Field‐scale phosphorus losses from a drained clay soil in Sweden     

Barbro Uln  Kristian Persson 《水文研究》1999,13(17):2801-2812

The objective of this study was to determine and discuss field‐scale phosphorus losses via subsurface tile drains. A total phosphorous (Tot‐P) export, which averaged 0·29 kg ha⁻¹ year⁻¹, was measured over a six‐year period from the 4·43 ha drainage system of a Eutric Cambisol in Central Sweden. The main part (63%) was in particulate form (PP) while the remainder was either in phosphate form (PO₄‐P) or in other dissolved or colloidal forms. A very small area, less than 1% of the soil surface, was demonstrated to be hydraulically active by using a staining technique in soil monoliths taken from the field. The stained macropores were few, but were continuous downward, and were relatively evenly distributed among the eight 7 dm² areas that were investigated. The transport from the field mainly occurred in episodes during which the relationship between phosphorus concentration and discharge was characterized by hysteresis loops. On average, half of the yearly P transport occurred in 140 hours. Compared with flow‐proportional and frequent sampling, manual and fortnightly sampling underestimated the transport of Tot‐P and suspended solids (SS) by 59 and 42%, respectively, during the six years studied. Amounts of different phosphorus forms exported through the tile drains were very similar to those reported from other clay soils in Northern Europe and North America. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

Scale‐Dependent Variability of As and Heavy Metals in a River Elbe Floodplain     

Dana Zimmer  Kristian Kiersch  Christel Baum  Ralph Meissner  Robert Müller  Gerald Jandl  Peter Leinweber 《洁净——土壤、空气、水》2011,39(4):328-337

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A comparative study of peat proxies from two eastern central Swedish bogs and their relation to meteorological data     

Anders Borgmark  Kristian Schoning 《第四纪科学杂志》2006,21(2):109-114

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Surface wave effects on water temperature in the Baltic Sea: simulations with the coupled NEMO-WAM model   总被引：1，自引：1，他引：0  

Victor Alari  Joanna Staneva  Øyvind Breivik  Jean-Raymond Bidlot  Kristian Mogensen  Peter Janssen 《Ocean Dynamics》2016,66(8):917-930

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On the Fringe of Neoliberalism: residential development in outer suburban Sydney     

Dr Nicole Cook  Kristian Ruming 《The Australian geographer》2008,39(2):211-228

Although there is widespread consensus in human geography that neoliberalism is achieved through the intersection of multiple scales and states, there has been growing emphasis in recent years on the hybrid qualities of neoliberalist-styles of governance. Because hybrid approaches draw attention to the wide range of actors and contradictory agendas underpinning the always uneven expression of neoliberalist projects, they are particularly suited to the identification of residual state capacities in contexts where neoliberalist forms dominate economic and political life. Drawing on two cases of large-scale residential development in New South Wales, namely Warnervale Town Centre on the New South Wales Central Coast and the Australian Defence Industry site at St Marys in Sydney's west, the present paper adopts an hybrid approach in order to identify current state capacities. Through a comparison of both sites, it identifies the potential for socially and ecologically balanced development in the outer suburban context.  相似文献   

A scaling law of internal run-up duration     

John Grue  J. Kristian Sveen 《Ocean Dynamics》2010,60(4):993-1006

Wave tank experiments with long internal waves of elevation, of different initial length l, moving in a two-fluid system, interacting with a weak slope of 0.045 rad, show an onshore flow of the dense water, at the undisturbed pycnocline-slope intersection, of duration $11.3\sqrt{l/g'}Wave tank experiments with long internal waves of elevation, of different initial length l, moving in a two-fluid system, interacting with a weak slope of 0.045 rad, show an onshore flow of the dense water, at the undisturbed pycnocline-slope intersection, of duration 11.3?{l/g￠}11.3\sqrt{l/g'} (g′ reduced gravity). This period corresponds to that of a strong bottom current event measured in the stratified ocean at the Ormen Lange gas field, at 850 m depth, lasting for 24 hrs, corresponding to 11.2?{l/g￠}11.2\sqrt{l/g'}, using the width l = 300 km of the Norwegian Atlantic Current (NAC) at the site as length scale, suggesting a lateral sloshing motion of the NAC causing the event. The onshore velocity of the dense fluid has a maximal velocity of 0.4?{g￠h₂}0.4\sqrt{g'h_2} in laboratory and 0.5 ms^-1=0.3?{g￠h₂}^{-1}=0.3\sqrt{g'h_2} in the field (h ₂ mixed upper layer thickness). Run-up of the dense fluid, beyond the undisturbed pycnocline-slope intersection, has initially a front velocity of 0.35?{g￠h₂}0.35\sqrt{g'h_2}, corresponding to the velocity of the head of a density current on a flat bottom. Due to disintegration, an initially depressed pycnocline results in comparatively smaller run-up and velocity. While moving past the turning point, a dispersive wave train is formed in the back part of the depression wave, developing by breaking into a sequence of up to eight boluses moving by the undisturbed pycnocline-slope intersection.  相似文献   

Note on the parallel propagation effects of unstable Farley-Buneman waves at high latitudes     

Kristian Schlegel  J.P. St-Maurice 《Planetary and Space Science》1982,30(4):315-318

We have studied the effect that substantially enhanced electron temperatures produce on the higher-frequency shorter-wavelength modes of the Farley-Buneman instability at high latitudes. In all cases the value of the parallel wave vector is reduced and the results are closer to those obtained from fluid theory than previous calculations had revealed. The large electron temperatures are themselves the product of heating by unstable plasma waves so that the corrections described in the present work become increasingly important as the linear growth rate increases.  相似文献   

盐卤对接井溶腔计算方法探讨     

秦沛  齐如明  李斌 《城市地质》2008,3(1):11-13

盐卤井对接施工中,能否成功对接（中靶）,一方面取决于定向井的定向精度,另一方面决定于直井溶腔的建立（通称“建槽”）是否达到设计要求。建槽未能严格按要求进行会导致溶腔与计算不符,造成对接失败或重复工作。而溶腔的设计计算,与目的（盐）层厚度、倾角及采卤方式有关。  相似文献   

Distribution and effects on hepatic xenobiotic metabolizing enzymes of 2,3,3′,4,4′- pentachlorobiphenyl (PCB-105) in cod (Gadus morhua) and rainbow trout (Oncorhynchus mykiss)     

Aksel Bernhoft  Halvor Hektoen  Janneche Utne Skaare  Kristian Ingerbrigtsen 《Marine environmental research》1995,39(1-4)

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Numerical prediction of green water incidents     

Kristian Bendix Nielsen  Stefan Mayer 《Ocean Engineering》2004,31(3-4):363-399

Green water loads on moored or sailing ships occur when an incoming wave significantly exceeds the freeboard and water runs onto the deck. In this paper, a Navier–Stokes solver with a free surface capturing scheme (i.e. the VOF model; [Hirt and Nichols, 1981]) is used to numerically model green water loads on a moored FPSO exposed to head sea waves. Two cases are investigated: first, green water on a fixed vessel has been analysed, where resulting waterheight on deck, and impact pressure on a deck mounted structure have been computed. These results have been compared to experimental data obtained by [Greco, 2001] and show very favourable agreement. Second, a full green water incident, including vessel motions has been modelled. In these computations, the vertical motion has been modelled by the use of transfer functions for heave and pitch, but the rotational contribution from the pitch motion has been neglected. The computed water height on deck has been compared to the experimental data obtained by [Buchner, 1995a] and it also shows very good agreement. The modelling in the second case was performed in both 2-D and 3-D with very similar results, which indicates that 3-D effects are not dominant.  相似文献