Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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    We will mail you new results for this query: keywords==Precipitation
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Electrochemically mediated calcium phosphate precipitation from phosphonates: Implications on phosphorus recovery from non-orthophosphate
Lei, Yang ; Saakes, Michel ; Weijden, Renata D. van der; Buisman, Cees J.N. - \ 2020
Water Research 169 (2020). - ISSN 0043-1354
Calcium phosphate - Local high pH - Organic phosphorus - Oxidation - Precipitation

Phosphonates are an important type of phosphorus-containing compounds and have possible eutrophication potential. Therefore, the removal of phosphonates from waste streams is as important as orthophosphate. Herein, we achieved simultaneously removal and recovery of phosphorus from nitrilotris (methylene phosphonic acid) (NTMP) using an electrochemical cell. It was found that the C–N and C–P bonds of NTMP were cleaved at the anode, leading to the formation of orthophosphate and formic acid. Meanwhile, the converted orthophosphate reacted with coexisting calcium ions and precipitated on the cathode as recoverable calcium phosphate solids, due to an electrochemically induced high pH region near the cathode. Electrochemical removal of NTMP (30 mg/L) was more efficient when dosed to effluent of a wastewater treatment plant (89% in 24 h) than dosed to synthetic solutions of 1.0 mM Ca and 50 mM Na2SO4 (43% in 168 h) while applying a current density of 28 A/m2 and using a Pt anode and Ti cathode. The higher removal efficiency of NTMP in real waste water is due to the presence of chloride ions, which resulted in anodic formation of chlorine. This study establishes a one-step approach for simultaneously phosphorus removal and recovery of calcium phosphate from non-orthophosphates.

Large-scale flow patterns associated with extreme precipitation and atmospheric rivers over Norway
Benedict, Imme ; Ødemark, Karianne ; Nipen, Thomas ; Moore, Richard - \ 2019
Monthly Weather Review 147 (2019)4. - ISSN 0027-0644 - p. 1415 - 1428.
Atmosphere - Empirical orthogonal functions - Precipitation - Reanalysis data - Topographic effects - Water vapor

A climatology of extreme cold season precipitation events in Norway from 1979 to 2014 is presented, based on the 99th percentile of the 24-h accumulated precipitation. Three regions, termed north, west, and south are identified, each exhibiting a unique seasonal distribution. There is a proclivity for events to occur during the positive phase of the NAO. The result is statistically significant at the 95th percentile for the north and west regions. An overarching hypothesis of this work is that anomalous moisture flux, or so-called atmospheric rivers (ARs), are integral to extreme precipitation events during the Norwegian cold season. An objective analysis of the integrated vapor transport illustrates that more than 85% of the events are associated with ARs. An empirical orthogonal function and fuzzy cluster technique is used to identify the large-scale weather patterns conducive to the moisture flux and extreme precipitation. Five days before the event and for each of the three regions, two patterns are found. The first represents an intense, southward-shifted jet with a southwest-northeast orientation. The second identifies a weak, northward-shifted, zonal jet. As the event approaches, regional differences become more apparent. The distinctive flow pattern conducive to orographically enhanced precipitation emerges in the two clusters for each region. For the north and west regions, this entails primarily zonal flow impinging upon the south-north-orientated topography, the difference being the latitude of the strong flow. In contrast, the south region exhibits a significant southerly component to the flow.

Observed and model simulated twenty-first century hydro-climatic change of Northern Ethiopia
Tesfaye, Samuale ; Taye, Gebeyehu ; Birhane, Emiru ; Zee, Sjoerd E.A.T.M. van der - \ 2019
Journal of Hydrology: Regional Studies 22 (2019). - ISSN 2214-5818
Artificial neural networks - Climate change - GCM - Precipitation - Streamflow - Temperature

Study region: This study focuses on Tekeze river basin of northern Ethiopia, and it is characterized by a typical dry biogeophysical environment. Study focus: In recent years, recurrent droughts are having an adverse impact on agricultural production and water resources in northern Ethiopia. Climate change through changes on temperature, precipitation and streamflow, may further strain this critical situation. This study has investigated the observed (1961–2014) and potential (2006–2099) hydro-climatic changes in Tekeze river basin of northern Ethiopia. Artificial Neural Networks (ANNs) are used to downscale temperature and precipitation predicated by 30 General Circulation Models (GCMs) as well as the projected streamflow changes for two Representative Concentration Pathways (RCP4.5 and RCP8.5) scenario. New hydrological insights for the region: Results indicate that the variability of climatic factors as temperature and precipitation was observed to be both spatially and temporally diverse for the considered Tekeze river basin. Accordingly, the response of streamflow was also spatiotemporally complex. GCMs were evaluated with several performance indictors regarding patterns in hydro-climatic variables. The analysis showed the superiority of the multimodel ensemble means compared with individual GCM output. GCM projections for the 21century indicate a gradual reductions in streamflow attributed to the combined effect of increasing temperature and decreasing precipitation. The persistent increase of temperature and decrease of precipitation will have negative impacts on water availability and agriculture, hence site specific adaptation strategies are necessary.

