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281.
Satellite imagery is a useful tool for large-scale habitat analysis; however, its limitations need to be tested. We tested
these limitations by varying the methods of a habitat evaluation for white-tailed deer (Odocoileus virginianus) in the Adirondack Park, New York, USA, utilizing harvest data to create and validate the assessment models. We used two
classified images, one with a large minimum mapping unit but high accuracy and one with no minimum mapping unit but slightly
lower accuracy, to test the sensitivity of the evaluation to these differences. We tested the utility of two methods of assessment,
habitat suitability index modeling, and pattern recognition modeling. We varied the scale at which the models were applied
by using five separate sizes of analysis windows. Results showed that the presence of a large minimum mapping unit eliminates
important details of the habitat. Window size is relatively unimportant if the data are averaged to a large resolution (i.e.,
township), but if the data are used at the smaller resolution, then the window size is an important consideration. In the
Adirondacks, the proportion of hardwood and softwood in an area is most important to the spatial dynamics of deer populations.
The low occurrence of open area in all parts of the park either limits the effect of this cover type on the population or
limits our ability to detect the effect. The arrangement and interspersion of cover types were not significant to deer populations. 相似文献
282.
Use of Microbial Community to Evaluate Performance of a Wetland System in Treating Pb/Zn Mine Drainage 总被引:2,自引:0,他引:2
The performance of a wetland system in treating lead (Pb)/zinc (Zn) mine drainage was evaluated by using the polyurethane
foam unit (PFU) microbial community (method), which has been adopted by China as a standardized procedure for monitoring water
quality. The wetland system consisted of four cells with three dominant plants: Typha latifolia, Phragmites australis and Paspalum distichum. Physicochemical characteristics [pH, EC, content of total suspended solid (TSS) and metals (Pb, Zn, Cd, and Cu)] and PFU
microbial community in water samples had been investigated from seven sampling sites. The results indicated that the concentrations
of Pb, Zn, Cd, Cu, and TSS in the mine drainage were gradually reduced from the inlet to the outlet of the wetland system
and 99%, 98%, 75%, 83%, and 68% of these metals and TSS respectively, had been reduced in concentration after the drainage
passed through the wetland system. A total of 105 protozoan species were identified, the number of protozoa species and the
diversity index (DI) gradually increased, while the heterotrophic index (HI) gradually decreased from the inlet to the outlet
of the wetland system. The results indicated that DI, HI, and total number species of protozoa could be used as biological
indicators indicating the improvement of water quality. 相似文献
283.
284.
Leo M. Eisel Kimberly M. Bradley Charles F Leaf 《Journal of the American Water Resources Association》1990,26(3):519-526
ABSTRACT: The consumptive loss from man-made snowmaking at six Colorado ski areas is calculated. The focus of the procedures in this investigation is on the consumptive loss that occurs to man-made snow particles during the period they reside on or in the snowpack until spring snowmelt (termed the watershed loss). Calculated watershed losses under a variety of precipitation and temperature conditions at six ski areas varied from 7 to 33 percent. These calculations were made using the calibrated Subalpine Water Balance Simulation Model (Leaf and Brink, 1973a, 1973b). The watershed loss of 7 to 33 percent indicates the range of likely watershed losses that can be expected at Colorado ski areas. A previous paper by the authors (Eisel et al., 1988) provided estimates of the mean consumptive loss during the snowmaking process (termed initial loss) for conditions existing at Colorado ski areas to be 6 percent of water applied. Therefore, based on the mean initial loss, the total consumptive loss from man-made snowmaking under conditions found at Colorado ski areas could be expected to range from 13 to 37 percent. These results demonstrate the range of total consumptive losses that could be expected in various years and for various watershed conditions. These total percentage losses cannot be extrapolated directly to other specific sites because the total consumptive loss is dependent on temperature during actual snowmaking, temperature and precipitation throughout the winter at the specific ski area, and watershed conditions at the ski area. Consumptive losses to man-made snow for a specific ski area should be estimated using the handbook procedures developed especially for this purpose (Colorado Ski Country USA, 1986b). 相似文献
285.
Waste materials for activated carbon preparation and its use in aqueous-phase treatment: a review 总被引:6,自引:0,他引:6
Dias JM Alvim-Ferraz MC Almeida MF Rivera-Utrilla J Sánchez-Polo M 《Journal of environmental management》2007,85(4):833-846
Commercial activated carbon is a preferred adsorbent for the removal of micropollutants from the aqueous phase; however, its widespread use is restricted due to high associated costs. To decrease treatment costs, attempts have been made to find inexpensive alternative activated carbon (AC) precursors, such as waste materials. Some reviews report the use of waste materials for the preparation of AC; however, these studies are restricted to either type of wastes, preparation procedures, or specific aqueous-phase applications. The present work reviews and evaluates literature dedicated both to the preparation of AC by recycling different types of waste materials and also to its application in various aqueous-phase treatments. It is clear that conventional (from agriculture and wood industry) and non-conventional (from municipal and industrial activities) wastes can be used to prepare AC, that can be applied in various aqueous treatment processes, namely to remove organic pollutants, dyes, volatile organic compounds, and heavy metals. Moreover, high surface areas can be obtained using either physical or chemical activation; however, combined treatments might enhance the surface properties of the adsorbent, therefore increasing its adsorption capacity. It is evident from the revision made that AC prepared from both conventional and non-conventional wastes might effectively compete with the commercial ones. This happens mostly when the activation procedures are optimized considering both the raw material used to produce the carbons and the contaminants to be removed. 相似文献
286.
L. M. Cox W. J. Rawls J. F. Zuzel 《Journal of the American Water Resources Association》1975,11(5):1009-1012
ABSTRACT: Snow, one of Nature's greatest reservoirs, supplies most of the usable water in the Western United States. Reliable predictions of the quantity and timing of the release of this water are used in making management decisions involving irrigation, stock water and municipal water supplies, hydro-power generation, recreation, navigation, and pollution control Practically oriented research is vital for the proper development and management of this resource. In southwestern Idaho, the Northwest Watershed Research Center, ARS, USDA, is conducting intensive investigations for assessing snow Volumes, snow water content, and snow-melt over a watershed. Application of these research findings will result in better development and management of the water stored as snow in Nature's reservoir. 相似文献
287.
288.
289.
290.
Inclusion compounds of cyclodextrins 总被引:1,自引:0,他引:1