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51.
Golam Saleh Ahmed Salem So Kazama Shamsuddin Shahid Nepal C. Dey 《Mitigation and Adaptation Strategies for Global Change》2018,23(6):953-979
The effects of a 1.5 °C global change on irrigation costs and carbon emissions in a groundwater-dependent irrigation system were assessed in the northwestern region of Bangladesh and examined at the global scale to determine possible global impacts and propose necessary adaptation measures. Downscaled climate projections were obtained from an ensemble of eight general circulation models (GCMs) for three representative concentration pathways (RCPs), RCP2.6, RCP4.5, and RCP8.5 and were used to generate the 1.5 °C warming scenarios. A water balance model was used to estimate irrigation demand, a support vector machine (SVM) model was used to simulate groundwater levels, an energy-use model was used to estimate carbon emissions from the irrigation pump, and a multiple linear regression (MLR) model was used to simulate the irrigation costs. The results showed that groundwater levels would likely drop by only 0.03 to 0.4 m under a 1.5 °C temperature increase, which would result in an increase in irrigation costs and carbon emissions ranging from 11.14 to 148.4 Bangladesh taka (BDT) and 0.3 to 4% CO2 emissions/ha, respectively, in northwestern Bangladesh. The results indicate that the impacts of climate change on irrigation costs for groundwater-dependent irrigation would be negligible if warming is limited to 1.5 °C; however, increased emissions, up to 4%, from irrigation pumps can have a significant impact on the total emissions from agriculture. This study revealed that similar impacts from irrigation pumps worldwide would result in an increase in carbon emissions by 4.65 to 65.06 thousand tons, based only on emissions from groundwater-dependent rice fields. Restricting groundwater-based irrigation in regions where the groundwater is already vulnerable, improving irrigation efficiency by educating farmers and enhancing pump efficiency by following optimum pumping guidelines can mitigate the impacts of climate change on groundwater resources, increase farmers’ profits, and reduce carbon emissions in regions with groundwater-dependent irrigation. 相似文献
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Soğukpınar Fatih Erkal Gökhan Özer Hüseyin 《Environmental science and pollution research international》2023,30(13):35891-35912
Environmental Science and Pollution Research - Energy is an essential requirement for sustainable development, society, and the world. Turkey has been trying to increase the use of renewable... 相似文献
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Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured
and monitored around the city using a portable light-sensing device called the Sky Quality Meter over a 15-month period beginning
in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all
18 Administrative Districts of Hong Kong. The survey shows that the environmental light pollution problem in Hong Kong is
severe—the urban night skies (sky brightness at 15.0 mag arcsec − 2) are on average ~ 100 times brighter than at the darkest rural sites (20.1 mag arcsec − 2), indicating that the high lighting densities in the densely populated residential and commercial areas lead to light pollution.
In the worst polluted urban location studied, the night-sky at 13.2 mag arcsec − 2 can be over 500 times brighter than the darkest sites in Hong Kong. The observed night-sky brightness is found to be affected
by human factors such as land utilization and population density of the observation sites, together with meteorological and/or
environmental factors. Moreover, earlier night skies (at 9:30 p.m. local time) are generally brighter than later time (at
11:30 p.m.), which can be attributed to some public and commercial lightings being turned off later at night. On the other
hand, no concrete relationship between the observed sky brightness and air pollutant concentrations could be established with
the limited survey sampling. Results from this survey will serve as an important database for the public to assess whether
new rules and regulations are necessary to control the use of outdoor lightings in Hong Kong. 相似文献
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Objective: The conflicts among motorists entering a signalized intersection with the red light indication have become a national safety issue. Because of its sensitivity, efforts have been made to investigate the possible causes and effectiveness of countermeasures using comparison sites and/or before-and-after studies. Nevertheless, these approaches are ineffective when comparison sites cannot be found, or crash data sets are not readily available or not reliable for statistical analysis. Considering the random nature of red light running (RLR) crashes, an inventive approach regardless of data availability is necessary to evaluate the effectiveness of each countermeasure face to face.Method: The aims of this research are to (1) review erstwhile literature related to red light running and traffic safety models; (2) propose a practical methodology for evaluation of RLR countermeasures with a microscopic traffic simulation model and surrogate safety assessment model (SSAM); (3) apply the proposed methodology to actual signalized intersection in Virginia, with the most prevalent scenarios—increasing the yellow signal interval duration, installing an advance warning sign, and an RLR camera; and (4) analyze the relative effectiveness by RLR frequency and the number of conflicts (rear-end and crossing).Results: All scenarios show a reduction in RLR frequency (?7.8, ?45.5, and ?52.4%, respectively), but only increasing the yellow signal interval duration results in a reduced total number of conflicts (?11.3%; a surrogate safety measure of possible RLR-related crashes). An RLR camera makes the greatest reduction (?60.9%) in crossing conflicts (a surrogate safety measure of possible angle crashes), whereas increasing the yellow signal interval duration results in only a 12.8% reduction of rear-end conflicts (a surrogate safety measure of possible rear-end crash).Conclusions: Although increasing the yellow signal interval duration is advantageous because this reduces the total conflicts (a possibility of total RLR-related crashes), each countermeasure shows different effects by RLR-related conflict types that can be referred to when making a decision. Given that each intersection has different RLR crash issues, evaluated countermeasures are directly applicable to enhance the cost and time effectiveness, according to the situation of the target intersection. In addition, the proposed methodology is replicable at any site that has a dearth of crash data and/or comparison sites in order to test any other countermeasures (both engineering and enforcement countermeasures) for RLR crashes. 相似文献
