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21.
Norman K. Whittlesey Kenneth C. Gibbs Walter R. Butcher 《Journal of the American Water Resources Association》1978,14(3):663-678
ABSTRACT: Increased irrigation as a means of achieving economic development can impose significant social costs on the state or region of growth. The growth in population induced by additional irrigation will require new roads, water and sewage facilities, schools, fire and police protection, etc. Also the increased energy demands due to irrigation and growth in economic activity must be met. Capital investments required to service these needs of new development can become very large. This study attempts to measure such social overhead costs or irrigation development for some specific irrigation project areas of Eastern Washington. It is shown that investment costs in overhead items can reach $2,000 per acre irrigated or $70,000 per job created. Alternatively, the annual costs can equal $180 per acre or $6,700 per worker. These costs must be paid locally through increased taxes, utility rates, or costs for services. 相似文献
22.
The morphogenesis of ephyrae of Atorella vanhoeffeni Bigelow, 1909 (Werner, 1967) and of Nausithoe maculata Jarms, 1990 during strobilation is described. We found differences in the developmental pattern of marginal structures and structural
changes of longitudinal muscle tubes in particular. During strobilation the polyp’s tetraradiate symmetry is passed to the
ephyra of both taxa as a tetraradiate central symmetry that we consider a major plesiomorphic character. The present results
also indicate divergent patterns of ephyra development during strobilation that lead to variable marginal symmetries of ephyrae
and thus of medusae. Therefore, the marginal symmetry of medusae of N. maculata is octoradiate and of A. vanhoeffeni is hexaradiate. We conclude the latter is stated as derived pattern. These results lead us to maintain both families Nausithoidae
and Atorellidae. 相似文献
23.
Norman A. Lyshkow 《Journal of the Air & Waste Management Association (1995)》2013,63(10):687-689
Sulfur dioxide is quantitatively scrubbed from atmospheric and stack gas samples through the use of a unique rotary scrubber which provides collection efficiencies in excess of 97% in the PPB through PPM range. The scrubber in addition permits the use of water as a scrubbing vehicle which, when combined with a bleached pararosanaline reagent, provides high specificity and sensitivity for the analysis. By the elimination of the tetrachloromercurate solution, cell staining is eliminated and the stability required for continuous analysis by the reagent is achieved. 相似文献
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In many species reproduction and embryonic development have been shown to be sensitive to environmental contaminants. Understanding embryonic exposure to environmental contaminants is thus highly important. In this study concentrations of brominated flame retardants (BFRs) were measured in zebrafish eggs after parental exposure for 42 days via the diet. Zebrafish were exposed to two doses of eleven structurally-diverse BFRs. Eight BFRs were detected in the female zebrafish and maternal transfer to eggs was evident for all eight compounds. The highest concentrations in eggs were observed for hexabromocyclododecane (HBCD) and 2,4,4'-tribromodiphenyl ether (BDE 28), followed by 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE 183) and tetrabromobisphenol A 2,3-dibromopropyl ether (TBBPA DBPE). Five potential BFR metabolites were tentatively identified in female fish and maternal transfer was observed also for these compounds. The lipid adjusted concentrations in eggs were significantly higher than the concentrations in female fish for several of the BFRs. Further, the results showed a generally higher transfer in the lower exposure level and also indicated a dependency on the physico-chemical properties of the compounds. 相似文献
28.
Using GIS to Generate Spatially Balanced Random Survey Designs for Natural Resource Applications 总被引:2,自引:0,他引:2
Theobald DM Stevens DL White D Urquhart NS Olsen AR Norman JB 《Environmental management》2007,40(1):134-146
Sampling of a population is frequently required to understand trends and patterns in natural resource management because financial
and time constraints preclude a complete census. A rigorous probability-based survey design specifies where to sample so that
inferences from the sample apply to the entire population. Probability survey designs should be used in natural resource and
environmental management situations because they provide the mathematical foundation for statistical inference. Development
of long-term monitoring designs demand survey designs that achieve statistical rigor and are efficient but remain flexible
to inevitable logistical or practical constraints during field data collection. Here we describe an approach to probability-based
survey design, called the Reversed Randomized Quadrant-Recursive Raster, based on the concept of spatially balanced sampling
and implemented in a geographic information system. This provides environmental managers a practical tool to generate flexible
and efficient survey designs for natural resource applications. Factors commonly used to modify sampling intensity, such as
categories, gradients, or accessibility, can be readily incorporated into the spatially balanced sample design. 相似文献
29.
Mark S. Reed Anil Graves Norman Dandy Helena Posthumus Klaus Hubacek Joe Morris Christina Prell Claire H. Quinn Lindsay C. Stringer 《Journal of environmental management》2009
Stakeholder analysis means many things to different people. Various methods and approaches have been developed in different fields for different purposes, leading to confusion over the concept and practice of stakeholder analysis. This paper asks how and why stakeholder analysis should be conducted for participatory natural resource management research. This is achieved by reviewing the development of stakeholder analysis in business management, development and natural resource management. The normative and instrumental theoretical basis for stakeholder analysis is discussed, and a stakeholder analysis typology is proposed. This consists of methods for: i) identifying stakeholders; ii) differentiating between and categorising stakeholders; and iii) investigating relationships between stakeholders. The range of methods that can be used to carry out each type of analysis is reviewed. These methods and approaches are then illustrated through a series of case studies funded through the Rural Economy and Land Use (RELU) programme. These case studies show the wide range of participatory and non-participatory methods that can be used, and discuss some of the challenges and limitations of existing methods for stakeholder analysis. The case studies also propose new tools and combinations of methods that can more effectively identify and categorise stakeholders and help understand their inter-relationships. 相似文献
30.
The investigation is concerned with the reported incidence and frequency of homesickness following an environmental transition to university in a group of 101 first year university students. Definitions provided by students indicated that homesickness is a collective term for a number of cognitive and emotional/motivational experiences primarily associated with missing home and wanting to visit it. 60% reported homesickness. Geographical distance of the move and relative lack of satisfaction with features of the psychosocial and physical environment in the new place were found to be associated with homesickness reporting. Personality and circumstantial factors such as decisional control over the move and cognitive failure levels were also associated with homesickness reporting. A two-stage risk model is proposed in which an environmental relocation is a necessary but not a sufficient condition for homesickness; features of the new place combine with personality factors to precipitate the experience. 相似文献