伊犁河谷退耕还草的模式及生态经济效益探讨

退耕还林还草、进行生态环境建设是我国政府制定的一项战略性措施。伊犁河谷需要退耕还草的面积为14.13×104hm2,河谷自然地理条件较复杂,不同地域水、土、光、热条件差异较大,本文就伊犁河谷不同地域退耕还草的模式、生态经济效益及相关技术问题进行了探讨。     

Women, Health and Humanitarian Aid in Conflict

The burden of political conflict on civilian populations has increased significantly over the last few decades. Increasingly, the provision of resources and services to these populations is coming under scrutiny; we highlight here the limited attention to gender in their provision. Women and men have different exposures to situations that affect health and access to health-care and have differential power to influence decisions regarding the provision of health services. We argue that the role of women in planning is central to the provision of effective, efficient and sensitive health-care to conflict-affected populations.     

一种新型的煤气回火安全装置

介绍了一种新型的煤气回火安全装置,说明了它的工作原理,主要参数,工艺结构等,叙述了其研制过程和应用情况。     

The Pollution Prevention Act of 1990: A Policy Whose Time Has Come or Symbolic Legislation?

/ In 1990, the United States officially entered the era of pollution prevention with passage of the Pollution Prevention Act. This paper analyzes EPA's implementation of the Pollution Prevention Act from its passage in 1990 to the present. It examines the barriers EPA must overcome if it is to effectively integrate pollution prevention into its existing regulatory structure, including impediments created by statutory and organizational structure, the existing relationship between EPA and the groups it regulates, the fragmented implementation scheme of national environmental regulation, the balancing of conflicting demands advanced by powerful interests, industry's economic and technical concerns, and institutional inertia. It also examines issues such as industry commitment, the limits of prevention, and measurement concerns. The findings suggest that EPA's efforts at shifting to a pollution prevention regulatory ethic that holds primacy over pollution control are mixed. Its organizational structure, statutory authority, and incentives system still reflect a single-medium pollution control focus, appropriations for pollution prevention programs and activities are paltry compared to traditional pollution control programs, and participation in the program is voluntary. Yet, the findings also point to some promising programs that are working to institutionalize a pollution prevention regulatory ethic, and many states appear very committed to the concept.KEY WORDS: Pollution prevention; Source reduction; Pollution control; Alternative regulatory design; Barriers to implementation     

“The Kesterson effect”

Hypothesized to be derived from Cretaceous marine sedimentary rocks, selenium contamination of the Kesterson National Wildlife Refuge is traced through irrigation drainage to the source bedrock of the California Coast Ranges. This biogeochemical pathway of selenium is defined here as the “Kesterson effect.” At the refuge ponds, this effect culminated in 1983 in a 64% rate of deformity and death of embryos and hatchlings of wild aquatic birds. From the previous companion paper on irrigation drainage, the Kesterson effect has been implicated in nine of 11 reconnaissance areas studied in the western United States. Deformities have resulted in at least five of these sites. Climatic, geologic, hydrologic, and soil conditions in these reconnaissance areas are similar to those in the area surrounding Kesterson National Wildlife Refuge in the west-central San Joaquin Valley of California. In California, selenium, as selenate, was ultimately found weathered with sulfur from marine sources in soluble sodium and magnesium sulfate salts, which are concentrated by evaporation on farmland soils. The Se, mobilized by irrigation drainage, is bioaccumulated to toxic levels in refuge wetland ponds that are located mainly in hydrologically closed basins and thus act as concentrating disposal points. The depositional environment of the ponds may be similar to that of the nutrient-rich continental shelf edge and slope in which Cretaceous, Eocene, and Miocene sediments found to be seleniferous in the California Coast Ranges were deposited. Bioaccumulation may be therefore a primary mechanism of selenium enrichment in ancient sediments in addition to that of the formerly suggested Cretaceous volcanic pathway.     

