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61.
本文对小型造纸厂的碱回收在技术上和经济上的可行性进行了分析,作出了当前是中、小型造纸厂搞碱回收的有利时机的初步评价。 相似文献
62.
Trends and issues in land and water resources management: Setting the agenda for change 总被引:1,自引:0,他引:1
The classical model of a paradigm shift is used to explore changes that are occurring in public lands and water resources
management. Recent policy developments suggest that the traditional paradigm, which is characterized by sustained yield, is
in the process of being invalidated. While no new paradigm has been fully accepted, the emerging paradigm does appear to be
based on two principles: ecosystem management and collaborative decision making. Implementation of these two principles is
likely to require extensive revision of traditional management practices and institutions. Failure to address these issues
could result in adoption of the rhetoric of change without any lasting shift in management practices or professional attitudes. 相似文献
63.
Thomas M. Bonnicksen 《Environmental management》1985,9(5):379-391
Initial decision analysis (IDA) is a microcomputer based decision-making technique that is organized so that a rational, step-by-step, procedure can be followed to use existing knowledge to develop resource policies. The IDA process provides a systematic way for participants to define their own problem and to explore jointly alternative solutions. IDA is particularly suited to resolving complex problems involving many groups with conflicting interests. IDA is illustrated with data from the US Forest Service's Draft Environmental Impact Statement for the 1985 to 2030 Resource Planning Act Program for the United States. Four policy options are evaluated: maximization of timber production, of grazing, and of wilderness, and a dominant use policy that concentrates timber management on productive sites. Policies were evaluated using a new mathematical satisficing procedure. Mathematical satisficing of simulated policy consequences showed that, for selected performance standards, current RPA policies are superior to the four alternative policies examined. 相似文献
64.
Aregai Tecle Martin M. Fogel Lucien Duckstein 《Journal of the American Water Resources Association》1988,24(6):1169-1178
ABSTRACT: The impacts of alternative forest watershed management practices are examined from a multicriterion viewpoint in order to select the most satisfactory management scheme. The selection process is carried out using two types of multicriterion decision making techniques: the outranking types of ELECTRE I and II, and the distance-based type of compromise programming (CP). The process is illustrated using the U.S. Forest Service Beaver Creek Experimental Watershed in the Salt-Verde River Basin of Arizona as an example. The desired objectives of the experimental study and the alternative forest watershed resources management schemes are transformed into an evaluation matrix of alternatives versus criteria array. Analyses of the matrix using the aforementioned techniques result in a complete preference ordering of the feasible alternatives in the cases of ELECTRE LI and CP and a partial ordering when ELECTRE I is used. In addition, some sensitivity analyses have been performed and showed ELECTRE II and CP to be fairly robust with respect to parameter changes, while ELECTRE I being highly sensitive to changes in threshold levels. Overall the three techniques pointed out that 65 percent vegetation cut is the best management scheme, while the next best is shown to be 50 percent vegetation cut. 相似文献
65.
Julia Badal Graf 《Journal of the American Water Resources Association》1995,31(2):265-281
ABSTRACT: The effect of unsteadiness of dam releases on velocity and longitudinal dispersion of flow was evaluated by injecting a fluorescent dye into the Colorado River below Glen Canyon Dam and sampling for dye concentration at selected sites downstream. Measurements of a 26-kilometer reach of Glen Canyon, just below Glen Canyon Dam, were made at nearly steady dam releases of 139, 425, and 651 cubic meters per second. Measurements of a 380-kilometer reach of Grand Canyon were made at steady releases of 425 cubic meters per second and at unsteady releases with a daily mean of about 425 cubic meters per second. In Glen Canyon, average flow velocity through the study reach increased directly with discharge, but dispersion was greatest at the lowest of the three flows measured. In Grand Canyon, average flow velocity varied slightly from subreach to subreach at both steady and unsteady flow but was not significantly different at steady and unsteady flow over the entire study reach. Also, longitudinal dispersion was not significantly different during steady and unsteady flow. Long tails on the time-concentration curves at a site, characteristic of most rivers but not predicted by the one-dimensional theory, were not found in this study. Absence of tails on the curves shows that, at the measured flows, the eddies that are characteristic of the Grand Canyon reach do not trap water for a significant length of time. Data from the measurements were used to calibrate a one-dimensional flow model and a solute-transport model. The combined set of calibrated flow and solute-transport models was then used to predict velocity and dispersion at potential dam-release patterns. 相似文献
66.
