Greening international shipping through private governance: A case study of the Clean Shipping Project     

Lindsey Wuisan  Judith van Leeuwen C.S.A. van Koppen 《Marine Policy》2012,36(1):165-173

This article aims to generate insights into both private governance and partnerships within the shipping industry, but also tries to improve understanding of the complex process of institutionalisation.This is achieved through a case study of the Clean Shipping Project, a public/private partnership that aims to promote sustainability in the shipping industry. A set of enabling and constraining factors are examined that shape the institutionalisation process and determine to what extent the Clean Shipping Project can establish and expand authority as an industry norm.Overall, the Clean Shipping Project cannot yet be considered a full-fledged private governance institution, because of an insufficient level of collaborative advantage mainly due to weak system robustness and unfavourable market characteristics and conditions. However, institutionalisation is an ongoing process and the future outlook for the Clean Shipping Project remains promising. The Clean Shipping Project is certainly a relevant supplement to existing regulations and there is a basic level of commitment and cohesion within the partnership, so it is not unlikely that in the future this initiative may help to uncouple growth in shipping activities from environmental harm.  相似文献   

Schmidt‐hammer exposure‐age dating (SHD) of snow‐avalanche impact ramparts in southern Norway: approaches,results and implications for landform age,dynamics and development          下载免费PDF全文

John A. Matthews  Lindsey J. McEwen  Geraint Owen 《地球表面变化过程与地形》2015,40(13):1705-1718

Schmidt‐hammer exposure‐age dating (SHD) was applied to the problem of dating the diachronous surfaces of five distal river‐bank boulder ramparts deposited by snow avalanches plunging into the Jostedøla and Sprongdøla rivers in the Jostedalsbreen region of southern Norway. Approaches to local high‐precision linear age calibration, which controlled in different ways for boulder roundness, were developed. The mean age (SHD_mean) and the maximum age (SHD_max) of surface boulders were estimated for whole ramparts, crests and distal fringes. Interpretation was further assisted by reference to R‐value distributions. SHD_mean ages (with 95% confidence intervals) ranged from 520 ± 270 years to 5375 ± 965 years, whereas SHD_max ages (expected to be exceeded by <5% of surface boulders) ranged from 675 to 9065 years. SHD ages from the Jostedøla ramparts tended to be older than those associated with the Sprongdøla, rampart crests were younger than the respective distal fringes, and use of relatively rounded boulders yielded more consistent SHD ages than angular boulders. The SHD_mean ages indicate differences in recent levels of snow‐avalanche activity between ramparts and provide insights into rampart dynamics as boulders are deposited on rampart crests and, in smaller numbers, on the distal fringes. SHD_max ages provide minimum age estimates of rampart age (i.e. the time elapsed since the ramparts began to form) and suggest that at least some of the ramparts have been developing since the early Holocene. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Physical Properties of Wave Motion in Inclined Magnetic Fields within Sunspot Penumbrae     

H. Schunker  D. C. Braun  C. Lindsey  P. S. Cally 《Solar physics》2008,251(1-2):341-359

At the surface of the Sun, acoustic waves appear to be affected by the presence of strong magnetic fields in active regions. We explore the possibility that the inclined magnetic field in sunspot penumbrae may convert primarily vertically-propagating acoustic waves into elliptical motion. We use helioseismic holography to measure the modulus and phase of the correlation between incoming acoustic waves and the local surface motion within two sunspots. These correlations are modeled by assuming the surface motion to be elliptical, and we explore the properties of the elliptical motion on the magnetic-field inclination. We also demonstrate that the phase shift of the outward-propagating waves is opposite to the phase shift of the inward-propagating waves in stronger, more vertical fields, but similar to the inward phase shifts in weaker, more-inclined fields.  相似文献   

Hydrologic,geomorphic and climatic processes controlling willow establishment in a montane ecosystem     

David J. Cooper  Joyce Dickens  N. Thompson Hobbs  Lindsey Christensen  Laura Landrum 《水文研究》2006,20(8):1845-1864

Willow communities dominate mid‐elevation riparian areas throughout the Rocky Mountains of North America. However, many willow stands are rapidly declining in aerial cover and individual plants in stature. A poor understanding of the processes that control willow establishment hinders identifying the causes of this decline. We analysed the processes that have facilitated or limited willow establishment over the last half of the 20th century on two large floodplains in Rocky Mountain National Park in Colorado by addressing two questions: (1) How does hydrologic regime control willow establishment on different fluvial landforms? (2) How might climate‐driven variations in hydrologic regime affect future willow establishment? We precisely aged willows on the three most common fluvial landforms, stream point bars, drained beaver ponds, and abandoned channels, and statistically related establishment dates to patterns of annual stream peak flow. The role of peak flow on willow establishment varied significantly by landform. Willow recruitment had occurred nearly every year on point bars. In former beaver complexes, most willows had established following dam breaches, whereas willows had established on abandoned channels for several years following channel avulsion. Establishment on point bars and abandoned channels was driven by peak flows of 2‐ to 5‐year return intervals, whereas in abandoned beaver ponds most establishment was associated with flow events of >5‐year return interval. Models of climate change suggest that temperatures will increase and precipitation seasonality will shift over the coming decades in the Rocky Mountains, leading to earlier spring runoff, lower summer and fall flows, decreased snowpack and decreased soil moisture. Such changes are likely to diminish opportunities for willow establishment. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Selection and quality assessment of Landsat data for the North American forest dynamics forest history maps of the US     