Determining sectoral and regional sensitivity to climate and socio-economic change in Europe using impact response surfaces
Fronzek, Stefan ; Carter, Timothy R. ; Pirttioja, Nina ; Alkemade, Rob ; Audsley, Eric ; Bugmann, Harald ; Flörke, Martina ; Holman, Ian ; Honda, Yasushi ; Ito, Akihiko ; Janes-Bassett, Victoria ; Lafond, Valentine ; Leemans, Rik ; Mokrech, Marc ; Nunez, Sarahi ; Sandars, Daniel ; Snell, Rebecca ; Takahashi, Kiyoshi ; Tanaka, Akemi ; Wimmer, Florian ; Yoshikawa, Minoru - \ 2019
Regional Environmental Change 19 (2019)3. - ISSN 1436-3798 - p. 679 - 693.
Gross domestic product (GDP) - Impact model - Population - Precipitation - Sensitivity analysis - Temperature

Responses to future changes in climatic and socio-economic conditions can be expected to vary between sectors and regions, reflecting differential sensitivity to these highly uncertain factors. A sensitivity analysis was conducted using a suite of impact models (for health, agriculture, biodiversity, land use, floods and forestry) across Europe with respect to changes in key climate and socio-economic variables. Depending on the indicators, aggregated grid or indicative site results are reported for eight rectangular sub-regions that together span Europe from northern Finland to southern Spain and from western Ireland to the Baltic States and eastern Mediterranean, each plotted as scenario-neutral impact response surfaces (IRSs). These depict the modelled behaviour of an impact variable in response to changes in two key explanatory variables. To our knowledge, this is the first time the IRS approach has been applied to changes in socio-economic drivers and over such large regions. The British Isles region showed the smallest sensitivity to both temperature and precipitation, whereas Central Europe showed the strongest responses to temperature and Eastern Europe to precipitation. Across the regions, sensitivity to temperature was lowest for the two indicators of river discharge and highest for Norway spruce productivity. Sensitivity to precipitation was lowest for intensive agricultural land use, maize and potato yields and Scots pine productivity, and highest for Norway spruce productivity. Under future climate projections, North-eastern Europe showed increases in yields of all crops and productivity of all tree species, whereas Central and East Europe showed declines. River discharge indicators and forest productivity (except Holm oak) were projected to decline over southern European regions. Responses were more sensitive to socio-economic than to climate drivers for some impact indicators, as demonstrated for heat-related mortality, coastal flooding and land use.

Rainfall Monitoring Using Microwave Links from Cellular Communication Networks : The Dutch Experience
Overeem, Aart ; Leijnse, Hidde ; Uijlenhoet, Remko - \ 2018
In: 2018 IEEE Statistical Signal Processing Workshop, SSP 2018. - Institute of Electrical and Electronics Engineers Inc. - ISBN 9781538615720 - p. 110 - 114.
commercial microwave links - hydrometeorology - Precipitation - rainfall

Microwave links from commercial cellular communication networks have been used for rainfall monitoring in The Netherlands since 2003. Here we report on the start of our work on this topic using a dedicated microwave link in 1999, our first trails with commercial microwave links (CMLs) from Vodafone in 2003, our first published results in 2007, our work on sources of error and uncertainties in rainfall retrievals using microwave links of different lengths and frequencies, and finally the fruitful collaboration with T-Mobile NL, which lead to areal rainfall estimation for the Rotterdam metropolitan area in 2009 and 2010 and country-wide rainfall mapping for the entire land surface area of The Netherlands since 2012. Our current work on this topic follows three lines of research: (1) further refinement of our rainfall retrieval and mapping algorithm; (2) further quantification of sources of error and uncertainties using a dedicated experimental setup of multiple microwave links and a line configuration of disdrometers for ground validation; (3) promotion of the international replication of this method for rainfall monitoring through collaboration with partners in Europe and beyond.

