Modelling discharge from a coastal watershed in southeast Sweden using an integrated framework     

Osvaldo Salazar  Abraham Joel  Ingrid Wesström  Harry Linnér  R. Wayne Skaggs 《水文研究》2010,24(26):3837-3851

The field hydrology model DRAINMOD integrated with Arc Hydro in geographical information system (GIS) framework (Arc Hydro–DRAINMOD) was used to simulate the hydrological response of a coastal watershed in southeast Sweden. Arc Hydro–DRAINMOD uses a distributed approach to route water from each field edge to the watershed outlet. In the framework the Arc Hydro data model was used to describe the stream network in the watershed and to connect the individual simulated DRAINMOD‐field outflow time series from each plot using Arc Hydro schema‐links features, which were summed at Arc Hydro schema‐nodes features along the stream network to generate the stream network flow. Hydrology data collected during six periods between 2003 and 2008 were used to test Arc Hydro–DRAINMOD and its performance was evaluated by considering uncertainties in model inputs using generalized likelihood uncertainty estimation (GLUE). The GLUE estimates obtained (uncertainty bands 5% and 95%) agreed satisfactorily with measured monthly discharges. The percentage of time in which the observed discharges were bracketed by the uncertainty bands was 88% in calibration periods and 75% in validation periods. Although monthly time step simulations showed good agreement with observed discharges during the two main discharge events in spring, the contradictory daily time step results indicate that the watershed response simulations on a daily basis need to be improved. The uncertainty analysis showed that in periods of higher discharge, such as spring periods, the uncertainty in prediction was higher. It is important to note that these uncertainty estimations using the GLUE procedure include the uncertainties in measured discharge values, model inputs, boundary conditions and model structures. It was estimated that stream baseflow represented 42% of the total watershed discharge, but further research is needed to confirm this. These results show that the new Arc Hydro–DRAINMOD framework is applicable for predicting discharge from artificially drained watersheds in southeast Sweden. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Northwest Africa 482: A crystalline impact‐melt breccia from the lunar highlands     

Ingrid J. Daubar  David A. Kring  Timothy D. Swindle  A. J. Timothy Jull 《Meteoritics & planetary science》2002,37(12):1797-1813

Abstract— Northwest Africa 482 (NWA 482) is a crystalline impact‐melt breccia from the Moon with highlands affinities. The recrystallized matrix and the clast population are both highly anorthositic. Clasts are all related to the ferroan anorthosite suite, and include isolated plagioclase crystals and lithic anorthosites, troctolites, and spinel troctolites. Potassium‐, rare‐earth‐element‐, and phosphorus‐bearing (KREEP) and mare lithologies are both absent, constraining the source area of this meteorite to a highland terrain with little to no KREEP component, most likely on the far side of the Moon. Glass is present in shock veins cutting through the sample and in several large melt pockets, indicating a second impact event. There are two separate events recorded in the ⁴⁰Ar‐³⁹Ar system: one at ～3750 Ma, which completely reset the K‐Ar system, and one at ?2400 Ma, which caused only partial degassing. These events could represent, respectively, crystallization of the impact‐melt breccia and later formation of the glass, or the formation of the glass and a later thermal event. The terrestrial age of the meteorite is 8.6 ± 1.3 ka. This age corresponds well with the modest amount of weathering in the rock, in the form of secondary phyllosilicates and carbonates. Based on terrestrial age and location, lithology, and chemistry, NWA 482 is unique among known lunar meteorites.  相似文献   

Integrated modelling of Polycyclic Aromatic Hydrocarbons in the marine environment: Coupling of hydrodynamic, fate and transport, bioaccumulation and planktonic food-web models   总被引：1，自引：0，他引：1  

Dimitar Marinov  Ingrid Puillat  Elena Jurado  Jordi Dachs 《Marine pollution bulletin》2009,58(10):1554-1561

