Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    '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.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

    Current refinement(s):

    Records 1 - 20 / 77

    • help
    • print

      Print search results

    • export

      Export search results

    Check title to add to marked list
    Impact of human activities on the reproduction of Hooded Vultures Necrosyrtes monachus in Burkina Faso
    Daboné, Clément ; Buij, Ralph ; Oueda, Adama ; Adjakpa, Jacques Boko ; Guenda, Wendengoudi ; Weesie, Peter D.M. - \ 2019
    Ostrich 90 (2019)1. - ISSN 0030-6525 - p. 53 - 61.
    Burkina Faso - conservation - Hooded Vulture - human impact - reproduction

    During the last decades, the critically endangered Hooded Vulture Necrosyrtes monachus has strongly declined across its African range. Although direct persecution has been suggested as a major cause of this decline, little is known about the impact of humans on reproductive output in West Africa. We studied the impact of human activities on the reproductive output of Hooded Vultures in the Garango area of Burkina Faso. Twenty and 56 nesting attempts were monitored, respectively, during the breeding season in 2013/14 and 2014/15, to determine reproductive success and identify causes of nest failure. Annual breeding success varied between 0.68 and 0.71 chicks fledged per breeding pair per year and productivity was assessed at 0.57 chicks fledged per territorial pair in 2014/15. The main threats imposed by humans were poaching of eggs, chicks and collection of nest materials, leading to 20% (13 out of 64 breeding attempts) of nest failures over the two years. An additional important reason for nest failure was the pruning and (partial) cutting of nest trees. Despite this high level of human interference, we found that Hooded Vulture nest success increased with proximity to human settlements, probably because breeding vultures benefit from protection by people against persecution and disturbance.

    Controls on late-Holocene drift-sand dynamics : The dominant role of human pressure in the Netherlands
    Pierik, Harm J. ; Lanen, Rowin J. van; Gouw-Bouman, Marjolein T.I.J. ; Groenewoudt, Bert J. ; Wallinga, Jakob ; Hoek, Wim Z. - \ 2018
    Holocene 28 (2018)9. - ISSN 0959-6836 - p. 1361 - 1381.
    chronology - climate - drift-sand activity - Holocene - human impact - vegetation development

    Holocene drift-sand activity in the northwest European sand belt is commonly directly linked to population pressure (agricultural activity) or to climate change (e.g. storminess). In the Pleistocene sand areas of the Netherlands, small-scale Holocene drift-sand activity began in the Mesolithic, whereas large-scale sand drifting started during the Middle Ages. This last phase not only coincides with the intensification of farming and demographic pressure but also is commonly associated with a colder climate and enhanced storminess. This raises the question to what extent drift-sand activity can be attributed to either human activities or natural forcing factors. In this study, we compare the spatial and temporal patterns of drift-sand occurrence for the four characteristic Pleistocene sand regions in the Netherlands for the period between 1000 BC and AD 1700. To this end, we compiled a new supra-regional overview of drift-sand activity based on age estimates (14C, optically stimulated luminescence (OSL), archaeological and historical ages). The occurrence of sand drifting was then compared in time and space with historical-route networks, relative vegetation openness and climate. Results indicate a constant but low drift-sand activity between 1000 BC and AD 1000, interrupted by a remarkable decrease in activity around the BC/AD transition. It is evident that human pressure on the landscape was most influential on initiating sand drifting: this is supported by more frequent occurrences close to routes and the uninterrupted increase of drift-sand activity from AD 900 onwards, a period of high population density and large-scale deforestation. Once triggered by human activities, this drift-sand development was probably further intensified several centuries later during the cold and stormier ‘Little Ice Age’ (LIA; AD 1570–1850).

