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461.
The cost of developing groundwater resources in northeastern Illinois from 198cL2020 is estimated for the purpose of providing a basis for comparing alternative sources. Demands for each township in the study area are estimated at 10-year increments and are satisfied, where the supply is sufficient, in such a way as to minimize the cost subject to constraints on supply. Sources of water are two shallow aquifers with known potential yields and a series of deep aquifers treated as a single unit and modeled on a digital computer. For each township the costs of wells, pumps, power and rehabilitation is estimated for each aquifer on a per million gallons of water per day basis. In addition the cost of groundwater treatment necessary to raise the quality to that of treated Lake Michigan water is considered. Raw water costs are found to vary from 2 to 14 cents per 1000 gallons depending upon the depth to the deep aquifer water. Treated water costs vary from 22 to 53 cents per 1000 gallons, the lower costs applying to the largest users because of the economy of scale. It is found that with proper distribution of pumpage there is sufficient water in storage in the deep aquifers to meet groundwater demands through 2020.  相似文献   
462.
ABSTRACT: Watershed management decision making is a complex process. Cooperation and communication among federal, state, and local stakeholders is required while balancing biophysical and socioeconomic concerns. The public is taking part in environmental decisions, and the need for technology transfer from public agencies to stakeholders is increasing. Information technology has had a profound influence on watershed management over the past decade. Advances in data acquisition through remote sensing, data utilization through geographic information systems (GIS), and data sharing through the Internet have provided watershed managers access to more information for management decisions. In the future, applications incorporating hydrologic simulation models, GIS, and decision support systems will be deployed through the Internet. In addition to challenges in making complex modeling technology available to diverse audiences, new information technology issues, such as interoperability, Internet access, and security, are introduced when GIS, simulation models, and decision support systems are integrated in an Internet environment. This paper presents a review of current use of information technology in watershed management decision making and a discussion of issues created when developing Internet based, integrated watershed management decision support systems. A prototype spatial decision support system (SDSS) for rangeland watershed management was developed using web services, which are components that communicate using text based messages, thus eliminating proprietary protocols. This new framework provides an extensible, accessible, and interoperable approach for SDSS.  相似文献   
463.
介绍了专家系统在火电厂湿法烟气脱硫系统中的作用,利用ACCESS建立了湿法烟气脱硫专家系统的知识库;以Visual Basic 6.0语言为开发工具,对湿法烟气脱硫专家系统软件进行了开发,该软件具有专家帮助功能、故障诊断功能、工艺仿真功能、知识库管理功能等。  相似文献   
464.
长江经济带建设的可持续发展研究   总被引:3,自引:2,他引:3  
90年代以来长江沿江地区经济发展速度明显加快,为实现其快速协调发展,须大力发展外向型经济。中快中上游开发开放促进区域经济合作,借鉴国外大河开发经验进行统一规划和建设。构筑上中下注重协调发展的农业支持系统,挖掘土地生产潜力,建设农业生产基地。  相似文献   
465.
Abstract: The U.S. Environmental Protection Agency is charged with establishing standards and criteria for assessing lake water quality. It is, however, increasingly evident that a single set of national water quality standards that do not take into account regional hydrogeologic and ecological differences will not be viable as lakes clearly have different inherent capacities to meet such standards. We demonstrate a GIS‐based watershed classification strategy for identifying groups of Nebraska reservoirs that have similar potential capacity to attain a certain level of water quality standard. A preliminary cluster analysis of 78 reservoirs was performed to determine the potential number of Nebraska reservoir groups. Subsequently, a Classification Trees method was used to refine number of classes, describe the structure of reservoir watershed classes, and to develop a predictive model that relates watershed conditions to reservoir classes. Results suggest that Nebraska reservoirs can be represented by nine classes and that soil organic matter content in the watershed is the most important single variable for segregating the reservoirs. The cross‐validation prediction error rate of the Classification Tree model was 26.3%. Because all geospatial data used in this work are available nationally, the method could be adopted throughout the U.S. Hence, this GIS‐based watershed classification approach could provide water resources managers an effective decision‐support tool in managing reservoir water quality.  相似文献   
466.
In recent years, a number of so-called “farm protection” or “ag-gag” laws have been proposed and passed in state legislatures across the USA. These laws generally ban the undercover photographing or videotaping of industrial animal agricultural production and processing facilities. Proponents of the legislation suggest that such bills protect local farm economies and prevent misinformation campaigns by animal rights activists. Diverse sets of critics have argued against the bills, suggesting that they prevent whistleblowers from exposing animal cruelty and stand in the way of the public's right to know. This paper analyzes the debate by blending theory from science and technology studies regarding the social production of knowledge and ignorance with communication theory that explores the power of storytelling in shaping public understandings of social life. It investigates the stories told by three oppositional stakeholder groups—members of industrial animal agribusiness who defend the legislation, small-scale producers and consumers who believe the legislation prevents productive transparency, as well as animal advocacy and first amendment interests who believe the legislation masks fundamental flaws in the contemporary animal agricultural system. The paper provides insight into how competing mediated narratives frame ideological battles over the present and future of animal production processes. It demonstrates how fundamental and often opposing value systems construct what we consider knowledge and non-knowledge in the context of our contemporary risk society and in the digital media age.  相似文献   
467.
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   
468.
研究借助GB/T 20438—2006的系统安全完整性理念,在分析了液氯充装系统工艺流程的基础上,建立了液氯充装系统的4个独立保护层并对其进行了安全性分析,根据液氯充装的危险性,确立了液氯充装系统的安全完整性等级为SIL3。从系统安全完整性出发,对系统安全性要求分配进行了探讨,提出了以各保护层失效概率为基础的液氯充装系统安全完整性审核评估,为系统的风险分析评估提供了一种新的思路。  相似文献   
469.
Cations in soil are essential for the growth of plants and micro-organisms. Their availability is dependent on soil organic matter. Soil organic matter (SOM) is heterogeneous comprising amino, aliphatic and phenolic acids, but particularly humic substances. All these substances can complex cations selectively. Mechanisms of complexation with dissolved organic matter are discussed. Such complexation can lead to the apparently contradictory observations that dissolved organic matter (DOM) can either increase the concentration of some less soluble nutrients, making them more available for plant uptake, or make them less available and hence less toxic. the importance of DOM is discussed in relation to soil solution, particularly the rhizosphere, and also in relation to aquatic systems. the latter systems contain mainly dissolved humic substances whereas in the soil, non-humic substances assume a greater importance.

SOM in the rhizosphere is derived from plant, microbial and animal remains but much, especially the water-soluble compounds, are acquired through root exudation. Exudation has important consequences for enhanced nutrient availability as a result of the production of non-humic substances such as amino, aliphatic and phenolic acids. in future, the role of root exudation in relation to DOM and nutrient availability should be investigated more fully, particularly as predicted elevated CO2 levels are likely to have a major impact on root exudation, nutrient availability, and possibly ecosystem community structure and functioning. It is likely that more information will become available on aquatic systems as more highly sensitive techniques and equipment capable of dealing with low concentrations of DOM in these systems become available.  相似文献   
470.
GIS in planning     
This paper outlines some of the potential uses of GIS in planning authorities, and identifies some of the pitfalls to be avoided. It begins with some practical considerations in the area of data sources and system configurations, goes on to envision ways in which GIS might benefit the work of a planning department, and finally considers some of the management issues which surround the introduction and use of GIS in planning.  相似文献   
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