THE POTENTIAL FOR INCREASING STREAMFLOW FROM SIERRA NEVADA WATERSHEDS1

The Sierra Nevada produces over 50 percent of California's water. Improvement of water yields from the Sierra Nevada through watershed management has long been suggested as a means of augmenting the state's water supply. Vegetation and snowpack management can increase runoff from small watersheds by reducing losses due to evapotranspiration, snow interception by canopy, and snow evaporation. Small clearcuts or group selection cuts creating openings less than half a hectare, with the narrow dimension from south to north, appear to be ideal for both increasing and delaying water delivery in the red fir-lodgepole pine and mixed-conifer types of the Sierra west slope. Such openings can have up to 40 percent more snow-water equivalent than does uncut forest. However, the water yield increase drops to 1/2-2 percent of current yield for an entire management unit, due to the small number of openings that can be cut at one time, physical and management constraints, and multiple use/sustained yield guidelines. As a rough forecast, water production from National Forest land in the Sierra Nevada can probably be increased by about 1 percent (0.6 cm) under intensive forest watershed management. Given the state of reservoir storage and water use in California, delaying streamflow is perhaps the greatest contribution watershed management can make to meeting future water demands.     

CHEMICAL MEASUREMENT OF MEAN TEMPERATURE

Mean temperature is employed universally as an index to the energy status of the environment, and to indicate probable reaction rates of physical and biological processes in nature. A versatile chemical method of temperature integration, based on the temperature dependence of sucrose hydrolysis, has been tested in central Pennsylvania. The chemical technique (after Pallmann) permits economical mass sampling of air, water, and soil temperatures in situations where conventional methods are too expensive or otherwise unsatisfactory. Short-wave radiation effects are negligible since the sensing elements are transparent. Repeatability is excellent: in field tests duplicate sensors yield the same mean temperature ± 0.02°C. Non-linearity of sensor response has been resolved, and the data can be related directly to measurements obtained in standard climatological networks. The technique can be used to good advantage in a variety of hydrological investigations, including evaporation, consumptive-use, and them pollution studies.     

IMPACT OF DROUGHT ON QUALITY IN A NEW JERSEY WATER SUPPLY SYSTEM1

ABSTRACT. New Jersey, together with other states in the northeast, was stricken with drought during 1961-66. The effect of this drought was most severe in the northern part of the State. The water quality of the Passaic River, which drains the urban, industrialized northeast, perhaps deteriorated the most among the major drainage systems. This river system is used as a raw-water source by 10 water suppliers. The impact of the drought upon the water supply of the Passaic Valley Water Commission, the most downstream of the basin's suppliers, which supplies an average of about 90 million gallons a day to more than 650,000 persons, is evaluated herein. The drought's impact on the raw-water quality is appraised by the comparison of before-and-after qualities of dissolved solids, dissolved oxygen, biochemical-oxygen demand, turbidity, and hardness. For example, at the worst point during the drought, monthly average dissolved-solids content in the raw water were about 210 percent, hardness, about 167 percent, and biochemical-oxygen demand about 270 percent higher than antecedent values. In general, the study concludes that the drought produced a deterioration in both raw and finished water quality, and is estimated to have increased chemical-treatment costs during the drought by about $650,000.     

煤炭企业清洁生产的中/高费方案评述

简述了煤炭企业在清洁生产审核过程中如何产生中／高费方案，分析了中／高费方案所占的比例。通过3个工程实例的分析证明，中／高费方案的实施给煤炭企业带来良好的环境效益和经济效益。     

Multicriteria Decision Aid in Supporting Decisions Related to Groundwater Protection

In the recent decades, there have been frequent conflicts between groundwater resources and environmentally hazardous activities. An example is the construction of the new highway through the important glaciofluvial esker aquifer Nybroåsen, which passes the protection zone of the water supply for the Kalmar municipality, in the southeastern part of Sweden. The decision to build the new road through this important aquifer has been strongly questioned by the municipality and the public because the value of the water resources in Nybroåsen was not taken into consideration during the first phase of the decision-making process. Multicriteria decision aid (MCDA) is applied as a tool to structure and analyze the four road alternatives proposed in the environmental impact assessment for the above conflict. The alternatives, including the existing road, are in conflict with water resources, agriculture, natural, and cultural values. The impacts on the water resources have been predicted by a two-dimensional physically based time-variant flow and solute groundwater model, which has been calibrated and evaluated. The MCDA illustrates how it can be used to identify (1) actors and their concerns, (2) ranking of alternative road scenarios according to actors preferences, and (3) coalition groups of actors, i.e., groups that have similar views with regard to the road alternatives. The analysis shows that the two best compromise solutions obtained in the MCDA were unacceptable by the strongest coalition group, showing that either the family of criteria was not well chosen or new alternatives should have been developed.     