    Standard Data Form Natura 2000 : bepaling van de belangrijkste drukfactoren in Natura 2000-gebieden
    Schippers, P. ; Schmidt, A.M. ; Kleunen, A. van; Bremer, L. van den - \ 2015
    Wettelijke Onderzoekstaken Natuur & Milieu (WOt-technical report 56) - 30
    natura 2000 - natuurgebieden - habitatrichtlijn - vogelrichtlijn - milieueffect - menselijke invloed - natuurbeheer - natura 2000 - natural areas - habitats directive - birds directive - environmental impact - human impact - nature management
    Dit rapport betreft de documentatie van de gevolgde werkwijze van hoofdstuk 4.3 van het Standard Data
    Form. Het rapport beschrijft de methodiek die gevolgd is om per Natura 2000-gebied de belangrijkste
    drukfactoren uit de voorgeschreven lijst van de EC (de EC-indeling) te bepalen. Hierbij is de informatie over
    de drukfactoren die een negatief effect hebben op de staat van instandhouding van soorten en habitattypen
    uit de landelijke rapportages toegepast. Om de binnen de EC-systematiek geconstateerde problemen op te
    lossen, is er gezocht naar een nieuwe Nederlandse indeling in drukfactoren, waarbij duidelijk onderscheid
    wordt gemaakt tussen de oorzaken van drukfactoren (menselijke activiteiten en natuurlijke processen) en de
    effecten (bv. versnippering, vermesting en verdroging). Door de landelijke EC-indeling te vertalen naar de
    NL-indeling (en vice versa) is de informatie ook geschikter voor praktisch gebruik
    Effecten van militaire en civiele helikopters op vogels op het Kooijhoekschor
    Smit, C.J. ; Schermer, D.S. - \ 2015
    Den Burg : IMARES (Rapport C156/15) - 111
    vogels - helikopters - militaire activiteiten - diergedrag - invloeden - menselijke invloed - noord-holland - birds - helicopters - military activities - animal behaviour - influences - human impact - noord-holland
    Het Maritiem Vliegkamp De Kooy en de civiele medegebruiker van het vliegveld, Den Helder Airport, zijn gelegen op korte afstand van de Waddenzee. Bij de nadering of bij het vertrek van het vliegveld moet, afhankelijk van de windrichting, in de helft van de gevallen op relatief geringe hoogte over de Waddenzee worden gevlogen. Het vliegveld wordt vooral gebruikt ten behoeve van helikopterverkeer. Den Helder Airport gebruikt het vliegveld vooral voor het vervoer van offshore-arbeiders van en naar olie- en gasplatforms op het Nederlands Continentaal Plat. De groep Maritieme Helikopters is de belangrijkste gebruiker vanuit het Ministerie van Defensie. De 12 hier gestationeerde NH90 helikopters hebben De Kooy als thuisbasis. Ook het onderhoud aan deze helikopters vindt hier plaats. Het vliegkamp wordt vooral gebruikt voor trainingsvluchten. De effecten van de uitbreiding van civiel helikopterverkeer op vogels zijn de afgelopen jaren gemonitord. Tijdens deze onderzoeken zijn ook steeds de effecten van militair vliegverkeer meegenomen. Er is na 2006 echter vrijwel geen onderzoek uitgevoerd op de minder intensief gebruikte aan- en afvliegroute via het Kooijhoekschor. Doel van het in deze rapportage beschreven deelonderzoek was de effecten van militair vliegverkeer op deze route nauwkeuriger in kaart te brengen en te actualiseren. Primaire doel van het in deze rapportage beschreven onderzoek was het bepalen van het effect van vliegbewegingen met militaire helikopters op wad- en watervogels op de locatie Kooijhoekschor, gelegen aan de rand van het Balgzand, ten zuidoosten van het Maritiem Vliegkamp De Kooy. Daarbij is vooral gekeken of overvliegende helikopters vogels doen opvliegen, hoe vaak dit gebeurt en beoordeeld of dit wellicht negatieve effecten voor vogels kan hebben.
    Assessing the observed impact of anthropogenic climate change
    Hansen, G.E. - \ 2015
    Wageningen University. Promotor(en): Rik Leemans, co-promotor(en): M. Auffhammer. - Wageningen : Wageningen University - ISBN 9789462574298 - 186
    klimaatverandering - milieueffect - menselijke invloed - climatic change - environmental impact - human impact

    Assessing the observed impact of anthropogenic climate change

    Gerrit Hansen

    Global climate change is unequivocal, and greenhouse gas emissions continue rising despite international mitigation efforts. Hence whether and to what extent the impacts of human induced climate change are already being felt around the world is a timely question.

    The thesis assesses the observed impact of anthropogenic climate change across systems, sectors and world regions. A clear framework for impact attribution studies is laid out and applied to several examples from the literature. The development of the evidence of climate change impacts over the last two decades is documented, and an overview of the status of knowledge is provided with a focus on recent trends in human and managed systems.

    The role of human influence, compared to natural variability, for climate related impacts is assessed for a large range of individual observations that have been reported in the Intergovernmental Panel on Climate Change’s Fifth Assessment Report. The analysis is based on a novel method that explicitly considers information on the quality and appropriateness of observational and model data for each observation. The thesis discusses caveats and challenges in attributing observed effects to climate change, and points out the consequence of those limitations for scientific policy advice. Key issues concern the question whether extreme weather events and their impacts can be attributed to human induced climate change and the limited availability of long-term monitoring records in many vulnerable regions. The impact of anthropogenic climate change is confirmed for a broad range of natural system effects, and to a lesser degree for human systems. Confident conclusions are mostly limited to direct temperature effects while precipitation effects remaining more uncertain.

