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161.
"03.8"渭河下游特大洪涝灾害的"三情"分析 总被引:8,自引:0,他引:8
应用渭河流域各气象站及下游重灾区华县水文站的资料,对2003年渭河下游特大洪灾的雨情、水情及灾情进行了分析.阐述了大气环流背景,从降水的时间分布、大降水的落区和分类,总结了特大洪灾的降水特点;从洪水的水位、流量、过程线及与历史洪灾过程的对比分析,得出"03.8"洪水具有"峰次多、水位高、历时长、总量大"之特征;通过洪水前后卫星遥感监测图像的对比分析,清楚地看出渭河主河道明显加宽了3~8倍,造成直接经济损失高达40多亿元;经过以上分析,还揭示了本次洪灾形成的主要原因,从而提出了有关治理渭河、减少洪灾的发展对策. 相似文献
162.
The Lower Rio Grande Valley (LRGV) region in South Texas emerges as a warehouse and transportation center between Central America and the US with positive growth impacts due to the North American Free Trade Agreement (NAFTA). In 10 years time, a 39.8% population increase has resulted in a 25% boost in solid waste per capita disposal rate in the region. A landfill space shortage drives a need for landfill operators to understand their optimal management strategies in this highly-competitive market. Initially, a strategic plan for optimal solid waste pattern distribution minimizes net costs for cities. This is accomplished through a grey integer programming algorithm that encapsulates all uncertainty present in the solid waste system. Secondly, a series of grey integer submodels construct payoff matrices for a zero-sum two-person game. The ensuing game theoretic analysis is critical for evaluating optimal pricing strategies for tipping fees available to the most significant regional landfills (e.g. Browning-Ferris Industries (BFI) and City of Edinburg) as they compete over disposal contracts. The BFI landfill intrinsically benefits from its competitive pricing policy and central location to solid waste generators. The City of Edinburg landfill, on the other hand, wishes to secure its lucrative solid waste management revenue. It desires a gaming strategy backed by optimality that integrates ambiguity in solid waste generation, design capacity boundaries, and unitary shipping costs. Results show that a two-tiered analysis via grey integer programming-based games may pave the way for 'grey Nash equilibria' pricing tactics that will help the Edinburg landfill maintain its waste contracts. 相似文献
163.
164.
David W. Layton 《Journal of the American Water Resources Association》1978,14(1):133-143
Abstract: There are four known geothermal resource areas in the Imperial Valley that have a combined potential of over 4,000 megawatts of electrical energy for 25 years. Water resources available to support geothermal enerfy development are imprted Colorado River water, agricultural waste waters, Salton Sea water, and groundwater. In addtion, geothermal power plants can produce their own cooling water from steam condensate. Nevertheless, the relatively high water requirements of geothermal facilities along with a series of real and potential constraints may cause water supply dilemmas involving both the acquistion and use of cooling water. Important constraints are institutional policies, water supply costs, technical problems, and impacts upon the Salton Sea. These constranits and related dilemmas are examined in light of relevanty information on the valley's water resources, geothermal resources and energy technologies, cooling water requrements, and water supply options. 相似文献
165.
Silicon carbide (SiC) heating elements (siliconits) are widely used at high-temperature fields. The raw materials, manufacture process and application fields of siliconits are all related to heavy energy consumption and pollutions, and bring high environmental loads. The resources consumption and pollution emissions in siliconit manufacture process were quantificationally estimated by input/output method. Difference between two traditional techniques to produce siliconits in China was also compared and analyzed. The results show that siliconit manufacture processes consume large quantities of resources because the furnace is open to environment and too much thermal-protection materials are used. For the thick-end technique is more complicated and the thick-end siliconits have a bigger size and mass, there are more resources and energy consumptions and pollution emissions for thick-end process than that for equal-diameter process. Some suggestions were introduced to improve the traditional techniques and a new process was designed. It is the most important that the open furnace should be replaced by close vacuum furnace. Sintering and siliconizing process can be combined into one high-temperature process. As results of process simplification and vacuum sintering, resources and energy consumption and wastes emission can be decreased remarkably. 相似文献
166.
