije, T.J. (author)

Tailoring the physical properties of hybrid lead metal halide APbX₃ perovskites by means of compositional engineering is one of the key factors contributing to the development of highly efficient and stable perovskite solar cells. While the beneficial effects of partial ionic replacement at the A- and X-sites are largely...

journal article 2018

document

Constraining Conceptual Hydrological Models With Multiple Information Sources

Nijzink, R.C. (author), Almeida, S. (author), Pechlivanidis, I. G. (author), Capell, R. (author), Gustafssons, D. (author), Arheimer, B. (author), Parajka, J. (author), Freer, J. (author), Han, D. (author), Wagener, T. (author), van Nooijen, R.R.P. (author), Savenije, Hubert (author), Hrachowitz, M. (author)

The calibration of hydrological models without streamflow observations is problematic, and the simultaneous, combined use of remotely sensed products for this purpose has not been exhaustively tested thus far. Our hypothesis is that the combined use of products can (1) reduce the parameter search space and (2) improve the representation of...

journal article 2018

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HESS Opinions "Catchments as meta-organisms – a new blueprint for hydrological modelling"

Savenije, Hubert (author), Hrachowitz, M. (author)

Catchment-scale hydrological models frequently miss essential characteristics of what determines the functioning of catchments. The most important active agent in catchments is the ecosystem. It manipulates and partitions moisture in a way that supports the essential functions of survival and productivity: infiltration of water, retention of...

journal article 2017

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Looking beyond general metrics for model comparison: lessons from an international model intercomparison study

de Boer-Euser, Tanja (author), Bouaziz, L.J.E. (author), De Niel, J. (author), Brauer, C. (author), Dewals, B. (author), Drogue, G. (author), Fenicia, F. (author), Grelier, B. (author), Nossent, J. (author), Pereira, F. (author), Savenije, Hubert (author), Thirel, G. (author), Willems, P (author)

International collaboration between research institutes and universities is a promising way to reach consensus on hydrological model development. Although model comparison studies are very valuable for international cooperation, they do often not lead to very clear new insights regarding the relevance of the modelled processes. We hypothesise...

journal article 2017

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Global root zone storage capacity from satellite-based evaporation

Wang-Erlandsson, L. (author), Bastiaanssen, W.G.M. (author), Gao, H. (author), Jägermeyr, Jonas (author), Senay, Gabriel B. (author), Van Dijk, Albert I J M (author), Guerschman, Juan P. (author), Keys, Patrick W. (author), Gordon, Line J. (author), Savenije, Hubert (author)

This study presents an "Earth observation-based" method for estimating root zone storage capacity-a critical, yet uncertain parameter in hydrological and land surface modelling. By assuming that vegetation optimises its root zone storage capacity to bridge critical dry periods, we were able to use state-of-the-art satellite-based evaporation...

journal article 2016

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The importance of topography-controlled sub-grid process heterogeneity and semi-quantitative prior constraints in distributed hydrological models

Nijzink, R.C. (author), Samaniego, L (author), Mai, J (author), Kumar, R (author), Thober, S (author), Zink, M (author), Schafer, D (author), Savenije, Hubert (author), Hrachowitz, M. (author)

journal article 2016

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Predicting the salt water intrusion in the Shatt al-Arab estuary using an analytical approach

Abdullah, A.D.A. (author), Gisen, J.I.A. (author), van der Zaag, P. (author), Savenije, Hubert (author), Karim, UFA (author), Masih, I (author), Popescu, I (author)

Longitudinal and vertical salinity measurements are used in this study to predict the extent of inland seawater intrusion in a deltaic river estuary. A predictive model is constructed to apply to the specific tidal, seasonal, and discharge variability and geometric characteristics of the Shatt al-Arab River (SAR) situated along the border of...

journal article 2016

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Revised predictive equations for salt intrusion modelling in estuaries

Gisen, J.I.A. (author), Savenije, H.H.G. (author), Nijzink, R.C. (author)

For one-dimensional salt intrusion models to be predictive, we need predictive equations to link model parameters to observable hydraulic and geometric variables. The one-dimensional model of Savenije (1993b) made use of predictive equations for the Van der Burgh coefficient $K$ and the dispersion at the seaward boundary D0. Here we have...

journal article 2015

document

The open boundary equation (discussion paper)

Diederen, D. (author), Savenije, H.H.G. (author), Toffolon, M. (author)

