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991.
新疆是我国自然灾害群生的典型地区和频发地区,每年自然灾害造成的损失巨大。在未来十年灾害形势十分严峻的背景下,为参与联合国倡义的“国际减灾十年”活动和推动新疆的减轻工作,我们对新疆1949~1990年主要灾害进行了分析研究和统计,并对今后的减灾工作提出了建议。 相似文献
992.
Roger B. Long 《Journal of the American Water Resources Association》1980,16(6):1002-1005
ABSTRACT: At a time in history when water resource development in the United States is being condemned as both economically inefficient and an environmental disaster, perhaps economists need to look back at previous development to see what the fruits of water development (be they sweet or sour) have been. The Boise Project of south-western Idaho is 70 years old and to some people it represents a gross error in resource use, while to others it represents a means of livelihood and well being. A recent research project at the University of Idaho attempted to measure not only the direct economic income benefits of the project (from irrigation), but also the indirect or secondary income benefits (from the food processing industry). Periodic regional input-output tables were constructed to assess the income generated from irrigation and food processing over the period from 1946 to 1970. Input-output analysis allowed researchers to evaluate the direct and indirect impacts of both the irrigation sector and the food processing sector and to compare their growth over time. 相似文献
993.
Effects of different forest management policies on long-term vegetation development are incorporated into a computer simulation of a western Washington watershed. The response of a Rocky Mountain elk(Cervus canadensis nelsoni) population to these vegetation changes is simulated using information on their differential use of vegetation types. Simulations include: 1) a cessation of timber harvesting leading to an immediate decline in elk members resulting from a reduction in summer habitats; 2) a stable elk population, similar to the present one, resulting from a constant timber harvesting rate, and 3) initial increases in herd size, followed within 50 years by a sharp decrease, resulting from cutting all old growth timber within the next decade and then a cessation of timber harvestings. 相似文献
994.
酿造废水属于高浓度有机废水,要将其处理达到排放标准,必须经过多种处理工艺的组合才能办到。通过物化处理、生化处理的实验室研究,我们得出了资源化和净化相结合的优化工艺组合,使酿酒废水的排放达到规定的排放标准,且运行费用和收益基本持平,解决了环保工程与经济效益间的矛盾。 相似文献
995.
依据国内外城市气候的观测资料和分析研究文献,从合理利用城市气候资源和防灾减灾角度,首次论述了城市气象灾害种类(公共、特定和相关三大类9种)以及防治对策。 相似文献
996.
铁路行车安全与司机生理和心理素质关系的研究 总被引:2,自引:5,他引:2
从确保铁路行车安全的角度,结合铁路机车乘务工作的职业特点和要求,分析了影响铁路行车安全的诸多因素中最为重要的人的因素在安全驾驶中的作用,以及作为能够胜任我国铁路机车驾驶工作要求的合格司机应具备的生理、心理因素;论文采用国际先进的分析技术和分析软件(SAS),对抽取的1278 名现役铁路司机的88 个测试因子数据进行了全面综合的统计分析,得出有关司机的心理和生理特征以及与行车安全的内在关系,为提高铁路司机的整体素质及铁路行车安全可靠性提供了科学的依据 相似文献
997.
Roger B. Long 《Journal of the American Water Resources Association》1985,21(4):553-564
ABSTRACT: Economic models sometimes indicate that irrigation water is misallocated in agriculture, especially when it appears that the marginal value product is higher in other uses (such as for hydro-power). Historically, trends tend to contradict this reasoning, however, especially since irrigation has grown from 20 million acres in 1940 to over 50 million acres in 1980. Results of this study tend to indicate that as agriculture becomes more and more intensive (in terms of inputs), irrigation is part of that long term trend. Further, major economic variables, such as output and investments in agriculture, appear to be more highly correlated with irrigated land than with dryland agriculture. Recent data indicate an upper limit of about 320 million acres for dryland farming in the United States, while no such constraint is apparent for irrigated agriculture. 相似文献
998.
对现场监测环境空气中PM10 的两种测定方法—β射线衰减法和微量振荡天平法的测量作了对比实验。实验表明 ,两种测定方法的结果具有一致性、相关性和可比性 ,能用回归直线方程来描述两者之间的关系。β射线衰减法的测定结果平均高于微量振荡天平法 15 8% ,它们之间平均偏差为 7 5 %。微量振荡天平法在现场测定中受干扰物和不确定因素的影响较少 ,其测量准确性优于 β射线衰减法。两种监测仪的运行费用大致相同 ,维护量和故障率均 较低 相似文献
999.
采用流动注射分光光度法测定水中的硫化物,在酸化条件下,通过在线蒸馏释放出H:S气体,在酸性介质中与对氨基二甲基苯胺和三氯化铁反应,形成亚甲基蓝,于660nm处比色测定。方法检出限为0.004mg/L,精密度和准确度均较好,操作简便,能满足大批量水样及时准确分析的需求。 相似文献
1000.
Long ER Dutch M Aasen S Welch K Hameedi MJ 《Environmental monitoring and assessment》2005,111(1-3):173-222
A survey was designed and conducted to determine the severity, spatial patterns, and spatial extent of degraded sediment quality
in Puget Sound (Washington State, USA). A weight of evidence compiled from results of chemical analyses, toxicity tests, and
benthic infaunal analyses was used to classify the quality of sediments. Sediment samples were collected from 300 locations
within a 2363 km2 area extending from the US/Canada border to the inlets of southern Puget Sound and Hood Canal. Degraded conditions, as indicated
with a combination of high chemical concentrations, significant toxicity, and adversely altered benthos, occurred in samples
that represented about 1% of the total area. These conditions invariably occurred in samples collected within urbanized bays
and industrial waterways, especially near the urban centers of Everett, Seattle, Tacoma, and Bremerton. Sediments with high
quality (as indicated by no toxicity, no contamination, and the presence of a relatively abundant and diverse infauna) occurred
in samples that represented a majority (68%) of the total study area. Sediments in which results of the three kinds of analyses
were not in agreement were classified as intermediate in quality and represented about 31% of the total area. Relative to
many other estuaries and marine bays of the USA, Puget Sound sediments ranked among those with minimal evidence of toxicant-induced
degradation. 相似文献