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651.
Aimei Yang Wenlin Liu 《Environmental Communication: A Journal of Nature and Culture》2018,12(1):99-114
With the rise of global environmental issues and the emerging trend of corporate social responsibility (CSR) and corporation–non-governmental organization (NGO) alliances, organizations are developing collaborative alliances across sectors and nations to address environment problems. An international perspective is needed to explain the global structure of cross-sector alliance networks and the divergence or similarity of CSR communication across nations. This exploratory study draws insights from the national business systems (NBS) approach and applies social network analysis to examine the cross-sector alliance network among Global 500 Fortune corporations and 441 environmental international NGOs. Findings suggest that (1) an NBS approach to CSR can explain the network structural features of a cross-sector alliance network; (2) political context and national education level strongly predict green partnerships; and (3) regional differences are apparent in the global network, with Asian corporations lagging behind in cross-sector alliance building. 相似文献
652.
Five hypotheses have been proposed to explain polygyny in the red-winged blackbird (Agelaius phoeniceus). We categorized the hypotheses into three groups based on female preference for unmated versus monogamously mated males:
(1) the “polygyny threshold” model, “sexy son” hypothesis and the “asynchronous settlement” model, which assume that females
prefer unmated males to mated males on breeding situations of homogeneous quality; (2) the “neutral mate choice” hypothesis,
which assumes that females have no preference; and (3) the “cooperative female choice” model, which assumes that females prefer
monogamously mated males to unmated males. We tested the direction of female preference in two field experiments. In both
experiments, newly settling females were given a choice of two adjacent territories, one defended by an unmated male and the
other by a monogamously mated male. Male mating status was randomized with respect to the variation in territory quality and
male quality. Early in the breeding season, significantly more females settled with the unmated males than with the mated
males. Although more females settled with the unmated males than with the mated males late in the breeding season, the difference
was no longer significant. Female settlement late in the season appeared to be related to the tenure of the resident females:
the new females avoided territories where the resident females were in early stages of their nesting, but settled on territories
where the resident females were in late stages. The pattern of female settlement shows that females prefer unmated males to
mated males. The preference is consistent with the polygyny threshold model, sexy son hypothesis and the asynchronous settlement
model, and inconsistent with the neutral mate choice hypothesis and the cooperative female choice model. For this reason,
the latter two hypotheses are unlikely to explain the occurrence of polygyny in our population of red-winged blackbirds.
Received: 1 December 1994 / Accepted after revision: 28 October 1995 相似文献
653.
Gary D. Lynne 《Journal of the American Water Resources Association》1988,24(1):95-101
ABSTRACT: Economic information for efficient water allocation is difficult and costly to acquire under administrative water systems evolving under the Model Water Code. One approach to obtaining more information is to use a simulator like the Florida AGWATER model. The advantage of AGWATER is the potential for realistic prediction, because it operates at the field and day levels, using detailed information for each crop and tract. Unfortunately, such simulators are complex and require large amounts of costly input data. A better solution to the information problem may be to use markets for the marketable goods associated with water, because information is inherent in such a process. This approach will allow limited modeling and management resources to be put into using water models to generate information for the goods dependent on water that are difficult to market, like wildlife services. 相似文献
654.
Stephen D. Field Steven W. Effler 《Journal of the American Water Resources Association》1988,24(2):325-328
ABSTRACT: Seventy-three in situ primary productivity experiments over a six-month period in hypereutrophic Onondaga Lake near Syracuse, New York, demonstrated variations in the light saturation parameter, Ip, which in part describes the interaction between productivity and light. Substantial variations in Ip were observed (coefficient of variation = 60 percent). Variations in Ip were significantly correlated (greater than 99 percent confidence level) with temperature (°C). An Arrhenius-type relationship (Ip= 1.312 × 1.088 (T-20)) accounted for approximately 37 percent of the variation in Ip and may be appropriate for other systems dominated by green algae. 相似文献
655.
Zhuang Yahui Zhang Hongxun Wang Xiaoke & Li Changsheng Research Center for Eco-Environmental Sciences Chinese Academy of Sciences PO Box Beijing China Institute for the Study of Earth Oceans and Space University of New Hampshire Durham NH U.S.A. 《中国人口.资源与环境(英文版)》2004,(3)
The report summarizes surveys on carbon inventories and initiatives on sustainable carbon cycling taken by the Research Center for Eco-Environmental Sciences, where the authors work/worked. The first part of the report, which appeared in the preceding issue of this journal, deals with the concept of sustainable carbon cycling, the historic evolution of carbon cycling processes in China, carbon pool enhancement, value addition, carbon sequestration and carbon balance. This very paper, as the second part of the report, covers the results of carbon dynamics modeling, emission inventories of various carbon-containing greenhouse gases and their potential abatement measures. 相似文献
656.