Modelling the present and futurewater level and discharge of the tidal betna river
Islam, M.M.M. ; Hofstra, Nynke ; Sokolova, Ekaterina - \ 2018
Geosciences 8 (2018)8. - ISSN 2076-3263
Discharge - Flood - General circulation models (GCM) - MIKE 21 FM model - Precipitation - Water level

Climate change, comprising of changes in precipitation patterns, higher temperatures and sea level rises, increases the likelihood of future flooding in the Betna River basin, Bangladesh. Hydrodynamic modellingwas performed to simulate the present and future water level and discharge for different scenarios using bias-corrected, downscaled data from two general circulation models. The modelling results indicated that, compared to the baseline year (2014–2015), the water level is expected to increase by 11–16% by the 2040s and 14–23% by the 2090s, and the monsoon daily maximum discharge is expected to increase by up to 13% by the 2040s and 21% by the 2090s. Sea level rise is mostly responsible for the increase in water level. The duration of water level exceedance of the established danger threshold and extreme discharge events can increase by up to half a month by the 2040s and above one month by the 2090s. The combined influence of the increased water level and discharge has the potential to cause major floods in the Betna River basin. The results of our study increase the knowledge base on climate change influence on water level and discharge at a local scale. This is valuable for water managers in flood-risk mitigation and water management.

Effects of current density, bicarbonate and humic acid on electrochemical induced calcium phosphate precipitation
Lei, Yang ; Saakes, Michel ; Weijden, Renata D. van der; Buisman, Cees J.N. - \ 2018
Chemical Engineering Journal 342 (2018). - ISSN 1385-8947 - p. 350 - 356.
Bicarbonate - Electrochemical - Humic acid - Phosphate removal - Precipitation
Phosphorus (P) removal and recovery from sewage as calcium phosphate (CaP) by chemical precipitation is a widely used method. To avoid the addition of chemicals to increase the pH of the bulk solution and the need for a further separation step in conventional chemical precipitation process, we developed an electrochemical method, which can locally increase the pH near a Ti cathode. The separation of product and liquid then happens simultaneously by accumulating CaP at the electrode surface. The current density plays a crucial role in this system. A current density of 19 A/m2 results in the formation of crystalline CaP rather than amorphous CaP, but it does not enhance the removal of P in 24 h. Moreover, the current efficiency decreases with increasing current density. Furthermore, the increased H2 production at high current density may push the precipitated CaP back to the bulk solution, resulting in its dissolution. In the presence of bicarbonate (1–5 mM) or humic acid (1–20 mg/L), the removal of P was higher. This is probably due to the inhibited CaP precipitation in the bulk solution which in turn leaves more Ca and P ions available for the local precipitation on the cathode. However, bicarbonate at high concentration (10 mM) dropped P removal from 52 to 25%. This is caused by competition of carbonate and phosphate with the free Ca2+ ions and also by buffering the producted hydroxide ions at the cathode. The study shows that P can be removed as CaP by electrochemical precipitation at low current densities at common concentrations of bicarbonate and humic acid.
Bacterial communities in soil become sensitive to drought under intensive grazing
Jurburg, Stephanie D. ; Natal-da-Luz, Tiago ; Raimundo, João ; Morais, Paula V. ; Sousa, José Paulo ; Elsas, Jan Dirk van; Salles, Joana Falcao - \ 2018
Science of the Total Environment 618 (2018). - ISSN 0048-9697 - p. 1638 - 1646.
Bacteria - Climate change - Land management - Microbiome - Precipitation - Resilience - Soil

Increasing climatic and anthropogenic pressures on soil ecosystems are expected to create a global patchwork of disturbance scenarios. Some regions will be strongly impacted by climate change, others by agricultural intensification, and others by both. Soil microbial communities are integral components of terrestrial ecosystems, but their responses to multiple perturbations are poorly understood. Here, we exposed soils from sustainably- or intensively-managed grasslands in an agro-silvo-pastoral oak woodland to month-long intensified drought and flood simulation treatments in a controlled mesocosm setting. We monitored the response of the bacterial communities at the end of one month as well as during the following month of recovery. The communities in sustainably-managed plots under all precipitation regimes were richer and more diverse than those in intensively-managed plots, and contained a lower proportion of rapidly-growing taxa. Soils from both land managements exhibited changes in bacterial community composition in response to flooding, but only intensively-managed soils were affected by drought. The ecologies of bacteria favored by both drought and flood point to both opportunism and stress tolerance as key traits shaping the community following disturbance. Finally, the response of several taxa (i.e. Chloracidobacteria RB41, Janthinobacterium sp.) to precipitation depended on land management, suggesting that the community itself affected individual disturbance responses. Our findings provide an in-depth view of the complexity of soil bacterial community responses to climatic and anthropogenic pressures in time, and highlight the potential of these stressors to have multiplicative effects on the soil biota.

