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51.
Oliveira Amauri P. Bornstein Robert D. Soares Jacyra 《Water, Air, & Soil Pollution: Focus》2003,3(5-6):3-15
The major topographic, mesoscale, and urban influences on the wind patterns of the City of São Paulo are characterized using one year of surface wind velocity data observed at 11 surface stations within its urban limits. The data was used to study the diurnal and annual variations of wind velocity and horizontal wind divergence within the city. Results showed that the circulation over the investigated area is dominated by three major factors: sea breeze; mountain-valley circulations; and urban effects, such as roughness, building-barrier, and urban heat island. The sea breeze was found to be the dominant feature of the monthly-averaged diurnal variation of São Paulo surface winds during the eight warmest months of the year. The sea breeze front induces a velocity minimum at the time of its passage and a post-frontal afternoon velocity maximum. Mountain-valley thermal effects on the flow can be seen in the temporal divergence/convergence patterns. These thermal effects tend to be more important during colder months, at night, and when the wind velocities are low. Nighttime downslope convergent flows are present over the city during winter and spring and daytime upslope divergent flows are present over the city during summer months. 相似文献
52.
Frank A. Ward James F. Booker 《Journal of the American Water Resources Association》2003,39(2):427-440
ABSTRACT: The U.S. Endangered Species Act (ESA) restricts federal agencies from carrying out actions that jeopardize the continued existence of any endangered species. The U.S. Supreme Court has emphasized that the language of the ESA and its amendments permits few exceptions to the requirement to give endangered species the highest priority. This paper estimates economic costs associated with one measure for increasing instream flows to meet critical habitat requirements of the endangered Rio Grande silvery minnow. Impacts are derived from an integrated regional model of the hydrology, economics, and institutions of the upper Rio Grande Basin in Colorado, New Mexico, Texas, and Mexico. One proposal for providing minimum streamflows to protect the silvery minnow from extinction would provide guaranteed year round streamflows of at least 50 cubic feet per second in the San Acacia reach of the upper Rio Grande. These added flows can be accomplished through reduced surface diversions by New Mexico water users in dry years when flows would otherwise be reduced below the critical level required by the minnow. Based on a 44‐year simulation of future inflows to the basin, we find that some agricultural users suffer damages, but New Mexico water users as a whole do not incur damages from a policy that reduces stream depletions sufficiently to provide habitat for the minnow. The same policy actually benefits downstream users, producing average annual benefits of over $200,000 per year for west Texas agriculture, and over $1 million for El Paso municipal and industrial water users, respectively. Economic impacts of instream flow deliveries for the minnow are highest in drought years. 相似文献
53.
Charles M. Buchanan Debra Dorschel Robert M. Gardner Ron J. Komarek Andrew J. Matosky Alan W. White Matthew D. Wood 《Journal of Polymers and the Environment》1996,4(3):179-195
In this account, we report our findings on blends of cellulose acetate having a degree of substitution (DS) of 2.49 (CA2.5) with a cellulose acetate having a DS of 2.06 (CA2.0). This blend system was examined over the composition range of 0–100% CA2.0 employing both solvent casting of films (no plasticizer) and thermal processing (melt-compressed films and injection molding) using poly(ethylene glycol) as a common plasticizer. All thermally processed blends were optically clear and showed no loss in optical quality after storage for several months. Thermal analysis and measurement of physical properties indicate that blends in the middle composition range are partially miscible, while those at the ends of the composition range are miscible. We suggest that the miscibility of these cellulose acetate blends is influenced primarily by the monomer composition of the copolymers. Bench-scale simulated municipal composting confirmed the biodestructability of these blends and indicated that incorporation of a plasticizer accelerated the composting rates of the blends.In vitro aerobic biodegradation testing involving radiochemical labeling conclusively demonstrated that both the lower DS CA2.0 and the plasticizer significantly enhanced the biodegradation of the more highly substituted CA2.5.While this work was in progress, Robert Gardner was struck with cancer and died on June 6, 1995. This paper is dedicated to his memory and to his contributions as a friend and colleague. 相似文献
54.
Robert B. Olshansky 《Environmental management》1996,20(1):11-23
The California Environmental Quality Act (CEQA) has evolved from a mini-NEPA, first enacted in 1970, into a procedural act
that affects the approval process of all large developments in California. In 1990, California local governments produced
over 1600 environmental impact reports and 30,000 initial studies under CEQA. Because of its widespread use, CEQA has periodically
drawn the attention of the state legislature, most recently in 1993, when over 60 CEQA reform bills were introduced. This
paper describes the CEQA process and evaluates its success at meeting its explicit and implicit goals. The research includes
a statewide survey of CEQA practice, sent to the planning departments of all 513 local governments in California in 1991.
