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951.
Through human history, wealth has been measured in grain, gold, and, now, dollars. Though counterfeiting of coins and notes
goes back a long way, it is only with electronic financial accounting in a global economy tainted by toxic loans and imaginary
funds that there is an urgency to search for a realistic objective way to monitor and regulate what we are doing to our Earth
and ourselves. Various schemes using analysis of utility functions, oil equivalents, entropy, energy, and other units have
been tried and, while helping to understand some basic processes and flows, have always been swamped by the machinations of
financiers and the attention big sums of money attract. Now, the concept of exergy, pioneered in Eastern Europe in the 1950s,
is being researched, developed, and applied, especially in China, driven by the desperation to measure the reality beyond
the twin specters of global financial and environmental crises. A rough inventory of the matter in the biosphere at the coordinate
details of an angstrom and an appreciation of how humans harness and manipulate electromagnetic forces can be enlightening
as to what is and is not sustainable. Without that understanding, any financial estimate and proposed stimulus packages or
IMF reform will be wildly wrong and may even be headed in the wrong direction. 相似文献
952.
Since 1980, liver neoplasms in brown bullhead and polynuclear aromatic hydrocarbons (PAH) in sediment have been researched in a series of studies on the Black River in Lorain, Ohio. In the early 1980s the liver cancer prevalence in fish of age 3 and older was high, ranging from 22% to 39% of the adult population. These high cancer rates corresponded to high levels of PAHs in the sediment resulting from long-term releases by an upstream coking facility (USX). In 1983 this coking plant was closed, and by 1987 the PAH in sediment had declined by about two orders of magnitude. Coincidentally the tumor prevalence in 1987 was only about one-fourth of that in the early 1980s. In 1990, the most contaminated sediments were dredged. Neoplasm surveys in 1992 and 1993 found liver tumor frequencies in mature bullhead were as high as or higher than in the early 1980s. However liver tumor incidence declined in 1994, especially among age 3 fish, where neoplasm incidence was zero. These age 3 fish were the first group sampled that were not present during the 1990 dredging. These data are consistent with a hypothesis that the increase in tumor prevalence in 1992 and 1993 was caused by exposure to buried PAH-contaminated sediments released by the dredging. This research points out the insight provided by long term effects studies. 相似文献
953.
Jamie W. Baxter John D. Eyles Susan J. Elliott 《Journal of Environmental Planning and Management》1999,42(4):501-525
This paper contributes to the noxious facilities siting literature by exploring some implications of adhering to some recommended principles and practices for competent siting. Through a qualitative case study of a landfill siting process in Peel (Ontario, Canada) three principles are critically assessed: trust; equity; and community participation. While laudable notions in principle, in practice they can impact each other in important ways which can (potentially) undermine the siting process. These impacts result mainly from the failure to achieve meaningful goals associated with one principle (e.g. community participation) which can exacerbate problems achieving goals associated with other principles (e.g. trust). The resulting discord can be further aggravated by the snowballing of adverse effects over time. In particular, practices for achieving trust and equity were adversely linked, as were the relationships between spatial equity and procedural equity and interregional and intraregional equity. These adverse synergisms were linked together with ineffective community participation which brought the process to a halt. Siting inertia (a process momentum difficult to redirect) and an inflexible siting context contributed to these conflicts. Implications for siting and further research are discussed. 相似文献
954.
Robert Wood John Handley Sue Kidd 《Journal of Environmental Planning and Management》1999,42(3):341-354
The Mersey Basin Campaign was established in 1985 in the North West of England to address continuing problems of water quality and associated landward dereliction of the River Mersey and its tributaries. The Campaign's premise that water quality should be improved both for its own sake and as a stimulus to regeneration has proved to be well founded and has subsequently been extended to embrace community action to help nurture watercourse improvement and care. The Campaign can now be seen as a model for engaging co-ordinated environmental action through a partnership approach. This paper explores the nature of the Mersey Basin Campaign as an example of the new structures which are being developed in order to help deliver the new environmentalpolicy agenda. It is argued that the Campaign stands as a model for what will become an increasing need to develop focused environmental planning and management at the sub-regional and regional scales. 相似文献
955.
Eduardo Soto-Galera Joel Paulo-Maya Eugenia López-López José Angel Serna-Hernández John Lyons 《Environmental management》1999,24(1):133-140
Chirostoma charari and C. compressum, and they are presumed extinct. Twelve (63%) of the remaining species had declines in distribution. Sixteen (80%) of the 20
localities sampled had lost species. The greatest declines occurred in Lago de Cuitzeo proper and in the lower portion of
the Río Grande de Morelia watershed. Species losses from the lake were attributable to drying and hypereutrophication of the
lake because of substantial reductions in the amount and quality of tributary inputs, whereas losses from the Río Grande de
Morelia watershed were the result of pollution from agricultural, municipal, and industrial sources, especially in the region
around the city of Morelia. Three localities in the upper portion of the Río Grande de Morelia watershed—Cointzio reservoir,
La Mintzita spring, and Insurgente Morelos stream—contained most of the remaining fish species diversity in the basin and
deserve additional protection. Fish faunal changes indicated major declines in the health of aquatic ecosystems in the Morelia–Cuitzeo
basin. 相似文献
956.
