Xiamen Bay in South China has experienced extensive coastal exploitation since the 1950s,resulting in some severe environmental problems.Local authorities now have completed or are implementing many environmental rest...Xiamen Bay in South China has experienced extensive coastal exploitation since the 1950s,resulting in some severe environmental problems.Local authorities now have completed or are implementing many environmental restoration projects.Evaluating the cumulative impact of exploitation and restoration activities on the environment is a complicated multi-disciplinary problem.However,hydrodynamic changes in the bay caused by such coastal projects can be characterized directly and definitively through numerical modeling.This paper assesses the cumulative effect of coastal projects on the hydrodynamic setting using a high-resolution numerical modeling method that makes use of tidal current speeds and the tidal prism as two hydrodynamic indices.Changes in tidal velocity and the characteristics of the tidal prism show that hydrodynamic conditions have declined from 1938 to 2007 in the full-tide area.The tidal current speed and tidal prism have decreased by 40% in the western part of the bay and 20% in the eastern part of the bay.Because of the linear relationship between tidal prism and area,the degraded hydrodynamic conditions are anticipated to be restored to 1972 levels following the completion of current and proposed restoration projects,i.e.33% and 15% decrease in the hydrodynamic conditions of 1938 for the western and eastern parts of the bay,respectively.The results indicate that hydrodynamic conditions can be restored to some extent with the implementation of a sustainable coastal development plan,although a full reversal of conditions is not possible.To fully assess the environmental changes in a region,more indices,e.g.,water quality and ecosystem parameters,should be considered in future evaluations.展开更多
Project-based learning （PBL） as an instructional approach focuses on student-centeredness through contextualizing learning by presenting students with real world issues and practices that aim at achieving enduring l...Project-based learning （PBL） as an instructional approach focuses on student-centeredness through contextualizing learning by presenting students with real world issues and practices that aim at achieving enduring learning effects. As a challenge to traditional lecture-based instruction, PBL may generate positive backwash assessment effects via documenting the process of developing authentic language skills. These skills-oriented outcomes are achieved through proper curricula in appropriate learning situations via various dimensions. However, problems may occur such as management, pressure from administration, evaluation doing their selected projects. teacher/student attitude, class size and proper group process and criteria, and students＇ likely frustrations in展开更多
The construction of wind power project is conducive to saving energy,reducing emissions and regulating energy structure. But it inevitably causes some impacts on the environment in the construction process. Because th...The construction of wind power project is conducive to saving energy,reducing emissions and regulating energy structure. But it inevitably causes some impacts on the environment in the construction process. Because that the height of wind power generator generally exceeds 100 m,and visual range in plain region is farther,it is necessary to scientifically and rationally evaluate and analyze landscape visual environment impact of wind power generator in plain region. One wind power farm project of Zhanjiang is located in typical plain region of Guangdong coast. Referring to traditional analytic method of landscape visual impact and comparing with actual situation for the same kind of project in the region,results show that it is ＂ extremely sensitive＂ area at 0- 2. 5 km from wind power generator, ＂ very sensitive＂ area at 2. 5- 5. 0 km, ＂ sensitive＂ area at 5- 10 km, ＂generally sensitive＂ area at 10- 20 km,and non-sensitive area outside 20 km.展开更多
Objective image quality measure, which is a fundamental and challenging job in image processing, evaluates the image quality consistently with human perception automatically. On the assumption that any image distortio...Objective image quality measure, which is a fundamental and challenging job in image processing, evaluates the image quality consistently with human perception automatically. On the assumption that any image distortion could be modeled as the difference between the directional projection-based maps of reference and distortion images, we propose a new objective quality assessment method based on directional projection for full reference model. Experimental results show that the proposed metrics are well consistent with the subjective quality score.展开更多
