Relationships between three dispersion measures used in flood frequency analysis

Three dispersion measures of a random variable, i.e., the standard deviation, the mean deviation (MD) about the mean and the second L-moment, are analyzed in terms of their properties and mutual relationships. Emphasis is placed on the MD, as it is less recognized than two other dispersion measures. The relationships between the dispersion measures are derived for distributions commonly applied in flood frequency analysis (FFA). For distributions that are unbounded, there is a distribution-dependent constant value of the ratio of dispersion measures, or equivalently of respective coefficients of variation. For two-parameter distributions that are lower-bounded, the relationship between the coefficients of variation is also distribution dependent and is not linear. For lower-bounded three-parameter distributions, the dispersion measure ratios, or equivalently the ratios of coefficients of variation, depend on the coefficient of skewness and show a strong distributional dependence. For selected distributions, the three dispersion measures are compared both in terms of the robustness to the largest samples element and the accuracy of upper quantile estimation. The MD statistics may be highly competitive to the two other dispersion measure statistics if applied in FFA for parameters estimation.     

泰安基准台洞体及环境改造

大部分形变仪器长年工作在山洞内,洞室的潮湿对仪器及房间内装修材料影响很大,“十五”期间中国地震局投资近十万元对泰安台形变仪器专用山洞进行了改造。本文从改造内容,改造方法及改造效果几方面进行了阐述,为同类山洞改造提供借鉴。     

Influence of IHSS Standard and Reference Materials on Copper and Mercury Toxicity to Vibrio fischeri

The reduction in light emission of the marine bacterium Vibrio fischeri used in the standard Microtox^® bioassay was measured for the metals copper and mercury. The concentration at which the light emission was reduced by 50% (EC₅₀) was determined to be (3.43 ± 0.83) μmol/L for Cu²⁺ and (0.66 ± 0.01) μmol/L for Hg²⁺. The reduction of the toxicity of these metals by humic and fulvic acids were studied using IHSS Standard and Reference Materials. Copper toxicity was reduced 17...20% by the soil and peat fulvic acids and 9...20% by the aquatic fulvic acids. While there appeared to be little difference in the reduction of Cu toxicity by fulvic acids from soils, peats, or aquatic systems, Hg toxicity was reduced 3.6...7.3% by the soils and peats, while aquatic fulvic acids reduced Hg toxicity 14...16%. Soil fulvic acids appear to have significantly less capacity to reduce Hg toxicity than Cu toxicity. Humic acids had much higher reductions of Cu toxicity (44...124%) compared to the fulvic acids, with little difference between aquatic and soil or peat humic acids, 44...124% and 67...100%, respectively. However, humic and fulvic acids, regardless of origin, had approximately the same effect on Hg toxicity with 3.5...16% reduction by fulvic acids and 8...20% reduction by humic acids. Unlike the fulvic acids, no clear trend was observed relative to origin of the humic acids. There was no correlation between percent reduction of Cu or Hg toxicity by the organic compounds and copper binding capacity (CuBC), C/N ratio, or carboxyl content of the materials. Examination of natural organic matter (NOM) isolated by reverse osmosis techniques from three water sources had reductions of both Cu and Hg toxicity that were most similar to the Suwannee River and Nordic fulvic acids.     

Die neue EG‐Wasserrahmenrichtlinie: Bewertung der chemischen und ökologischen Qualität von Oberflächengewässern

The New EC Framework Water Directive: Assessment of the Chemical and Ecological Status of Surface Waters The main objective of the draft EC Framework Water Directive is the good quality of all surface waters. The directive provides for an assessment of the chemical status of surface waters (EU‐wide valid environmental quality standards for approximately 30 priority substances) and a five‐stage ecological classification of waters, comprising the stages high, good, moderate, poor, and bad. The starting point for the assessment are the reference conditions, which are defined as corresponding to high water quality and characterising a water status with no significant anthropogenic impact. The reference sites in the various water body types are to be selected using hydromorphological and physico‐chemical parameters and subsequently characterised by means of biological parameters. For surface waters, three groups of characteristics are provided for, namely: 1. with priority the biology – in the case of surface waters – with the four elements phytoplankton, macrophytes/phytobenthos, benthic invertebrate fauna, and fish fauna; 2. supporting the hydromorphology, e.g. flowing waters with the three elements hydrological regime, river continuity, and morphological conditions and 3. supporting the physico‐chemical conditions with the three elements general conditions, specific synthetic pollutants, and specific non synthetic pollutants (other than the priority substances of the chemical status).     