Do spatially homogenising and heterogenising processes affect transitions between alternative stable states?
Groen, Thomas A. ; Vijver, Claudius A.D.M. Van de; Langevelde, Frank Van - \ 2017
Ecological Modelling 365 (2017). - ISSN 0304-3800 - p. 119 - 128.
Dispersion - Fire - Grazing - Precipitation - Savannas - Spatial modelling
Large-scale sudden transitions in ecosystems are expected as result of changing global climate or land use. Current theory predicts such sudden transitions especially to occur in spatially homogeneous ecosystems, whereas transitions in spatially heterogeneous systems will be more gradual. The spatial heterogeneity of ecosystems is determined as result of opposing spatial processes that are either increasing or decreasing heterogeneity. Hence, the relative strength of these opposing processes is expected to determine how sensitive the system is to transitions, which has not been explored to date. In our study, fire, as a spatially heterogenising process, and plant dispersion, as a spatially homogenising process, in tropical savannas were modelled to analyse how these processes affect the occurrence of sudden transitions from grass dominance to tree dominance. Savannas are expected to change due to precipitation or land use changes towards either tree dominance or grass dominance. We found that high rates of grass dispersion can create homogeneous grass patches, but only when the spatial extent of fire is limited to small patches that are spread across the landscape. When fires occur in larger patches, a heterogeneous pattern is generated. In spatially heterogeneous savannas, we found a more gradual responses to increasing grazing pressure compared to the sudden transitions when savannas are spatially homogeneous. The most sudden transitions were found in near-homogeneous grass distributions where the interaction between grazing, grass dispersion and fire led to a few homogeneous patches. Within these homogeneous patches, transitions were complete and sudden. We conclude that when spatially heterogenising processes are stronger than spatially homogenising processes, heterogeneous systems are created. In these systems large-scale sudden transitions are less likely to occur, because transitions at smaller scales are averaged over space. We discuss how this has implications for responses of savannas to climatic and land use change.
Climatic controls of ecohydrological responses in the highlands of northern Ethiopia
Tesfaye, Samuale ; Birhane, Emiru ; Leijnse, Toon ; Zee, S.E.A.T.M. van der - \ 2017
Science of the Total Environment 609 (2017). - ISSN 0048-9697 - p. 77 - 91.
Ecosystem model - Land use - Precipitation - Primary productivity - Semi-arid - Streamflow
Climate variability and recurrent droughts have a strong negative impact on agricultural production and hydrology in the highlands northern Ethiopia. Since the 1980s, numerous mitigation and land rehabilitation measures have been implemented by local and national authorities to reduce these impacts, are often poorly effective. As underlying reason may be that controlling relationships between climate and ecohydrology at medium-sized catchments (10–10,000 km2) of semi-arid highlands are not well known. We investigated trends and relationships in precipitation, temperature, streamflow, and net primary productivity (NPP). The results were mixed, with both significant increasing and decreasing trends for temperature and streamflow. Precipitation time series did not show a significant trend for the majority of stations, both over the years and over each season, except for a few stations. A time series indicated a significant abrupt increase of NPP in annual, seasonal and monthly timescale. Cross-correlation and regression analysis indicate precipitation and maximum temperature were the dominant climatic variables in the Geba catchment for streamflow and NPP. In view of these results, also land use and land cover change over the past three decades was analysed as a possible factor of importance, as human intervention, may affect streamflow and NPP. Factors that mainly correlate with streamflow and NPP are precipitation and maximum temperature. Important interventions that appear beneficial for these responses are construction of micro-dams, soil and water conservation and ecological restoration measures. The awareness that interactions can be quite different in semi-arid and semi-humid regions, as well as in upstream and downstream areas, should be reflected in management aimed at sustainable water and land resources use.
The Impact of Environmental Variables on Faecal Indicator Bacteria in the Betna River Basin, Bangladesh
Islam, Majedul ; Hofstra, Nynke ; Islam, Md Atikul - \ 2017
Environmental Processes 4 (2017)2. - ISSN 2198-7491 - p. 319 - 332.
E. coli - Enterococci - Precipitation - Regression - Salinity - Water temperature

