水利工程环境影响研究若干问题探讨

本文简述当代水资源利用和水利工程环境影响研究的发展趋势,总结我国在水利工程环境影响研究上的进步,成绩和不足。着重提出加强水利工程环境影响研究和评价的六点建议:①强调价值观在环境影响评价中的指导作用;②深化和拓宽移民环境容量研究;③加强环境影响的经济评价研究;④开展水利工程环境影响的风险分析;⑤充实环境对策体系研究;⑥积极建立长期定位观测台站。     

一体化污水处理设备的应用与发展

针对目前的污水处理形势 ,分析了一体化污水处理设备的优点和优势。并介绍了一体化污水处理设备一般工艺及其近年来技术发展概况     

渣油-水乳化液作为路面抑尘剂的研究

为了有效抑制汽车运输路面的扬尘,选择低浓度渣油－水乳化液作为抑尘剂,通过在实验室大量的试验,掌握一组渣油乳化的最佳配方及其制备工艺,即渣油３％－６％,乳化剂约０．５％,水９３．５％－９６．５％,制备温度〉７０℃经过室内和现场大规模试验表明,当路面喷洒量达到２．２ｋｇ／ｍ＾２时,其有效抑尘时间达到１０ｄ以上,并且在一定程度起到养路的作用,长期使用可取得显著的综合经济效益。     

Implications of Atmospheric Change for Biodiversity of Aquatic Ecosystems in Canada

Overall, the greatest threats to Canadian and global biodiversity are associated with conversions of natural ecosystems to anthropogenic ones, and over-exploitation of biological resources. This circumstance does not, however, trivialize the importance of atmospheric influences. Although scientific understanding of the risks is incomplete, it is nevertheless clear that anthropogenic changes in atmospheric stressors are potentially damaging to biodiversity and other ecological values over medium- and longer-term scales. It is important that greater investments be made in support of longer-term monitoring and research designed to understand the effects of atmospheric and other environmental stressors on the biodiversity and structure and function of Canadian ecosystems.     

A Systems Approach to Biodiversity Conservation Planning

With a recent media-fueled transition from a scientific to a political perspective, biodiversity has become an issue of ethics and ensuing values, beyond its traditional ecological roots. More fundamentally, the traditional perspective of biodiversity is being challenged by the emergence of a post-normal or systems-based approach to science. A systems-based perspective of living systems rests on the central tenets of complexity and uncertainty, and necessitates flexibility, anticipation and adaptation rather than prediction and control in conservation planning and management. What are the implications of this new perspective? This paper examines these challenges in the context of biodiversity conservation planning. The new perspectives of biodiversity are identified and explored, and the emergence of a new ecological context for biodiversity conservation is discussed. From the analysis, the challenges and implications for conservation planning are considered, and a systems-based or post-normal approach to conservation planning and management is proposed. In light of the new perspectives for biodiversity, conservation planning and management approaches should ultimately reflect the essence of living systems: they should be diverse, adaptive, and self-organizing, accepting the ecological realities of change.     

基于影响因子分析的滑坡位移预测模型研究

将滑坡的影响因索引入到滑坡的位移预测模型中．从滑坡的位移动态变化特征和响应组成组分研究入手,将滑坡的位移分解为趋势项、周期项、脉动项和随机项．针对每一项进行研究,分别选取合适的影响因子变量和函数关系来模拟,并将各项耦合在一起得到位移的初步预测模型。通过对监测数据进行非线性多元统计回归分析,得到位移的最终预测模型。以长江三峡库区的新滩滑坡为实例,通过验证研究,发现将滑坡的影响因子引入滑坡的预测预报模型中的思路是有效可行的,而且可以明显地改善预测预报的时间尺度。     

PCB Levels and Trends Within the Detroit River-Western Lake Erie Basin: A Historical Perspective of Ecosystem Monitoring

An international workshop held in the spring of 2002 convened a group of technical experts to address monitoring, modeling, and management of PCBs within the Detroit River-Western Lake Erie basin. Participants shared and discussed a diverse set of research data bases pertaining to PCB levels within the region, discussed observed changes within different components of the local ecosystem, and identified several primary issues impacting future PCB management strategies. Results presented at the workshop indicate dramatic reductions in PCB contamination levels have been observed in much of study area between the late 1970s and mid-1990s. Estimates of loadings attributable to water and atmospheric sources have generally declined, as have PCB concentrations in herring gull eggs, smelt and walleye. Nevertheless, additional improvements have not been observed during recent years and elevated contamination levels remain a concern within local hot spots, particularly in the lower Detroit River and Trenton Channel. A primary recommendation broadly supported by workshop participants is the need to maintain, support, and coordinate a comprehensive ecosystem monitoring program for the Detroit River-Western Lake Erie basin, one that incorporates both near-field and far-field monitoring elements. Such a program is crucial to provide necessary data in support of understanding ecosystem trends, calculating annual mass loadings to the system, assessing impacts of remediation actions, developing improved modeling frameworks, and formulating cost-effective management strategies for the future.     

Changes of Land Use and of Ecosystem Service Values in Sanjiang Plain, Northeast China

Agricultural activities, especially reclamation, are considered major threats to the wetland ecosystems in Sanjiang Plain, the largest concentrated area of the freshwater wetlands in China. In the past decades, the area of the cultivated land and its grain production have been increased at the cost of wetlands shrinkage. The large-scale land reclamation severely affected the ecosystems in this region. However, such effects at the regional scale are seldom evaluated quantitatively. We used three datasets of LANDSAT MSS and/or TM imagery to estimate the area changes and the transition of land use types from 1980 to 2000. We also valued changes in ecosystem services delivered by each land category using value coefficients published by Costanza et al. [Nature 387, 1997, 253–260]. Sensitivity analysis suggested that these estimates were relatively robust. Finally, the contribution of various ecosystem functions was ranked to the overall value of the ecosystem services in this study. According to our estimates, the total annual ecosystem service values in Sanjiang Plain have declined by about 40% between 1980 and 2000 ($156284–182572.18 million in total over 20 years). This substantial decline is largely attributed to the 53.4% loss of wetlands. For individual ecosystem functions, waste treatment, water supply and disturbance regulation account for more than 60% to the total ecological values. During those two decades, the contribution of disturbance regulation, cultural and recreation decreased, while the contribution of water regulation, nutrient cycling, food production, raw materials and climate regulation increased during the same period. We also put forward a few proposals concerning the future land use policy formulation and sustainable ecosystems. They are adjusting the ‘food first’ agricultural policy, establishing more nature reserves for wetlands, creating systems for the rational use of water, harnessing the degraded cultivated land and encouraging eco-tourism.     

Shine a light: Under-ice light and its ecological implications in a changing Arctic Ocean

The Arctic marine ecosystem is shaped by the seasonality of the solar cycle, spanning from 24-h light at the sea surface in summer to 24-h darkness in winter. The amount of light available for under-ice ecosystems is the result of different physical and biological processes that affect its path through atmosphere, snow, sea ice and water. In this article, we review the present state of knowledge of the abiotic (clouds, sea ice, snow, suspended matter) and biotic (sea ice algae and phytoplankton) controls on the underwater light field. We focus on how the available light affects the seasonal cycle of primary production (sympagic and pelagic) and discuss the sensitivity of ecosystems to changes in the light field based on model simulations. Lastly, we discuss predicted future changes in under-ice light as a consequence of climate change and their potential ecological implications, with the aim of providing a guide for future research.     

电动机火灾原因及其对策

对电动机的火灾原因进行分析,并根据火灾原因找出相应的对策,从而体现"安全第一,预防为主"的理念.