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551.
John B. Whitcomb 《Journal of the American Water Resources Association》1990,26(6):921-926
ABSTRACT: A water use model was developed to estimate water savings from installation of low-flow showerheads and toilet displacement devices in residential housing. The model measures household water use in per capita terms with adjustments for age of occupants, household income, if occupants responsible for direct payment of water bill, and type of water fixtures. Detailed data on 308 single family residences involved with a pilot retrofit program in the Seattle, Washington, area were analyzed. We estimated per capita indoor water use to decline by 6.4 and 2.1 percent from complete installation of low-flow showerheads and toilet displacement devices, respectively. 相似文献
552.
553.
Summary Plants and animals were investigated to ascertain their- radioactivity values on both dune sites (machair) and inter-tidal sites on the western coast of Barra, Outer Hebrides, UK. Material in both habitats was clearly contaminated. The accumulation of-radioactivity through food webs to organisms such asNucella lapillus (dog whelk) in the inter-tidal sites and in sheep and cattle in terrestrial sites is described.Dr F.B. Pyatt is the Section Leader and Principal Lecturer in Ecology in the Department of Life Sciences at Trent Polytechnic. Dr E.H. Beaumont was previously Lecturer in Zoology at St Hugh's College, University of Oxford, Oxford, UK. 相似文献
554.
James B. Reynolds Rodney C. Simmons Alan R. Burkholder 《Journal of the American Water Resources Association》1989,25(3):625-635
ABSTRACT: During the summers of 1982, 1983, and 1985, we assessed the effects of placer mining sedimentation on Arctic grayling, Thymallus arcticus, in the headwaters of Birch Creek, northeast of Fairbanks, Alaska. We compared differences between two streams (one that was undisturbed and one with mining activity upstream) near the confluence. Studies of caged fish demonstrated that, if grayling could not escape from streams carrying mining sediments, they would either die at high rates (sac fry) or suffer gill damage, starvation, and slowed maturation (age-O fingerlings and age-2 juveniles). Indirect effects of sedimentation, through loss of summer habitat for feeding and reproduction, may more severely affect grayling populations than the direct effects of sedimentation on the health and survival of individual fish. 相似文献
555.
556.
Craig B. Andrews 《Natural resources forum》1991,15(1):50-58
Attitudes in developing countries with respect to private investment in natural resources have changed substantially in recent years. Countries must now compete for such investment by ensuring that policies pertaining to state participation, financing, marketing and taxation of mining ventures provide the investor with returns that are commensurate with the risks taken. Governments must also be prepared to help the investor compete on world markets through lower capital and operating costs. This entails granting exemptions of customs, excise and value added taxes as well as providing for policies on taxation, government participation, industrial relations, safety and environment, and procurement and personnel that are in line with international mining industry standards. Efforts to promote mining sector investment through the strengthening of technical ministries, preparation of basic geological and project information, investment symposia and an international mining council can be helpful in bringing opportunities to the attention of the investment community. But, these efforts can only succeed if the policy changes now being put into place continue to evolve and contribute to an atmosphere in which entrepreneurship and private investment can flourish. 相似文献
557.
F B. Pierson W. H. Blackburn S. S. Van Vactor J. C. Wood 《Journal of the American Water Resources Association》1994,30(6):1081-1089
ABSTRACT: Most hydrologic models require input parameters which represent the variability found across an entire landscape. The estimation of such parameters is very difficult, particularly on rangeland. Improved model parameter estimation procedures are needed which incorporate the small-scale and temporal variability found on rangeland. This study investigates the use of a surface soil classification scheme to partition the spatial variability in hydrologic and interrill erosion processes in a sagebrush plant community. Four distinct microsites were found to exist within the sagebrush coppice-dune dune-interspace complex. The microsites explained the majority of variation in hydrologic and interrill erosion response found on the site and were discernable based on readily available soil and vegetation information. The variability within each microsite was quite low and was not well correlated with soil and vegetation properties. The surface soil classification scheme defined in this study can be quite useful for defining sampling procedures, for understanding hydrologic and erosion processes, and for parameterizing hydrologic models for use on sagebrush range-land. 相似文献
558.
Saud A. Amer Timothy O. Keefer Mark A. Weltz David C. Goodrich Leslie B. Bach 《Journal of the American Water Resources Association》1994,30(1):69-83
ABSTRACT: Certain physical and chemical properties of soil vary with soil water content. The relationship between these properties and water content is complex and involves both the pore structure and constituents of the soil solution. One of the most economical techniques to quantify soil water content involves the measurement of electrical resistance of a dielectric medium that is in equilibrium with the soil water content. The objective of this research was to test the reliability and accuracy of fiberglass soil-moisture electrical resistance sensors (ERS) as compared to gravimetric sampling and Time Domain Reflectometry (TDR). The response of the ERS was compared to gravimetric measurements at eight locations on the USDA-ABS Walnut Gulch Experimental Watershed. The comparisons with TDR sensors were made at three additional locations on the same watershed. The high soil rock content (≥45 percent) at seven locations resulted in consistent overestimation of soil water content by the ERS method. Where rock content was less than 10 percent, estimation of soil water was within 5 percent of the gravimetric soil water content. New methodology to calibrate the ERS sensors for rocky soils will need to be developed before soil water content values can be determined with these sensors. 相似文献
559.
Lawrence B. Cahill 《环境质量管理》1994,4(2):71-81
Both opening and closing conferences are crucial elements of an effective environmental audit program. As many firms reengineer their auditing process, focusing on the beginning and end points of the on-site process makes eminent sense. This article discusses a variety of issues that often arise during the preparation and conduct of opening and closing conferences that can ultimately affect the success of the audit. 相似文献
560.
B. Bowonder 《The Environmentalist》1985,5(2):89-103
Summary The author summarizes the events of the Bhopal disaster as they are currently known, and draws a number of very important conclusions regarding safety procedures. These have implications for all developing countries.Dr. B. Bowonder is Chairman of the Centre for Energy, Environment and Technology at the Staff College and, as a regular contributor to this journal, he was invited to analyze the Bhopal incident. 相似文献