Environmental variables influence Faecal Indicator Bacteria (FIB) in surface water. Understanding that influence is important, because presence of FIB, which are an indication of faecal contamination, means that harmful pathogens could be present that could also be influenced by environmental variables. Although some recent studies have focused on this topic, most of this work has been conducted in developed countries. Similar studies in developing countries and in a (sub)tropical climate are lacking. In this study we assess the influence of environmental variables on fluctuations in FIB concentrations of the Betna River in southwest Bangladesh that floods almost every year. Monthly water samples from five locations along Betna River were tested for FIB (E. coli and enterococci) in 2014–2015. A linear regression model was developed to assess the effect of the environmental variables on FIB concentrations. The study revealed increased FIB concentrations during wet weather conditions. Precipitation and water temperature were positively correlated with FIB concentrations. Water temperature was positively correlated, because the warm May to September period coincides with frequent precipitation. Precipitation increases manure release from land to surface water. The regression model explains nearly half of the variability in FIB concentrations (R2 of 0.46 for E. coli and 0.48 for enterococci). This study indicates that increased precipitation combined with higher water temperature, as is expected in this region with climate change, likely increases FIB concentrations. Waterborne pathogens are expected to respond similarly to these environmental changes, indicating that disease outbreaks could well become more frequent and severe.

Multi-wheat-model ensemble responses to interannual climate variability
Ruane, Alex C. ; Hudson, Nicholas I. ; Asseng, Senthold ; Camarrano, Davide ; Ewert, Frank ; Martre, Pierre ; Boote, Kenneth J. ; Thorburn, Peter J. ; Aggarwal, Pramod K. ; Angulo, Carlos ; Basso, Bruno ; Bertuzzi, Patrick ; Biernath, Christian ; Brisson, Nadine ; Challinor, Andrew J. ; Doltra, Jordi ; Gayler, Sebastian ; Goldberg, Richard ; Grant, Robert F. ; Heng, Lee ; Hooker, Josh ; Hunt, Leslie A. ; Ingwersen, Joachim ; Izaurralde, Roberto C. ; Kersebaum, Kurt Christian ; Kumar, Soora Naresh ; Müller, Christoph ; Nendel, Claas ; O'Leary, Garry ; Olesen, Jørgen E. ; Osborne, Tom M. ; Palosuo, Taru ; Priesack, Eckart ; Ripoche, Dominique ; Rötter, Reimund P. ; Semenov, Mikhail A. ; Shcherbak, Iurii ; Steduto, Pasquale ; Stöckle, Claudio O. ; Stratonovitch, Pierre ; Streck, Thilo ; Supit, Iwan ; Tao, Fulu ; Travasso, Maria ; Waha, Katharina ; Wallach, Daniel ; White, Jeffrey W. ; Wolf, Joost - \ 2016
Environmental Modelling & Software 81 (2016). - ISSN 1364-8152 - p. 86 - 101.
AgMIP - Climate impacts - Crop modeling - Interannual variability - Multi-model ensemble - Precipitation - Temperature - Uncertainty - Wheat

We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981-2010 grain yield, and we evaluate results against the interannual variability of growing season temperature, precipitation, and solar radiation. The amount of information used for calibration has only a minor effect on most models' climate response, and even small multi-model ensembles prove beneficial. Wheat model clusters reveal common characteristics of yield response to climate; however models rarely share the same cluster at all four sites indicating substantial independence. Only a weak relationship (R2 ≤ 0.24) was found between the models' sensitivities to interannual temperature variability and their response to long-term warming, suggesting that additional processes differentiate climate change impacts from observed climate variability analogs and motivating continuing analysis and model development efforts.

Distinguishing the impacts of human activities and climate variability on runoff and sediment load change based on paired periods with similar weather conditions : A case in the Yan River, China
Wang, Fei ; Hessel, Rudi ; Mu, Xingmin ; Maroulis, Jerry ; Zhao, Guangju ; Geissen, Violette ; Ritsema, Coen - \ 2015
Journal of Hydrology 527 (2015). - ISSN 0022-1694 - p. 884 - 893.
Climate variability - Human activity - Precipitation - Reference evapotranspiration (ET0) - Similar weather condition (SWC) - Surface runoff

Runoff and sediment loads from river basin are largely affected by the interplay of climate variability and human activities within the basin. However, distinguishing the impacts of climate variability and human activities would vastly improve our knowledge of water resources, climate variability and climate adaptation, and watershed management. We propose a new and simple method to determine the impact of human activities within paired datasets under the same or similar weather conditions (SWC). These weather conditions cover one or more meteorological elements such as precipitation, temperature, or evaporation. If there are two or more periods with similar weather conditions but different runoff, the relative runoff and sediment load changes can be considered a consequence of human-induced land surface changes. This study will report on the application of this new method, using the Yan River Basin in China as a case study. We found 10 sets PPs (paired periods) in 1. year intervals and 12 sets of PPs in intervals of 3. years when (1) there was a 2.0% and 1.0% difference of annual precipitation and annual ET0, respectively, (2) the relationship between monthly precipitation and ET0 of PPs was significant (. P

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