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281.
The European Recommendation on Integrated Coastal Zone Management has six core principles. These form two groups, one concerned with strategic goals and one that has a local focus. The principles are presented as a menu of free-standing options, with no prioritization either within or between groups. In the case of coastal erosion management these characteristics result in irreconcilable conflicts, and actively hinder sustainable management of eroding coasts. The principles require clarification, and recognition that they are an indivisible integrated set which should not be used to select principles to advance a particular agenda. It is essential that the strategic principles are given priority, because only they can underpin a sustainable approach to the issue of coastal erosion.  相似文献   
282.
This article examines how small and medium enterprises (SMEs) can improve their capital investment decisionmaking process for both environmental and general capital projects. It proposes a framework that helps integrate environmental impacts into capital investment decisions, while recognizing SMEs' specific management practices, unique culture, and constraints. The framework presented here is also applicable to independent strategic business units of larger organizations where the capital investment decision process is decentralized. ©2000 John Wiley & Sons, Inc.  相似文献   
283.
The Nile delta sedimentation constitutes a continuous high-resolution record of Ethiopian African monsoon (EAM) regime intensity. Multi-proxy analyses performed on hemipelagic sediments deposited on the Nile deep-sea fan allow the quantification of the Saharan aeolian dust and the Blue/White Nile River suspended matter frequency fluctuations during the last 21,000 years. The radiogenic strontium and neodymium isotopes, clay mineralogy, elemental composition and preliminary palynological analyses reveal large changes in source components, oscillating between a dominant aeolian Saharan contribution during the Last Glacial Maximum (LGM) and the late Holocene (~4,000–2,000 years), a dominant Blue/Atbara Nile River contribution during the early Holocene (15,000–8,000 years) and a probable White Nile River contribution during the middle Holocene (8,000–4,000 years). The following main features are highlighted: (1) The rapid shift from the LGM arid conditions to the African Humid Period (AHP) started at about 15,000 years. The AHP extends until 8,000 years, and we suggest that the EAM maximum between 15,000 and 8,000 years is responsible for a larger Blue/Atbara Nile sediment load and freshwater input into the eastern Mediterranean Sea. (2) The transition between the AHP and the arid late Holocene is gradual and occurs in two main phases between 8,400–6,500 years and 6,500–3,200 years. We suggest that the main rain belt shifted southward from 8,000 to ~4,000 years and was responsible for progressively reduced sediment load and freshwater input into the eastern Mediterranean Sea. (3) The aridification along the Nile catchments occurred from ~4,000 to 2,000 years. This dry period, which culminates at 3,200 year, seems to coincide with a re-establishment of increased oceanic primary productivity in the western Mediterranean Sea. Such a pattern imposes a large and rapid northward shift of the rain belt over the Ethiopian highlands (5–15°N) since 15,000 years. Precipitation over Ethiopia increased from 15,000 to 8,000 years. It was followed by a gradual southward shift of the rain belt over the equator from 8,000 to 4,000 years and finally a large shift of the rain belt south the equator between 4,000 and 2,000 years inducing North African aridification. We postulate that the decrease in thermohaline water Mediterranean circulation could be part of a response to huge volumes of freshwater delivered principally by the Nile River from 15,000 to 8,000 years in the eastern Mediterranean.  相似文献   
284.
Based on consumption data statistics, food items from four regions in Sweden were sampled in a so-called market basket study. Food items from five food groups, i.e. fish, meat, dairy products, eggs and fat/oils, were analyzed for persistent organic pollutants (POPs) followed by per capita intake calculations. The highest levels of PCDD/F, PCB, PBDE, HBCD and chlorinated pesticides were found in the fish/fish products. The estimated market basket per capita intake of PCDD/F and dl-PCB was 0.7 pg WHO-TEQ kg bw−1 d−1 (TEFs from 1998). The intake of ∑PCB was estimated to 4.9 ng kg bw−1 d−1 and fish was found to be the major contributor with 64%. The intake of ∑PBDE was found to be 0.7 ng kg bw−1 d−1. Fish (38%) and dairy products (31%) were the largest contributors to the total PBDE intake. The intake of HBCD was estimated to 0.14 ng kg bw−1 d−1. HBCD mainly came from fish (65%), but also dairy products (24%) and meat (10%) contributed. Also regarding the chlorinated pesticides, fish was found to be the major contributor, with 51% of the ∑DDT coming from fish. The intake of ∑DDT, ∑HCH and HCB was 4.0, 1.0 and 1.1 ng kg bw−1 d−1, respectively. Most of the ∑HCH and HCB originate from dairy products (43% and 55%, respectively). This study shows that the levels, and intake, of different POPs from food of animal origin in the market basket of 2005 seem to have decreased since the market basket study in 1999.  相似文献   
285.
