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101.
Martin W. Doyle F. Douglas Shields 《Journal of the American Water Resources Association》2012,48(3):494-509
Doyle, Martin W. and F. Douglas Shields, 2012. Compensatory Mitigation for Streams Under the Clean Water Act: Reassessing Science and Redirecting Policy. Journal of the American Water Resources Association (JAWRA) 48(3): 494-509. DOI: 10.1111/j.1752-1688.2011.00631.x Abstract: Current stream restoration science is not adequate to assume high rates of success in recovering ecosystem functional integrity. The physical scale of most stream restoration projects is insufficient because watershed land use controls ambient water quality and hydrology, and land use surrounding many restoration projects at the time of their construction, or in the future, do not provide sufficient conditions for functional integrity recovery. Reach scale channel restoration or modification has limited benefits within the broader landscape context. Physical habitat variables are often the basis for indicating success, but are now increasingly seen as poor surrogates for actual biological function; the assumption “if you build it they will come” lacks support of empirical studies. If stream restoration is to play a continued role in compensatory mitigation under the United States Clean Water Act, then significant policy changes are needed to adapt to the limitations of restoration science and the social environment under which most projects are constructed. When used for compensatory mitigation, stream restoration should be held to effectiveness standards for actual and measurable physical, chemical, or biological functional improvement. To achieve improved mitigation results, greater flexibility may be required for the location and funding of restoration projects, the size of projects, and the restoration process itself. 相似文献
102.
攀枝花地区河流沉积物的重金属污染研究 总被引:11,自引:0,他引:11
攀枝花市是长江流域经济带上游区第一城,几十年的开发建设使该地区的经济、社会得到了飞速的发展,但同时也造成了一定的环境影响。采用地质累积指数评价了该区水系沉积物中的重金属污染状况,结果表明,水系沉积物中各元素的污染程度由高到低为:Ti、Cu、V、Pb、Zn、Cr、As;总体上看,各元素在攀钢采矿场、选矿厂、冶炼厂及尾矿坝等地的污染程度较高,表明该区水系沉积物中重金属和攀枝花地区金沙江水质的污染主要与该区钒钛磁铁矿的采、选、冶等矿业活动有关。该区应采取如下措施减轻环境影响:(1)加强矿区环境恢复和环境管理,确保区域资源、环境、经济、社会可持续发展;(2)加强城市环境监测,特别是重金属和其他微量元素污染的监测,进行城市生态环境安全预警。 相似文献
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105.
Mark A. Tumeo 《Journal of the American Water Resources Association》1992,28(6):1083-1094
ABSTRACT: The Fairbanks Water Treatment Plant in Fairbanks, Alaska, processes approximately 3 MGD of drinking water using lime softening. Approximately 0.3 MGD of lime-sludge from the treatment process is combined with effluent from a nearby power plant and discharged to the Chena River. There is little information available on the impact of water-treatment sludge discharges, and virtually no information on the impacts of such discharges in polar environments. Concern surrounding the discharge of water treatment sludges have centered on alum-sludge due to the potential toxic effects of aluminum. Because of the relatively benign composition of lime-sludge, very little research has been published. However, there is the possibility that discharge of solids will result in sedimentation, accumulation of solids, and subsequent impacts on benthic organisms. This paper reports on the results of a study to determine if lime-sludge discharge from the water treatment plant is adversely impacting the river environment. The results provide basic information on the important variables of concern in lime-discharges to rivers. Samples from the discharge of the water treatment plant and combined water treatment plant/power plant effluent were collected weekly over a one-year period, and in-stream benthic and water column samples were collected biweekly during the fall and spring. Sediment and water quality data indicate that while significant accumulation of sludge solids is found downstream of the water treatment plant outfall, they are flushed out of the system by spring flows, which are significantly increased by snow melt. This process is most likely repeated on a yearly cycle. Hence, the data suggest that the FMUS water treatment plant's discharge of lime-sludge is probably not adversely impacting the river. More generally, this may indicate that the natural flow variations and sediment-laden characteristics of Arctic, glacier-fed rivers may assimilate large quantities of nonputrescible solids without significant changes in the natural river environment. Further research in this area is required to verify this conclusion. 相似文献
106.
