三峡水库蓄水前后长江干流主要污染物浓度变化趋势分析研究

利用三峡库区长江干流1998年-2010年水质监测数据,以1998年-2003年代表蓄水前,2004年-2010年代表蓄水后,对比分析蓄水前后主要污染物浓度变化情况,用Spearman秩相关系数法判断其变化趋势的显著性。分析可知,蓄水后氨氮、化学需氧量、总磷指标的平均浓度要低于蓄水前,氨氮、化学需氧量浓度变化幅度大于蓄水前,总磷浓度变化幅度小于蓄水前;Spearman秩相关系数计算结果表明,三峡水库常年回水区内的断面,污染物浓度多数呈下降趋势,但只有晒网坝和培石断面的氨氮指标浓度下降趋势具有显著意义。     

挥发性有机污染物(VOCs)治理进展及发展前沿思考

本文介绍了近年国内外在治理可挥发性有机化合物的研究进展,并对吸附与催化技术,低温等离子体-光催化技术等几种先进的处理技术最新发展作了较全面的综述,并对发展前景进行展望。     

甘南县空气变化趋势分析

运用近五年的大气监测数据分析了甘南县大气污染特征,指出了影响甘南县空气质量的主要污染物及变化趋势。     

ESTIMATION OF COASTAL WATER CONTAMINATION LONG-TERM TREND USING SEASONAL LINEAR MODELS1

ABSTRACT: Bivalves are used as bioindicators to assess trends of the chemical quality of coastal and marine environments due to their ability to concentrate chemicals. These shellfish are subject to seasonal physiological changes influencing the chemical concentration. Using quarterly data, we model concentration via linear regression with a biologically based seasonal component. This was applied to cadmium concentration measured in the blue mussel (Mytilus edulis) at three sites in the Seine estuary (Normandy, France). In this case we have a high concentration season from January to June and a “low concentration” season from July to December. This season definition was checked a posteriori, using box-and-whisker plots and a statistical test of comparison of pair-wise adjusted least-squares mean differences, and it appears to be very reasonable. We averaged data by season and across sites. Our final model (R²= 0.846 with N= 27 observations) includes highly significant terms: a season effect, which accounts for 45% of the total variability, a linear and a quadratic time term. Outliers were identified by high Studentized residual values and attributed to bias in the temporal sampling schemes. The methodology developed will further be used with other shellfish and/or other trace elements and organic chemicals.     

NORMALIZED AGRICULTURAL PRICES AND WATER RESOURCES PLANNING1

ABSTRACT: Short-term fluctuations in agricultural markets necesitate adjustments in market prices for use in water resources planning. Two procudures for this price normalizing are described and evaluated. The linear treand and weighted average normalizing procedures perform reasonably well, except in cases of dramatic price oscillations.     

NONPARAMETRIC TEST PERFORMANCE FOR TRENDS IN WATER QUALITY WITH SAMPLING DESIGN APPLICATIONS1

ABSTRACT: In this paper four nonparametric tests for monotonic trend detection are compared with respect to their power and accuracy. The importance of comparing powers at equal empirical significance levels rather than nominal levels is stressed. Therefore, an appropriate graphical method is presented. The effect of the sampling frequency is also assessed using Monte Carlo simulations and a trajectory representation that visualizes the dynamics of the trade-off between the type I and type II errors. These methods are applied to compare four nonparametrical tests (seasonal Mann. Kendall, modified seasonal Mann-Kendall, covariance eigenvalue and covariance inversion) under several conditions. It is concluded with respect to the power that it is not worthwhile for the modified seasonal Mann-Kendall test applied to the AR(1) process considered in this paper to increase the sampling frequency from monthly to biweekly for detecting a monotonic trend of 5 percent, 10 percent, or 15 percent of the process variance. Under these conditions the seasonal Mann-Kendall test is highly liberal, while the covariance inversion and the covariance eigenvalue test are conservative. This research is situated in the development of an efficient sampling design for the Flemish water quality monitoring network.     

采空区火源位置探测技术现状及发展方向

概述了国内外采空区火源位置探测技术的现状,着重介绍了温度探测法、气体探测法、磁力探测法、数理解算法、电磁波探测法及电阻探测法等探测技术,并展望了国内外采空区火源位置探测技术的发展方向     

我国钢铁工业废水治理及其发展趋势

我国水资源人均拥有量仅为世界人均拥有量的四分之一，而且降水在时空分布上很不均衡。这一现实，决定了节省水资源，保护水环境是我国一项长期的战略任务。文章概要地叙述了钢铁工业废水治理及其发展过程。作者认为，要从根本上解决钢铁工业废水对水环境的污染与破坏，必须采取综合防治措施，并把整套循环用水技术引入生产工艺过程，使废水与污染物都作为资源加以回收，并实现循环利用。上述过程的实质，是模拟大自然生物圈循环运行     

湖北省荒山荒地资源开发利用的原则和方向

荒山荒地是我省农业的重要后备，本文将主要探讨这部分资源的开发利用及其原则和方向，为发展农业寻求新的途径与措施。     

REGIONAL SCALE TREND MONITORING OF INDICATORS OF TROPHIC CONDITION OF LAKES1

ABSTRACT: The U.S. Environmental Protection Agency has proposed a sample survey design to answer questions about the ecological condition and trends in condition of U.S. ecological resources. To meet the objectives, the design relies on a probability sample of the resource population of interest (e.g., a random sample of lakes) each year on which measurements are made during an index period. Natural spatial and temporal variability and variability in the sampling process all affect the ability to describe the status of a population and the sensitivity for trend detection. We describe the important components of variance and estimate their magnitude for indicators of trophic condition of lakes to illustrate the process. We also describe models for trend detection and use them to demonstrate the sensitivity of the proposed design to detect trends. If the variance structure that develops during the probability surveys is like that synthesized from available databases and the literature, then the trends in common indicators of trophic condition of the specified magnitude should be detectable within about a decade for Secchi disk transparency (0.5–1 percentiyear) and total phosphorus (2–3 percent/year), but not for chlorophyll-a (> 3–4 percent/year), which will take longer.