    People, soil and manioc interactions in the upper Amazon region
    Peña Venegas, C.P. - \ 2015
    Wageningen University. Promotor(en): Paul Struik, co-promotor(en): Tjeerd-Jan Stomph; Gerard Verschoor. - Wageningen : Wageningen University - ISBN 9789462573222 - 210
    bodem - landbouw - inheemse kennis - bodemtypen (antropogeen) - inheemse volkeren - ecosystemen - cassave - manihot - diversiteit - menselijke invloed - amazonia - soil - agriculture - indigenous knowledge - soil types (anthropogenic) - indigenous people - ecosystems - cassava - manihot - diversity - human impact - amazonia

    Abstract

    Clara Patricia Peña Venegas (2015). People, soil and manioc interactions in the upper Amazon region. PhD thesis, Wageningen University, The Netherlands, with summaries in English and Dutch, 210 pp.

    The presence of anthropogenic soils, or Amazonian Dark Earths (ADE), fuels the debate about how pristine the Amazon ecosystem actually is, and about the degree to which humans affected Amazonian diversity in the past. Most upland soils of the Amazon region are very acid, highly weathered, and have a limited nutrient holding capacity; together, these characteristics limit permanent or intensive agriculture. Várzeas or floodplains that are periodically enriched with Andean sediments carried and deposited by rivers that cross the Amazon Basin, are moderately fertile but experience periodic floods that limit agriculture to crops able to produce in a short time. ADE patches in uplands usually are more fertile than non-anthropogenic uplands, providing a better environment for agriculture. Most studies about how people manage a broad portfolio of natural and anthropogenic soils come from non-indigenous farmers of Brazil. There is limited information about how indigenous people use a broad soil portfolio, and how this affects the diversity of their staple crop, manioc. With the aim to contribute to the understanding of the role of ADE in indigenous food production, as compared with other soils, and in order to provide information about how indigenous people use and create diversity in Amazonia, research was carried out among five different ethnic groups living in two locations of the Colombian Amazon.

    Several social and natural science methods were used during the study. These included ethnography, participant observation, structured and un-structured interviews, sampling of soil and manioc landraces, standardized protocols for the quantification of soil physical and chemical variables, and molecular techniques to assess genetic diversity of manioc and arbuscular mycorrhizal fungi.

    Results indicate that ADE patches from the Middle Caquetá region of Colombia are not contrastingly more fertile than surrounding, non-anthropogenic upland soils, except for higher levels of available phosphorus in ADE. Indigenous farmers from the Middle Caquetá region do not use ADE more frequently or more intensively than non-ADE uplands. The swidden agriculture practiced on ADE and on non-ADE uplands is similar. Although ADE patches were not specifically important for swiddens and therefore relatively unimportant for the production of manioc. They were important as sites for indigenous settlements and for maintaining agroforestry systems with native and exotic species that do not grow in soils with low available phosphorus. Várzeas were also used for agriculture, whether farmers had access to ADE or not. Differences occurred between locations in the type of floodplains selected and the way they were cultivated. Those differences were not related to differences in soil conditions but were associated with the cultural traditions of the different ethnic groups who cultivate low floodplains, as well as labor availability when organizing collective work (mingas) to harvest floodplains.

    Manioc diversity among indigenous communities was not predominantly related with differences in soil types. Complete manioc stocks were cultivated equally on ADE, non-ADE uplands or várzeas. One issue that could be related with this non-specificity in manioc-soil combinations was the similar arbuscular mycorrhizal fungi diversity of soils and the high number of arbuscular mycorrhizal symbionts associated to manioc roots; these were shown to be independent from the physicochemical composition of the soil or the manioc landrace. Differences in the diversity of manioc stocks among ethnic groups were predominantly related to cultural values attached to different manioc landraces.

    This study of indigenous agriculture in environments with natural and anthropogenic soils indicates that people have had an important role in transforming the Amazonian ecosystem through agriculture, with consequences on forest composition and forest dynamics. Pre-Columbian people contributed to this by creating an additional soil- the Amazonian Dark Earths. Although ADE are not presently considered to play a major role in indigenous food production, indigenous people believe that ADE have had an important role in the management of the first maniocs cultivated by their ancestors. The domestication of manioc and the creation and maintenance of hundreds of different landraces by indigenous people contributed, and still contributes, to the region’s plant diversity.