While terrestrial moss and other plants are frequently used for environmental mapping and monitoring projects, data on the regional geochemistry of humus are scarce. Humus, however, has a much larger life span than any plant material. It can be seen as the “environmental memory” of an area for at least the last 60-100 years. Here concentrations of 39 elements determined by ICP-MS and ICP AES, pH and ash content are presented for 259 samples of forest floor humus collected at an average sample density of 1 site/300 km2 in the Czech Republic. The scale of anomalies linked to known contamination sources (e.g., lignite mining and burning, metallurgical industry, coal fired power plants, metal smelters) is documented and discussed versus natural processes influencing humus quality. Most maps indicate a local impact from individual contamination sources: often more detailed sampling than used here would be needed to differentiate between likely sources.  相似文献   
286.
Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to water-quality problems including nutrient enrichment, chemical contamination, and bacterial contamination. This study presents 5 years of monitoring data assessing water quality of a residential subdivision pond and adjacent tidal creek in coastal South Carolina, USA. The stormwater pond is eutrophic, as described by elevated concentrations of chlorophyll and phosphorus, and experiences periodic cyanobacterial blooms. A maximum monthly average chlorophyll concentration of 318.75 μg/L was measured in the stormwater pond and 227.63 μg/L in the tidal creek. Fecal coliform bacteria (FCB) levels were measured in both the pond and the tidal creek that exceeded health and safety standards for safe recreational use. A maximum monthly average FCB level of 1,247 CFU/100 mL was measured in the stormwater pond and 12,850 CFU/100 mL in the tidal creek. In addition, the presence of antibiotic resistant bacteria and pathogenic bacteria were detected. Low concentrations of herbicides (atrazine and 2,4-D), a fungicide (chlorothalonil), and insecticides (pyrethroids and imidacloprid) were measured. Seasonal trends were identified, with the winter months having the lowest concentrations of chlorophyll and FCB. Statistical differences between the stormwater pond and the tidal creek were also noted within seasons. The tidal creek had higher FCB levels than the stormwater pond in the spring and summer, whereas the stormwater pond had higher chlorophyll levels than the tidal creek in the summer and fall seasons. Chlorophyll and FCB levels in the stormwater pond were significantly correlated with monthly average temperature and total rainfall. Pesticide concentrations were also significantly correlated with temperature and rainfall. Pesticide concentrations in the stormwater pond were significantly correlated with pesticide concentrations in the adjacent tidal creek. Chlorophyll and FCB levels in the tidal creek, however, were not significantly correlated with levels in the pond. While stormwater ponds are beneficial in controlling flooding, they may pose environmental and human health risks due to biological and chemical contamination. Management to reduce residential runoff may improve water quality in coastal stormwater ponds and their adjacent estuarine ecosystems.  相似文献   
287.
When a new drinking water regulation is being developed, the USEPA conducts a health risk reduction and cost analysis to, in part, estimate quantifiable and non-quantifiable cost and benefits of the various regulatory alternatives. Numerous methodologies are available for cumulative risk assessment ranging from primarily qualitative to primarily quantitative. This research developed a summary metric of relative cumulative health impacts resulting from drinking water, the relative health indicator (RHI). An intermediate level of quantification and modeling was chosen, one which retains the concept of an aggregated metric of public health impact and hence allows for comparisons to be made across “cups of water,” but avoids the need for development and use of complex models that are beyond the existing state of the science. Using the USEPA Six-Year Review data and available national occurrence surveys of drinking water contaminants, the metric is used to test risk reduction as it pertains to the implementation of the arsenic and uranium maximum contaminant levels and quantify “meaningful” risk reduction. Uranium represented the threshold risk reduction against which national non-compliance risk reduction was compared for arsenic, nitrate, and radium. Arsenic non-compliance is most significant and efforts focused on bringing those non-compliant utilities into compliance with the 10 μg/L maximum contaminant level would meet the threshold for meaningful risk reduction.  相似文献   
288.
