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601.
Alfredo M. Pereira Rui M. Pereira 《Journal of Environmental Planning and Management》2017,60(10):1825-1852
We assess the role of fossil fuel prices, energy efficiency, and carbon taxation in achieving climate policy goals using a dynamic general-equilibrium model of the Portuguese economy. Given the forecasts for international fossil fuel prices, improving energy efficiency and implementing a new carbon tax have significantly different economic and budgetary effects. Greater energy efficiency reduces emissions and has a positive economic effect, but increases public and foreign debt. A carbon tax reduces emissions at a cost for the economy, but leads to positive effects on public and foreign debt. Thus, it is important to pursue both strategies. We estimate that under the reference-price scenario, a steady energy efficiency gain of 2%–2.5% per year and a carbon tax of at least 35 € per tCO2 are needed to achieve the stated goal of reducing carbon dioxide emissions by 2030 by an amount equivalent to 40% of the emissions in 1990. These views were fully integrated in a proposal presented by the Commission for Environmental Tax Reform to the Portuguese Government in September 2014, and then discussed in Parliament in November 2014, before enacting a new carbon tax on 1 January 2015. 相似文献
602.
Enjie Li Shujuan Li Joanna Endter-Wada 《Journal of Environmental Planning and Management》2017,60(6):1056-1072
Linking water and land is essential in planning for the future of the western United States. We propose the concept of ‘water-smart growth’ and explore its implications through incorporating water considerations into the SLEUTH land-use model. The urban growth trajectory in Cache County, Utah, is modeled from 2007 to 2030 under four different scenarios: current trend; smart growth; water-smart growth with moderate implementation; and water-smart growth with full implementation. Comparisons of simulation results illustrate the extent and ways in which water-smart growth would alter current established land-use growth patterns. The approach represents an initial step to better integrate land and water in urban growth modeling and planning. This study's purposes are to provide improved understanding and representation of linkages between water and land in urbanizing environments, offer insights from a set of modeled options, and demonstrate the significance of integrating land and water in planning practices. 相似文献
603.
Enhancing the Ability of a Soil Moisture‐based Index for Agricultural Drought Monitoring by Incorporating Root Distribution
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Hongkui Zhou Jianjun Wu Guangpo Geng Xiaohan Li Qianfeng Wang Tianjie Lei Xinyu Mo Leizhen Liu 《Journal of the American Water Resources Association》2017,53(6):1409-1423
Agricultural drought differs from meteorological, hydrological, and socioeconomic drought, being closely related to soil water availability in the root zone, specifically for crop and crop growth stage. In previous studies, several soil moisture indices (e.g., the soil moisture index, soil water deficit index) based on soil water availability have been developed for agricultural drought monitoring. However, when developing these indices, it was generally assumed that soil water availability to crops was equal throughout the root zone, and the effects of root distribution and crop growth stage on soil water uptake were ignored. This article aims to incorporate root distribution into a soil moisture‐based index and to evaluate the performance of the improved soil moisture index for agricultural drought monitoring. The Huang‐Huai‐Hai Plain of China was used as the study area. Overall, soil moisture indices were significantly correlated with the crop moisture index (CMI), and the improved root‐weighted soil moisture index (RSMI) was more closely related to the CMI than averaged soil moisture indices. The RSMI correctly identified most of the observed drought events and performed well in the detection of drought levels. Furthermore, the RSMI had a better performance than averaged soil moisture indices when compared to crop yield. In conclusion, soil moisture indices could improve agricultural drought monitoring by incorporating root distribution. 相似文献
604.
Mohamed Kaddari Mahmoud El Mouden Abdelowahed Hajjaji 《International Journal of Green Energy》2017,14(10):839-844
This paper presents potential energy savings by installing high-efficiency motors instead of existing ones and their impact on greenhouse gases emissions reductions. This research study of the energy efficiency of electric motors has been performed in a typical thermal power plant. In the literature, the focus has been mainly on separate and away electric motors from operating facilities. The important advantage of this paper over other studies is that it uses the actual motors’ efficiency in the evaluation. The gains both in terms of electrical energy savings and in terms of financial economy by using high-efficiency motors have been discussed. As a result, the energy saving can be expected as 12.6% at the operating rate. This excellent result also reduces greenhouse gas emission by 1,423 tons every year. The analysis of the data provided an overview on energy losses often generated by the degradation and rewinding of electrical motors. This study represents very encouraging results that will help energy managers of industrial plants to become more involved in energy efficiency strategies. 相似文献
605.
对两株分离自内蒙古乌梁素海的氢噬胞菌X32和X12的培养条件和萘降解特性进行研究。实验结果表明:菌株X32和X12的最适生长pH为7.0,最适生长温度为30~35℃,最适盐度w(NaCl)为1%;当初始萘质量浓度为3 500 mg/L时,对数生长期的菌株X32对萘的降解活性可达53.9 nmol/(mg·min),而菌株X12可达34.8 nmol/(mg·min);菌株X32在培养48 h后进入稳定期,60 h时萘降解率达91.43%;菌株X12在培养60 h后进入稳定期,90 h时萘降解率达93.93%。氢噬胞菌X32和X12是两株具有较高应用价值的多环芳烃降解细菌。 相似文献
606.
为研究酸沉降对水生生态系统的影响,1991年至1992年间,对地处我国重酸雨区域的重庆市郊6个水体中的藻类进行了比较研究,结果表明,绿藻门的种类最多,占种类总数的50%以上,其次是蓝藻或硅藻。藻类的细胞密度、生物量和叶绿素a,在酸化水体中(pH值<5.0)分别为23.3~49.9万个/L,0.59~1.05mg/L和0.65~3.01mg/m3;在轻度酸化水体(6.0>pH值>5.0)分别为433.9~680.0万个/L,6.6~21.75mg/L和14.66~25.19mg/m3。三项指标均随水体酸度的增加而减少。酸化水体中的藻类生长潜力(AGP)很弱,低pH值和可给态磷的不足是造成AGP低的主要限制因素。 相似文献
607.
608.
609.
长白山北坡林线处岳桦年轮年表及其与气候的关系 总被引:1,自引:0,他引:1
运用相关函数及响应分析等树木年轮气候学方法,研究了长白山北坡林线处岳桦(Betula ermanii)径向生长及其与气候的关系.结果表明,林线处岳桦年轮宽度年表具有较强的气候敏感性.其径向生长与上年7月和当年3月的温度显著负相关(P<0.05),与上年9月和当年7月的温度显著正相关;同时与上年6月降水量显著正相关.与季节性气候因子的响应分析表明,岳桦径向生长与当年春季(1~3月)和当年生长季前(4、5月)的平均温度呈显著负相关,与当年生长季前的平均最高温度显著正相关,与降水量的相关关系不显著.利用多元逐步回归方法模拟了岳桦年轮宽度指数与气候因子间的关系,并据此预测在温度和降水增加的背景下,林线处岳桦径向生长将降低14.8%. 相似文献
610.
Jae S. Choi 《Environmental monitoring and assessment》1998,49(2-3):281-290
In this paper, we examine the consequences of rapid climate change on lake ecosystems in terms of two main effects: variability effects and magnitude effects. How these factors influence life history selection is considered by focusing upon body size as a quantifiable and strong correlate of life history variation (Pianka 1970, McNab 1980, Charnov 1991). We then consider the relationship between the concept of biological diversity and the diversity of life history strategies in the context of rapid climate change. 相似文献