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941.
Nancy T. Baker 《Journal of the American Water Resources Association》1993,29(3):445-448
ABSTRACT: A Geographic Information System (GIS) was used to develop an automated procedure for identifying the primary aquifers supplying ground water to individual wells in eastern Arkansas. As mandated by state law, water-use data are reported by ground-water withdrawers annually to the Arkansas Soil and Water Conservation Commission, and stored in the Arkansas Site-Specific Water-Use Data System provided and supported by the U.S. Geological Survey. Although most withdrawers are able to provide the amount of water withdrawn and the depth of their wells, very few are able to provide the name of the aquifer from which they withdraw water. GIS software was used to develop an automated procedure for identifying the primary aquifers supplying ground water to individual wells in eastern Arkansas. The software was used to generate a spatial representation of the bottom boundary for the Mississippi River Valley alluvial aquifer (the shallowest aquifer) in eastern Arkansas from well log-data collected by the U.S. Geological Survey. The software was then used to determine the depth of the aquifer bottom at reported well locations to ascertain whether the Mississippi River Valley alluvial aquifer or a deeper aquifer was the primary aquifer providing water to each well. The alluvial aquifer was identified as the primary aquifer for about 23,500 wells. 相似文献
942.
Third World countries should exploit the genetic information stored in their flora and fauna to develop independent and highly competitive biotechnological and pharmaceutical industries. The necessary condition for this policy to succeed is the reshaping of their universities and hospitals—to turn them into high-caliber research institutions dedicated to the creation of original knowledge and biomedical invention. Part of the service of the Third World foreign debt should be co-invested with the lending banks in high technology enterprises. This should be complemented with an active program of investments in First World biotech companies and university research departments which could contribute to the solving of problems connected with the First World. These strategic alliances would allow effective training of molecular biologists, improvement of South American universities, and education of biotechnologists, managers, and lawyers in the complexities of high-technology business. The establishment of real joint ventures between developed and underdeveloped countries might contribute to change the present strained relations between the North and the South, and science and technology could become real forces of social and economic development. 相似文献
943.
Jefferson Fox Rebekah Kanter Sanay Yarnasarn Methi Ekasingh Royce Jones 《Environmental management》1994,18(3):391-399
This research has two interrelated objectives. The first is to determine the extent to which a relationship exists between
farmer characteristics and farming practices in three villages in northern Thailand. The second is to use standard statistical
methods for incorporating spatial variables into the analysis and to assess the effects of these variables on farmer decision
making. The data base includes information on the location and size of villages, roads, streams, and fields; a digital elevation
model with information on elevation, slope, and aspect; and information keyed to individual fields on crops and cropping methods
and the ethnicity, income, and religion of farmers. The map data (517 plots) were entered into a computerized geographic information
systems (GIS). Results suggest several hypotheses about the relationships between land use and owner characteristics. More
significantly, the study concludes that spatial analysis appears to be most useful when the dependent variable is either continuous
or ordinal. The outlook is not quite as optimistic when the dependent variable is a nonordinal categorical variable. Before
spatial analysis can be applied regularly to social science data, better computational tools need to be developed. 相似文献
944.
John L. Hammen Philip J. Gerla 《Journal of the American Water Resources Association》1994,30(5):833-840
ABSTRACT: The 1986 Amendments to the Safe Drinking Water Act mandate a multifaceted approach to wellhead protection. This approach includes: (1) delineating wellhead protection areas; (2) identifying and managing potential contaminants; (3) developing contingency plans in the event of weilfield contamination; (4) siting new wells; and (5) encouraging public participation. These elements encompass technical, administrative, and educational considerations. In functioning both as a research tool and as a decision support system, a geographic information system (GIS) is shown to have proven utility in addressing these issues. This article describes the application of common GIS functionality in facilitating a comprehensive wellhead protection scheme for an agricultural municipality in North Dakota. 相似文献
945.
Martha W. Gilliland Wanada Baxter-Potter 《Journal of the American Water Resources Association》1987,23(2):281-291
ABSTRACT: Bacterial densities (total coliform, fecal coliform, and fecal streptococci) and suspended solids in runoff from a feedlot, pasture, and corn field were measured. Densities of fecal coliform were highest from the feedlot but were 1000 to 10,000 times greater than the water quality standard for swimmable waters from all three land uses. Densities of fecal streptococci were highest from the corn field, which suggests that wildlife are the source of bacteria. Fecal coliform/fecal streptococci ratios distinguished cattle from wildlife as the source of bacterial pollution both among land uses and among seasons of the year. Suspended solids concentrations in runoff ranged from 423 to 925 mg/l and were highest from the corn field. A Geographic Information System (GIS), which utilizes a raster or grid-cell format, was developed to include algorithms associated with non-point source pollution. The system accepts digitally mapped information on soil type, topography, and land use. It calculates characteristics such as slope and slope length, and relates these characteristics to soils and land use parameters in order to produce three dimensional maps of runoff potential, sediment pollution potential, and bacterial pollution potential. It offers the advantages of retaining the geographic character of pollution potential information and of conveying in three-dimensional graphical terms the effects of topography, soil type, land use, and land management practices. 相似文献
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948.
信息网络的安全已成为目前企业至关重要的问题,防火墙技术是保护企业信息安全中最基本、最成熟的一种.本文简要介绍了防火墙的主要技术、防火墙体系结构,并对防火墙的选择方案提出了建议. 相似文献
949.
以某大型危险化学品储运企业为背景,对重大危险源应急救援信息系统进行研究,首先对重大危险源应急救援过程中各种信息需求进行分析,将信息分为基础信息、预防信息和救援信息3个方面;然后在单机和网络两种版本硬件结构比较的基础上,以工艺参数传感器、泄漏传感器、火灾报警器、应急设备控制器等主要设备为基础构建了单机版的硬件结构;最后,采用C/S软件结构,运用组件式GIS技术,从系统的总体结构、数据库结构以及功能设计等几个方面对应急救援信息系统进行了研究。 相似文献
950.