Chemical composition of precipitation and its sources in Hangzhou, China

To understand the origin and chemical characteristics of precipitation in Hangzhou, rainwater samples were collected from June 2006 to May 2008. All samples were analyzed for pH, electrical conductivity, and major ions (NH??, Ca2?, Mg2?, Na?, K?, SO?2?, NO??, F?, and Cl?). Acidification of precipitation in Hangzhou was serious with volume-weighted mean pH value of 4.5, while frequency of acid rain was 95%. The calculated SO?2?/NO?? ratio in Hangzhou precipitation was 2.87, which indicated that the precipitation of Hangzhou belonged to sulfate-based acid rain. The results of acid neutralization analysis showed that not all the acidity in the precipitation of Hangzhou was neutralized by alkaline constituents. The results of sea salt contribution analysis showed that nearly all SO?2?, Ca2?, and Mg2? and 33.7% of K? were of non-sea origins, while all Na? and Cl? and 66.3% of K? originated from sea sources. The principal component analysis which was used to analyze the sources of various ions indicated that chemical compositions of precipitation in Hangzhou mainly came from terrestrial sources, factory emissions, fuel wood burning, and marine sources.     

Estimation of late twentieth century land-cover change in California

We present the first comprehensive multi-temporal analysis of land-cover change for California across its major ecological regions and primary land-cover types. Recently completed satellite-based estimates of land-cover and land-use change information for large portions of the United States allow for consistent measurement and comparison across heterogeneous landscapes. Landsat data were employed within a pure-panel stratified one-stage cluster sample to estimate and characterize land-cover change for 1973?C2000. Results indicate anthropogenic and natural disturbances, such as forest cutting and fire, were the dominant changes, followed by large fluctuations between agriculture and rangelands. Contrary to common perception, agriculture remained relatively stable over the 27-year period with an estimated loss of 1.0% of agricultural land. The largest net declines occurred in the grasslands/shrubs class at 5,131 km² and forest class at 4,722 km². Developed lands increased by 37.6%, composing an estimated 4.2% of the state??s land cover by 2000.     

Occurrence, distribution, and source of polybrominated diphenyl ethers in soil and leaves from Shenzhen Special Economic Zone, China

Polybrominated diphenyl ethers (PBDEs) were measured in soil and three plant species samples taken at different land use areas in Shenzhen China. The concentrations of ??₇BDEs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183) and BDE-209 in the surface soils ranged from 0.23 to 271 and 8.9 to 5,956 ng/g dry weight (dw), respectively. These figures are comparable to that in the soils of electronic waste dismantling sites. BDE-209 was the predominant congener (contributes 85?C99% of ??₈PBDEs (??₇PBDEs plus BDE-209)) in soils. The regression slopes of total organic carbon and individual BDE congeners were rather gentle, indicating that factors other than soil organic matter regulated the soil concentrations. Proximity to sources of deposition processes might be the major factors. In the plant leaves, ??₇BDEs and BDE-209 concentrations ranged from 1.29 to 5.91 and 5.49 to 28.2 ng/g dw, respectively. BDE-209 is also the dominant component, but the contribution was much lower compared with that in soils. Bauhinia purpurea Linn. and Michelia alba DC. show some similarities on the uptake of PBDEs, while Ficus microcarpa var. pusillifolia is different from them. The correlations between plant leaf concentrations and predicted gaseous concentrations were moderate, indicating that gaseous concentration did not influence the leaf concentration significantly.     

Polycyclic aromatic hydrocarbons in effluents from wastewater treatment plants and receiving streams in Tianjin, China

Surface water, suspended particulate matter, pore water, and sediment samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) in Yongding New River, South Drainage Canal and North Drainage Canal, which receive most of wastewater from industrial city of Tianjin. PAH concentrations in effluent samples of wastewater treatment plants (WTP) discharging into the South Drainage Canal and North Drainage Canal were quantified for the first time. The results showed that the discharge of the WTPs recently only contributed to the PAH contamination in the canals near the outlets of the WTPs. PAH levels in sediments of the streams were greatly higher than those in soils by riverbank probably due to receiving large amounts of untreated wastewater. Unusually high benz[a] anthracene concentration strongly influenced the seasonal and spatial variation of total PAH concentrations in South Drainage Canal. Paired samples t test of ??Nap, Fl, Phe, Fluo and ??Nap, Phe, Fluo, Chry concentrations, which were dominant components in the air samples from non-heating and heating season, respectively, in the suspended particulate matters from the streams showed that PAH source from air deposition was more important for Yongding New River than that for South Drainage Canal and North Drainage Canal. Source apportionment based on PAH profiles indicated that coal combustion was the major PAH contamination source, and coke oven sources and wood combustion also contributed to the PAH contamination of the streams. This was further indicated by organic petrography analysis.     