    Seal monitoring and evaluation for the Luchterduinen offshore wind farm: 2. Tconstruction - 2014 report
    Kirkwood, R.J. ; Aarts, G.M. ; Brasseur, S.M.J.M. - \ 2015
    Den Helder : IMARES (Rapport / IMARES Wageningen UR C152/14) - 65
    zeehonden - habitats - halichoerus grypus - phoca vitulina - menselijke invloed - windmolenpark - constructie - monitoring - ecologische verstoring - noordzee - zuid-holland - seals - habitats - halichoerus grypus - phoca vitulina - human impact - wind farms - construction - monitoring - ecological disturbance - north sea - zuid-holland
    Two seal species live in Dutch waters: the harbour seal (Phoca vitulina) and the grey seal (Halichoerus grypus). They occupy land-based sites (haul-outs) in both the Wadden Sea and the Delta region, and move between these regions along the North Sea coastal zone. Human activities, such as construction of a wind farm in this zone, may influence movement and use of the zone by the seals. Monitoring of potential impacts on seals to Luchterduinen construction was required in the permit to construct. The Luchterduinen offshore wind farm is the third wind farm development in the Dutch North Sea coastal zone (between Den Helder and Rotterdam). Pile-driving of the turbine towers occurred between 31 July and 16 October, 2014. Seals exposed to pile-driving, even at close distances of
    An exposure-effect approach for evaluating ecosystem-wide risks from human activities
    Knights, A.M. ; Piet, G.J. ; Jongbloed, R.H. ; Tamis, J.E. ; Robinson, L.A. - \ 2015
    ICES Journal of Marine Science 72 (2015)3. - ISSN 1054-3139 - p. 1105 - 1115.
    baltic sea - fisheries management - environmental-change - coastal ecosystems - marine ecosystems - human impact - new-zealand - food webs - support - climate
    Ecosystem-based management (EBM) is promoted as the solution for sustainable use. An ecosystem-wide assessment methodology is therefore required. In this paper, we present an approach to assess the risk to ecosystem components from human activities common to marine and coastal ecosystems. We build on: (i) a linkage framework that describes how human activities can impact the ecosystem through pressures, and (ii) a qualitative expert judgement assessment of impact chains describing the exposure and sensitivity of ecological components to those activities. Using case study examples applied at European regional sea scale, we evaluate the risk of an adverse ecological impact from current human activities to a suite of ecological components and, once impacted, the time required for recovery to pre-impact conditions should those activities subside. Grouping impact chains by sectors, pressure type, or ecological components enabled impact risks and recovery times to be identified, supporting resource managers in their efforts to prioritize threats for management, identify most at-risk components, and generate time frames for ecosystem recovery.
    Andean grasslands are as productive as tropical cloud forests
    Oliveras Menor, I. ; Girardin, C. ; Doughty, C.E. ; Cahuana, N. ; Arenas, C.E. ; Oliver, V. ; Huaraca Huasco, W. ; Malhi, Y. - \ 2014
    Environmental Research Letters 9 (2014)11. - ISSN 1748-9326 - 10 p.
    net primary productivity - climate-change - peruvian andes - carbon storage - elevational transect - human impact - biomass - vegetation - dynamics - fire
    We aim to assess net primary productivity (NPP) and carbon cycling in Andean tropical alpine grasslands (puna) and compare it with NPP of tropical montane cloud forests. We ask the following questions: (1) how do NPP and soil respiration of grasslands vary over the seasonal cycle? (2) how do burning and grazing affect puna productivity? (3) if the montane forest expands into the puna, what will be the resulting change in productivity? The study sites are located at the South-eastern Peruvian Andes; one grassland site and the forest sites are in Wayqecha biological station, and another grassland site in Manu National Park. At each grassland site, we selected a burnt and an unburnt area, installed unfenced and fenced transects in each area, and monitored above-ground productivity (NPPAG), below-ground productivity (NPPBG) and soil respiration (Rs) for 2 yr. In the forest, we monitored NPPAG, NPPBG and Rs for 2–4 yr. Grassland NPP varied between 4.6 ± 0.25 (disturbed areas) to 15.3 ± 0.9 Mg C ha-1 yr-1 (undisturbed areas) and cloud forest NPP was between 7.05 ± 0.39 and 8.0 ± 0.47 Mg C ha-1 yr-1, while soil carbon stocks were in the range of 126 ± 22 to 285 ± 31Mg C ha-1. There were no significant differences on NPP between the puna and forest sites. The most undisturbed site had significantly higher NPP than other grassland sites, but no differences were found when relating grazing and fire at other sites. There were lower residence times of above-ground biomass compared to below-ground biomass. There was a strong seasonal signal on grassland NPPAG and NPPBG, with a shift on allocation at the beginning of the austral summer. High elevation tropical grasslands can be as productive as adjacent cloud forests, but have very different carbon cycling and retention properties than cloud forests. S Online supplementary data available from stacks.iop.org/ERL/9/115011/mmedia Keywords: tropical alpine wetlands, above-ground productivity, below-ground productivity, fire, grazing, disturbances, puna