Survey respondents agreed that CEQA helps in evaluating environmental impacts, reducing impacts, informing the public, and
coordinating public agency review. It is effective in reducing the environmental impacts of individual projects, but is not
as effective in improving environmental quality on an areawide scale. This research concludes that CEQA has led to positive
outcomes and is not as deeply flawed as many of its critics claim. Still, CEQA as currently designed may not be the optimal
vehicle for ensuring environmental quality. 相似文献
55.
Results from a survey of power utility biologists indicate that terrestrial biodiversity is considered a major issue by only a few utilities; however, a majority believe it may be a future issue. Over half of the respondents indicated that their company is involved in some management for biodiversity, and nearly all feel that it should be a goal for resource management. Only a few utilities are funding biodiversity research, but a majority felt more research was needed. Generally, larger utilities with extensive land holdings had greater opportunities and resources for biodiversity management. Biodiversity will most likely be a concern with transmission rights-of-way construction and maintenance, endangered species issues and general land resource management, including mining reclamation and hydro relicensing commitments. Over half of the companies surveyed have established voluntary partnerships with management groups, and biodiversity is a goal in nearly all the joint projects. Endangered species management and protection, prevention of forest fragmentation, wetland protection, and habitat creation and protection are the most common partnerships involving utility companies. Common management practices and unique approaches are presented, along with details of the survey. 相似文献
56.
This is a case study that describes a survey of anglers that was used to assist in modifying fishing regulations for indigenous trout in the Snake River, Wyoming. A mail survey of anglers who purchased 1991 Wyoming fishing licenses in the two counties adjacent to the Snake River was conducted during fall 1992. Differences in angler preferences were noted between anglers who purchased licenses in two adjacent counties with different socioeconomic structures, as well as between residents and nonresidents in each county. Anglers who purchased licenses in Teton County, where there is extensive tourism and immigration by relatively wealthy residents, tended to be more specialized and less harvest oriented. Anglers in Lincoln County, which is largely agricultural and has substantially less tourism and immigration of residents, tended to fish in many different ways and indicated more desire to harvest fish. Anglers from the two counties segregated themselves; those from Teton County primarily used the upstream portion of the study reach, and those from Lincoln County primarily used a short downstream portion of the reach. Modification of fishing regulations to reduce harvest of spawning-size cutthroat trout in the Snake River probably was acceptable to most anglers due to spatial segregation and their attitudes toward harvest.The unit is jointly supported by the University of Wyoming, the Wyoming Game and Fish Department, and the National Biological Survey. 相似文献
57.
Adaptive management: Promises and pitfalls 总被引:3,自引:1,他引:3
Proponents of the scientific adaptive management approach argue that it increases knowledge acquisition rates, enhances information flow among policy actors, and provides opportunities for creating shared understandings. However, evidence from efforts to implement the approach in New Brunswick, British Columbia, Canada, and the Columbia River Basin indicates that these promises have not been met. The data show that scientific adaptive management relies excessively on the use of linear systems models, discounts nonscientific forms of knowledge, and pays inadequate attention to policy processes that promote the development of shared understandings among diverse stakeholders. To be effective, new adaptive management efforts will need to incorporate knowledge from multiple sources, make use of multiple systems models, and support new forms of cooperation among stakeholders. 相似文献
58.
Frank A. Ward Thomas P Lynch 《Journal of the American Water Resources Association》1996,32(6):1127-1138
ABSTRACT: This paper presents an integrated optimal control model that optimizes economic performance of reservoir management in watersheds in which there are significant economic and hydrologic interdependencies. The model is solved using the General Algebraic Modeling System (GAMS). Results show that application of this model to New Mexico's Rio Chama basin can increase total system benefits over historical benefits by exploiting complementarities between hydroelectricity production, instream recreation, and downstream lake recreation. 相似文献
59.
60.
Ben A. Minteer Elizabeth A. Corley Robert E. Manning 《Journal of Agricultural and Environmental Ethics》2004,17(2):131-156
Many nonanthropocentric environmental ethicists subscribe to a ``principle-ist' approach to moral argument, whereby specific natural resource and environmental policy judgments are deduced from the prior articulation of a general moral principle. More often than not, this principle is one requiring the promotion of the intrinsic value of nonhuman nature. Yet there are several problems with this method of moral reasoning, including the short-circuiting of reflective inquiry and the disregard of the complex nature of specific environmental problems and policy arguments. In the present paper, we advance an alternative, pragmatic contextualist approach to environmental ethics, one grounded in the moral theory of John Dewey. We present the results of an empirical study of public environmental ethics and natural resource management attitudes to support our position, and we conclude with a few recommendations for future inquiry in the field of environmental ethics. 相似文献