Scott J. Goetz 《Journal of the American Water Resources Association》2006,42(1):133-143
Riparian buffer zone management is an area of increasing relevance as human modification of the landscape continues unabated. Land and water resource managers are continually challenged to maintain stream ecosystem integrity and water quality in the context of rapidly changing land use, which often offsets management gains. Approaches are needed not only to map vegetation cover in riparian zones, but also to monitor the changes taking place, target restoration activities, and assess the success of previous management actions. To date, these objectives have been difficult to meet using traditional techniques based on aerial photos and field visits, particularly over large areas. Recent advances in remote sensing have the potential to substantially aid buffer zone management. Very high resolution imagery is now available that allows detailed mapping and monitoring of buffer zone vegetation and provides a basis for consistent assessments using moderately high resolution remote sensing (e.g., Landsat). Laser‐based remote sensing is another advance that permits even more detailed information on buffer zone properties, such as refined topographic derivatives and multidimensional vegetation structure. These sources of image data and map information are reviewed in this paper, examples of their application to riparian buffer mapping and stream health assessment are provided, and future prospects for improved buffer monitoring are discussed. 相似文献
107.
沙颖河闸坝调控与淮河干流水质风险管理 总被引:4,自引:0,他引:4
文章分析了沙颖河闸上重污染水集中泄流与淮河干流突发性污染事故的关系。结果表明:在目前排污条件下,淮河干流突发性污染事故的风险,是沙颖河河道节制闸上蓄积实际用水量数十倍及至近百倍的重污染水所造成的。但是,只要闸上始终保持10 ̄15d蓄积水量的规模,然后每天不间断地泄流日均蓄水量规模的水量,则完全可以协调农业生产与淮河干流水质保护之间的关系。 相似文献
108.
Heavy Metal Distribution in Valley Sediments in Wadi Al-Karak Catchment Area, South Jordan 总被引:4,自引:0,他引:4
Valley sediments samples collected from the major and minor valleys of Al-Karak catchment area (southern Jordan) were leached with hot dilute HCl and analysed for their heavy metals content. The results of leachable metal concentrations indicated the absence of anomalous values for metal occurrences. However, appreciable contamination of the sediments with Cu, Zn, Pb, Cd and Cr was observed. Using an index of pollution the extent of contamination was better delineated. The geographical distribution of the samples showed higher Cu, Zn, Pb, Cd and Cr concentrations mainly around heavily inhabited areas indicating an anthropogenic source of contamination. Lithological influence indicated from the anomalies of Fe and Mn was found to be very low. 相似文献
109.
Brett B. Roper Jeffrey L. Kershner Eric Archer Richard Henderson Nicolaas Bouwes 《Journal of the American Water Resources Association》2002,38(6):1637-1646
ABSTRACT: The last few decades have seen an increased reliance on the use of stream attributes to monitor stream conditions. The use of stream attributes has been criticized because of variation in how observers evaluate them, inconsistent protocol application, lack of consistent training, and the difficulty in using them to detect change caused by management activity. In this paper, we evaluate the effect of environmental heterogeneity and observer variation on the use of physical stream attributes as monitoring tools. For most stream habitat attributes evaluated, difference among streams accounted for greater than 80 percent of the total survey variation. To minimize the effect that variation among streams has on evaluating stream conditions, it may be necessary to design survey protocols and analysis that include stratification, permanent sites, and/or analysis of covariance. Although total variation was primarily due to differences among streams, observers also differed in their evaluation of stream attributes. This study suggests that if trained observers conducting a study that is designed to account for environmental heterogeneity can objectively evaluate defined stream attributes, results should prove valuable in monitoring differences in reach scale stream conditions. The failure to address any of these factors will likely lead to the failure of stream attributes as effective monitoring tools. 相似文献
110.