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941.
A multivariate statistical method for analyzing spatial patterns of water quality in Georgia and Kansas was tested using data in the US Environmental Protection Agency's STORET data system. Water quality data for Georgia and Kansas were organized by watersheds. We evaluated three questions: (a) can distinctive regional water quality patterns be detected and predicted using only a few water quality variables, (b) are regional water quality patterns correlated with terrestrial biotic regions, and (c) are regional water quality patterns correlated with fish distributions? Using existing data, this method can distinguish regions with water quality very different from the average conditions (as in Georgia), but it does not discriminate well between regions that do not have diverse water quality conditions (as in Kansas). Data that are spatially and temporally adequate for representing large regions and for multivariate statistical analysis are available for only a few common water quality parameters. Regional climate, lithology, and biotic regimes all have the potential to affect water quality, and terrestrial biotic regions and fish distributions do compare with regional water quality patterns, especially in a state like Georgia, where watershed characteristics are diverse. Thus, identifiable relationships between watershed characteristics and water quality should allow the development of an integrated landaquatic classification system that would be a valuable tool for resource management. Because geographical distributions of species may be limited by Zoogeographic and environmental factors, the recognition of patterns in fish distributions that correlate with regional water quality patterns could influence management strategies and aid regional assessments. 相似文献
942.
Richard L. Cooley Aldo V. Vecchia 《Journal of the American Water Resources Association》1987,23(4):581-599
ABSTRACT: A method is derived to efficiently compute nonlinear confidence and prediction intervals on any function of parameters derived as output from a mathematical model of a physical system. The method is applied to the problem of obtaining confidence and prediction intervals for manually-calibrated ground-water flow models. To obtain confidence and prediction intervals resulting from uncertainties in parameters, the calibrated model and information on extreme ranges and ordering of the model parameters within one or more independent groups are required. If random errors in the dependent variable are present in addition to uncertainties in parameters, then calculation of prediction intervals also requires information on the extreme range of error expected. A simple Monte Carlo method is used to compute the quantiles necessary to establish probability levels for the confidence and prediction intervals. Application of the method to a hypothetical example showed that includsion of random errors in the dependent variable in addition to uncertainties in parameters can considerably widen the prediction intervals. 相似文献
943.
Nicholas L. Clesceri Sidney J. Curran Richard I. Sedlak 《Journal of the American Water Resources Association》1986,22(6):983-990
ABSTRACT: Export coefficients (kg/km2/yr) for dissolved ortho-phosphate (OP), total phosphorus (TP), total inorganic nitrogen (TIN), and total nitrogen (TN) were derived for watersheds in Wisconsin using data bases available for 17 basins from the U.S. Environmental Protection Agency — National Eutrophication Survey, U.S. Geological Survey, and the Wisconsin Department of Natural Resources. Three general land use categories, representative of most regions in Wisconsin, were established: forest, mixed, and agricultural. Data for the 17 basins indicated greater exports of OP. TP, TIN, and TN as the percentage of forest decreased and agriculture increased. These region-specific coefficients are compared to the values reported in the literature representing much broader areas of the U.S. 相似文献
944.
Indonesia is a major exporter of tropical hardwoods. The country's goal is to establish integrated wood industries by reducing the export of unprocessed sawlogs. The value of hardwood sawlog exports has decreased by twothirds in 1986 dollars since 1978, while the value of hardwood sawnwood and plywood exports has increased sixfold. Sawlog exports are now banned. This article contrasts the official governmental policy on forest industry development with the operational realities of doing business in Indonesia. 相似文献
945.
Richard J. Tobin 《Environmental management》1986,10(6):785-796
An important goal of the Reagan administration has been to shift responsibility for many public programs from the US federal government to the states. This New Federalism seeks to restore a proper balance to the federal system and to ensure an effective working partnership between the states and the federal government. Such a partnership is especially important for many environmental laws because these laws often give states primary responsibility for the control and abatement of pollution.This research examines the extent to which the Reagan administration has succeeded in improving intergovernmental environmental relations in terms of state implementation of the Clean Water Act. Data from a 1985 survey of directors of state water quality control programs are compared with responses to a similar survey that the US General Accounting Office conducted in 1979. The latter survey found considerable dissatisfaction on the part of state directors with the quality of their relations with the US Environmental Protection Agency. Although some improvement can be noted between 1979 and 1985, the Reagan administration's efforts to improve intergovernmental relations appear to have been of limited consequence, to the possible detriment of effective implementation of the Clean Water Act. 相似文献
946.
