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271.
Ni-Bin Chang Y. Jeffrey Yang James A. Goodrich Ammarin Daranpob 《Journal of environmental management》2010,91(6):1397-1413
Global climate change will influence environmental conditions including temperature, surface radiation, soil moisture, and sea level, and it will also significantly impact regional-scale hydrologic processes such as evapotranspiration (ET), precipitation, runoff, and snowmelt. The quantity and quality of water available for drinking and other domestic usage is also likely to be affected by changes in these processes. Consequently, it is necessary to assess and reflect upon the challenges ahead for water infrastructure and the general public in metropolitan regions. One approach to the problem is to use index-based assessment, forecasting and planning. The drought indices previously developed were not developed for domestic water supplies, and thus are insufficient for the purpose of such an assessment. This paper aims to propose and develop a “Metropolitan Water Availability Index (MWAI)” to assess the status of both the quantity and quality of available potable water sources diverted from the hydrologic cycle in a metropolitan region. In this approach, the accessible water may be expressed as volume per month or week (i.e., m3/month or m3/week) relative to a prescribed historical record, and such a trend analysis may result in final MWAI values ranging from ?1 to +1 for regional water management decision making. The MWAI computation uses data and information from both historical point measurements and spatial remote-sensing based monitoring. Variables such as precipitation, river discharge, and water quality changes at drinking water plant intakes at specific locations are past “point” measurements in MWAI calculations. On the other hand, remote sensing provides information on both spatial and temporal distributions of key variables. Examples of remote-sensing images and sensor network technologies are in-situ sensor networks, ground-based radar, air-borne aircraft, and even space-borne satellites. A case study in Tampa Bay, Florida is described to demonstrate the short-term assessment of the MWAI concept at a practical level. It is anticipated that such a forecasting methodology may be extended for middle-term and long-term water supply assessment. 相似文献
272.
乌东德水库为季调节水库,采用宽度平均的立面二维水温数学模型对水库水温结构进行预测,结果表明:乌东德水库水温结构呈季节性分层特征,电站运行对下游水温过程有一定程度的春季低温水和冬季高温水影响。如果采用单层取水方案,在2~8月的下泄水温低于坝址现状水温,最大降幅为2.0℃,下泄低温水将对坝下鱼类产卵繁殖产生不利影响。乌东德水电站拟采取分层取水的措施,对低温水较为敏感的鱼类产卵期3~6月采用叠梁门取水。相比于单层取水,叠梁门方案对低温水的改善效果较明显,下泄水温提高了0.8~1.1℃,能一定程度地减缓升温期水温延迟效应。 相似文献
273.
Environmentally Friendly Polyurethane Composites: Preparation, Characterization and Mechanical Properties 总被引:1,自引:0,他引:1
J. L. Zhang D. M. Wu D. Y. Yang F. X. Qiu 《Journal of Polymers and the Environment》2010,18(2):128-134
The waterborne polyurethane (PU) prepolymer was prepared based on isophorone diisocyanate (IPDI), polyester polyol (N220), dimethylol propionic acid (DMPA) and hydroxyethyl methyl acrylate (HEMA). The modified waterborne polyurethane–acrylate (PUA) emulsions were obtained with different proportions of acrylate (butyl acrylate and methyl methacrylate) and initiating agent by in situ dispersion technique. The structures and thermal properties of prepared PU and PUA were analyzed and characterized with FT-IR, UV–Vis spectroscopy and DSC. The PUA hybrid samples had lower glass transition temperature of hard segment and higher decomposition temperatures than PU sample. Performances of the emulsion and film were studied by means of apparent viscidity, particle size and polydispersity, surface tension and mechanical properties. The results indicated that the particle sizes of the PUA dispersions were larger than those of the pure PU and the solvent resistance, mechanical properties of PUA films was improved compare with the unmodified polyurethane film. The film had the biggest hardness and the least water absorption when the BA/MMA mass ratio 5:5 modified PU. The obtained PUA have great potential application such as coatings, leather finishing, adhesives, sealants, plastic coatings and wood finishes. 相似文献
274.
275.
为研究昌黎生态监控区夏季浮游植物群落结构特征及其与环境因子关系,采用2005~2013年夏季(8月)昌黎生态监控区海域浮游植物及环境因子的监测资料,基于Arc GIS 10.0和Canoco软件平台,运用典范对应分析方法,对浮游植物群落结构进行分析.结果表明,近9 a共鉴定出浮游植物3门23科39属105种,其中,硅藻门16科32属90种,占浮游植物总数的85.7%;甲藻门共6科6属14种,占总种类数的13.3%;金藻门1种.各年的优势种存在很大差异,按照优势度Y值的大小包括辐射圆筛藻(Coscinodiscus radiatus)、柔弱角毛藻(Coscinodiscus debilis)、笔尖根管藻(Rhizosolenia styliformis)、柏氏角管藻(Cerataulina bergoni)、威氏圆筛藻(Coscinodiscus wailesii)、海链藻(Thalassiosira sp.)、三角角藻(Ceratium tripos)、洛氏角毛藻(Coscinodiscus wailesii)、中肋骨条藻(Ceratium tripos)等.夏季细胞丰度年际变化较大,呈现逐渐降低的趋势.浮游植物的多样性指数H'值介于0.015~3.889,均匀度指数J值介于0.009~1,年际变化幅度较小;各站位间物种分布不均匀,优势种较少且优势度较大.对浮游植物群落与环境因子进行典范对应分析(CCA),结果表明影响夏季浮游植物群落结构变化的环境因子包括水温、营养盐(磷酸盐、硝酸氮、氨氮)、盐度等,且是各个环境因子相互作用的结果. 相似文献
276.
Zhang Xiaoli Cai Xuewei Wang Zhaowei Yang Xing Li Shan Liang Guiwei Xie Xiaoyun 《Environmental science and pollution research international》2021,28(11):13375-13393
Environmental Science and Pollution Research - A large amount of biochar-derived dissolved organic matter (BDOM) will be released into the environment with biochars application into repairing... 相似文献
277.
Liu Xi Wang Xuelei Zhang Lu Fan Weiying Yang Chao Li Enhua Wang Zhi 《Environmental science and pollution research international》2021,28(2):1712-1724
Environmental Science and Pollution Research - Groundwater pollution seriously threatens water resource safety due to high-intensity land use throughout the world. However, the relationship between... 相似文献
278.
Sammarchi Sergio Li Jia Yang Qiang 《Environmental science and pollution research international》2021,28(30):40088-40102
Environmental Science and Pollution Research - China’s extraordinary economic development has provided the country’s growing population with easier access to animal food products,... 相似文献
279.
Yuan Shaofeng Xia Hao Yang Lixia 《Environmental science and pollution research international》2021,28(30):40060-40074
Environmental Science and Pollution Research - Urbanization has led to the rapid and large-scale changes in land use and land cover and has affected the spatial distribution of land surface... 相似文献
280.
Qin Hangdao Yang Yingchang Shi Wei She Yuanbin 《Environmental science and pollution research international》2021,28(21):26558-26570
Environmental Science and Pollution Research - Magnetic nanostructured MnFe2O4 with different morphologies, synthesized via chemical co-precipitation and hydrothermal method, was assayed as... 相似文献