Climate change adaptation and relevant policy-making need reliable projections of future climate.Methods based on multi-model ensemble are generally considered as the most efficient way to achieve the goal.However,the...Climate change adaptation and relevant policy-making need reliable projections of future climate.Methods based on multi-model ensemble are generally considered as the most efficient way to achieve the goal.However,their efficiency varies and inter-comparison is a challenging task,as they use a variety of target variables,geographic regions,time periods,or model pools.Here,we construct and use a consistent framework to evaluate the performance of five ensemble-processing methods,i.e.,multimodel ensemble mean(MME),rank-based weighting(RANK),reliability ensemble averaging(REA),climate model weighting by independence and performance(ClimWIP),and Bayesian model averaging(BMA).We investigate the annual mean temperature(Tav)and total precipitation(Prcptot)changes(relative to 1995–2014)over China and its seven subregions at 1.5 and 2℃warming levels(relative to pre-industrial).All ensemble-processing methods perform better than MME,and achieve generally consistent results in terms of median values.But they show different results in terms of inter-model spread,served as a measure of uncertainty,and signal-to-noise ratio(SNR).ClimWIP is the most optimal method with its good performance in simulating current climate and in providing credible future projections.The uncertainty,measured by the range of 10th–90th percentiles,is reduced by about 30%for Tav,and 15%for Prcptot in China,with a certain variation among subregions.Based on ClimWIP,and averaged over whole China under 1.5/2℃global warming levels,Tav increases by about 1.1/1.8℃(relative to 1995–2014),while Prcptot increases by about 5.4%/11.2%,respectively.Reliability of projections is found dependent on investigated regions and indices.The projection for Tav is credible across all regions,as its SNR is generally larger than 2,while the SNR is lower than 1 for Prcptot over most regions under 1.5℃warming.The largest warming is found in northeastern China,with increase of 1.3(0.6–1.7)/2.0(1.4–2.6)℃(ensemble’s median and range of the 10th–90th percentiles)under 1.5/2℃warming,followed by northern and northwestern China.The smallest but the most robust warming is in southwestern China,with values exceeding 0.9(0.6–1.1)/1.5(1.1–1.7)℃.The most robust projection and largest increase is achieved in northwestern China for Prcptot,with increase of 9.1%(–1.6–24.7%)/17.9%(0.5–36.4%)under 1.5/2℃warming.Followed by northern China,where the increase is 6.0%(–2.6–17.8%)/11.8%(2.4–25.1%),respectively.The precipitation projection is of large uncertainty in southwestern China,even with uncertain sign of variation.For the additional half-degree warming,Tav increases more than 0.5℃throughout China.Almost all regions witness an increase of Prcptot,with the largest increase in northwestern China.展开更多
In this paper, the writers systematically introduce the contents and methods for thesubsequent assessment about China highway construction projects, the principles for the evaluationtargets and the subsequent assessme...In this paper, the writers systematically introduce the contents and methods for thesubsequent assessment about China highway construction projects, the principles for the evaluationtargets and the subsequent assessment results of the typical projects. These can offer good referencefor other work.展开更多
A simulation of the upper-tropospheric temperature (UTT) by the Beijing Climate Center Climate System Model version 1.1 (BCC_CSM1.1) model is evaluated through a comparison with NCEP/NCAR reanalysis data. It is shown ...A simulation of the upper-tropospheric temperature (UTT) by the Beijing Climate Center Climate System Model version 1.1 (BCC_CSM1.1) model is evaluated through a comparison with NCEP/NCAR reanalysis data. It is shown that this model has the ability to simulate the climate pattern of the UTT in all four seasons. The spatial correlation on the climatological distribution between the simulation and the observation is 0.92, 0.93, 0.90, and 0.93 for spring, summer, autumn, and winter, respectively. The first leading mode of the UTT in the simulation agrees with that in the observation, except that the simulated second leading mode corresponds to the observed first leading mode in spring. The standard deviation distribution of the simulation is also roughly consistent with the observation, with a pattern coefficient of 0.82, 0.78, 0.82, and 0.82 in spring, summer, autumn, and winter, respectively. The potential UTT change in the second half of the 21st century under the Representative Concentration Pathway 8.5 (RCP8.5) scenario is examined. The prominent change is that the summer UTT will increase over Eurasia and decrease over the North Pacific compared with the present, indicating that the zonal thermal contrast between Asia and the North Pacific will be strengthened within the context of future global warming. The intensity of the interannual variability of the UTT over the Asian-Pacific region is also generally increased. The zonal thermal contrast between Asia and the North Pacific will tend to be enhanced in winter, concurrent with the intensified interannual variability.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.41076001,40810069004)the Fundamental Research Funds for the Central Universities(No.2010121029)