Food habits of white-tailed deer (Odocoileus virginianus) were examined from January to November 1984 via fecal-pellet analysis at Valley Forge National Historical Park (VFNHP), which represents an island habitat for deer surrounded by extensive urbanization, in southeastern Pennsylvania. In addition, use of fields by deer was compared to food habits. Herbaceous vegetation (forbs, leaves of woody plants, and conifer needles) was the predominant food type in all seasons except fall. Acorns and graminoids (grasses and sedges) were important food resources in fall and spring, respectively. Use of woody browse (twigs) was similar among seasons. Field use was relatively high during fall, winter without snow cover (<20 cm), and spring when food resources in fields were readily available. In contrast, use of fields was lowest in summer when preferred woodland foods were available and in winter with snow cover when food in fields was not readily accessible. Patterns of food-type use by deer at VFNHP indicate the year-round importance of nonwoody foods and field habitats to deer populations on public lands such as national parks in the northeastern United States. 相似文献
947.
948.
Ernest T. Smerdon John A. Gronouski Judith M. Clarkson 《Journal of the American Water Resources Association》1988,24(6):1257-1262
ABSTRACT: Texas is one of the states in which limitations in water supplies could severely constrain economic growth in certain areas. The traditional planning approach for addressing this problem has involved devising schemes for large water development projects, which for many years included the importation of water from other states. Now the attitude towards water resource management is changing, and it is generally agreed that better management of existing supplies is the preferred approach. In this paper we review some of the changes that have recently occurred in Texas, including attempts to streamline the water institutions in such a way that they might be more responsive to the need for more comprehensive management of water resources statewide, with greater emphasis on social and environmental concerns. 相似文献
949.
Hypotheses were developed based on a coping model that views political behaviour (voice) as a fight response and turnover (exit) as a flight response to job stress. Data were collected from a group of professional, public employees and turnover dates were obtained for the group 13 months after completion of questionnaires. Multiple regression analysis was employed to test hypotheses. Stressors of interest were person-environment fit (P-E fit), role conflict (RC), and role ambiguity (RA). Psychological strains (job dissatisfaction and lowered commitment) were hypothesized to mediate the stressor-coping behaviour relationship. Turnover (TO) behaviour was the ultimate organizationally relevant outcome of coping behaviours. Job satisfaction and commitment were significantly related to intentions to leave. Political action was directly related to P-E fit and this relationship was not mediated by satisfaction or commitment. The relationship between RA and politics was moderated by commitment. Less committed employees tended to exhibit political behaviour in response to RA. Both coping responses (intentions to leave and political action) predicted significant portions of retention/turnover variance. 相似文献
950.
Using structural equations, we estimated the relationship between employees' experiences of seven job conditions, that have been identified as potential job stressors, and psychological distress in a random sample of 504 full-time employed men and women in dual-earner couples. The seven job conditions were: skill discretion, decision authority, schedule control, job demands, pay adequacy, job security, and relations with supervisor. We found that two job conditions — skill discretion and job demands — were related to psychological distress, whereas five other conditions were not. These findings lend partial support to Karasek's job demand — job control model. In our analysis, skill discretion, one of the two components of job control (referred to jointly as decision latitude) was related to distress, however, decision authority, the second component, was not. A third aspect of control, schedule control, was also unrelated to distress. For full-time employed women and men in dual-earner couples, the additive effects of feeling concerned about having to do dull, monotonous work and having to work under pressure of time and conflicting demands were associated with psychological distress. Finally, the magnitude of the relationships between these job experiences and psychological distress did not differ between men and women. 相似文献