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991.
Aaron C. Kite‐Powell Anna K. Harding 《Journal of the American Water Resources Association》2006,42(4):975-987
ABSTRACT: Approximately 4.5 million people in the United States who rely on well water are exposed to nitrate‐N concentrations exceeding the 10 mg/l standard. In this study in the Southern Willamette Valley in Oregon we reassessed nitrate‐N in rural wells sampled in 2000–2001, compared nitrate‐N concentrations among geological units, and surveyed residents about their perceptions of well water quality. Nitrate‐N concentrations were again sampled in 2002 and found to have increased significantly from the previous period. With rapid population growth in the area, the potential health risk in drinking well water that exceeds 10 mg/l nitrate‐N warrants continued public education. Nitrate‐N concentrations were found to be higher in the Holocene alluvium of the Willamette River and the Pleistocene sand and gravel post‐Missoula Flood deposits. Researchers conducting future studies may choose to stratify and monitor wells by geologic unit and by other parameters that estimate input of nutrients to the environment. Opinions differed between agricultural landowners and nonagricultural landowners with regard to the impact that agricultural fertilizers may have on water quality. Participants were supportive of a range of regulatory actions that might be used by homeowners or landowners to address ground water contamination. Given that the area is now designated a Groundwater Management Area, understanding local stakeholders’perceptions is critical and strategic and has the potential to help public agencies manage potential conflicts of opinion among stakeholders, build consensus, and help guide the approach to restoring ground water quality. 相似文献
992.
Lorenz King 《中国减灾(英文版)》2002,(3)
20 0 0wasarelativelynormalyearintermsofglobaldisasterevents.Thegloballossfromnaturaldisasterswasapproximately 30billionUSD ,whereasthatinanyofthepreviousyearshadexceeded 1 0 0billionUSD .Theinsurancelossin 2 0 0 0wasonly 8.3billionUSD ,with 92 0 0 personskilled .Therewasn… 相似文献
993.
用纳滤膜分离技术处理发电厂循环冷却水 总被引:2,自引:1,他引:2
简要介绍了纳滤膜的定义和原理,并且对用纳滤膜处理厂循环冷却水进行工艺和经济技术分析。 相似文献
994.
P. Herzsprung K. Friese R. Frömmichen J. Göttlicher M. Koschorreck W. V. Tümpling Jr. K. Wendt-Potthoff 《Water, Air, & Soil Pollution: Focus》2002,2(3):123-140
In the past five years, enclosures have beeninstalled in an acidic mining lake in Lusatia to investigate insitu remediation processes. They were treated with straw, withstraw and Carbokalk, or with Carbokalk alone, where Carbokalkis a by-product of the sugar industry (solid precipitate ofnon-sugars after lime clarification of extracted sugar beetjuice). Sediment samples were taken as cores to get informationabout the behaviour of organic and inorganic components insediment pore-water with depth. Vertical distributions of pH,soluble reactive phosphate, nitrate, ammonium, silica,aluminium, iron, manganese, calcium, magnesium, sodium,potassium, sulphate, and DOC were measured. The resultingprofiles, each consisting of 15 data points at differentdepths, were compared by cluster analysis. The similarities ofsediment cores from different treated enclosures relating toprofiles of chemical components were discussed. Increasedconcentrations of potassium and sulphate were found in pore-water after substrate treatment. The data imply dissolution ofpotassium iron sulphate hydroxide minerals (jarosite) after anincrease of pH caused by dissolution of lime and by sulphatereducing processes which were stimulated by organic substrateaddition. 相似文献
995.
Estimation of Cumulative Frequency Distribution for Carbon Monoxide Concentration from Wind-Speed Data, in Buenos Aires (Argentina) 总被引:2,自引:0,他引:2
In this article we apply and test a methodology to estimate cumulative frequency distribution for air pollutant concentration from wind-speed data. We use the inverse relationship after Simpson et al. (Atmospheric Environment, 19, 75–82, 1985) between the opposing percentile values in the statistical distributions for air pollutant concentrations and wind-speed data. This relationship is valid, irrespective of the statistical distributions of both variables, if an inverse relationship between them is also applicable. The available data are five years of 8-h average carbon monoxide concentration and 8-h mean wind-speed, observed in Buenos Aires (Argentina). The performance of the obtained empirical expressions in estimating cumulative frequency distributions for 8-h CO is statistically evaluated. The results show that it is possible to obtain an acceptable cumulative frequency distribution for 8-h CO concentration at the site if the cumulative frequency distribution for wind-speed is known. Q–Q plots show a good agreement between estimated and observed values. From our data, the mean relative error of the estimations was found to be as much as 8.0%. 相似文献
996.
This paper presents an integrated system for the assessmentof technical and non-technical measures that are putforward in order to reduce air pollution levels in urbanareas. In contrast to the majority of the currentlyemployed assessment tools, this system allows for theevaluation of any proposed air pollution control measure interms of its combined impact on air quality and socialwelfare, by correlating the environmental and economicaspects of alternative air pollution abatement solutions.Based on the multi-pollutant, multi-effect concept, thesystem presented aims in providing policy-makers with areliable tool for the objective assessment of the mostcost-effective packages of measures, the latter beingallocated according to the particular features and needs ofthe areas examined. 相似文献
997.
998.
999.
水资源的可持续开发与利用 总被引:1,自引:0,他引:1
水是一切生物生存环境的最重要支撑,只有可持续地开发利用水资源,才能创造一个可持续发展的社会和生存环境。针对日趋严重的淡水资源危机,本文以水资源的可持续存在为基础,从整体的角度出发,而不是就水论水,探讨了可持续开发、利用水资源的五个途径:经济向生态效益型转向、可持续开发水资源、建立水资源核算体系、建立水资源政策分析机制、人人参与水资源管理,从而实现环境完整性、经济效率和平衡三个基本目标。 相似文献
1000.
临夏回族自治州旅游客源市场分析与定位 总被引:2,自引:0,他引:2
本文在临夏州客源市场调查与分析的基础上,确定其客源市场应定位在周边地区,包括兰州、定西、甘南、青海省西宁、同仁等地市;在完善和发展观光休闲旅游的基础上,发展文化修学游、民族节庆体验游、生态休闲度假游、黄河三峡风情游、穆斯林民俗游、古生物考古游,并提出了相应的市场开发策略。 相似文献