多举措集成提升电厂节水减排成效

本着分级使用、减少排放、综合利用的原则,根据现场实际情况进行综合治理,重点是增加并完善梯级利用程度,提高水资源利用效率。对除灰、输煤废水这类浊度较大的废水进行自循环利用,禁止外排;完善循环水排污水利用系统;对高含盐量化学废水进行综合利用,达到既减排又可以改善废水水质的目的。     

Exploring the lay/expert divide: the attribution of responsibilities for coal ash pollution in Tuzla,Bosnia and Herzegovina

Invoking expert knowledge is a common strategy in attempts to settle environmental disputes. However, the validity of expertise is contingent upon the context in which an actor is recognised as an expert. In complex environmental conflicts the distinction between lay and expert knowledge is not always fixed a priori. However, as conflicts unfold, intervening parties tend to present their cases in ways that reinforce this distinction. This is apparent in the attribution of environmental responsibilities. This paper presents an empirical case of an environmental conflict related to land contamination due to coal ash disposal in Bosnia and Herzegovina. The analysis revealed two polar positions in the conflict: the first one, mainly held by scientists and industry representatives, invoked expert knowledge and presented a distributed approach to the attribution of responsibilities; the second one, mainly held by local residents and municipal officials, presented an experiential understanding of pollution, as lay knowledge, and attributed direct responsibilities to the local energy industry. The paper concludes that the persistence of the distinction between expert and lay knowledge is a manifestation of the social structures that underlie the conflict.     

Flooding in Texas: Examination of Temporal Changes and Impacts of Tropical Cyclones

Annual maximum peak discharge measurements from 62 stations with a record of at least 70 years are used to assess extreme flooding in Texas at the regional scale. This work focuses on examination of the validity of the stationarity assumption and on the impact of tropical cyclones (TCs) on the upper tail of the flood peak distribution. We assess the validity of the stationarity assumption by testing the records for abrupt and gradual changes. The presence of abrupt changes in the first two moments of the flood peak distribution is assessed using the Lombard test. We use the Mann‐Kendall test to examine the presence of monotonic trends. Results indicate that violations of the stationarity assumption are most commonly caused by abrupt changes, which are often associated with river regulation. We fit the time series of stationary flood records with the generalized extreme value distribution to investigate whether TCs control the upper tail of the flood peak distribution. Our results indicate that TCs play a diminished role in shaping the upper tail of the flood peak distribution compared with areas of the eastern United States subject to frequent TCs.     

Air‐Water Temperature Relationships in the Trout Streams of Southeastern Minnesota's Carbonate‐Sandstone Landscape

Carbonate‐sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface‐water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater‐fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air‐water temperature relationships for 40 GWFS in southeastern Minnesota. A 40‐stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R² of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface‐water dominated streams. Regression models for streams with high R² values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater‐fed systems, but will do so at a slower rate than surface‐water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.     

Estimating Crop Water Use via Remote Sensing Techniques vs. Conventional Methods in the South Platte River Basin,Colorado

We compared two methods of estimating crop water consumption to assess whether remote sensing techniques provide consumptive use (CU) estimates commensurate with conventional methods. Using available historical satellite and meteorological data, we applied Mapping EvapoTranspiration at high Resolution using Internalized Calibration (METRIC) to 317,455 ha in the South Platte basin, in northeastern Colorado, for the 2001 irrigation season. We then compared these derived CU estimates with values calculated by using the Colorado Water Conservation Board's South Platte Decision Support System StateCU model. Evaluating the data by irrigation ditch service area, we disaggregated the output to allow for comparison by service area size, crop type, irrigation method, water supply source, and water availability. We concluded that METRIC is a suitable alternative to StateCU in the South Platte basin and could help to identify areas with inhibited crop growth or deficit irrigation practices. In addition, METRIC could be used as a complement to StateCU to refine StateCU model parameters, allowing for more accurate estimates of crop water shortages and groundwater recharge associated with irrigation delivery and application.     