    Toepassing ODEMM - methodiek voor het Nederlandse KRM Programma van Maatregelen
    Piet, G.J. ; Sluis, M.T. van der; Paijmans, A.J. - \ 2014
    IJmuiden : IMARES (Rapport / IMARES Wageningen UR C162/14) - 61
    evaluatie - risicoschatting - ecologische risicoschatting - maatregelen - milieueffect - menselijke invloed - ecosysteembeheer - mariene ecologie - natuurbeheer - evaluation - risk assessment - ecological risk assessment - measures - environmental impact - human impact - ecosystem management - marine ecology - nature management
    Het Nederlandse Kaderrichtlijn Mariene strategie Programma van Maatregelen (PvM) is geëvalueerd met behulp van de ODEMM methodiek. Deze methodiek is ontwikkeld binnen het door de EU gesubsidieerde FP7 project ODEMM (Options for Delivering Ecosystem-based Marine Management). Met deze methodiek kan worden vastgesteld in hoeverre het PvM de menselijke activiteiten die hun invloed op het mariene ecosysteem hebben, in potentie kan mitigeren, zodat een goede milieutoestand behaald kan worden.
    Carbon accumulation in peat deposits from northern Sweden to northern Germany during the last millennium
    Linden, M. van der; Heijmans, M.M.P.D. ; Geel, B. van - \ 2014
    Holocene 24 (2014)9. - ISSN 0959-6836 - p. 1117 - 1125.
    climate-change - human impact - bog - sphagnum - temperature - rates - vegetation - peatlands - growth - ams
    Historic carbon accumulation rates in four bogs on a north to south transect from Sweden to Germany were calculated by using the bulk densities and carbon concentrations of 1-cm peat layers and a fine-resolution radiocarbon chronology. Carbon accumulation rates were compared to environmental data to explore the effects of climatic factors. Carbon accumulation rates in a period without clear human impact on the bog ecosystems (c.ad 1700–ad 1800) ranged from 25 g C/m2/yr in the most northern site to 50 g C/m2/yr in the southernmost site, which coincided with increasing annual temperatures from north to south. This suggests that temperature or growing season length is a major factor influencing carbon accumulation rates at different geographical sites. The temporal variations in carbon accumulation rates within the sites tentatively suggest that carbon accumulation rates may still increase with further warming in northern peat bogs, but decrease in southern peat bogs.
    Coupling socio-economic factors and eco-hydrological processes using a cascade-modeling approach
    Odongo, V.O. ; Mulatu, D.W. ; Muthoni, F.K. ; Oel, P.R. van; Meins, F.M. ; Tol, C. van der; Skidmore, A.K. ; Groen, T.A. ; Becht, R. ; Onyando, J.O. ; Veen, A. van der - \ 2014
    Journal of Hydrology 518 (2014)Part A. - ISSN 0022-1694 - p. 49 - 59.
    land-use change - murray-darling basin - lake naivasha - population-dynamics - water availability - stream ecosystems - human impact - east-africa - kenya - rainfall
    Most hydrological studies do not account for the socio-economic influences on eco-hydrological processes. However, socio-economic developments often change the water balance substantially and are highly relevant in understanding changes in hydrological responses. In this study a multi-disciplinary approach was used to study the cascading impacts of socio-economic drivers of land use and land cover (LULC) changes on the eco-hydrological regime of the Lake Naivasha Basin. The basin has recently experienced substantial LULC changes exacerbated by socio-economic drivers. The simplified cascade models provided insights for an improved understanding of the socio-ecohydrological system. Results show that the upstream population has transformed LULC such that runoff during the period 1986–2010 was 32% higher than during the period 1961–1985. Cut-flower export volumes and downstream population growth explain 71% of the water abstracted from Lake Naivasha. The influence of upstream population on LULC and upstream hydrological processes explained 59% and 30% of the variance in lake storage volumes and sediment yield respectively. The downstream LULC changes had significant impact on large wild herbivore mammal species on the fringe zone of the lake. This study shows that, in cases where observed socio-economic developments are substantial, the use of a cascade-modeling approach, that couple socio-economic factors to eco-hydrological processes, can greatly improve our understanding of the eco-hydrological processes of a catchment.
    Supporting IWRM through spatial integrated assessment in the Lake Naivasha basin, Kenya
    Oel, P.R. van; Odongo, V.O. ; Mulatu, D.W. ; Muthoni, F.K. ; Ndungu, J.N. ; Ogada, J.O. ; Veen, A. van der - \ 2014
    International Journal of Water Resources Development 30 (2014)3. - ISSN 0790-0627 - p. 605 - 618.
    water-resources management - surface-water - african lake - human impact - catchment - ecology - availability - complexity - nutrients - framework