Richard S. Krannich Sean P. Keenan Michael S. Walker Donald L. Hardesty 《Journal of the American Water Resources Association》1995,31(5):851-865
ABSTRACT: Survey data collected in the San Joaquin Valley of southern California and the Grand Valley of western Colorado reveal that residents of both areas believe that a severe sustained drought is likely to occur within the next 20–25 years and that their communities would be seriously impacted by such an event. Although a severe sustained drought affecting the Colorado River Basin would cause major economic and social disruptions in these and other communities, residents express little support for water management alternatives that would require significant shifts in economic development activities or in water use and allocation patterns. In particular, residents of these areas express little support for strategies such as construction and growth moratoriums, mandatory water conservation programs, water transfers from low-to high-population areas, water marketing, or reallocations of water from agricultural to municipal/industrial uses. This rejection of water management strategies that would require a departure from “business as usual” with respect to water use and allocations severely restricts the capacity of these and similar communities to respond effectively should a severe sustained drought occur. 相似文献
67.
Taiye B. Sangoyomi Benjamin L. Harding 《Journal of the American Water Resources Association》1995,31(5):925-938
ABSTRACT: We evaluated the effects of institutional responses developed for coping with a severe sustained drought (SSD) in the Colorado River Basin on selected system variables using a SSD inflow hydrology derived from the drought which occurred in the Colorado River basin from 1579–1616. Institutional responses considered are reverse equalization, salinity reduction, minimum flow requirements, and temporary suspension of the delivery obligation of the Colorado River Compact. Selected system variables (reservoir contents, streamflows, consumptive uses, salinity, and power generation) from scenarios incorporating the drought-coping responses were compared to those from Baseline conditions using the current operating criteria. The coping responses successfully mitigated some impacts of the SSD on consumptive uses in the Upper Basin with only slight impacts on consumptive uses in the Lower Basin, and successfully maintained specified minimum streamflows throughout the drought with no apparent effect on consumptive uses. The impacts of the coping responses on other system variables were not as clear cut. We also assessed the effects of the drought-coping responses to normal and wet hydrologic conditions to determine if they were overly conservative. The results show that the rules would have inconsequential effects on the system during normal and wet years. 相似文献
68.
城市防洪工程风险决策方法 总被引:2,自引:2,他引:2
本文着重讨论了与城市防洪工程决策制定密切相关的几个问题:①城市防洪工程设计标准的确定;②现有防洪工程的性能评估,③最优防洪工程对策的确定等,并在风险分析的基础上,给出了解决上述问题的方法。所得结论可为城市防洪工程决策的制定提供较为科学的理论依据。 相似文献
69.
Jessica Sargent‐Michaud Kevin J. Boyle Andrew E. Smith 《Journal of the American Water Resources Association》2006,42(5):1237-1245
ABSTRACT: This study was undertaken to investigate the cost effectiveness of selected arsenic avoidance methods. Annual costs of reverse osmosis (RO), activated alumina (AA), bottled water, and rented and purchased water coolers for various household sizes in Maine were compared. Relative ranking of systems shows that RO ($411 annually) is the most cost effective, followed by AA ($518) and one‐gallon jugs of water ($321 to $1,285), respectively, for households larger than one person. One‐gallon jugs ($321) followed by 2.5‐gallon jugs ($358) of water were found to be the most cost effective for households of one person or for households with arsenic III concentrations of 0.02 to 0.06 mg/L and arsenic V concentrations of 0.08 to 1.0 mg/L. Point‐of‐entry systems and water coolers were not found to be cost effective under any of the study's conditions. The research reported here will help states make more definitive treatment recommendations to households regarding the cost effectiveness of alternative treatment systems to reduce arsenic concentrations below 0.01 mg/L. While arsenic removal technologies are improving, which enhances removal rates and reduces costs, the major insights from this analysis appear to be reinforced by technological improvements. 相似文献
70.
Donald M. Anderson Mark W. Rodney 《Journal of the American Water Resources Association》2006,42(5):1391-1403
ABSTRACT: Efforts are under way to recover habitat for several threatened and endangered species in and along the Platte River in central Nebraska. A proposed recovery program for these species requires a means of characterizing “wet” versus “normal” versus “dry” hydrologic conditions in order to set corresponding Platte River instream flow targets. Methods of characterizing hydrologic conditions in real time were investigated for this purpose. Initially, 10 watershed variables were identified as potentially valuable indicators of hydrologic conditions. Ultimately, six multiple linear regression equations were developed for six periods of the year using a subset of these variables expressed as frequencies of nonexceedence. The adequacy of these equations for characterizing conditions was assessed by evaluating their historic correlation to subsequent flow in the central Platte River (1947–1994). These equations explained 54 to 82 percent of variability in the observed flow exceedences in the validation datasets, depending upon the period of year evaluated. These equations will provide initial criteria for setting applicable flow targets to determine, in real time, whether water regulation projects associated with the species recovery effort can divert or store flows without conflicting with recovery objectives. 相似文献