An Optimization Method for Estimating Constituent Mean Concentrations in Base Flow‐Dominated Flow

Pollutant coefficients have been widely used to assess runoff nonpoint source pollution from individual land uses (e.g., agricultural, residential) of a watershed. Pollutant coefficients, known as event mean concentrations (EMCs), were developed by the U.S. Environmental Protection Agency's Nationwide Urban Runoff Program (NURP) to serve as a national measure for characterizing pollutant loading in a receiving water body. The term “baseflow pollutant coefficient (BPC)” is used in this study as a surrogate for EMC to describe mean concentration of pollutants in base flow‐dominated flow. A method for characterizing base flow quantity and quality for different land uses was explored using inverse modeling with two optimization techniques (a least square method and a genetic algorithm [GA] optimization), land use information, and streamflow quantity and quality data. The inverse model was formulated as a constrained minimization problem and demonstrated with data for 15 watersheds in Indiana. Results showed that estimated pollutant coefficients are comparable to the published literature. This indicates that the proposed method has the potential to effectively estimate constituent mean concentrations for pollutant load determination in gauged and ungauged watersheds, albeit more analysis with larger and more robust datasets is desirable to further refine and validate the accuracy of the approach.     

镇江城市降雨径流营养盐污染特征研究

城市降雨径流污染是城市水体水质恶化的主要原因之一,为了分析降雨径流的污染特征,从2006-05开始,选择镇江具有代表性的土地使用功能对其降雨径流水质进行监测,分析了径流中固体悬浮物和营养盐的变化特征.结果表明,镇江不同功能区中5～40 μm粒径的固体悬浮物体积分数最大;商业区径流污染物浓度很高,其中SS浓度高达978 mg/L,是城市面源污染的主要来源;降雨初期的30 min径流污染物浓度很高,随降雨历时的延长污染物浓度逐渐下降并趋于稳定;溶解态氮、颗粒态磷和固体悬浮物是径流中污染物输出的主要形态;通过分析固体悬浮物与其他污染物的相关性,发现固体悬浮物是径流中营养盐吸附的载体,去除固体悬浮物是治理镇江降雨径流污染的有效途径.     

能值分析理论在耕地可持续利用评价中的应用研究——以南京市为例

评价指标体系是耕地可持续利用评价研究的难点,正确选择评价理论与方法,构建科学、合理的评价指标体系,为正确认识耕地利用的可持续性及制定相应政策提供理论与实践依据。文章引入能值理论,在传统评价方法基础上对耕地利用中物流、能流等以太阳能值为统一衡量标准,建立新的指标体系,并对南京市1995~2004年的耕地利用进行评价。结果表明,研究时段内南京市耕地利用是向可持续方向发展的,且其可持续利用经历了两个阶段:①1995~1998年可持续性下降阶段,综合系数从1995年的1逐渐下降到1998年的0.9570;②1998~2004年可持续性上升阶段,综合系数逐年上升到2004年的1.1123。与传统评价方法相比,引入能值理论后的评价结果更能全面、客观地反映耕地利用的可持续状况。     

贵州土地复垦发展现状及其对策研究

详细分析了贵州省土地复垦的发展现状以及近年来所做的工作及成效,研究了矿山开采等活动对贵州省土地资源造成的破坏及生态危害,提出了具体的土地复垦的技术措施。为了实现能源、环境、社会、人口和经济的可持续发展,土地复垦是必然选择。     

回归分析方法在环境领域中的应用评述

回归分析是一种处理变量间相关关系的有效数理统计方法,回归分析模型目前已应用于环境领域的多个方面,并在实际应用中证实了其准确性和可行性。基本回归分析方法有一元线性回归、多元线性回归和逐步回归等,通过概述了这几种基本回归分析方法的原理及其在环境领域中的应用现状,评述了其应用效果,并预测了回归分析技术在环境领域中应用的发展方向;对在众多环境科学与工程研究领域中,更好地发挥回归分析的作用具有很好的参考价值。