    This study describes the mismatch between required knowledge and efforts by scientists and stakeholders in the Lake Naivasha basin, Kenya. In the basin, integrated water resources management (IWRM) suffers from the absence of critically relevant knowledge. This study further presents a spatial integrated assessment framework for supporting IWRM in the basin. This framework resulted from an ongoing debate between stakeholders and scientists studying the basin's issues. It builds on jointly identified indicators for sustainable governance, and their interdependency, and knowledge gaps. For IWRM in the basin this is a first important step towards a more structured debate on the implementation of IWRM.
    Nile perch (Lates niloticus, L.) and cichlids (Haplochromis spp.) in Lake Victoria: could prey mortality promote invasion of tis predator?
    Wolfshaar, K.E. van de; Hille Ris Lambers, R. ; Goudswaard, P.C. ; Rijnsdorp, A.D. ; Scheffer, M. - \ 2014
    Theoretical Ecology 7 (2014)3. - ISSN 1874-1738 - p. 253 - 261.
    east-africa - mwanza gulf - human impact - ecosystems - productivity - coexistence - competition - recovery - kyoga
    The invasion of Nile perch into Lake Victoria is one of the iconic examples of the destructive effect of an introduced species on an ecosystem but no convincing explanation exists of why Nile perch only increased dramatically after a 25 year lag. Here, we consider this problem using a mathematical model that takes into account interactions between Nile perch and its cichlid prey. We examined competing hypotheses to explain Nile perch invasion and show that suppression of juvenile Nile perch by cichlids may cause the system to have two alternative stable states: one with only cichlids and one with coexistence of cichlids and Nile perch. Without cichlid predation on Nile perch, alternative stable states did not occur. Our analysis indicates that cichlid mortality, for example fishing mortality, may have induced the observed shift between the states.
    The Effects of Groundwater and Surface Water Use on Total Water Availability and Implication for Water Management: The Case of Lake Naivasha, Kenya
    Oel, P.R. van; Mulatu, D.W. ; Odongo, V.O. ; Meins, F.M. ; Hogeboom, R.J. ; Brecht, R. ; Stein, A. ; Onyando, J.O. ; Veen, A. van der - \ 2013
    Water Resources Management 27 (2013)9. - ISSN 0920-4741 - p. 3477 - 3492.
    resources management - human impact - basin
    This study discusses the effects of water abstractions from two alternative sources on the available water volume around Lake Naivasha, Kenya: the lake itself and a connected aquifer. An estimation of the water abstraction pattern for the period 1999–2010 is made and its effect on the available water volume in Lake Naivasha and its connected aquifer is evaluated using a simple water balance modeling approach. This study shows that accurate estimates of annual volume changes of Lake Naivasha can be made using a simple monthly water balance approach that takes into account the exchange of water between the lake and its connected aquifer. The amount of water that is used for irrigation in the area around Lake Naivasha has a substantial adverse effect on the availability of water. Simulation results of our simple water balance model suggests that abstractions from groundwater affect the lake volume less than direct abstractions from the lake. Groundwater volumes, in contrast, are much more affected by groundwater abstractions and therefore lead to much lower groundwater levels. Moreover, when groundwater is used instead of surface water, evaporation losses from the lake are potentially higher due to a larger lake surface area. If that would be the case then the overall water availability in the area is more strongly affected by the abstraction of groundwater than by the abstraction of surface water. Therefore water managers should be cautious when using lake levels as the only indicator of water availability for restricting water abstractions.
    The first wolf found in the Netherlands in 150 years was the victim of a wildlife crime
    Gravendeel, B. ; Groot, G.A. de; Kik, M. ; Beentjes, K. ; Bergman, H. ; Caniglia, R. ; Cremers, H. ; Fabbri, E. ; Groenenberg, D. ; Grone, A. ; Groot Bruinderink, G.W.T.A. ; Font, I. ; Hakhof, J. ; Harms, V. ; Jansman, H.A.H. ; Janssen, R. ; Lammertsma, D.R. ; Laros, I. ; Linnartz, L. ; Marel, D. van der; Mulder, J.L. ; Mije, S. van der; Nieman, A.M. ; Nowak, C. ; Randi, E. ; Rijks, M. ; Speksnijder, A. ; Vonhof, H.B. - \ 2013
    Lutra 56 (2013)2. - ISSN 0024-7634 - p. 93 - 109.
    wolven - fauna - migratie - diergedrag - dna - biochemie - menselijke invloed - centraal-europa - noordoostpolder - wolves - fauna - migration - animal behaviour - dna - biochemistry - human impact - central europe - noordoostpolder
