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771.
772.
R. K. Rudel H. J. Stockwell R. G. Walsh 《Journal of the American Water Resources Association》1973,9(1):116-128
ABSTRACT. Experimental results of cloud seeding in Southwestern Colorado suggest that runoff can be increased by 25 percent over a 3,300 mile area. There is a need to estimate the economic consequences in the Colorado River Basin. The evidence presented suggests that weather modification is an economically feasible means to provide additional water for the basin. Compared with other proposed means of augmenting water supplies, weather modifications appear to be one of the least cost alternatives. A very low proportion of weather modification costs are fixed; thus the program is easily reversible. Also, a relatively small increase in daily precipitation covers the direct costs of operation. Benefits of water produced by weather modification included power production and irrigation of forage crops. In the long run, if additional water is used for higher valued fruit and vegetable production, or for domestic and industrial purposes, its value would rise sharply. Preliminary investigation of extra-market costs and benefits suggests that while they have little effect on the benefit-cost ratio, they may be very important to individuals and groups affected. The distribution of costs and benefits is important as the benefits accrue to downstream users and some of the costs are incurred by Coloradoans. There is a need for further research on the long-run economic effects of weather modification programs, particularly with respect to extra-market factors. 相似文献
773.
Effective communication is essential to the success of collaborative ecosystem management projects. In this paper, we investigated the dynamics of the Interior Columbia Basin Ecosystem Management Projects (ICBEMP) cross-disciplinary integration process in the assessment phase. Using a case study research design, we captured the rich trail of experience through conducting in-depth interviews and collecting information from internal and public documents, videos, and meetings related to the ICBEMP. Coding and analysis was facilitated by a qualitative analysis software, NVivo. Results include the range of internal perspectives on barriers and facilitators of cross-disciplinary integration in the Science Integration Team (SIT). These are arrayed in terms of discipline-based differences, organizational structures and activities, individual traits of scientists, and previous working relationships. The ICBEMP organization included a team of communication staffs (CT), and the data described the CT as a mixed group in terms of qualifications and educational backgrounds that played a major role in communication with actors external to the ICBEMP organization but a minor one in terms of internal communication. The data indicated that the CT-SIT communication was influenced by characteristics of actors and structures related to organizations and their cultures. We conclude that the ICBEMP members may not have had a sufficient level of shared understanding of central domains, such as the task at hand and ways and timing of information sharing. The paper concludes by suggesting that future ecosystem management assessment teams use qualified communications specialists to design and monitor the development of shared cognition among organization members in order to improve the effectiveness of communication and cross-disciplinary integration. 相似文献
774.
Walter P. Neely Ronald M. North James C. Fortson 《Journal of the American Water Resources Association》1976,12(1):19-25
ABSTRACT. A multiple goal planning approach is proposed as a solution to the public water resources project selection problem. The goal programming technique enables a comprehensive water resources model. The model considers both economic and environmental objectives and may be implemented with data which are available to project planners. 相似文献
775.
鄂尔多斯白垩系环河含水岩组中的地球化学反向模拟 总被引:1,自引:0,他引:1
在了解鄂尔多斯盆地的地形、地势、地貌、新构造运动、岩石类型、岩性构造和其他特征的基础上,运用化学热力学原理、质量作用定律和质量守恒定律,用反向模拟的方法对白垩系环河组地下水进行了水-岩作用的地球化学模拟。对该区地下水的演化过程进行了定量的分析研究,揭示了其水化学场的形成机理,总结了矿物的溶解沉淀规律,为该区水文地质模型的建立、地下水资源的水质水量评价及其合理开发利用和科学管理提供了科学依据,可供该地区水土流失等地质灾害的预防和综合治理参考。 相似文献
776.
777.
Soil erosion is a severe problem for many developing regions that lack adequate infrastructure to combat the problem. The
authors established a first-order method for prioritizing areas to be examined and remediated using preexisting data and expert
knowledge where data are lacking. The Universal Soil Loss Equation was applied to the Rio Lempa Basin in Central America using
geographic information systems and remote sensing technologies, and the estimated erosion rates were compared with sediment
delivery ratios. Spatial analysis indicates that agriculture on very steep slopes contributes only a small fraction to the
total estimated soil erosion, whereas agriculture on gentle and moderately steep slopes contributes a large fraction of the
erosion. Although much of the basin is in El Salvador, the greatest estimated amount of erosion is from Honduras. Data quality
and availability were impaired by a lack of coordination among agencies and across countries. Several avenues for improving
the authors’ methods are described. 相似文献
778.
William A. Pike 《Journal of the American Water Resources Association》2004,40(6):1563-1578
ABSTRACT: Compliance violations at community water systems are rare but represent significant human health risks. These risks are mediated by the decision schema of human operators at water treatment facilities. However, causal uncertainty among physical and human factors involved in water quality problems complicates assessment of their probability and severity. This study uses a probabilistic Bayesian network modeling approach to explore the causes of compliance violations in a sample of water treatment systems in Pennsylvania. The model presented here is one of several created by treatment system operators during an expert elicitation process. The expert model alone predicts violations poorly, suggesting that experts make inaccurate quantitative estimates. However, Bayesian networks are capable of combining the subjective expertise of treatment system operators with the objective compliance histories of the facilities they manage, and the expert model accurately predicts violations when trained with historical compliance data. Analysis of the trained network reveals those components of the treatment process, including environmental and system characteristics as well as operator decisions, that play the greatest role in determining the likelihood of major violation types. Among operator decisions, coagulant dosing and filter backwash frequency are the most important determinants of violation likelihood. 相似文献
779.
Stephen T. Gray Stephen T. Jackson Julio L. Betancourt 《Journal of the American Water Resources Association》2004,40(4):947-960
ABSTRACT: Samples from 107 piñon pines (Pinns edulis) at four sites were used to develop a proxy record of annual (June to June) precipitation spanning the 1226 to 2001 AD interval for the Uinta Basin Watershed of northeastern Utah. The reconstruction reveals significant precipitation variability at interannual to decadal scales. Single‐year dry events before the instrumental period tended to be more severe than those after 1900. In general, decadal scale dry events were longer and more severe prior to 1900. In particular, dry events in the late 13th, 16th, and 18th Centuries surpass the magnitude and duration of droughts seen in the Uinta Basin after 1900. The last four decades of the 20th Century also represent one of the wettest periods in the reconstruction. The proxy record indicates that the instrumental record (approximately 1900 to the Present) underestimates the potential frequency and severity of severe, sustained droughts in this area, while over representing the prominence of wet episodes. In the longer record, the empirical probability of any decadal scale drought exceeding the duration of the 1954 through 1964 drought is 94 percent, while the probability for any wet event exceeding the duration of the 1965 through 1999 wet spell is only 1 percent. Hence, estimates of future water availability in the Uinta Basin and forecasts for exports to the Colorado River, based on the 1961 to 1990 and 1971 to 2000 “normal” periods, may be overly optimistic. 相似文献
780.