文摘Xiamen Bay in South China has experienced extensive coastal exploitation since the 1950s,resulting in some severe environmental problems.Local authorities now have completed or are implementing many environmental restoration projects.Evaluating the cumulative impact of exploitation and restoration activities on the environment is a complicated multi-disciplinary problem.However,hydrodynamic changes in the bay caused by such coastal projects can be characterized directly and definitively through numerical modeling.This paper assesses the cumulative effect of coastal projects on the hydrodynamic setting using a high-resolution numerical modeling method that makes use of tidal current speeds and the tidal prism as two hydrodynamic indices.Changes in tidal velocity and the characteristics of the tidal prism show that hydrodynamic conditions have declined from 1938 to 2007 in the full-tide area.The tidal current speed and tidal prism have decreased by 40% in the western part of the bay and 20% in the eastern part of the bay.Because of the linear relationship between tidal prism and area,the degraded hydrodynamic conditions are anticipated to be restored to 1972 levels following the completion of current and proposed restoration projects,i.e.33% and 15% decrease in the hydrodynamic conditions of 1938 for the western and eastern parts of the bay,respectively.The results indicate that hydrodynamic conditions can be restored to some extent with the implementation of a sustainable coastal development plan,although a full reversal of conditions is not possible.To fully assess the environmental changes in a region,more indices,e.g.,water quality and ecosystem parameters,should be considered in future evaluations.
文摘Project-based learning （PBL） as an instructional approach focuses on student-centeredness through contextualizing learning by presenting students with real world issues and practices that aim at achieving enduring learning effects. As a challenge to traditional lecture-based instruction, PBL may generate positive backwash assessment effects via documenting the process of developing authentic language skills. These skills-oriented outcomes are achieved through proper curricula in appropriate learning situations via various dimensions. However, problems may occur such as management, pressure from administration, evaluation doing their selected projects. teacher/student attitude, class size and proper group process and criteria, and students＇ likely frustrations in
文摘The construction of wind power project is conducive to saving energy,reducing emissions and regulating energy structure. But it inevitably causes some impacts on the environment in the construction process. Because that the height of wind power generator generally exceeds 100 m,and visual range in plain region is farther,it is necessary to scientifically and rationally evaluate and analyze landscape visual environment impact of wind power generator in plain region. One wind power farm project of Zhanjiang is located in typical plain region of Guangdong coast. Referring to traditional analytic method of landscape visual impact and comparing with actual situation for the same kind of project in the region,results show that it is ＂ extremely sensitive＂ area at 0- 2. 5 km from wind power generator, ＂ very sensitive＂ area at 2. 5- 5. 0 km, ＂ sensitive＂ area at 5- 10 km, ＂generally sensitive＂ area at 10- 20 km,and non-sensitive area outside 20 km.
文摘Objective image quality measure, which is a fundamental and challenging job in image processing, evaluates the image quality consistently with human perception automatically. On the assumption that any image distortion could be modeled as the difference between the directional projection-based maps of reference and distortion images, we propose a new objective quality assessment method based on directional projection for full reference model. Experimental results show that the proposed metrics are well consistent with the subjective quality score.
基金supported by the National Natural Science Foundation of China(Grant No.42275184)the National Key Research and Development Program of China(Grant No.2017YFA0603804)the Postgraduate Research and Practice Innovation Program of Government of Jiangsu Province(Grant No.KYCX22_1135).