    On July 4th 2013 a dead subadult female wolf-like canid was found by the roadside between Luttelgeest and Marknesse in the Noordoostpolder in the central part of the Netherlands. As the last observations of wild wolves in the Netherlands date back to 1869 the discovery of this animal generated a lot of media attention. European wolf populations have been expanding since the 1950s and the first packs recently established themselves in Germany in geographic proximity of the Dutch border, so natural re-appearance of the species in the Netherlands seemed likely. We investigated the taxonomy of the animal, its geographical origin, and its most recent history. Macroscopic and biochemical analyses of the dead animal convincingly showed that it was a purebred wolf, related to populations from eastern Europe. Bullet impacts and shattered fragments found in the chest and flank, and a discrepancy between the timing of the post mortem and rigor mortis intervals indicated that this wolf was shot prior to illegal transport to the Netherlands. The wolf fed on beaver in either the Carpathian mountains or the Eifel which is too far for the animal to have walked from by itself within the 24 hours needed to digest its last meal. These geographical areas are the only regions where haplotypes and 87Sr/86Sr isotopes retrieved from both the dead wolf and the beaver remains in its stomach co-occur. We therefore conclude that the first Dutch wolf found in the Netherlands in 150 years did not enter the Netherlands by itself but sadly proved to be the victim of wildlife crime. Keywords: Canis lupus, Europe, haplotypes, isotopes, microsatellites, wildlife forensics, wolf.
    Trends in indicatoren van KRM-Zeebodemintegriteit : impact van natuurlijke factoren en menselijk handelen: analyse van schaal en methodiek
    Mesel, I.G. de; Craeymeersch, J.A.M. ; Vries, P. de; Wal, J.T. van der; Schellekens, T. ; Brummelhuis, E.B.M. - \ 2012
    IJmuiden [etc.] : IMARES (Rapport / IMARES Wageningen UR C119/12) - 52
    mariene ecologie - aquatische ecologie - menselijke invloed - waterbodems - milieueffect - benthos - natuurbescherming - methodologie - eu regelingen - marine ecology - aquatic ecology - human impact - water bottoms - environmental impact - benthos - nature conservation - methodology - eu regulations
    De Kaderrichtlijn Mariene Strategie (KRM) is door de EU in 2008 vastgesteld. Het doel van de KRM is om uiterlijk in 2020 te komen tot een Goede milieutoestand (GMT) van alle Europese mariene wateren. Onder een goede milieutoestand wordt begrepen dat de zee schoon, gezond en productief is en dat het gebruik van de zee op een duurzame wijze plaatsvindt. De beschrijving van de GMT geschiedt aan de hand van elf ecosysteemgerichte descriptoren. Descriptor 6 ‘zeebodemintegriteit’ is één van de elf descriptoren van de KRM en heeft direct betrekking op allerhande handelingen waarbij de zeebodem wordt beroerd. Rijkswaterstaat heeft meer inzicht nodig in de manier waarop de natuurlijke variaties en antropogene handelingen de temporele en ruimtelijke verspreidingspatronen van de bodemgemeenschappen op zee beïnvloeden om zo de impact van de mens op het ecosysteem te kunnen inschatten.
    Baseline survey of anthropogenic pressures for the Lac Bay ecosystem, Bonaire
    Debrot, A.O. - \ 2012
    Den Helder : IMARES (Report / IMARES Wageningen UR C092/12) - 71
    natuurbescherming - ecosysteembeheer - menselijke invloed - verontreiniging - recreatieactiviteiten - zeereservaten - bonaire - nature conservation - ecosystem management - human impact - pollution - recreational activities - marine protected areas - bonaire
    Lac Bay of Bonaire is a shallow non-estuarine lagoon of about 700 hectares, separated from the open sea by a shallow coral barrier-reef. It possesses the only major concentration of seagrass beds and mangroves of the island. It is a designated Ramsar wetland of international significance, an Birdlife International IBA (Important Bird Area) and also fulfills a critical fish nursery function for the reefs of the island. The bay has consequently been designated as a protected area and is managed by Stinapa-Bonaire. The bay has been losing effective seagrass nursery habitat surface and quality as a consequence of mangrove-driven land acclamation. This in-turn is potentially being exacerbated by human-mediated eutrophication and erosion caused by agricultural and animal husbandry in the wider watershed, as well as other factors. The number of visitors to Bonaire and to Lac has been increasing dramatically over the last decades particularly from cruise ships. Yet little has been done to document and map the various types of human use that occur on and in the vicinity of the bay which might affect the ecological carrying capacity of the bay and the critical roles it plays. In this survey we do preliminary mapping and analysis of the level and distribution of human activity in and around Lac and discuss what possible threats these may entail for the environment of the bay.
    Mind the gap: modelling event-based and millennial-scale landscape dynamics
    Baartman, J.E.M. - \ 2012
    Wageningen University. Promotor(en): Tom Veldkamp; Coen Ritsema, co-promotor(en): Jeroen Schoorl. - S.l. : s.n. - ISBN 9789461732668 - 216
    geomorfologie - erosie - sedimentatie - dynamica - tijdschalen - landschapsanalyse - modelleren - rivieren - regen - menselijke invloed - landschap - ontwikkeling - spanje - pleistoceen - holoceen - geomorphology - erosion - sedimentation - dynamics - time scales - landscape analysis - modeling - rivers - rain - human impact - landscape - development - spain - pleistocene - holocene

