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651.
How do local communities adapt to climate changes along heavily damaged coasts? A Stakeholder Delphi study in Ky Anh (Central Vietnam) 总被引:1,自引:0,他引:1
An?Thinh?NguyenEmail author Anh?Dung?Vu Giang?T.?H.?Dang Anh?Huy?Hoang Luc?Hens 《Environment, Development and Sustainability》2018,20(2):749-767
The Central Vietnamese coast faces increasing impacts on the local livelihoods of coastal communities as a result of the increasing natural hazards which include tropical storms, heavy rains, and floods. A challenge for the local populations is improving their adaptation capacity to climate change hazards in a sustainable way. This study deals with the impacts of climate change-associated hazards and adaptation capacity in coastal communes of the Ky Anh district, Ha Tinh province along the coast in Central Vietnam. A combination of the Stakeholder Delphi technique and the DPSIR (drivers–pressures–states–impacts–responses) framework was used. Delphi questionnaires allowed assessing the consensus among the respondents of a stakeholder group. Twenty questions and 20 statements were listed reflecting the DPSIR components. Thirty-six panel members, which were randomly selected from four stakeholder groups which included local authorities, farmers, fishermen, and fish traders, were involved in a two-round Delphi process. The results show that, both agricultural and non-agricultural sectors are main drivers (D); migration, calamities, population growth, mineral mining, aquaculture processing, and agriculture are main pressures (P); changes in the frequency of extreme weather events, increasing intensity of storms, floods, and droughts indicate main states (S); changes in agricultural land use and productivity are main impacts (I); construction of and upgrading dykes and irrigation systems should be the principal responses (R) in the vision of the local stakeholders. The Kendall’s W value for the second round is 0.681, indicating a high degree of consensus among the panel members and confidence in the ranks. Overall, the study advocates developing sustainable ecosystems, an upgraded New Rural Planning, and renewable energy strategies as the main local adaptations to climate change hazards in this area. 相似文献
652.
攀枝花市位于金沙江与雅砻江的交汇处是长江上游生态脆弱区,也是天然林保护工程和退耕还林工程等的重点实施区。基于2001~2010年MODIS NDVI数据,以及同时期的气象数据和其他辅助数据,利用最大值合成法(MVC)、趋势分析法以及线性相关分析等方法研究了攀枝花市植被覆盖时空变化及其与气候因素和人类活动的关系。研究结果表明:攀枝花市植被覆盖整体较高,属于高植被覆盖区域,年际尺度上,植被覆盖呈上升的趋势,增长速率为0.02/10 a;从年内来看,9月NDVI达到最大值,NDVI最小值出现在3月;植被覆盖在水平空间上呈“南低北高”的分布特征,并在垂直空间上呈现出显著的差异性,研究区植被覆盖分别在海拔2 000~3 000 m、坡度30°~40°达到最大值;受水热条件的影响,阴坡(0°~45°, 315°~360°)植被覆盖高于阳坡(135°~225°),而平地(-1°)植被覆盖度最低;就整个研究区而言,植被退化的面积与增加的面积分别占0.7%和44.4%,增加的面积远大于退化的面积;年际尺度上植被受气温的影响高于受降水的影响;大规模生态工程建设是研究区植被覆盖增加的主要驱动因素。
关键词: 植被覆盖变化;归一化植被指数;气候变化;人类活动;攀枝花市 相似文献
653.
An Du Genaro A. Gelves Donghun Koo Uttandaraman Sundararaj Richard Cairncross 《Journal of Polymers and the Environment》2013,21(1):8-15
Polylactide–montmorillonite composites were fabricated by melt-blending followed by compression molding, and water permeability of the composites was studied by both experiments and theoretical models. The water permeation in composites decreases with increasing concentration of montmorillonite. Specifically, at a concentration of 10 wt% of montmorillonite, the water permeation is 34 % less than in the neat polymer. Transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) results show that most of the montmorillonite particles are well-dispersed and randomly exfoliated in the polymer matrix. A fit of theoretical models to the permeation data estimates that montmorillonite platelets are mostly exfoliated in the polymer matrix and oriented randomly, which matches with results from WAXS and TEM. 相似文献
654.
