我国海洋环境污染监测质量保证的回顾与展望

我国海洋环境污染监测质量保证的发展历史可大致分为三个阶段：孕育阶段（１９７２～１９７７年）起步阶段（１９７８～１９８３年）和发展阶段（１９８４～）。各个阶段有不同的特色和侧重点，１９７８年前主要探索与污染物质的分析方法，１９８４年后是监测质量保证工作进入管理时期。     

Characterizing ionic species in PM2:5 and PM10 in four Pearl River Delta cities, South China

PM_(2.5)and PM_(10)samples were collected at four major cities in the Pearl River Delta(PRD),South China,during winter and summer in 2002.Six water-soluble ions,Na~ ,NH_4~ ,K~ ,Cl~-,NO_3~- and SO_4~(2-)were measured using ion chromatography.On average,ionic species accounted for 53.3% and 40.5% for PM_(2.5)and PM_(10),respectively in winter and 39.4% and 35.2%,respectively in summer. Secondary ions such as sulfate,nitrate and ammonium accounted for the major part of the total ionic species.Sulfate was the most abundant species followed by nitrate.Overall,a regional pollution tendency was shown that there were higher concentrations of sulfate, nitrate and ammonium in Guangzhou City than those in the other PRD cities.Significant seasonal variations were also observed with higher levels of species in winter but lower in summer.The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well.NO_3~-/SO_4~(2-) ratio indicated that mobile sources have considerably contribution to the urban aerosol,and stationary sources should not be neglected. Besides the primary emissions,complex atmospheric reactions under favorable weather conditions should be paid more attention for the control of primary emission in the PRD region.     

环境经济学在中国的发展

本文讨论了环境经济学在中国的发展过程,并对新时期环境经济学面临的理论和现实问题进行了展望。在新的时期,环境经济学应更加注重以环境问题表现的社会利益结构和利益均衡的实证分析,并对满足可持续发展要求的宏观经济政策变革和微观环境管理提供理论支持。     

我国银杏种植业开发前景分析

本文根据我国银杏种植业的发展现状,分析了我国银杏种植业的开发前景     

生物技术在环境保护中的应用及前景

本文从废水、废气、固体废弃物处理及环境监测等几个方面介绍了生物技术在环境保护中的应用和研究进展 ,分析了生物处理工艺的特点及优越性 ,展望了生物技术未来的发展方向和前景     

秸秆发电的现状和展望

介绍了秸秆发电的重要意义以及在国内外的发展现状，分析了秸秆发电存在的问题，并提出相应的解决办法，最后展望了秸秆发电在国内的市场前景。     

制约湖南地区节能建筑发展的主要因素及应对技术研究

根据湖南地区节能建筑的发展现状和问题,比较国际建筑节能方面的一些先进经验,通过工程设计实例,探讨建筑产业可持续发展这一关键环节的重要性及其改进措施,并预测了节能建筑在我省的发展态势。     

WATER QUALITY MODELING OF ALTERNATIVE AGRICULTURAL SCENARIOS IN THE U.S. CORN BELT1

ABSTRACT: Simulated water quality resulting from three alternative future land‐use scenarios for two agricultural watersheds in central Iowa was compared to water quality under current and historic land use/land cover to explore both the potential water quality impact of perpetuating current trends and potential benefits of major changes in agricultural practices in the U.S. Corn Belt. The Soil Water Assessment Tool (SWAT) was applied to evaluate the effect of management practices on surface water discharge and annual loads of sediment and nitrate in these watersheds. The agricultural practices comprising Scenario 1, which assumes perpetuation of current trends (conversion to conservation tillage, increase in farm size and land in production, use of currently‐employed Best Management Practices (BMPs)) result in simulated increased export of nitrate and decreased export of sediment relative to the present. However, simulations indicate that the substantial changes in agricultural practices envisioned in Scenarios 2 and 3 (conversion to conservation tillage, strip intercropping, rotational grazing, conservation set‐asides and greatly extended use of best management practices (BMPs) such as riparian buffers, engineered wetlands, grassed waterways, filter strips and field borders) could potentially reduce current loadings of sediment by 37 to 67 percent and nutrients by 54 to 75 percent. Results from the study indicate that major improvements in water quality in these agricultural watersheds could be achieved if such environmentally‐targeted agricultural practices were employed. Traditional approaches to water quality improvement through application of traditional BMPs will result in little or no change in nutrient export and minor decreases in sediment export from Corn Belt watersheds.     

干旱灾害风险评估的研究进展

干旱灾害风险评估是风险管理和减灾管理的基础,其成果可以为救灾减灾提供科学依据.对干旱灾害系统的复杂性与非线性以及干旱灾害风险评估的程序、方法模型与研究内容等进展进行了综述.在此基础上,展望了干旱灾害风险评估的综合性、动态性等发展趋势,并预测了进一步研究的重点.