Employee reactivity and adaptation to observation on the job

In the course of studying police dispatchers, five observers recorded the reactions of the employees (N = 37) to their presence throughout the work shift on three separate occasions. Four major research questions were considered: (a) extent of reaction, (b) relationship between interactions with the observer and changes in employees' work activities, (c) independence of verbal and nonverbal behavioral reactions, and (d) adaptation. On average, subjects or other employees initiated 10 interactions per hour with observers. These interactions were classified as subject-initiated (a) verbal, content related to research procedures; (b) verbal, non-research-related in content; (c) nonverbal only or (d) other employee-initiated verbal comment. Interaction with the observer was not related to the amount of work the subject did. Subjects' nonverbal and verbal responses were unrelated to each other as well as to the verbal responses of other employees. A priori expectations concerning adaptation to observation were tested with a 3 × 3 (segment by day) repeated-measures factorial design. Significant adaptation (P < 0·01) occurred within and between days in subjects' comments about research procedures and all comments from other employees. However, other behaviors showed with no evidence of adaptation or actual increases. The implications of these findings for measuring reactivity and deciding when adaptation has occurred are discussed.     

PAST AND FUTURE OF ANALYSIS OF WATER RESOURCES TIME SERIES1

ABSTRACT: water resources supply and demand time series consist of several or all of the four basic characteristics: tendency, intermittency, periodicity and stochasticity. Their importance changes from one type of variables to another. Historic developments of analysis of time series in hydrology have varied significantly over the past, from the stress on search for periodicities and persistence in annual series to the emphasis on the series stochastic properties. Supply and demand series are often highly interrelated, which fact is most often neglected in planning water resources systems in general, and water storage capacities in particular. The future of series analysis in water resources will likely be by a joint use of physically-based structural analysis and the use of advanced methods of treating data by stochastic processes, statistical estimation and inference techniques. The most intriguing challenge of the future of this analysis may be the treatment of nonnormal, nonlinear and in general nonstationary hydrologic and water use time series. The proper treatment of complex multivariate processes will also challenge the specialists, especially for the purposes of transfer of information between data on variables at given points, or between data at several points of a given variable, or both.     

RESISTANCE TO FLOW OVER RIPRAP IN STEEP CHANNELS1

ABSTRACT: A series of flume tests were conducted to determine the flow resistance of angular shaped riprap in steep channels. Flow resistance was expressed in terms of the Darcy-Weisbach friction factor and the Manning's roughness coefficient. Prototype channels of 4 ft. (1.2 m) and 12 ft. (3.7 m) in width were constructed at slopes ranging from 0.01 to 0.20. The channel beds were comprised of angular riprap of median diameters of 1, 2, 4, 5, and 6 inches (2.59, 5.59, 10.41, 12.95, and 15.75 cms). The Darcy-Weisbach and Manning's coefficients were determined for each test condition prior to bed failure. The resulting Darcy-Weisbach coefficients were related to the channel energy gradient and the bed relative submergence for highly turbulent flow. Also, Manning's roughness coefficients were related to the product of the median stone diameter and energy gradient. Because of the angular shape of the riprap and the wedging and/or packing of the bed materials, the resistance to flow was found to exceed the flow resistance values predicted by previous studies. Expressions were presented for estimating the resistance to flow for angular riprap in steep channels.     

EIA training courses organized by the centre for environmental management and planning,University of Aberdeen: An analysis of experience

In 1980, the World Health Organization (Regional Office for Europe) invited The Centre for Environmental Management and Planning (CEMP) to organize a two-week training course on Environmental Impact Assessment (EIA) to provide a comprehensive introduction to EIA with emphasis on methods and techniques for impact identification, prediction and assessment. Not suprisingly the topic of environmental health impact assessment was to be a major focus. Since 1980, the course has been held each year at the University of Aberdeen. An analysis of participation in the course during its first five years yields several impressions about the success of this training effort and the ways in which it might be improved.     

Success in negotiating environmental regulations

The US Environmental Protection Agency recently completed two regulatory negotiation demonstrations. These demonstrations suggest that the current EPA rule-making process could be improved through the introduction of face-to-face negotiation at the earliest stages of rulemaking. In the demonstrations, EPA (1) relied on a consensus building process to forestall litigation after the promulgation of the final rule; (2) Used a nonpartisan facilitator to convene the negotiations; (3) Defined criteria to determine which parties should be represented in the negotiation. From the perspective of participants, the negotiating consensus version of a draft regulation is a successful alternative to the traditional rulemaking process. It is still too soon to say negotiated rulemaking significantly reduces the likelihood of ligitation. The results of the demonstration indicate that it is possible for either an agency employee or a neutral outsider to facilitate the sessions. A successful negotiation also requires top level agency support as well as the confidence of the environmental community. The single most important outcome of the negotiations was that the participants developed a greater understanding of the interests of the other parties. The demonstrations also suggest possible changes in future regulatory negotiations.