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561.
Andreas Kannen 《Regional Environmental Change》2014,14(6):2139-2150
Today, increasing use intensity and establishment of new sea uses such as offshore wind farming can be observed in coastal and marine waters. This development also increases the pressure on coastal and marine ecosystems. The exclusive economic zone of the German North Sea can serve as an example for this development, in particular illustrating the need to combine multiple uses and societal demands within a given sea area. In order to deal with the resulting conflicts and cumulative impacts, new planning tools and integrated approaches to planning and management are developing. While the sea becomes a contested but at the same time politically recognised area, also conflicts rooted in different perceptions, values and attitudes of coastal people can be observed. In order to deal with the current challenges in marine areas, marine spatial planning and similar tools for integrated planning need to be developed in the form of communication processes, which link diverse sets of information and span a dialogue between groups of society and across spatial scales including the transnational dimension. 相似文献
562.
Christian?González David?H.?Richter Diogo?Bolster Samuel?Bateman Joseph?Calantoni Cristián?EscauriazaEmail authorView authors OrcID profile 《Environmental Fluid Mechanics》2017,17(1):111-137
At the smallest scales of sediment transport in rivers, the coherent structures of the turbulent boundary layer constitute the fundamental mechanisms of bedload transport, locally increasing the instantaneous hydrodynamic forces acting on sediment particles, and mobilizing them downstream. Near the critical threshold for initiating sediment motion, the interactions of the particles with these unsteady coherent structures and with other sediment grains, produce localized transport events with brief episodes of collective motion occurring due to the near-bed velocity fluctuations. Simulations of these flows pose a significant challenge for numerical models aimed at capturing the physical processes and complex non-linear interactions that generate highly intermittent and self-similar bedload transport fluxes. In this investigation we carry out direct numerical simulations of the flow in a rectangular flat-bed channel, at a Reynolds number equal to Re = 3632, coupled with the discrete element method to simulate the dynamics of spherical particles near the bed. We perform two-way coupled Lagrangian simulations of 48,510 sediment particles, with 4851 fixed particles to account for bed roughness. Our simulations consider a total of eight different values of the non-dimensional Shields parameter to study the evolution of transport statistics. From the trajectory and velocity of each sediment particle, we compute the changes in the probability distribution functions of velocities, bed activity, and jump lengths as the Shields number increases. For the lower shear stresses, the intermittency of the global bedload transport flux is described by computing the singularity or multifr actal spectrum of transport, which also characterizes the widespread range of transport event magnitudes. These findings can help to identify the mechanisms of sediment transport at the particle scale. The statistical analysis can also be used as an ingredient to develop larger, upscaled models for predicting mean transport rates, considering the variability of entrainment and deposition that characterizes the transport near the threshold of motion. 相似文献
563.
Recent plans to alter the Loliondo Game Controlled Area (GCA), a nature conservation area located in Northern Tanzania, would result in substantial reduction of rangelands in the region. We quantify the current and hypothetical levels of the aboveground Human Appropriation of Net Primary Production (aHANPP) in one of the affected villages, and estimate the maximum exploitability rate of rangelands by livestock in the region. We find that the current aHANPP of the village amounts to 34–38% of the potential productivity, which could increase to 59–67% due to the altered GCA. On rangelands, livestock-induced aHANPP would increase from the current level of 30–34% to 54–61%, which is far above a maximum exploitability rate of 40–41%. Our results reveal that the intended changes to the Loliondo GCA will severely affect the current livelihood strategy of the Maasai, which is based on pastoralism. 相似文献
564.
Andreas Westergaard-Nielsen Magnus Lund Stine Højlund Pedersen Niels Martin Schmidt Stephen Klosterman Jakob Abermann Birger Ulf Hansen 《Ambio》2017,46(1):39-52
Climate-induced changes in vegetation phenology at northern latitudes are still poorly understood. Continued monitoring and research are therefore needed to improve the understanding of abiotic drivers. Here we used 14 years of time lapse imagery and climate data from high-Arctic Northeast Greenland to assess the seasonal response of a dwarf shrub heath, grassland, and fen, to inter-annual variation in snow-cover, soil moisture, and air and soil temperatures. A late snow melt and start of growing season is counterbalanced by a fast greenup and a tendency to higher peak greenness values. Snow water equivalents and soil moisture explained up to 77 % of growing season duration and senescence phase, highlighting that water availability is a prominent driver in the heath site, rather than temperatures. We found a significant advance in the start of spring by 10 days and in the end of fall by 11 days, resulting in an unchanged growing season length. Vegetation greenness, derived from the imagery, was correlated to primary productivity, showing that the imagery holds valuable information on vegetation productivity. 相似文献
565.