王如松 《中国人口.资源与环境》1997,7(3):11-14
本文提出了社会发展综合实验区建设的实质就是协调好人口、资源与环境间的生态关系,为了促进社会—经济—自然复合生态系统的持续发展,探讨了科技引导实验区生态建设的途径。 相似文献
657.
Ambrose Goicoechea Eugene Z. Stakhiv Fu Li 《Journal of the American Water Resources Association》1992,28(1):89-102
ABSTRACT: A research project was undertaken for the U.S. Army Corps of Engineers to determine the relative utility and effectiveness of four well-known multicriteria decision making (MCDM) models for applications in realistic water resources planning settings. A series of experiments was devised to examine the impact of rating and ranking procedures on the decision making behavior of users (e.g., planners, managers, analysts, etc.) when faced with situations involving multiple evaluation criteria and numerous alternative planning projects. The four MCDM models tested were MATS-PC, EXPERT CHOICE, ARIADNE, and ELECTRE. Two groups of analysts and decision makers were tested. One group consisted of experienced U.S. Army Corps planners, while the other was comprised of graduate students. Based on a series of nonparametric statistical tests, the results identified EXPERT CHOICE as the preferred MCDM model by both groups based largely on ease of use and understandability. ARIADNE fostered the largest degree of agreement within and among the two groups of individuals tested. The tests also lend support to the claim that rankings are not affected significantly by the choice of decision maker (i.e., who uses any of these MCDM models) or which of these four models is used. 相似文献
658.
Wesley P. James John Warinner Michael Reedy 《Journal of the American Water Resources Association》1992,28(3):623-635
ABSTRACT: A computer model was developed, based on the Green-Ampt infiltration equation, to computed rainfall excess for a single precipitation event. The model requires an estimate of parameters related to hydraulic conductivity, wetting front section, and fillable porosity of the soil layers. Values of parameters were estimated from soil textural averages or regression equations based on percent sand, percent clay, and porosity. Average values of effective porosity and wetting front suction were largely acceptable due to the relatively low variability and low model sensitivity to the parameters. Hydraulic conductivity was the most erratic constituent of the loss rate computation due to the high variability and the high sensitivity of the computed infiltration to the parameter. The performance of the Green-Ampt infiltration model was tested through a comparison with the SCS curve number procedure. Seven watersheds and 23 storms with precipitation of one inch or greater were used in the comparison. For storms with less than one inch of rainfall excess, the SCS curve number procedure generally gave the best results; however, for six of the seven storms with precipitation excess greater than one inch, the Green-Ampt procedure delivered better results. In this comparison, both procedures used the same initial abstractions. The separation of rainfall losses into infiltration, interception, and surface retention is, in theory, an accurate method of estimating precipitation excess. In the second phase of the study using nine watersheds and 39 storms, interception and surface retention losses were computed by the Horton equations. Green-Ampt and interception parameters were estimated from value sin the literature, while the surface retention parameter was calibrated so that the computed runoff volumes matched observed volumes. A relationship was found between the surface retention storage capacity and the 15-day antecedent precipitation index, month of year, and precipitation amount. 相似文献
659.
Management of riparian habitats has been recognized for its importance in reducing instream effects of agricultural nonpoint
source pollution. By serving as a buffer, well structured riparian habitats can reduce nonpoint source impacts by filtering
surface runoff from field to stream. A system has been developed where key characteristics of riparian habitat, vegetation
type, height, width, riparian and shoreline bank slope, and land use are classified as discrete categorical units. This classification
system recognizes seven riparian vegetation types, which are determined by dominant plant type. Riparian and shoreline bank
slope, in addition to riparian width and height, each consist of five categories. Classification by discrete units allows
for ready digitizing of information for production of spatial maps using a geographic information system (GIS). The classification
system was tested for field efficiency on Tom Beall Creek watershed, an agriculturally impacted third-order stream in the
Clearwater River drainage, Nez Perce County, Idaho, USA. The classification system was simple to use during field applications
and provided a good inventory of riparian habitat. After successful field tests, spatial maps were produced for each component
using the Professional Map Analysis Package (pMAP), a GIS program. With pMAP, a map describing general riparian habitat condition
was produced by combining the maps of components of riparian habitat, and the condition map was integrated with a map of soil
erosion potential in order to determine areas along the stream that are susceptible to nonpoint source pollution inputs. Integration
of spatial maps of riparian classification and watershed characteristics has great potential as a tool for aiding in making
management decisions for mitigating off-site impacts of agricultural nonpoint source pollution. 相似文献
660.
The integration of Landsat TM and environmental GIS data sets using artificial intelligence rule-induction and decision-tree
analysis is shown to facilitate the production of vegetation maps with both floristic and structural information. This technique
is particularly suited to vegetation mapping in disturbed or hilly environments that are unsuited to either conventional remote
sensing methods or GIS modeling using environmental data bases. 相似文献