Spatio-temporal variability of pollutants in the environment is a complex phenomenon that requires a combined approach for its analysis. Whereas data on measured levels of contaminants in various environmental compartments is essential, it is not always possible to monitor at the necessary frequency and with the adequate spatial sampling distribution to capture this variability. Therefore a modelling approach able to complement experimental data and close the gaps in the monitoring programs is useful for assessing the contaminant dynamics occurring at different time scales. In this work a 1D water column fate model has been developed and tested for Polycyclic Aromatic Hydrocarbons (PAHs). The model has been coupled with a simple ecological model that includes a bioaccumulation module. Afterwards, the model has been used to study the temporal variability of contaminant concentrations as well as the fluxes between compartments. The results evidence the complex coupling between spatio-temporal scales and its influence on environmental concentration levels.  相似文献   

Modelled effect of changes in the CO₂ concentration on the middle and upper atmosphere: Sensitivity to gravity wave parameterization     

Ingrid Cnossen  Matthew J. Harris  Neil F. Arnold  Erdal Yiit 《Journal of Atmospheric and Solar》2009,71(13):1484-1496

We have studied the temperature response to changes in the CO₂ concentration in the middle and upper atmosphere using the Coupled Middle Atmosphere–Thermosphere Model 2 (CMAT2). We have performed simulations with a range of CO₂ concentrations and three different ways of accounting for the effects of gravity waves, to allow for comparison with previous studies and sensitivity analyses. We initially find that the response of the model to the changes in CO₂ concentration which took place between 1965 and 1995 (320–360 ppm) is strongly dependent on the gravity wave parameterization that is used, but this is to a large degree due to steps or kinks in an otherwise nearly linear curve describing the temperature as a function of CO₂ concentration. We have not been able to identify the cause of these steps as part of the present study, which is a limitation and must be studied in future work. Here we treated the steps as model noise and rather focused on correcting for their effects by fitting straight lines to the temperature–CO₂ curves to estimate the overall slope of the curves. From these slopes we were able to obtain more robust trend estimates than can be obtained by comparing only two model simulations, as is normally done in other, similar studies. The corrected temperature responses to a 40 ppm change in CO₂ concentration still show up to 15–17% sensitivity to the gravity wave parameterization in the mesosphere and thermosphere. This remaining sensitivity is likely to be related to the fundamental differences in the way a change in temperature modifies the propagation and dissipation characteristics of gravity waves in each parameterization, which is particularly different for linear and non-linear schemes. The corrected trends we find are largely in agreement with other modelling studies, and therefore do not fully explain observed trends, which are typically larger than those predicted by modelling studies. However, modelling results could be similarly sensitive to other model parameters and settings, for example to gravity wave characteristics or solar activity level, and this should be further investigated as well.  相似文献   

Potential impact of climate change on ecosystems of the Barents Sea Region     

Hedwig Roderfeld  Eleanor Blyth  Rutger Dankers  Geir Huse  Dag Slagstad  Ingrid Ellingsen  Annett Wolf  Manfred A. Lange 《Climatic change》2008,87(1-2):283-303

The EU project BALANCE (Global Change Vulnerabilities in the Barents region: Linking Arctic Natural Resources, Climate Change and Economies) aims to assess vulnerability to climate change in the Barents Sea Region. As a prerequisite the potential impact of climate change on selected ecosystems of the study area has to be quantified, which is the subject of the present paper. A set of ecosystem models was run to generate baseline and future scenarios for 1990, 2020, 2050 and 2080. The models are based on data from the Regional Climate Model (REMO), driven by a GCM which in turn is forced by the IPCC-B2 scenario. The climate change is documented by means of the Köppen climate classification. Since the multitude of models requires the effect of climate change on individual terrestrial and marine systems to be integrated, the paper concentrates on a standardised visualisation of potential impacts by use of a Geographical Information System for the timeslices 2050 and 2080. The resulting maps show that both terrestrial and marine ecosystems of the Barents region will undergo significant changes until both 2050 and 2080.  相似文献   