Survey on the pesticide residues in tea in south India

Tea is considered as a ‘health beverage’ due its antioxidant properties and resultant beneficial effects on human health. Such a beverage should be free from toxic elements such as pesticide residues and heavy metals. A large scale survey of teas produced in the tea factories of south India had been carried out for a period of three years from 2006 to 2008 and 912 tea samples were analysed for the residues of certain pesticides such as dicofol, ethion, quinalphos, hexaconazole, fenpropathrin, fenvalerate and propargite which are used for pest and disease control in tea in this part of the country. The analytical data proved that only less than 0.5 percentage of tea samples had residues of these pesticides. However, residues of pesticides were below their maximum limits in tea, stipulated by the European Union, Codex Alimentarius Commission of FAO/WHO and Prevention of Food Adulteration Act of Govt. of India.     

A Method for Ensemble Wildland Fire Simulation

An ensemble simulation system that accounts for uncertainty in long-range weather conditions and two-dimensional wildland fire spread is described. Fuel moisture is expressed based on the energy release component, a US fire danger rating index, and its variation throughout the fire season is modeled using time series analysis of historical weather data. This analysis is used to characterize the seasonal trend in ERC, autocorrelation of residuals, and daily standard deviation and stochastically generate artificial time series of afternoon fuel moisture. Daily wind speed and direction are sampled stochastically from joint probabilities of historical wind speed and direction for the date range of the fire simulation period. Hundreds or thousands of fire growth simulations are then performed using the synthetic fire weather sequences. The performance of these methods is evaluated in terms of the number of ensemble member simulations, one- versus two-dimensional fire spread simulations, and comparison with results from 91 fires occurring from 2007 to 2009. Simulations were found to be in consistent agreement with observations, but trends indicate that the ensemble average of simulated fire sizes were consistently larger than actual fires whereas the farthest extent burned by fires was underestimated.     

Confronting Management Challenges in Highly Uncertain Natural Resource Systems: a Robustness–Vulnerability Trade-off Approach

This paper presents a framework for the study of policy implementation in highly uncertain natural resource systems in which uncertainty cannot be characterized by probability distributions. We apply the framework to parametric uncertainty in the traditional Gordon–Schaefer model of a fishery to illustrate how performance can be sacrificed (traded-off) for reduced sensitivity and hence increased robustness, with respect to model parameter uncertainty. With sufficient data, our robustness–vulnerability analysis provides tools to discuss policy options. When less data are available, it can be used to inform the early stages of a learning process. Several key insights emerge from this analysis: (1) the classic optimal control policy can be very sensitive to parametric uncertainty, (2) even mild robustness properties are difficult to achieve for the simple Gordon–Schaefer model, and (3) achieving increased robustness with respect to some parameters (e.g., biological parameters) necessarily results in increased sensitivity (decreased robustness) with respect to other parameters (e.g., economic parameters). We thus illustrate fundamental robustness–vulnerability trade-offs and the limits to robust natural resource management. Finally, we use the framework to explore the effects of infrequent sampling and delays on policy performance.     

关于沈阳市沈河区环境噪声污染及综合治理研究

阐述了沈阳市沈河区环境噪声污染的现状和存在的问题，并提出了综合治理的对策。     

生态建设理论与实践

自然生态系统是可持续发展的，人类传统的社会经济发展以破坏生态系统８为代价。生态建设以社会－经济－自然人类复合生态系统理论为依据，以区域或行业为单元，或以解决生态环境问题或以生态恢复为宗旨而进行的。我国生态建设的基本经验是：站在可持续发展的高度，以生态革命的新思路进行战略规划，以生态经济学、产业生态学和生态工程学原理为指导进行技术规划，同时提出优先发展的生态产业类型、技术和方法，第一性生产量最大、生     

PW—W膜分离式活性污泥法处理中小规模高浓度有机废水

阐述ＰＷ－Ｗ膜分离式活性污泥法处理高浓度有机废水的原理、工艺流程及特点。处理系统集生化处理功能和固液分离于一体，对高浓度有机废水的处理取得了良好的效果，且剩余污泥量少，处理水质稳定，维护管理方便，运行费用低。