Remote sensing of aquatic vegetation distribution in Taihu Lake using an improved classification tree with modified thresholds 总被引:2,自引:0,他引:2
Classification trees (CT) have been used successfully in the past to classify aquatic vegetation from spectral indices (SI) obtained from remotely-sensed images. However, applying CT models developed for certain image dates to other time periods within the same year or among different years can reduce the classification accuracy. In this study, we developed CT models with modified thresholds using extreme SI values (CT(m)) to improve the stability of the models when applying them to different time periods. A total of 903 ground-truth samples were obtained in September of 2009 and 2010 and classified as emergent, floating-leaf, or submerged vegetation or other cover types. Classification trees were developed for 2009 (Model-09) and 2010 (Model-10) using field samples and a combination of two images from winter and summer. Overall accuracies of these models were 92.8% and 94.9%, respectively, which confirmed the ability of CT analysis to map aquatic vegetation in Taihu Lake. However, Model-10 had only 58.9-71.6% classification accuracy and 31.1-58.3% agreement (i.e., pixels classified the same in the two maps) for aquatic vegetation when it was applied to image pairs from both a different time period in 2010 and a similar time period in 2009. We developed a method to estimate the effects of extrinsic (EF) and intrinsic (IF) factors on model uncertainty using Modis images. Results indicated that 71.1% of the instability in classification between time periods was due to EF, which might include changes in atmospheric conditions, sun-view angle and water quality. The remainder was due to IF, such as phenological and growth status differences between time periods. The modified version of Model-10 (i.e. CT(m)) performed better than traditional CT with different image dates. When applied to 2009 images, the CT(m) version of Model-10 had very similar thresholds and performance as Model-09, with overall accuracies of 92.8% and 90.5% for Model-09 and the CT(m) version of Model-10, respectively. CT(m) decreased the variability related to EF and IF and thereby improved the applicability of the models to different time periods. In both practice and theory, our results suggested that CT(m) was more stable than traditional CT models and could be used to map aquatic vegetation in time periods other than the one for which the model was developed. 相似文献
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657.
技术减排措施协同控制效应评价研究 总被引:4,自引:0,他引:4
随着我国污染减排形势的日益严峻,采用协同控制措施实现多种污染物控制目标逐渐成为一种趋势,而合理评价减排措施的协同效应是正确选择协同控制措施和制定协同控制规划方案的基础.本研究首次从环境-经济-技术角度系统地提出了技术减排措施的协同控制效应评价方法,并以火电行业为案例进行分析.采用协同控制效应坐标系、污染物减排量交叉弹性(Elsa/b)分析和单位污染物减排成本等方法评价技术减排措施对SO2 、NO,和CO2的协同控制效应,三种评价方法相互配合,可以帮助我们从多角度检验不同减排措施的协同效果.对火电行业技术减排措施进行协同控制效应坐标系和污染物减排量交叉弹性分析的结果表明,末端治理措施不具有协同性,而前端控制措施和过程控制措施具有较好的协同性.单位污染物减排成本评价的结果表明,末端治理措施优先度排序靠后,而前端控制措施和过程控制措施排序靠前,且针对不同污染物的排序结果有所不同.在进行协同减排方案设计和规划时,应根据决策需要选择适宜的评价方法,参考评价结果选择最为成本有效的措施. 相似文献
658.
659.
Ecotoxicological effects of typical personal care products on seed germination and seedling development of wheat (Triticum aestivum L.) 总被引:1,自引:0,他引:1
Biochemical responses of wheat (Triticum aestivum L.) seedlings stressed by two typical personal care products (PCPs) – triclosan (TCS) and galaxolide (HHCB) were experimentally investigated to assess their ecological risks. The results showed that wheat shoot and root elongation was significantly inhibited by 50–250 mg L−1 TCS and HHCB. Wheat roots were sensitive to TCS, while shoots were sensitive to HHCB. The median effect concentration (EC50) of TCS and HHCB based on the inhibition of their sensitive sites were 147.8 and 143.4 mg L−1, respectively. Moreover, the damage of wheat seedlings treated by low concentration of TCS and HHCB during a long period cannot be neglected. After a 21-d exposure, 0.2–3.0 mg L−1 TCS and HHCB treatment caused the damage to the accumulation of chlorophyll (CHL), the synthesis of soluble protein (SP), and the activity of peroxidase (POD) and superoxide dismutases (SOD) in different degree. However, different changing trends of these physiological indexes treated by different PCPs were observed after 7-d to 14-d exposures, especially the activity of POD and SOD. The activity of POD and SOD in wheat leaves and roots decreased with an increase in the concentration of TCS and the exposure time. However, the enzyme activities in wheat leaves treated by 0.2–3.0 mg L−1 HHCB increased after a 14-d exposure, and with the prolongation of exposure time, the enzyme activities significantly decreased. The variations in these physiological indexes of wheat could be considered as good biomarkers of serious stress by TCS and HHCB in the environment. 相似文献
660.