文摘Climate change adaptation and relevant policy-making need reliable projections of future climate.Methods based on multi-model ensemble are generally considered as the most efficient way to achieve the goal.However,their efficiency varies and inter-comparison is a challenging task,as they use a variety of target variables,geographic regions,time periods,or model pools.Here,we construct and use a consistent framework to evaluate the performance of five ensemble-processing methods,i.e.,multimodel ensemble mean(MME),rank-based weighting(RANK),reliability ensemble averaging(REA),climate model weighting by independence and performance(ClimWIP),and Bayesian model averaging(BMA).We investigate the annual mean temperature(Tav)and total precipitation(Prcptot)changes(relative to 1995–2014)over China and its seven subregions at 1.5 and 2℃warming levels(relative to pre-industrial).All ensemble-processing methods perform better than MME,and achieve generally consistent results in terms of median values.But they show different results in terms of inter-model spread,served as a measure of uncertainty,and signal-to-noise ratio(SNR).ClimWIP is the most optimal method with its good performance in simulating current climate and in providing credible future projections.The uncertainty,measured by the range of 10th–90th percentiles,is reduced by about 30%for Tav,and 15%for Prcptot in China,with a certain variation among subregions.Based on ClimWIP,and averaged over whole China under 1.5/2℃global warming levels,Tav increases by about 1.1/1.8℃(relative to 1995–2014),while Prcptot increases by about 5.4%/11.2%,respectively.Reliability of projections is found dependent on investigated regions and indices.The projection for Tav is credible across all regions,as its SNR is generally larger than 2,while the SNR is lower than 1 for Prcptot over most regions under 1.5℃warming.The largest warming is found in northeastern China,with increase of 1.3(0.6–1.7)/2.0(1.4–2.6)℃(ensemble’s median and range of the 10th–90th percentiles)under 1.5/2℃warming,followed by northern and northwestern China.The smallest but the most robust warming is in southwestern China,with values exceeding 0.9(0.6–1.1)/1.5(1.1–1.7)℃.The most robust projection and largest increase is achieved in northwestern China for Prcptot,with increase of 9.1%(–1.6–24.7%)/17.9%(0.5–36.4%)under 1.5/2℃warming.Followed by northern China,where the increase is 6.0%(–2.6–17.8%)/11.8%(2.4–25.1%),respectively.The precipitation projection is of large uncertainty in southwestern China,even with uncertain sign of variation.For the additional half-degree warming,Tav increases more than 0.5℃throughout China.Almost all regions witness an increase of Prcptot,with the largest increase in northwestern China.
文摘In this paper, the writers systematically introduce the contents and methods for thesubsequent assessment about China highway construction projects, the principles for the evaluationtargets and the subsequent assessment results of the typical projects. These can offer good referencefor other work.
基金supported by the National Basic Research Program of China(2009CB421407)the National Natural Science Foundation of China(41275078)the National Science&Technology Pillar Program(2012BAC20B05)
文摘A simulation of the upper-tropospheric temperature (UTT) by the Beijing Climate Center Climate System Model version 1.1 (BCC_CSM1.1) model is evaluated through a comparison with NCEP/NCAR reanalysis data. It is shown that this model has the ability to simulate the climate pattern of the UTT in all four seasons. The spatial correlation on the climatological distribution between the simulation and the observation is 0.92, 0.93, 0.90, and 0.93 for spring, summer, autumn, and winter, respectively. The first leading mode of the UTT in the simulation agrees with that in the observation, except that the simulated second leading mode corresponds to the observed first leading mode in spring. The standard deviation distribution of the simulation is also roughly consistent with the observation, with a pattern coefficient of 0.82, 0.78, 0.82, and 0.82 in spring, summer, autumn, and winter, respectively. The potential UTT change in the second half of the 21st century under the Representative Concentration Pathway 8.5 (RCP8.5) scenario is examined. The prominent change is that the summer UTT will increase over Eurasia and decrease over the North Pacific compared with the present, indicating that the zonal thermal contrast between Asia and the North Pacific will be strengthened within the context of future global warming. The intensity of the interannual variability of the UTT over the Asian-Pacific region is also generally increased. The zonal thermal contrast between Asia and the North Pacific will tend to be enhanced in winter, concurrent with the intensified interannual variability.
