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351.
Gary D. Tasker Alan W. Burns 《Journal of the American Water Resources Association》1974,10(6):1133-1142
ABSTRACT: The empirical fit of an annual harmonic function to stream temperature measurements in central New England can be improved by considering a harmonic period of less than 365 days instead of 365 or 366 days. Generalized equations, developed using periodic temperature data from 27 streamflow stations, allow predictions of stream temperature at any site given (1) the mean basin altitude (E), in meters above mean sea level, and (2) station latitude (LAT), in degrees. Stream temperature t, in degrees Celsius, on day number d, in days starting with January 1, is estimated as: in which, M = 31.48 – 0.0025 (E) ? 0.4635 (LAT) with standard error of estimate of 0.62°C, and τ= 1228.88 – 21.01 (LAT) with standard error of estimate of 14.1 days. 相似文献
352.
环西宁地区旅游资源现状及开发对策 总被引:2,自引:0,他引:2
环西宁地区是青海省经济的重心,也是旅游资源丰富且特色鲜明的区域,该区旅游资源的开发对青海省旅游业的整体发展具有带动作用.在分析环西宁地区旅游资源开发的优势及存在问题的基础上,提出了旅游资源开发对策. 相似文献
353.
354.
Howard D. Passell Clifford N. Dahm Edward J. Bedrick 《Journal of the American Water Resources Association》2004,40(1):111-127
ABSTRACT: Hydrological and geochemical spatial patterns and temporal trends were analyzed using U.S. Geological Survey (USGS) water quality data collected from 1975 to 1999 along the uppermost 600 km of the Rio Grande in Colorado and New Mexico. Data on discharge, specific conductivity (SC), total dissolved solids (TDS), pH, Ca2+, Na+, Mg2+, K+, HCO3?, SO42‐, Cl?, F?, and SiO2 came from six USGS stations ranging from the Colorado‐New Mexico border to below Albuquerque, New Mexico. Linear regression, Kendall's S, and Seasonal Kendall's S’ were used to detect trends, and ANOVA was used to analyze spatial differences between stations. Statistically significant increasing trends occurred in SC, TDS, Ca2+, Na+, Mg2+, K+, Cl?, and F?in the uppermost reaches, and significant decreasing trends of SC, TDS, Ca2+, Mg2+, K+, HCO3?, and SO42‐occurred at the lower stations around Albuquerque. Both fluoride concentrations and pH values increased at and below Albuquerque over the study period. Discharge data show an increasing trend across all stations. Spatially, data for dissolved substances show generally linear upstream to downstream increases in concentrations in the upper four stations, with several notable nonlinear increases at and below Albuquerque (SC, TDS, Na+, Cl?). Significant increases in pH appear at and below Albuquerque, relative to upstream stations, probably due to improved sewage treatment. 相似文献
355.
Irene B. Wilson 《Journal of Environmental Planning and Management》1986,29(1):26-34
The new towns programme in France can be said to have run its course and now is an opportune moment to look back at the programme and review the context, content and progress. The paper gives a general context within which the new towns developed from the time of the Third National Plan, and subsequent policies aimed to stem migration to Paris. Progress of the new towns is discussed and some of the problems and successes are highlighted. 相似文献
356.
J. Wawrzynski 《Journal of Environmental Planning and Management》1986,29(1):34-38
No we Tychy is the most prominent and successful of the new towns in post‐war Poland. The paper describes the new town programme resulting from the Regional Plan for Upper Silesia and provides an appraisal of the town's achievement from the point of view of the residents’ living conditions, the usability of the housing stock and the spatial character of the town. The conclusions provide a critique of the process through which the town was developed and built. 相似文献
357.
Charles T. Roman Robert A. Zampella Andrew Z. Jaworski 《Journal of the American Water Resources Association》1985,21(6):1005-1012
Wetland protection regulations and guidelines often require the delineation of precise wetland boundaries on a case-by-case basis. In this study, conducted in the New Jersey Pinelands, an ecological characterization of vegetation composition, soil and hydrologic relationships along upland to wetland Pinus rigida - dominated transittions provided the basis for a multiparameter approach to wetland boundary delineation. The transitional data set was analyzed by direct gradient analysis, cluster analysis and ordination. It is concluded that vegetation composition can be a principal factor in delineating wetland boundaries along natural upland to wetland transitions. However, where distinct vegetation changes are not observed, a feature of our study sites, a multiparameter approach should be used. 相似文献
358.
Sean A. Weaver 《Journal of Agricultural and Environmental Ethics》2006,19(4):367-389
Sodium monofluoroacetate (1080) is a mammalian pesticide used in different parts of the world for the control of mammalian pest species. In New Zealand it is used extensively and very successfully as a conservation management tool for the control of brushtail possums (Trichosurus vulpecula) – an introduced marsupial that has become a substantial agricultural and conservation management pest. Possums pose a threat to cattle farming in New Zealand as they are a vector for bovine tuberculosis. In protected natural areas, possum browsing is responsible for large scale defoliation of native vegetation. As with many other pesticides, there has been some degree of popular concern about the use of this toxin and its safety, with particular reference to non-target effects. These concerns have been associated with potential non-target effects on human health, and the health of animals of recreational value (e.g., hunting dogs and game animals). This has led to the development of a strong “anti-1080” lobby in New Zealand. In contrast, this study encompasses a science-based risk analysis focusing on the potential risks to non-target native wildlife with a particular focus on chronic toxicity. It finds that there is evidence that 1080 may have endocrine disrupting capabilities (with potential relevance for non-target wildlife) but that this still needs more detailed investigation. This can be clarified by further targeted research. Further research is also needed to test the degradation rates of 1080 and its breakdown products at ecologically-relevant temperatures (i.e., winter stream temperatures – below 11 °C). Such research may demonstrate that some adjustment to 1080 risk management is warranted in New Zealand, or it may help to put to rest the current controversy over the use of this cost effective conservation management tool. 相似文献
359.
/ In general, diadromous (and particularly amphidromous and catadromous) freshwater fishes decline in frequency of occurrence, change age/size structure, and probably also decline in abundance with increasing elevation and distance upstream from the sea. In freshwater fish faunas with a high proportion of migratory species, as in New Zealand, these changes in occurrence and abundance result in a breakdown of the relationship between fish abundance and habitat quality, making application of the index of biotic integrity (IBI) as a measure of habitat quality problematical since the index depends on the relationship between population metrics and habitat quality. An alternative approach applicable to assessing temporal changes in habitat quality and that uses a large database on fish distributions, involves analysis of the distribution of species across their natural distributions. In this paper we generate curves of occurrence of species across ranges of altitude and distance inland and show, through comparisons of data subsets, that the curves are consistent estimators of species' occurrence and therefore useful as indicators of habitat quality. 相似文献
360.