A PRACTICAL MODEL INTEGRATING QUALITY ASSURANCE INTO ENVIRONMENTAL MONITORING1

ABSTRACT: A model of comprehensive environmental monitoring process with integral quality assurance is presented. This model views the monitoring process as iterative cycles of a series of elements: design, plan, protocols, preparation, field liaison, sample collection, sample handling, laboratory analysis, data transmission, data validation, data approval, data provision, statistical analysis, and reporting. Quality assurance is linked to each element, not just to laboratory analysis. The program of quality assurance ensures that environmental monitoring data are compatible with the project goals, are comparable between various sampling agencies, and maintain a high degree of scientific credibility. The key characteristics of the overall quality assurance process are detailed documentation, timely resolution of problems, regular reporting, and routine independent audits.     

Patchy Distribution Fields: Sampling Distance Unit of an Interleaved Survey and Reconstruction Adequacy

A mathematical model was used to examine the effects of choosing various units of sampling distance of an interleaved (two-pass) acoustic survey on the adequacy of reconstructing patchy distribution fields. The model simulates fish or plankton patches (or gaps) of different shapes and spatial orientations, and an interleaved survey by parallel or zigzag transects, along which a unit of sampling distance is set. The efficiency of a survey is determined by the adequacy of a reconstructed field to that originally generated, which is evaluated by calculating their correlations (r). Regarding immovable fields, the experiments conducted indicate that a patchy field can be reconstructed properly (r ² > 0.70) if the distance between transects D < (1.5–2.0)R and the unit of sampling distance d < (1.5– 2.0)R _p. As, for regular surveys d < (1.0–1.5)R _p, it may be concluded that interleaved surveys are more efficient than regular ones because of the factor studied. In regard to movable fields, a comparison of the results of interleaved surveys with those of regular surveys directly indicates that the former may ensure a more adequate field reconstruction than the latter do. This fact confirms the previous conclusion that an interleaved survey is expedient in cases where there is no preference regarding the position of a vessel for further work.     

高职高等数学教学与数学建模

高职数学教学中存在对应用性教学重视不够的现象,因此教学中应引进和加强数学建模教学.数学建模的过程体现了学以致用的原则,促进学生各学科的全面发展,提高学生运用现代化工具的能力,培养学生严谨、求实的科学态度和协作、创新的精神.当前,高职数学教学的改革应突出三条主线:教学内容的选择、教学模式的完善以及教学方法的更新,使学生真正受到理论与实践相结合的综合性教育.     

用数模表述分析远距离污染源对土壤环境的影响

在以哈密红星皮革厂铬鞣废水中的重金属污染物（铬）对土壤污染影响的调查分析中,就远距离污染源对环境影响的关系用试验公式作了研究表述就,选出了较为适宜的数学模型,就污染物含量与污染源距离的关系进行了分析。     

长江上游水质与产业密度关系数学模型

通过对长江上游（四川省）各地、市、州水质及相应地区产业密度的分析,以地区水质P'_j 为自变量,以产业密度Ｇ′为因变量,以１＋ ５P'_j 和ｌｎG′作散点图并进行数学拟合,得到四川省水质与产业密度数学模型．对数学模型求导并令导数等于１,得P'_j＝ ０．４０２,Ｇ′＝ １４１．７１; 当Ｇ′≤１４１．７１万元／ｋｍ² 时,水质的变差速度小于产业增长速度,当Ｇ′＞ １４１．７１ 万元／ｋｍ² 时,水质的变差速度大于产业密度的增长速度． 在考虑四川省经济发展时要注意到这个关系． 在产业密度大于１４１．７１ 万元／ｋｍ² 时,为保护水环境和促进经济持续健康发展,必须提高产业的技术水平、调整产业结构、采取必要的环保政策、加大环保投入和环保新技术的开发和应用．     

