Modelling Water Blending—Sensitivity of Optimal Policies

Water blending is modelled as a combination of a linear program and a stochastic dynamic program. Optimal policies are found for linear and integer-linear formulations using both an expected monetary value and conditional value-at-risk criterion. The sensitivity of these solutions to the discretisation over volume and over time is investigated.     

An Air Pollution Index Based on Sulfur Dioxide and Smoke Shade

First-prize winner in the student paper competition conducted by the Mid-Atlantic States Section of the Air Pollution Control Association was Marvin H. Green, a graduate student at Drexel Institute of Technology and assistant chief of Philadelphia’s Air Pollution Control Section. A condensation of his paper follows.     

Wellhead treatment costs for groundwater contaminated with pesticides: A preliminary analysis for pineapple in Hawaii

In Hawaii, trace concentrations of pesticides used in the production of pineapple were found in the groundwater supplies of Mililani Town in the Pearl Harbor Basin on the island of Oahu. Groundwater serves as the major source of drinking water and residents pay for wellhead treatment of the contaminated water, via their monthly water bill. The agricultural chemical users within the Pearl Harbor Basin do not include these wellhead treatment costs in their production costs. The agricultural industry benefits from using pesticides but does not pay the entire societal cost of using these chemicals. In this study we evaluate the specific financial cost of wellhead treatment, and not the economic value of groundwater. While wellhead treatment costs could conceivably be shared by several parties, this study focuses on the financial impact of the pineapple industry alone. This study factors annual wellhead treatment costs into annual pineapple production costs to measure the effect on annual financial return from pineapple production. Wellhead treatment costs are calculated from the existing granulated activated carbon (GAC) water treatment facility for Millilani Wells I and II. Pineapple production costs are estimated from previous cost of production studies. The inclusion of wellhead treatment costs produces different production-cost results, depending on the scale of analysis. At the local scale, the Mililani wellhead treatment costs can be factored into the production costs of the pineapple fields, which were probably responsible for contamination of the Mililani Wells, without causing a deficit in economic return. At the larger regional scale, however, the return from all of the pineapple grown in the Pearl Harbor Basin can not sustain the cost of wellhead treatmentfor the entire water supply of the basin. Recommendations point to the prevention of groundwater contamination as more cost-effective measure than wellhead treatment.     

THE IMPORTANCE OF INSTITUTIONAL STRUCTURE IN CONTROLLING AGRICULTURAL RUNOFF1

Abstract: Agricultural runoff, such as dissolved mineral salts and selenium, creates pronounced downstream impacts to agricultural producers and to wildlife. The ability to manage these problems efficiently depends critically on the institutional pricing structure of irrigation water delivery agencies. An important characteristic of irrigation water delivery is whether irrigators pay per unit of water received or make one payment regardless of the quantity of water received. In this study we compare the effectiveness of agricultural runoff reduction policies in two regions that employ these different water pricing structures. We find that reduction policy is more effective and can be achieved at a lower cost when water is priced on a per unit basis and that growers have greater incentive to act on their own to reduce runoff problems. Operating under a per unit pricing system encourages water conservation and runoff reduction, which creates public benefits that are not achieved under the single-payment, fixed allotment method of irrigation water delivery.     

Leadership self‐efficacy and managers' motivation for leading change

This study develops and tests a leadership model that focuses on managers' motivation for attempting the leadership of change. The construct of leadership self‐efficacy (LSE) is defined, and a measure comprising three dimensions (direction‐setting, gaining followers' commitment, and overcoming obstacles to change) is developed. Based on Bandura's (1986) social cognitive theory, the primary hypothesis is that high LSE managers will be seen by direct reports as engaging in more leadership attempts. Relationships are also proposed between LSE and several factors that are expected to influence this confidence judgment. Managers' organizational commitment and crisis perceptions are modelled as potential moderators of the relationship between LSE and leadership attempts. The model was tested through surveys distributed to managers (n = 150) and their direct reports (n = 415) in a real estate management company and an industrial chemicals firm. Positive relationships (p < 0.05) were found between the first two dimensions of LSE and managers' leadership attempts. An interaction effect involving organizational commitment was discovered for the LSE/overcoming obstacles dimension (p < 0.05). Several positive relationships were found between LSE dimensions and proposed antecedents, including self‐esteem (p < 0.05), subordinates' performance abilities (p < 0.05), and managers' job autonomy (p < 0.05). Copyright © 2002 John Wiley & Sons, Ltd.     

Residents' perceptions of water quality improvements following remediation work in the Pymme's Brook catchment, north London, UK

Residents' perceptions of water quality change following remediation work in the upper Pymme's Brook catchment (north London) were elicited by questionnaire and compared with monitored changes in Escherichia coli count and BMWP (The Biological Monitoring Working Party (BMWP)) score. The wider usefulness of consumer perception surveys was then discussed. Monthly data collected between 1990 and 1996 shows that both E. coli count and BMWP score improved following flushing of the foul sewerage system in 1992, but that only E. coli count improved following the subsequent completion of large-scale remedial engineering works. Local residents were surveyed regarding their awareness of the scheme, and the causes of pollution, together with their perceptions as to the effects of the engineering works and of the resulting water quality improvements. Most respondents selected and ranked indicators in a way that suggested they had an awareness of the significance of various indicators of pollution severity. Following completion of the remediation scheme, residents perceived the watercourse to contain less rubbish and sewage fungus, and to have an improved colour and smell, which corresponds favourably to the monitored improvements. However, respondents' perceptions were found to vary when the study population was sub-divided using a range of parameters. For instance, frequent observers of the brook were most likely to correctly identify sewage as the main form of pollution. These divergent perceptions suggest that there may be considerable difficulties when perception surveys are used to quantify 'benefits' following environmental improvement programmes. Nevertheless, the survey was clearly beneficial in enhancing residents' awareness of their environment and the role of their voice in its management.     

用心灵呵护生灵的摄影家葛玉修

葛玉修,山东人,现任青海银监局纪委书记,中国摄影家协会会员、中国金融摄影家协会副主席、中国艺术摄影学会会员、青海省摄影家协会理事,"青海青"网站站长,被誉为青海湖"鸟王"和"中华对角羚之父"。十年来他利用自己的节假日拍摄野生动物,捕捉了三万多个震撼人心的瞬间。     

对南京市发展绿色经济的思考

简述了发展绿色经济的重要性,指出了南京市发展绿色经济的有利条件及存在问题。提出,南京发展绿色经济,必须树立绿色发展理念,推动科学发展实践;制定绿色发展战略,推进可持续发展;支持绿色技术研发,培育新经济增长点;打造绿色优势产业,促进结构向高端转型;倡导绿色消费行为,推进资源节约、环境友好型社会建设;建立健全绿色制度,提供经济社会发展保障。