Brian D. Richter Stephen Andrews Rhaude Dahlinghaus Gabriella Freckmann Sam Ganis James Green Ian Hardman Marissa Palmer Jessica Shalvey 《Journal of the American Water Resources Association》2020,56(1):1-15
In recent decades, public and private environmental entities have been purchasing or leasing water rights across the Western United States (U.S.) in efforts to restore river flows and aquatic ecosystems. The need to pay for flow restoration arises from the fact that state governments did not begin to reserve water for instream purposes until the 1970s, long after water rights had become over‐appropriated and flows were substantially depleted in most rivers. As a consequence, flow depletion has become the leading cause of fish endangerment in the U.S., including the imperilment of two‐thirds of all native fish species in the Colorado River system. This paper takes stock of the progress made in buying water for the environment, specifically by reviewing and analyzing more than 50 transactions executed by public and private entities and the sources of funding underpinning these transactions. We conclude that nongovernmental actors — such as environmental organizations and state water trusts — are integral to regional efforts to restore river flows; these nongovernmental actors executed more than two‐thirds of the transactions we documented. However, we also conclude that the long‐term success of these nongovernmental actors depends upon the availability of sustained public funding that enables them to build capacity and engage in the large number of transactions needed to restore flows across each state. 相似文献
566.
Jurate Kumpiene Paolo Desogus Sven Schulenburg Mariarita Arenella Giancarlo Renella Evelina Brännvall Anders Lagerkvist Lale Andreas Rolf Sjöblom 《Environmental science and pollution research international》2013,20(12):8649-8662
The aim of the study was to determine if an As-contaminated soil, stabilized using zerovalent iron (Fe0) and its combination with gypsum waste, coal fly ash, peat, or sewage sludge, could be used as a construction material at the top layer of the landfill cover. A reproduction of 2 m thick protection/vegetation layer of a landfill cover using a column setup was used to determine the ability of the amendments to reduce As solubility and stimulate soil functionality along the soil profile. Soil amendment with Fe0 was highly efficient in reducing As in soil porewater reaching 99 % reduction, but only at the soil surface. In the deeper soil layers (below 0.5 m), the Fe treatment had a reverse effect, As solubility increased dramatically exceeding that of the untreated soil or any other treatment by one to two orders of magnitude. A slight bioluminescence inhibition of Vibrio fischeri was detected in the Fe0 treatment. Soil amendment with iron and peat showed no toxicity to bacteria and was the most efficient in reducing dissolved As in soil porewater throughout the 2 m soil profile followed by iron and gypsum treatment, most likely resulting from a low soil density and a good air diffusion to the soil. The least suitable combination of soil amendments for As immobilization was a mixture of iron with coal fly ash. An increase in all measured enzyme activities was observed in all treatments, particularly those receiving organic matter. For As to be stable in soil, a combination of amendments that can keep the soil porous and ensure the air diffusion through the entire soil layer of the landfill cover is required. 相似文献
567.
Katrina Mullan Andreas Kontoleon Timothy M. Swanson Shiqiu Zhang 《Environmental management》2010,45(3):513-525
In this study, we estimated the impact on local household livelihoods of the Natural Forest Protection Program (NFPP), which
is the largest logging-ban program in the world, which aims to protect watersheds and conserve natural forests. In doing so,
we used a series of microeconometric policy-evaluation techniques to assess the impacts of the NFPP on two interrelated facets
of household livelihoods: income and off-farm labor supply. We found that the NFPP has had a negative impact on incomes from
timber harvesting but has actually had a positive impact on total household incomes from all sources. Furthermore, we found
that off-farm labor supply outside the village has increased more rapidly in NFPP than in non-NFPP areas. Based on these results,
policy implications for household livelihoods were drawn and are presented herein. 相似文献
568.
Andreas Thiel 《Environmental management》2010,46(1):44-59
Water management has been significantly reshaped throughout recent decades in Europe and worldwide. Vivid examples of this
restructuring include Southern European coastal zones which have been transformed into the European “pleasure periphery” over
the last 40 years, requiring significant changes in water service provision. Taking it as an illustrative case of the Southern
European coastal freshwater crisis and the way different European Member States have dealt with it, the article provides an
account of the Algarve, indicative of typical Portuguese dynamics, and compares it with developments in other European countries.