Capelin migrations and climate change – a modelling analysis     

Geir Huse  Ingrid Ellingsen 《Climatic change》2008,87(1-2):177-197

The capelin is a small pelagic fish that performs long distance migrations. It is a key species in the Barents Sea ecosystem and its distribution is highly climate dependent. Here we use an individual based model to investigate consequences of global warming on capelin distribution and population dynamics. The model relies on input on physics and plankton from a biophysical ocean model, and the entire life cycle of capelin including spawning of eggs, larval drift and adult movement is simulated. Spawning day and adult movement strategies are adapted by a genetic algorithm. Spawning has to take place in designated near-shore spawning areas. The output generated by the model is capelin migration/distribution and population dynamics. We present simulations with present day climate and a future climate scenario. For the present climate the model evolves a spatial distribution resembling typical spatial dynamics of capelin with the coasts of Northern Norway and Murman as the main spawning areas. For the climate change simulation, the capelin is predicted to shift spawning eastwards and also utilize new spawning areas along Novaya Zemlya. There is also a shift in the adult distribution towards the north eastern part of the Barents Sea and earlier spawning associated with the warming.  相似文献   

Environmental and social recovery asymmetries to large-scale disturbances in small island communities     

Aswani  Shankar  van Putten  Ingrid  Miñarro  Sara 《Natural Hazards》2017,86(1):241-262

Natural Hazards - People’s livelihoods in tropical small-island developing states are greatly dependent on marine ecosystem services. Yet services such as fisheries and coastal buffering are...  相似文献   

Climate change impacts on streamflow extremes and summertime stream temperature and their possible consequences for freshwater salmon habitat in Washington State   总被引：4，自引：3，他引：1  

Nathan Mantua  Ingrid Tohver  Alan Hamlet 《Climatic change》2010,102(1-2):187-223

This study evaluates the sensitivity of Washington State’s freshwater habitat of Pacific Salmon (Oncorhynchus spp.) to climate change. Our analysis focuses on summertime stream temperatures, seasonal low flows, and changes in peak and base flows because these physical factors are likely to be key pressure points for many of Washington’s salmon populations. Weekly summertime water temperatures and extreme daily high and low streamflows are evaluated under multimodel composites for A1B and B1 greenhouse gas emissions scenarios. Simulations predict rising water temperatures will thermally stress salmon throughout Washington’s watersheds, becoming increasingly severe later in the twenty-first century. Streamflow simulations predict that basins strongly influenced by transient runoff (a mix of direct runoff from cool-season rainfall and springtime snowmelt) are most sensitive to climate change. By the 2080s, hydrologic simulations predict a complete loss of Washington’s snowmelt dominant basins, and only about ten transient basins remaining in the north Cascades. Historically transient runoff watersheds will shift towards rainfall dominant behavior, undergoing more severe summer low flow periods and more frequent days with intense winter flooding. While cool-season stream temperature changes and impacts on salmon are not assessed in this study, it is possible that climate-induced warming in winter and spring will benefit parts of the freshwater life-cycle of some salmon populations enough to increase their reproductive success (or overall fitness). However, the combined effects of warming summertime stream temperatures and altered streamflows will likely reduce the reproductive success for many Washington salmon populations, with impacts varying for different life history-types and watershed-types. Diminishing streamflows and higher stream temperatures in summer will be stressful for stream-type salmon populations that have freshwater rearing periods in summer. Increased winter flooding in transient runoff watersheds will likely reduce the egg-to-fry survival rates for ocean-type and stream-type salmon.  相似文献   

Levels and profiles of PCBs and OCPs in marine benthic species from the Belgian North Sea and the Western Scheldt Estuary   总被引：4，自引：0，他引：4  

Voorspoels S  Covaci A  Maervoet J  De Meester I  Schepens P 《Marine pollution bulletin》2004,49(5-6):393-404