Elizabeth Teresita Romero-Guzmán Lázaro Raymundo Reyes-Gutiérrez Anabel Sandoval-Pérez 《Chemistry and Ecology》2013,29(6):574-588
Scanning electron microscopy with energy-dispersive spectroscopy has been used for both morphological and elemental chemistry analyses of atmospheric particles. This technique allows the in situ observation of individual aerosol particles in the sample chamber. Aerotransported particles were analysed from seven monitoring stations located in the Metropolitan Zone of Toluca Valley (MZTV). Several different morphologies were identified: aggregates, porous spheres, rough and smooth compact material. The elemental composition included C, Na, Mg, Al, Si, S, Cl, K, Mn, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn and Ce. These are semiquantitative analyses considering the bulk sample or individual particles. It was possible to correlate or confirm some chemical associations such as C–S, Ca–S–O and Si–Al–O, probably due to the presence of compounds derived from incomplete combustion, building tailing materials and aluminosilicates of cortical origin. Bioaerosols such as pollen, spores, brochosomes and diatoms were identified in the zone; all these types of particles have a natural origin too. Several types of suspended particles were identified in the MZTV, they were from different sources (natural and anthropogenic) to which the population can be potentially exposed, and may cause harm in the short- and long-term, according to their chemical element composition and size. 相似文献
167.
采用固定样带法和样点法对梅江流域的鸟类群落进行了研究,共记录到201种,隶属16目49科127属,其中留鸟81种、冬候鸟67种、夏候鸟40种、旅鸟13种,分别占40.1%、33.3%、19.9%、6.7%;古北界种类95种(占47.3%),东洋界种类64种(占31.8%),广布型种类42种(占20.9%);国家I级保护种类1种,国家II级保护种类21种(占10%);《国际湿地公约》指定种类24种(占12%),《中澳候鸟保护协议》指定种类22种(占11%),《中日候鸟保护协议》指定种类76种(占38%),《濒危野生动植物种国际贸易公约》(CITES)指定种类19种(占9%),有益的、有重要经济价值的、有重要科学研究价值的物种155种(占77%)。该流域的鸟类群落多样性指数3.7617,均匀度指数0.7093。 相似文献
168.
Many of todays agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38° incidence angle (8-m resolution) to map the distribution of winter shorebird (Charadriiformes) habitat on agricultural lands in the Willamette Valley of western Oregon. We acquired imagery on three dates (10 December 1999, 27 January 2000, and 15 March 2000) and simultaneously collected ground reference data to classify radar signatures and evaluate map accuracy of four habitat classes: (1) wet with 50% vegetation (considered optimal shorebird habitat), (2) wet with > 50% vegetation, (3) dry with 50% vegetation, and (4) dry with > 50% vegetation. Overall accuracy varied from 45 to 60% among the three images, but the accuracy of focal class 1 was greater, ranging from 72 to 80%. Class 4 coverage was stable and dominated maps (40% of mapped study area) for all three dates, while coverage of class 3 decreased slightly throughout the study period. Among wet classes, class 1 was most abundant (about 30% coverage) in December and January, decreasing in March to approximately 15%. Conversely, class 2 increased dramatically from January to March, likely due to transition from class 1 as vegetation grew. This approach was successful in detecting optimal habitat for shorebirds on agricultural lands. For modest classification schemes, radar remote sensing is a valuable option for wetland mapping in areas where cloud cover is persistent.
Also, Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon 97331, USA 相似文献
169.
汉江流域经济发展评价与战略思考 总被引:4,自引:0,他引:4
陈国阶 《长江流域资源与环境》1997,6(2):97-103
汉江流域地处我国中纬度的腹心地带,战略地位十分重要。流域已有一定经济实力和发展基础,具备较快发展的条件,但目前发展水平尚不高,产业发展层次低,结构不合理,存在交通不便,资源不丰,开放不够,投资能力小等不利因素。流域的发展主要面向长江产业带,面向沿海和太平洋,实行点轴发展模式。以市场为导向,依靠科学技术,逐步实现产业集约化和持续发展。 相似文献
170.
卿永吉 《长江流域资源与环境》1994,3(2):147-151
阐述长江流域铀矿资源开发利用的情况,包括铀矿资源的特点、开发及水冶加工,铀矿开发与环境的问题。分析铀矿开发的技术经济问题,总结了经验,并提出铀矿资源开发的对策与建议。 相似文献