Salt Marsh Diking and Restoration: Biogeochemical Implications of Altered Wetland Hydrology 总被引:3,自引:0,他引:3
John W. Portnoy 《Environmental management》1999,24(1):111-120
Experimental short-term desalination and drainage of salt marsh cores in greenhouse microcosms caused Spartina production to increase after one growing season, reflecting decreased salt stress and sulfide toxicity. However, production
thereafter declined, likely due to pyrite oxidation and acidification in drained treatments and sulfide accumulation in waterlogged
treatments.
A survey of longer-term (decadal) effects of diking on peat composition of Cape Cod, Massachusetts, USA, marshes revealed
acidification, Fe(II) mobilization, and decreased organic content in drained sites. Despite the aerobic decomposition of organic
matter, abundant nutrients remained as sorbed NH4 and mineral-bound PO4. In diked, seasonally waterlogged sites, porewater alkalinity, sulfide, ammonium and orthophosphate were much lower, and
organic solids higher, than in adjacent natural marsh.
Seawater was added to cores from diked marshes to study the effects of tidal restoration. Salination of the drained peat increased
porewater pH, alkalinity, ammonium, orthophosphate, Fe, and Al; copious ammonium N, and Fe(II) for sulfide precipitation favored
Spartina growth. Salination of diked–waterlogged peat increased sulfate reduction and caused 6–8 cm of sediment subsidence. The resulting
increase in porewater sulfides and waterlogging decreased vigor of transplanted Spartina alterniflora. Results indicate that seawater restoration should proceed cautiously to avoid nutrient loading of surface waters in drained
sites or sulfide toxicity in diked–waterlogged marshes. 相似文献
957.
958.
Gary L. Ketcheson Walter F. Megahan John G. King 《Journal of the American Water Resources Association》1999,35(1):83-98
ABSTRACT: Erosion and sedimentation data from research watersheds in the Silver Creek Study Area in central Idaho were used to test the prediction of logging road erosion using the R1-R4 sediment yield model, and sediment delivery using the “BOISED” sediment yield prediction model. Three small watersheds were instrumented and monitored such that erosion from newly constructed roads and sediment delivery to the mouths of the watersheds could be measured for four years following road construction. The errors for annual surface erosion predictions for the two standard road tests ranged from +31.2 t/ha/yr (+15 percent) to -30.3 t/ha/yr (-63 percent) with an average of zero t/ha/yr and a standard deviation of the differences of 18.7 t/ha/yr. The annual prediction errors for the three watershed scale tests had a greater range from -40.8 t/ha/yr (-70 percent) to +65.3 t/ha/yr (+38 percent) with a mean of -1.9 t/ha/yr and a standard deviation of the differences of 25.2 t/ha/yr. Sediment yields predicted by BOISED (watershed scale tests) were consistently greater (average of 2.5 times) than measured sediment yields. Hillslope sediment delivery coefficients in BOISED appear to be overly conservative to account for average site conditions and road locations, and thus over-predict sediment delivery. Mass erosion predictions from BOISED appear to predict volume well (465 tonnes actual versus 710 tonnes predicted, or a 35 percent difference) over 15 to 20 years, however mass wasting is more episodic than the model predicts. 相似文献
959.
Peter H. Gleick Elizabeth L. Chalecki 《Journal of the American Water Resources Association》1999,35(6):1429-1441
ABSTRACT: A wide variety of regional assessments of the water-related impacts of climatic change have been done over the past two decades, using different methods, approaches, climate models, and assumptions. As part of the Water Sector research for the National Assessment of the Implications of Climatic Variability and Change for the United States, several major summaries have been prepared, looking at the differences and similarities in results among regional research projects. Two such summaries are presented here, for the Colorado River Basin and the Sacramento River Basin. Both of these watersheds are vitally important to the social, economic, and ecological character of their regions; both are large snowmelt-driven basins; both have extensive and complex water management systems in place; and both have had numerous, independent studies done on them. This review analyzes the models, methods, climate assumptions, and conclusions from these studies, and places them in the context of the new climate scenarios developed for the National Assessment. Some significant and consistent impacts have been identified for these basins, across a wide range of potential climate changes. Among the most important is the shift in the timing of runoff that results from changes in snowfall and snowmelt dynamics. This shift has been seen in every regional result across these two basins despite differences in models and climate change assumptions. The implications of these impacts for water management, planning, and policy are discussed. 相似文献
960.
A toxic axenic strain of Alexandrium fundyense is shown to be capable of removing dissolved free amino acids (DFAAs) until concentrations are similar (low nM) to those found in natural waters. Uptake is greatest during exponential growth, rather than during C and/or N-stress as
is usual in diatoms and other flagellates. A wide range of amino acids can be taken up, their concentration being decreased
within a few hours to the levels observed prior to DFAA addition. The maximum rate of DFAA-N uptake, during early exponential
phase, was 0.8 pmol-N cell−1 h−1, equivalent to ≃20% of the total N requirement. More typically, the contribution of DFAA-N was only ≃5%. However, these uptake
rates are not sustainable. It is apparent that this organism cannot use amino-N to support significant growth, even though
it can take up DFAAs. This, and the fact that the composition of the internal amino acid pool differed from that externally,
is further evidence that the N-physiology of this genus is abnormal (differences to other dinoflagellates include an abnormally
high concentration of glutamine and arginine, an effective absence of amine X, and release of nitrite during the␣concurrent
assimilation of nitrate and ammonium in␣darkness). There is no evidence that the use of DFAAs enhance toxin content, except
when cells are supplied with very high (unnatural) concentrations of arginine.
Received: 8 May 1989 / Accepted: 14 September 1998 相似文献