Expanding demands on water services in this region led to a crisis situation throughout the nineties, which was resolved by
shifting physical infrastructures and competencies to the supra-local level. The re-scaling of water management was instrumental
to expanding national control over the sector at the expense of local authorities and privatization. The national level used
European funds and regulations to re-configure the institutional and infrastructure set-up in order to provide for tourism
and agricultural expansion. Quality tourism was constructed as a decentral, hegemonic state spatial project, with the Algarvian’s
entire water resource base being put at its disposal. The solution found illustrates a modified version of the supply side
and surface water oriented “hydraulic paradigm” in Portugal: geared towards tourism and urban areas and the maintenance of
irrigation agriculture. Delays in infrastructures, ideological preferences, maintaining national control over strategic water
services and territoriality contributed towards the construction of water services as part of this hegemonic state spatial
strategy for tourism expansion. 相似文献
569.
Varun Sheel Shyam Lal Andreas Richter John P. Burrows 《Atmospheric environment (Oxford, England : 1994)》2010,44(27):3314-3321
Nitrogen dioxide (NO2) plays a key role in the chemistry of the atmosphere and is emitted mainly by combustion processes. These emissions have been increasing over India over the past few years due to rapid economic growth and yet there are very few systematic ground based observations of NO2 over this region. We thus take recourse to satellite data and compare tropospheric NO2 column abundances simulated by a chemical transport model, MOZART, with data from the Global Ozone Monitoring Experiment (GOME) for a few locations in India that have seen a rapid economic growth in the last decade. The model generally simulates higher columnar abundances of NO2 compared to GOME observations and does not reproduce the features of the observed seasonal behaviour. The combined uncertainties of the emission inventory and retrieval of the satellite data could be contributing factors to the discrepancies. It may be thus worthwhile to develop emission inventories for India at a higher resolution to include local level activity data. The ten year data (1996–2006) from GOME and SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) show increasing trends for Indian cities where rapid industrial and vehicular traffic growth has been observed during this period. 相似文献
570.
Toms LM Guerra P Eljarrat E Barceló D Harden FA Hobson P Sjodin A Ryan E Mueller JF 《Chemosphere》2012,89(4):398-403
Brominated flame retardants, including hexabromocyclododecane (HBCD) and polybrominated diphenyl ethers (PBDEs) are used to reduce the flammability of a multitude of electrical and electronic products, textiles and foams. The use of selected PBDEs has ceased, however, use of decaBDE and HBCD continues. While elevated concentrations of PBDEs in humans have been observed in Australia, no data is available on other BFRs such as HBCD. This study aimed to provide background HBCD concentrations from a representative sample of the Australian population and to assess temporal trends of HBCD and compare with PBDE concentrations over a 16 year period. Samples of human milk collected in Australia from 1993 to 2009, primarily from primiparae mothers were combined into 12 pools from 1993 (2 pools); 2001; 2002/2003 (4 pools); 2003/2004; 2006; 2007/2008 (2 pools); and 2009. Concentrations of ∑HBCD ranged from not quantified (nq) to 19 ng g(-1)lipid while α-HBCD and γ-HBCD ranged from nq to 10 ng g(-1)lipid and nq to 9.2 ng g(-1)lipid. β-HBCD was detected in only one sample at 3.6 ng g(-1)lipid while ∑(4)PBDE ranged from 2.5 to 15.8 ng g(-1)lipid. No temporal trend was apparent in HBCD concentrations in human milk collected in Australia from 1993 to 2009. In comparison, PBDE concentrations in human milk show a peak around 2002/03 (mean ∑(4)PBDEs=9.6 ng g(-1)lipid) and 2003/04 (12.4 ng g(-1)lipid) followed by a decrease in 2007/08 (2.7 ng g(-1)lipid) and 2009 (2.6 ng g(-1)lipid). In human blood serum samples collected from the Australian population, PBDE concentrations did not vary greatly (p=0.441) from 2002/03 to 2008/09. Continued monitoring including both human milk and serum for HBCD and PBDEs is required to observe trends in human body burden of HBCD and PBDEs body burden following changes to usage. 相似文献