The US Clean Water Act and habitat replacement: evaluation of mitigation sites in Orange County,California, USA

Both permit requirements and ecological assessments have been used to evaluate mitigation success. This analysis combines these two approaches to evaluate mitigation required under Section 404 of the United States Clean Water Act (CWA) and Section 10 of the Rivers and Harbors Act, which allow developers to provide compensatory mitigation for unavoidable impacts to wetlands. This study reviewed permit files and conducted field assessments of mitigation sites to evaluate the effectiveness of mitigation required by the US Army Corps of Engineers for all permits issued in Orange County, California from 1979 through 1993. The 535 permit actions approved during this period allowed 157 ha of impacts. Mitigation was required on 70 of these actions, with 152 ha of enhanced, restored, and created habitat required for 136 ha of impacts. In 15 permit actions, no mitigation project was constructed, but in only two cases was the originally permitted project built; the two cases resulted in an unmitigated loss of 1.6 ha. Of the remaining 55 sites, 55% were successful at meeting the permit conditions while 11% failed to do so. Based on a qualitative assessment of habitat quality, only 16% of the sites could be considered successful and 26% were considered failures. Thus, of the 126 ha of habitat lost due to the 55 projects, only 26 ha of mitigation was considered successful. The low success rate was not due to poor enforcement, although nearly half of the projects did not comply with all permit conditions. Mitigation success could best be improved by requiring mitigation plans to have performance standards based on habitat functions.     

Local Capacity for Groundwater Protection in Ontario

Preventing groundwater contamination is vastly cheaper than remediation. Recognizing this, attention in water and land management agencies in North America increasingly turn to groundwater protection. Local agencies, such as municipalities and watershed management districts, are vital to successful groundwater protection, but they face daunting challenges. In the United States, senior governments have recognized these challenges and provide considerable support for local agencies. In Ontario, Canada, local agencies are, to a much greater extent, on their own. The aims in this paper are to analyze factors that shape local capacity for groundwater protection, focusing on Ontario, and to recommend avenues for capacity building. Interrelationships among five dimensions of capacity (technical, financial, institutional, social, and political) are explored through an analysis of three smaller Ontario communities: City of Guelph (population 93,400), Town of Orangeville (population 22,188), and Town of Erin (population 11,000). Size clearly influences capacity for groundwater protection. However, other considerations unrelated to size appear to be as important. These other factors include the ability to form horizontal and vertical linkages with external agencies, political leadership and commitment, and citizen involvement. Thus, smaller communities in Ontario (and other jurisdictions with limited senior government support) would do well to focus on these areas at the same time as they develop their technical, financial, and institutional capacity.     

江苏省环境系统特点及环境污染状况

江苏省自然特点为单一而脆弱,表面为平原为主,水域面积较大,山地少,森林覆盖率低,生物种类少,江苏省社会环境特点为人均资源少,经济基础好,交通发达,城市密集和人才优势明显;江苏省的废气,废水,固体,噪声污染日益严重。由于上述特点和原因,江苏省农业机械化,现代化程度较高,水产养殖业发达,但应进一步提高农业集约化程度和大力推广生态农业整治环境污染,利用天在河道进一步发展养殖业;江苏省工业轻,重并举以轻为     

Visitor Response to Management Regulations—A Study Among Recreationists in Southern Norway

/ The objectives of nature area management are often twofold: To protect the natural environment and to facilitate recreational use. In order to maintain the natural setting, it is sometimes necessary to regulate the recreational use of an area. In deciding on a management action, one problem can be the lack of knowledge about the effects of management actions on visitors. In order to enhance the knowledge base for future management practices, this study empirically evaluates the effects of management regulations in a Norwegian nature area. In this area camping outside commercial campgrounds was restricted in 1992. The management regulations seems to have influenced the use of Sjodalen for camping in several ways. The number of campers using the area has decreased. The user composition seems to have changed, with new campers in the area after the regulation being more tolerant of human influence on the natural environment than the campers before the regulations. In addition, a considerable proportion of the existing users ceased to stay overnight in Sjodalen, totally or partly due to the regulations. The behavioral response among existing users is related both to environmental preferences and place attachment. Implications for management and future research studies on impact assessment in general, and displacement specifically, are discussed.KEY WORDS: Outdoor recreation; Management regulations; Behavioral response; Displacement, Place attachment