An empirical approach for the decomposition and reconstruction of long-term flowering records of eight eucalypt species is presented. Results from singular spectrum analysis (SSA) allow for characterisation of the dynamic and complex flowering patterns in response to temperature and rainfall throughout the year. SSA identified trend, annual, biennial and other sub-components of flowering. The ability to discriminate flowering and climate relationships is demonstrated based on SSA (cross-)correlation analysis. SSA also identified the cyclical influence of temperature and rainfall on peak flowering. For each species, there is, on average, 6 months of the annual cycle when temperature positively influences flowering and 6 months when the influence of temperature is negative. For all species, rainfall exerts a negative influence when temperature is positive. Investigation of short-term and long-term lags of climate on flowering provided best-case climatic scenarios for each species’ flowering; e.g. more intense peak flowering is likely in Eucalyptus leucoxylon when cool, wet conditions coincide with peak flowering and is further enhanced if the preceding autumn and winter were warm and dry, and the previous spring and summer cool and wet. Three clear species groupings, according to similar SSA (cross-)correlation signatures, were identified: (1) E. leucoxylon and E. tricarpa; (2) E. camaldulensis, E. melliodora and E. polyanthemos and (3) E. goniocalyx, E. microcarpa and E. macrorhyncha. Lastly, change point years for flowering based on SSA sub-components in four of the species seem to align with years of major shift in global ENSO signal (1951/1957/1958) as indicated by the extended multivariate ENSO index.  相似文献   
289.
Local authorities in the United Kingdom are currently changing their approach towards recycling as they attempt to meet legislative targets. An important part of this drive is the provision of an effective curbside recycling service and it is vital to understand the parameters that influence the performance of the system offered. In this article, three primary datasets, collected from over 1400 households each, are examined for parameters correlated to participation rates. Two measured parameters were found that are not commonly identified in previous studies of curbside recycling schemes, and they are shown to merit further investigation as useful tools for planning purposes. One is the number of types of material collected; participation rates are greater for schemes collecting more materials. The second is the number of households situated on the same road; the lower the number, the higher the participation rate. In both cases, evidence of the measured correlation is presented, justifying their usefulness for planning. The multiple underlying factors causing the correlations are not identified here, but suggestions are made for further studies.  相似文献   
290.
Promoting the use of crumb rubber concrete in developing countries   总被引:3,自引:0,他引:3  
The use of accumulated waste materials in third world countries is still in its early phases. It will take courage for contractors and others in the construction industry to recycle selected types of waste materials in the concrete mixes. This paper addresses the recycling of rubber tires accumulated every year in Jordan to be used in concrete mixes. The main objectives of this research were to provide more scientific evidence to support the use of legislation or incentive-based schemes to promote the reuse of accumulated waste tires. This research focused on using crumb tires as a replacement for a percentage of the local fine aggregates used in the concrete mixes in Jordan. Different concrete specimens were prepared and tested in terms of uniaxial compression and splitting tension. The main variable in the mixture was the volumetric percentage of crumb tires used in the mix. The test results showed that even though the compressive strength is reduced when using the crumb tires, it can meet the strength requirements of light weight concrete. In addition, test results and observations indicated that the addition of crumb rubber to the mix has a limited effect toward reducing the workability of the mixtures. The mechanical test results demonstrated that the tested specimens of the crumb rubber concrete remained relatively intact after failure compared to the conventional concrete specimens. It is also concluded that modified concrete would contribute to the disposal of the non-decaying scrap tires, since the amount being accumulated in third world countries is creating a challenge for proper disposal. Thus, obliging authorities to invest in facilitating the use of waste tires in concrete, a fundamental material to the booming construction industry in theses countries, serves two purposes.  相似文献   
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