We present a new equation describing the hydrodynamics in infinitely long tidal channels (i.e., no reflection) under the influence of oceanic forcing. The proposed equation is a simple relationship between partial derivatives of water level and velocity. It is formally derived for a progressive wave in a frictionless, prismatic, tidal channel...

journal article 2015

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Hydrological model parameter dimensionality is a weak measure of prediction uncertainty (discussion paper)

Pande, S. (author), Arkesteijn, L. (author), Savenije, H.H.G. (author), Bastidas, L.A. (author)

This paper shows that instability of hydrological system representation in response to different pieces of information and associated prediction uncertainty is a function of model complexity. After demonstrating the connection between unstable model representation and model complexity, complexity is analyzed in a step by step manner. This is...

journal article 2015

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A constraint-based search algorithm for parameter identification of environmental models

Gharari, S. (author), Shafiei, M. (author), Hrachowitz, M. (author), Kumar, R. (author), Fenicia, F. (author), Gupta, H.V. (author), Savenije, H.H.G. (author)

Many environmental systems models, such as conceptual rainfall-runoff models, rely on model calibration for parameter identification. For this, an observed output time series (such as runoff) is needed, but frequently not available (e.g., when making predictions in ungauged basins). In this study, we provide an alternative approach for parameter...

journal article 2014

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Using expert knowledge to increase realism in environmental system models can dramatically reduce the need for calibration

Gharari, S. (author), Hrachowitz, M. (author), Fenicia, F. (author), Gao, H. (author), Savenije, H.H.G. (author)

Conceptual environmental system models, such as rainfall runoff models, generally rely on calibration for parameter identification. Increasing complexity of this type of models for better representation of hydrological process heterogeneity, typically makes parameter identification more difficult. Although various, potentially valuable,...

journal article 2014

document

Analytical approach for predicting fresh water discharge in an estuary based on tidal water level observations

Cai, H. (author), Savenije, H.H.G. (author), Jiang, C. (author)

As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we...

journal article 2014

document

Determining slack tide with a GPS receiver on an anchored buoy

Valk, M. (author), Savenije, H.H.G. (author), Tiberius, C.C.J.M. (author), Luxemburg, W.M.J. (author)

In this paper we present a novel method to determine the time of occurrence of tidal slack with a GPS receiver mounted on an anchored buoy commonly used to delineate shipping lanes in estuaries and tidal channels. Slack tide occurs when the tide changes direction from ebb to flood flow or from flood to ebb. The determination of this point in...

journal article 2014

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Testing the realism of a topography-driven model (FLEX-Topo) in the nested catchments of the Upper Heihe, China

Gao, H. (author), Hrachowitz, M. (author), Fenicia, F.F. (author), Gharari, S. (author), Savenije, H.H.G. (author)

Although elevation data are globally available and used in many existing hydrological models, their information content is still underexploited. Topography is closely related to geology, soil, climate and land cover. As a result, it may reflect the dominant hydrological processes in a catchment. In this study, we evaluated this hypothesis...

journal article 2014

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Hydrological model parameter dimensionality is a weak measure of prediction uncertainty (discussion paper)

Pande, S. (author), Arkesteijn, L. (author), Savenije, H.H.G. (author), Bastidas, L.A. (author)

This paper presents evidence that model prediction uncertainty does not necessarily rise with parameter dimensionality (the number of parameters). Here by prediction we mean future simulation of a variable of interest conditioned on certain future values of input variables. We utilize a relationship between prediction uncertainty, sample size...

journal article 2014

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Evolving water science in the Anthropocene

Savenije, H.H.G. (author), Hoekstra, A.Y. (author), Van der Zaag, P. (author)

This paper reviews the changing relation between human beings and water since the Industrial Revolution, a period that has been called the Anthropocene because of the unprecedented scale at which humans have altered the planet during this time. We show how the rapidly changing world urges us to continuously improve our understanding of the...

journal article 2014

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Linking the river to the estuary: Influence of river discharge on tidal damping

Cai, H. (author), Savenije, H.H.G. (author), Toffolon, M. (author)

The effect of river discharge on tidal damping in estuaries is explored within one consistent theoretical framework where analytical solutions are obtained by solving four implicit equations, i.e. the phase lag, the scaling, the damping and the celerity equation. In this approach the damping equation is obtained by subtracting the envelope...

journal article 2014