Various benthic invertebrates (flying crab, common shrimp, and red starfish), small fish (sand goby), benthic flatfish (dab, plaice, and sole) and gadoids (bib and whiting) were collected in the Belgian North Sea and along the Scheldt Estuary, both representing areas impacted by various contaminants to different degrees. The levels of 25 polychlorinated biphenyls (PCBs) and 15 organochlorine pesticides (OCPs), which included penta- and hexachlorobenzene, alpha-, beta-, and gamma-hexachlorocyclohexane isomers, chlordanes, and DDT and metabolites, were determined. Sum of PCBs and OCPs in benthic invertebrates and goby ranged from 1.5 to 280 ng/g wet weight (ww) and from 0.27 to 23 ng/g ww, respectively. The fish livers revealed total PCB and OCP levels ranging from 20 to 3200 ng/g ww and from 6.0 to 410 ng/g ww, respectively. Levels of both contaminant groups were significantly higher in samples from the Scheldt Estuary compared to the Belgian North Sea. For most species a highly inverse correlation was found between the concentration of contaminants and the distance to Antwerp (r between 0.812 and 0.901, p < 0.05), pointing to a higher degree of exposure further upstream. PCB and OCP exposures are highly correlated (r between 0.836 and 1.000, p < 0.05), which suggests that the pollution can be classified as historical. However, because urban and industrial centres may still be emitting these compounds, more recent point and non-point sources cannot be ruled out.  相似文献   

Volcanic stratigraphy of large-volume silicic pyroclastic eruptions during Oligocene Afro-Arabian flood volcanism in Yemen   总被引：1，自引：0，他引：1  

Ingrid Ukstins Peate  Joel A. Baker  Mohamed Al-Kadasi  Abdulkarim Al-Subbary  Kim B. Knight  Peter Riisager  Matthew F. Thirlwall  David W. Peate  Paul R. Renne  Martin A. Menzies 《Bulletin of Volcanology》2005,68(2):135-156

A new stratigraphy for bimodal Oligocene flood volcanism that forms the volcanic plateau of northern Yemen is presented based on detailed field observations, petrography and geochemical correlations. The >1 km thick volcanic pile is divided into three phases of volcanism: a main basaltic stage (31 to 29.7 Ma), a main silicic stage (29.7 to 29.5 Ma), and a stage of upper bimodal volcanism (29.5 to 27.7 Ma). Eight large-volume silicic pyroclastic eruptive units are traceable throughout northern Yemen, and some units can be correlated with silicic eruptive units in the Ethiopian Traps and to tephra layers in the Indian Ocean. The silicic units comprise pyroclastic density current and fall deposits and a caldera-collapse breccia, and they display textures that unequivocally identify them as primary pyroclastic deposits: basal vitrophyres, eutaxitic fabrics, glass shards, vitroclastic ash matrices and accretionary lapilli. Individual pyroclastic eruptions have preserved on-land volumes of up to ∼850 km³. The largest units have associated co-ignimbrite plume ash fall deposits with dispersal areas >1×10⁷ km² and estimated maximum total volumes of up to 5,000 km³, which provide accurate and precisely dated marker horizons that can be used to link litho-, bio- and magnetostratigraphy studies. There is a marked change in eruption style of silicic units with time, from initial large-volume explosive pyroclastic eruptions producing ignimbrites and near-globally distributed tuffs, to smaller volume (<50 km³) mixed effusive-explosive eruptions emplacing silicic lavas intercalated with tuffs and ignimbrites. Although eruption volumes decrease by an order of magnitude from the first stage to the last, eruption intervals within each phase remain broadly similar. These changes may reflect the initiation of continental rifting and the transition from pre-break-up thick, stable crust supporting large-volume magma chambers, to syn-rift actively thinning crust hosting small-volume magma chambers.Electronic Supplementary Material Supplementary material is available for this article at  相似文献