SEDIMENT TRANSPORT IN A SHALLOW COASTAL ESTUARY DURING THE WINTER SEASON1

ABSTRACT: This project analyzes suspended sediment flux through the upper Barataria basin in Louisiana during the winter season defined from November through April. The Barataria is a shallow coastal estuary located in southeastern Louisiana. The controls exerted by environmental parameters (such as wind or atmospheric pressure) in wetlands‐shallow bay ecosystems on transport of water and sediment were examined. Water samples were taken at a bayou (which serve as the inlet for flow to the estuary) on a regular basis. These samples were analyzed for total suspended solids and volatile suspended solids. Velocity, depth, temperature, salinity, conductivity, and meteorological measurements were all recorded at the time of each sampling. A multi‐parameter field probe was employed to continually monitor turbidity, water level, conductivity, and temperature during frontal events. These data were used in a regression analysis to examine the factors that drive carbon flux in the region. Investigations have determined that synoptic climate and prevailing weather conditions explain much of the variations in water levels, flow circulation patterns, salinity, and suspended sediment. Relatively small amounts of sediment appear to leave the estuary during normal tidal activity, but winter storm fronts result in significant fluxes of sediment in both up‐basin and down‐basin directions.     

COMPARATIVE STUDY OF DROUGHT PREDICTION TECHNIQUES FOR RESERVOIR OPERATION1

ABSTRACT: Predicting the likelihood of a drought markedly enhances the efficiency of reservoir operations. This study applies the kriging method and time series analysis to predict inflows to Shihmen Reservoir in northern Taiwan. A subsequent reservoir operation simulation is employed to determine the drought lead time (DLT), the time before the onset of a drought. A more efficient reservoir operational strategy can be established with the aid of DLT and the probability of successful drought prediction (P s). Simulation results of reservoir operation over a period of three decades demonstrate that, at one month DLT, the kriging approach achieves 0.86 of P s for moderate droughts and 0.94 of P s for severe droughts. The kriging approach generally outperformed the time series approach in terms of DLT, P s of drought prediction, and the number of correctly predicted drought events.     

污水处理厂计算机仿真模拟研究

将上海市某城市污水处理厂的生产运行数据进行了计算机模拟,并将模拟结果中的COD及TSS、TN、NH3-N等组分的浓度与实测数据进行了比较。通过对模型参数进行修正和调整,仅改变ASM1数学模型中的4个参数,即取得了较好的预测效果。同时对城市污水处理厂进一步运用数学模型的可行性进行了讨论。     

2000年～2001年5月国内环境事件数据

简要介绍了2000年-2001年5月国内发生的各种环境事件,包括沙尘天气、赤潮、污染事件、山体滑坡。虫害、自然灾害等,进行了统计和分析。     

WATERSHED SCALING EFFECT ON BASE FLOW NITRATE,VALLEY AND RIDGE PHYSIOGRAPHIC PROVINCE1

ABSTRACT: A study of stream base flow and NO₃‐N concentration was conducted simultaneously in 51 subwatersheds within the 116‐square‐kilometer watershed of East Mahantango Creek near Klingerstown, Pennsylvania. The study was designed to test whether measurable results of processes and observations within the smaller watersheds were similar to or transferable to a larger scale. Ancillary data on land use were available for the small and large watersheds. Although the source of land‐use data was different for the small and large watersheds, comparisons showed that the differences in the two land‐use data sources were minimal. A land use‐based water‐quality model developed for the small‐scale 7.3‐square‐kilometer watershed for a previous study accurately predicted NO₃‐N concentrations from sampling in the same watershed. The water‐quality model was modified and, using the imagery‐based land use, was found to accurately predict NO₃‐N concentrations in the subwatersheds of the large‐scale 116‐square‐kilometer watershed as well. Because the model accurately predicts NO₃‐N concentrations at small and large scales, it is likely that in second‐order streams and higher, discharge of water and NO₃‐N is dominated by flow from smaller first‐order streams, and the contribution of ground‐water discharge to higher order streams is minimal at the large scale.