Karen Schleeweis  Samuel N. Goward  Chengquan Huang  John L. Dwyer  Jennifer L. Dungan  Mary A. Lindsey 《International Journal of Digital Earth》2016,9(10):963-980

Using the NASA Earth Exchange platform, the North American Forest Dynamics (NAFD) project mapped forest history wall-to-wall, annually for the contiguous US (1986–2010) using the Vegetation Change Tracker algorithm. As with any effort to identify real changes in remotely sensed time-series, data gaps, shifts in seasonality, misregistration, inconsistent radiometry and cloud contamination can be sources of error. We discuss the NAFD image selection and processing stream (NISPS) that was designed to minimize these sources of error. The NISPS image quality assessments highlighted issues with the Landsat archive and metadata including inadequate georegistration, unreliability of the pre-2009 L5 cloud cover assessments algorithm, missing growing-season imagery and paucity of clear views. Assessment maps of Landsat 5–7 image quantities and qualities are presented that offer novel perspectives on the growing-season archive considered for this study. Over 150,000+ Landsat images were considered for the NAFD project. Optimally, one high quality cloud-free image in each year or a total of 12,152 images would be used. However, to accommodate data gaps and cloud/shadow contamination 23,338 images were needed. In 220 specific path-row image years no acceptable images were found resulting in data gaps in the annual national map products.  相似文献   

Representing environments in flux: case studies from East Africa   总被引：1，自引：0，他引：1  

Lindsey Gillson  Michael Sheridan  Dan Brockington† 《Area》2003,35(4):371-389

The dominant view in the ecology and anthropology of the 1950s saw populations harmoniously interacting in self-regulating systems; climax forests and stable societies were the ruling hypotheses. Now, however, ecology and social sciences are investigating nature and culture in flux. The flux paradigms of nature and culture describe a human–ecological relationship that is non-equilibrial, historically contingent and constantly negotiated at both material and ideological levels by unequal actors. In this paper, we examine the effect of changing ecological and cultural paradigms on interpretations of environmental change in three areas of East Africa: the North Pare Mountains, Tanzania, the Mkomazi Game Reserve, Tanzania and the Tsavo National Park, Kenya. We explore how discursive and materialist approaches can complement one another, by expanding the domains of ecological inquiry and demanding that analysts cross-check their data for unquestioned assumptions regarding stability, variability and spatial and temporal scales. Rather than testing a ruling hypothesis, we suggest that ecologists and social scientists work with multiple hypotheses, with the aim of understanding the interplay between ecological, environmental and social influences.  相似文献   

Flood seasonality and generating conditions in the Tay catchment, Scotland from 1200 to present   总被引：1，自引：0，他引：1  

Lindsey J McEwen 《Area》2006,38(1):47-64

The new maximum recorded river flows in Scotland since 1988 have triggered widespread interest in whether floods are becoming more frequent and in the conditions that generate floods of different magnitudes and frequencies. There are questions about the longer-term variability in flood-generating characteristics, and whether there are past analogues for present hydroclimatic variability. The present paper builds on previous work reconstructing a detailed historic flood chronology for the Tay, the largest catchment in Scotland, and its tributaries over the past 800 years, extending the gauged discharge record (1952 onwards). It categorizes flood-generating factors in the Tay catchment and analyses the hydro-meteorological conditions that have generated extreme and moderate floods over a historical period. This work is placed in a broader literature context of historical 'climaxes of storminess', periods of higher storm frequency, flood patterns observed in Scotland and Europe during the Little Ice Age and longer-term rainfall and temperature patterns. The paper concludes that the variability in flood-generating characteristics is highly dependent on the timescale of observation. Inevitably the relative dominance of winter and early spring flooding can vary from year to year and within specific time-periods, but so can the level of augmentation of the flood series with summer and autumn floods to produce notable 'flood years' and flood clusters. The Tay provides a good 'all-Scotland surrogate' for historical flood patterns, reflecting its gathering areas in eastern and western Scotland. The value of a historical approach to the assessment of flood seasonality and generating characteristics is clearly demonstrated.  相似文献   

Properties of natural supraglacial debris in relation to modelling sub‐debris ice ablation     