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Wimmerová S Lancz K Tihányi J Sovčíková E Kočan A Drobná B Palkovičová L Jurečková D Fabišiková A Conka K Trnovec T 《Chemosphere》2011,82(5):687-691
The aim was to determine half-life of six most abundant PCB congeners in the body of early adolescents. In 304 environmentally exposed children, PCB serum concentration was determined at the age of 8 and 12 years. Half-life was determined for each child assuming exponential decrease or for the whole cohort using multiple regression. Results obtained by both approaches were in agreement. PCB reuptakes corrupting half-life estimates for each child and each congener were evaluated. If one of the serum PCB concentration values fell below the level of detection (LOD) the pair was excluded and if PCB half-life value exceeded the arbitrary value of 30 years. The following median half-lives in years 4.46, 10.59, 9.7, 4.7, 9.1 and 9.8 were obtained for PCB congeners 118, 138+163, 153, 156+171, 170 and 180, respectively. The elimination half-life values were not systematically related to PCB serum concentration at any examination age. Between half-life values, percentage of children with significant reuptakes and PCB congener abundance in serum were found significant associations. 相似文献
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Choi Yeon Seok Choi Sang Kyu Kim Seock Joon Han So Young Jung Du Su Yoon Tae Han Soysa Ramesh 《Journal of Material Cycles and Waste Management》2018,20(1):369-374
Journal of Material Cycles and Waste Management - An environment-friendly treatment of organic waste like swine manure and food waste is considered to be big challenge, because the residue of... 相似文献
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Journal of Material Cycles and Waste Management - This paper has outlined the measures and challenges facing Thailand, which was forced to address a surge in imports of plastic waste and e-waste... 相似文献
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H. Guo A.J. Ding K.L. So G. Ayoko Y.S. Li W.T. Hung 《Atmospheric environment (Oxford, England : 1994)》2009,43(6):1159-1169
Understanding the spatial–temporal variations of source apportionment of PM2.5 is critical to the effective control of particulate pollution. In this study, two one-year studies of PM2.5 composition were conducted at three contrasting sites in Hong Kong from November 2000 to October 2001, and from November 2004 to October 2005, respectively. A receptor model, principal component analysis (PCA) with absolute principal component scores (APCS) technique, was applied to the PM2.5 data for the identification and quantification of pollution sources at the rural, urban and roadside sites. The receptor modeling results identified that the major sources of PM2.5 in Hong Kong were vehicular emissions/road erosion, secondary sulfate, residual oil combustion, soil suspension and sea salt regardless of sampling sites and sampling periods. The secondary sulfate aerosols made the most significant contribution to the PM2.5 composition at the rural (HT) (44 ± 3%, mean ± 1σ standard error) and urban (TW) (28 ± 2%) sites, followed by vehicular emission (20 ± 3% for HT and 23 ± 4% for TW) and residual oil combustion (17 ± 2% for HT and 19 ± 1% for TW). However, at the roadside site (MK), vehicular emissions especially diesel vehicle emissions were the major source of PM2.5 composition (33 ± 1% for diesel vehicle plus 18 ± 2% for other vehicles), followed by secondary sulfate aerosols (24 ± 1%). We found that the contribution of residual oil combustion at both urban and rural sites was much higher than that at the roadside site (2 ± 0.4%), perhaps due to the marine vessel activities of the container terminal near the urban site and close distance of pathway for the marine vessels to the rural site. The large contribution of secondary sulfate aerosols at all the three sites reflected the wide influence of regional pollution. With regard to the temporal trend, the contributions of vehicular emission and secondary sulfate to PM2.5 showed higher autumn and winter values and lower summer levels at all the sites, particularly for the background site, suggesting that the seasonal variation of source apportionment in Hong Kong was mainly affected by the synoptic meteorological conditions and the long-range transport. Analysis of annual patterns indicated that the contribution of vehicular emission at the roadside was significantly reduced from 2000/01 to 2004/05 (p < 0.05, two-tail), especially the diesel vehicular emission (p < 0.001, two-tail). This is likely attributed to the implementation of the vehicular emission control programs with the tightening of diesel fuel contents and vehicular emission standards over these years by the Hong Kong government. In contrast, the contribution of secondary sulfate was remarkably increased from 2001 to 2005 (p < 0.001, two-tail), indicating a significant growth in regional sulfate pollution over the years. 相似文献
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Conflict and collective action in Tonle Sap fisheries: adapting governance to support community livelihoods 下载免费PDF全文
This paper presents the results of action research conducted from 2009 to 2015 on the dynamics of resource conflict concerning fisheries and livelihoods in the Tonle Sap Lake, as well as the institutional context and strategies for institutional adaptation to address such conflicts equitably. Over the past 15 years, Cambodia has made significant advances in building the policy framework, regulations and institutions to support community‐based fisheries management and increase the sector's contribution to the rural economy. However, fundamental challenges of increased resource conflict and loss of livelihoods by the most vulnerable remain. Key sources of conflict include destructive and illegal fishing practices, clearing of flooded forests, competing uses of land and water, and overlapping resource claims. Addressing these challenges requires collective action by all key actors: local fishers, the private sector, civil society, development partners, and government from the local to the national level. We identify and elaborate upon four governance priorities: (1) clarify roles and responsibilities in fisheries management; (2) link civil society and government efforts in law enforcement; (3) strengthen partnerships for livelihoods development; and (4) integrate fisheries management into decentralised development planning. 相似文献