    This research looks at landscape dynamics – erosion and deposition – from two different perspectives: long-term landscape evolution over millennial timescales on the one hand and short-term event-based erosion and deposition at the other hand. For the first, landscape evolution models (LEMs) are often used, which describe landscape forming processes by geomorphic transport laws, usually on annual temporal resolutions. LEM LAPSUS is used in this research to evaluate the landscape dynamics in a study area in south-east Spain: the Guadalentín Basin. The model is calibrated on dated river terrace levels, which show an erosion – deposition – erosion sequence that the model could reproduce. Annual precipitation in this dryland area shows large inter-annual variability and erosion is supposed to be mainly the results of low-frequency, high magnitude rainfall events. Therefore, in this research, landscape dynamics are also assessed using the event-based erosion model OpenLISEM. Eventually, the role of extreme events in long-term landscape evolution are explored by comparing the two models and by incorporating annual rainfall variability into LEM LAPSUS. Another issue that is being addressed in this study is the relative influence of humans as compared to erosion as a natural process. A conceptual model, derived on the basis of dated sediment archives, is tentatively correlated to periods of human impact on the land. Using LAPSUS, the potential influence of historical tillage erosion is simulated, showing that the relatively slow process of tillage erosion added to floodplain aggradation over thousands of years.

    Unravelling Late Pleistocene and Holocene landscape dynamics: The Upper Guadalentín Basin, SE Spain 9
    Baartman, J.E.M. ; Veldkamp, A. ; Schoorl, J.M. ; Wallinga, J. ; Cammeraat, L.H. - \ 2011
    Geomorphology 125 (2011)1. - ISSN 0169-555X - p. 172 - 185.
    south-east spain - human impact - ephemeral channels - land abandonment - hillslope runoff - fluvial deposits - climatic changes - river systems - dead-sea - evolution
    Landscapes in SE Spain have developed in response to tectonics, climate fluctuations and, more recently, human activity. Fluvial and colluvial sediments such as river terraces and slope deposits found in the valleys reflect a complex interplay between landscape forming processes. Investigating these sediment archives, we reconstructed landscape evolution for the Upper Guadalentín Basin, SE Spain, placing recent erosion processes in a landscape evolution context. Palaeo-lake sediments dated between ~ 17 and ~ 13.8 ka evidence that a Late Glacial lake existed in the area, probably formed by a sudden blockage of the Guadalentín river. Differences in relative height above the floodplain and age between the river terraces of parts of the Guadalentín river indicate that they have not been in equilibrium in the Late Quaternary. Deposition of river terraces along the upstream part of the river is recorded at ~ 13 and ~ 9.5 ka, whereas no evidence of deposition is found for that period along the lower part of the river. There, episodes of sedimentation occur at ~ 7.5–5 ka, ~ 3.4, ~ 1.6, ~ 0.7 and ~ 0.4 ka. This discrepancy is explained by the palaeo-lake and its influence on erosion and sedimentation processes through base level changes. Combining these processes, we propose a schematic model of Late Pleistocene and Holocene landscape evolution. From the model we can conclude that i) the influence of the palaeo-lake on deposition and erosion processes both upstream and downstream is evident; and for the younger river terraces that ii) episodes of deposition seem to coincide in time, but iii) episodes of erosion in between terrace level aggradation do not coincide and neither do terrace level heights and iv) no evidence of deposition is found for the upstream part of the river. Correlation of erosion and sedimentation episodes with climate change and human impact is discussed. Although some correlations can be made, there is strong evidence that climate was not the main driver of landscape processes. We suggest that internal dynamics and local processes are more important drivers for landscape dynamics in the Upper Guadalentín Basin than external and regional factors
    Check title to add to marked list
    << previous | next >>

    Show 20 50 100 records per page

     
    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.