Lindsey Nicholson  Douglas I. Benn 《地球表面变化过程与地形》2013,38(5):490-501

As debris‐covered glaciers become a more prominent feature of a shrinking mountain cryosphere, there is increasing need to successfully model the surface energy and mass balance of debris‐covered glaciers, yet measurements of the processes operating in natural supraglacial debris covers are sparse. We report measurements of vertical temperature profiles in debris on the Ngozumpa glacier in Nepal, that show: (i) conductive processes dominate during the ablation season in matrix‐supported diamict; (ii) ventilation may be possible in coarse surface layers; (iii) phase changes associated with seasonal change have a marked effect on the effective thermal diffusivity of the debris. Effective thermal conductivity determined from vertical temperature profiles in the debris is generally ~30% higher in summer than in winter, but values depend on the volume and phase of water in the debris. Surface albedo can vary widely over small spatial scales, as does the debris thickness. Measurements indicate that debris thickness is best represented as a probability density function with the peak debris thickness increasing down‐glacier. The findings from Ngozumpa glacier indicate that the probability distribution of debris thickness changes from positively skewed in the upper glacier towards a more normal distribution nearer the terminus. Although many of these effects remain to be quantified, our observations highlight aspects of spatial and temporal variability in supraglacial debris that may require consideration in annual or multi‐annual distributed modelling of debris‐covered glacier surface energy and mass balance. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Seasonal mixing from intermittent flow drives concentration-discharge behaviour in a stream affected by coal mine drainage     

Meaghan Shaw  Lindsey Yazbek  David Singer  Elizabeth Herndon 《水文研究》2020,34(17):3669-3682

Abandoned mining operations continue to severely degrade many ecosystems worldwide by releasing acidic water and/or heavy metals into surface and groundwater. Contaminant concentrations in affected streams vary with discharge in patterns that reflect both geochemical reactions and variable mixing of contaminated and non-contaminated waters. However, controls on concentration-discharge (C-Q) patterns remain unclear, particularly for constituents that experience changing solubility across redox and pH gradients. Understanding the C-Q behaviour of contaminants aids in predicting both downstream transport and effects on aquatic life under variable flow. Here, we examined the C-Q behaviours of non-reactive (Na, K, Ca, Mg, Cl⁻) and reactive (Fe, Mn, Al, H⁺, SO₄²⁻) solutes in a stream contaminated with acid mine drainage in northeastern Ohio, USA. Concentration-discharge patterns at the watershed outlet primarily reflected mixing of contaminated baseflow with intermittent inputs of high pH water draining from a passive limestone treatment system into the stream. The treatment system acted as an ephemeral tributary that mitigated contamination in the stream by diluting solutes, raising pH, and driving metal precipitation, but only when flow was present during wet seasons. Consequently, AMD-derived reactive solutes (H⁺, Fe, Mn, Al) decreased with increasing stream discharge while relatively conservative solutes (e.g., Ca, Mg, K, Na) decreased only slightly or were chemostatic. This study highlights both the unique C-Q patterns of reactive solutes when compared to those of non-reactive solutes and the potential for intermittent streams to control C-Q behaviour in headwater catchments.  相似文献   

Snow-Push Processes in Pronival (Protalus) Rampart Formation: Geomorphological Evidence from Smørbotn, Romsdalsalpane, Southern Norway     

Richard A. Shakesby  John A. Matthews  Mark S. Berrisford  & Lindsey J. McEwen 《Geografiska Annaler: Series A, Physical Geography》1999,81(1):31-45

It is demonstrated that pronival (protalus) ramparts can be formed by a snow-push mechanism and need not accumulate in the conventional manner as a result of supranival processes. Ridges in pronival positions up to 1.2 m high and of unequivocal snow-push origin are described from two sites in Smørbotn cirque, Romsdalsalpane, southern Norway. The seven lines of evidence are: (1) parallel abrasion tracks on large boulders embedded in the substrate; (2) displaced surface and embedded clasts with proximal furrows; (3) corrugated (flute-like) substrate surfaces; (4) the sickle-shaped plan-form of the ridges; (5) generally asymmetrical ridge cross-profiles (shallow, concave proximal; steep, convex distal); (6) strong preferred orientations and dips of surface-embedded clasts on ridge proximal slopes; and (7) a subnival/pronival ridge comprising loosely packed diamicton forming along the contact zone between the snowbed and substrate. This evidence indicates ridge formation by snow sliding involving bulldozing of the substrate. Factors considered important in favouring snow push producing distinct pronival ramparts at the sites include: a maritime periglacial climate with heavy winter snowfall and rapid snow-firn conversion producing snow densities of up to 900 kg m^–3; a deformable substrate with relatively small inputs of rockfall or avalanche debris; and a steep headwall susceptible to snow avalanching and hence enhanced snow supply. Consideration is given to the prospect that larger pronival ramparts can form incrementally by a snow-push mechanism.  相似文献