IMPLEMENTATION OF ACUTE CRITERIA FOR CONSERVATIVE SUBSTANCES1

ABSTRACT: Acute criteria are assigned to the fish and wildlife propagation beneficial use in Oklahoma's water quality standards. Dye studies are analyzed to show that these criteria can be implemented through acute regulatory mixing zones. Acute regulatory mixing zones may be defined as areas in receiving streams where acute numerical criteria may be exceeded without causing acute toxicity. Acute regulatory mixing zones are used to obtain acute waste load allocations. If effluent loading does not exceed acute waste load allocation, acute criteria exceedance is confined to the acute regulatory mixing zone and there is no acute toxicity in the receiving stream. Waste load allocations for acute and chronic criteria are compared to determine which is appropriate to develop permit limits for the dye studies.     

分洪区数字地形模型建立及其应用

从实用的角度介绍了建立分洪区数字地形模型（ＤＴＭ）方程,并给出了在分洪区信息可视化、分洪区特征曲线生成、分洪区二维洪水演进等等方面的应用。     

降水异常对三峡工程建设的影响

利用三峡库区17个站1997年的逐日降水资料,分析了三峡库区1997年的降水特点．结果表明,异常偏少的降水为大江截流成功提供了有利的天气气候条件;同时,从气候学角度指出,大江截流以后的施工期间仍面临着严峻的气候异常风险,应引起有关部门特别注意．     

南黄海6.1级地震的中期预报

归纳介绍了１９９５年两篇报告中的中期预报意见及主要依据，并据此讨论了这次中期预报与南黄海６．１级地震的对应关系及今后长南带海域６级以上地震中期预报的思路     

海平面上升对海岸带环境的影响与危害及其防治对策

本文阐述了过去近百年来和未来特定年份海平面上升的趋势，分析了海平面上升的原因及其对海岸带环境的影响与危害，最后提出了防治对策与措施。     

山东沿海的9216号台风暴潮灾害

在１９９２年第１６号强热带风暴和天文大潮的作用下，山东沿海发生了特大风暴潮灾害，直接经济损失４３．５亿元，死亡７６人；砂质海岸遭受强烈侵蚀，损失土地约１４５．３ｈａ。     

从慧木碰撞谈地球安全

从慧木碰撞事件出发，根据小天体与地球相撞的史实，分析了小天体撞击地球的可能性及其效应，探讨了地球免遭个天体碰撞的可能对策。     

Identification of critical areas on forest lands for control of nonpoint sources of pollution

Most nonpoint source pollution problems on forest lands can be controlled by careful planning and management of specific critical areas. Critical areas include sites with high mass and surface erosion hazards, overland flow areas, and the riparian zone. Some guides for identifying critical areas are presented along with examples of land-use constraints that might be applied.     

Critique of present wetlands mitigation policies in the united states based on an analysis of past restoration projects in San Francisco Bay

A detailed evaluation of past wetland restoration projects in San Francisco Bay was undertaken to determine their present status and degree of success. Many of the projects never reached the level of success purported and others have been plagued by serious problems. On the basis of these findings, it is debatable whether any sites in San Francisco Bay can be described as completed, active, or successful restoration projects at present. In spite of these limited accomplishments, wetland creation and restoration have been adopted in the coastal permit process as mitigation to offset environmental damage or loss of habitat. However, because the technology is still largely experimental, there is no guarantee that man-made wetlands will persist as permanent substitutes for sacrificed natural habitats. Existing permit policies should be reanalyzed to insure that they actually succeed in safeguarding diminishing wetlands resources rather than bartering them away for questionable habitat substitutes. Coastal managers must be more specific about project requirements and goals before approval is granted. Continued research on a regional basis is needed to advance marsh establishment techniques into a proven technology. In the meantime, policies encouraging or allowing quid pro quo exchanges of natural wetlands with man-made replacements should proceed with caution. The technology and management policies used at present are many steps ahead of the needed supporting documentation.     

REGIONAL MANAGEMENT OF DEPLETED AQUIFERS1

ABSTRACT: Aquifers with pressure head seriously reduced by overdrafting are referred to as depleted. In coastal areas they may be invaded by saltwater. An obvious remedy is to reduce the rate of withdrawal to the permanently available dependable yield. This is being done now in two areas for New Jersey, under the authority of the State's Water Supply Management Act; but it has not previously been accomplished on a regional scale. The dependable yield was estimated by means of detailed hydrogeological modeling. “Water Supply Critical Areas” were delimited on the basis of piezometric pressure, drawn down 30 feet below sea level. Within the depleted area, water withdrawals must be reduced by a fixed ratio (35 to 50 percent) below the amount withdrawn during 1983. This reduction is effective as soon as al alternative source of water can be made available, usually from a surface source. Special arrangements are made whereby ground water users unconnected to the alternative source of supply can pay to withdrawn their full needs from the depleted aquifers, the money being used to purchase additional water from the new surface water source, in return for which some other user will reduce his ground water withdrawal below his reduced allocation.