Economic analysis for the production of four grape cultivars using microcatchment water harvesting systems in Iran

An economic analysis was conducted for temporal yield variations of four local grape cultivars grown in rain-fed microcatchments in the Bajgah area of Fars province, in Islamic Republic of Iran. For this study, four local cultivars of grapes were considered. The cultivars examined were Black Rishbaba, Rotabi, Asgari and Black grapes. The soil type was a gravely loam with an average slope of 5–6%, in microcatchment systems, and in plots without microcatchments. Analysis of yield data with a multiple regression model indicated that a 9 m² (3×3 m) microcatchment area for each individual plant (vine) was the most appropriate area for vineyards in this region. The results also demonstrated that by using this area for each grapevine, yields (kg/ha) were 40% greater than yields obtained for vines in the standard vineyard (without microcatchments) in this area. Economic analysis was performed and the cost and income were compared for a depreciation period (life-span period) of 50 years and interest rate of 14%. The analysis showed that a microcatchment area of 9 m² is economically feasible. The Black Rishbaba rain-fed vines were the most suitable cultivar for this region. The benefit probabilities of rain-fed Black Rishbaba, Rotabi, Asgari and Black grapes with a microcatchment area of 9 m² and without such an area were 63.3% (i.e. two of 3 years), 52.4% (i.e. one of 2 years), 32.9% (i.e. one of 3 years), 13.3% (i.e. one of 8 years), and 59.5% (i.e. two of 3 years), 39.4% (i.e. two of 5 years), 31.8% (i.e. one of 3 years), and 10.7% (i.e. one of 9 years), respectively. Therefore, the Black Rishbaba and Rotabi cultivars are economically more stable in microcatchment system, while only the Black Rishbaba cultivar would be such in the standard vineyard system.     

规范化管理在枣庄市薛城区煤矿发展中的应用

根据枣庄市薛城区辖区内煤矿开采资源储量将近枯竭的现状,阐述了实施规范化管理,增强矿井发展潜力的必要性。针对矿井实际情况,建立了一整套的管理制度考核机制,并通过实施规范化管理,促进矿井的安全生产,使该矿的经济效益和社会效益有了明显提高。     

数据字典在地质矿产术语分类代码修编平台中的应用

基于B/S模式的《地质矿产术语分类代码》（GB 9649-1988）修编平台是提高该标准修编工作效率的一种必然手段,而数据字典在该平台中的穿插使用保证了修编工作的合理与安全.通过论述数据字典技术在实现修编平台的修编权限控制、修编版本管理功能中的具体应用,体现了数据字典技术在数据处理方面的独特优势.数据字典技术在该平台中的应用,不仅对修编人员的修编权限进行了灵活的约束,而且修编过程中产生的不同版本也得到了有效的管理.     

浅论水平定向钻进敷设管材

水平定向钻进铺设技术在国内应用日益广泛,但是现行相关管材标准严重滞后,难以满足实际需要。本文对现行水平定向钻进铺设所涉及到的管材进行简要论述,建议相关部门尽快制定相关的水平定向钻进铺设管材标准,并与现行水平定向钻进技术规范协调一致,以促进水平定向钻进工程在国内的健康发展。     

基于动力触探的砾性土液化判别方法通用性研究

能量传递率是衡量贯入类试验锤击效率的一个重要指标。国外对这一指标需要进行现场实测,进而修正贯入试验的锤击数,建立评价场地承载力、液化势等特性的标准化锤击数。国内规范中,则较少考虑贯入试验的锤击能量传递率的问题,且缺少现场试验测试数据,导致基于贯入类试验锤击数的地基评价方法难以与国外标准进行横向对比。为解决这一问题,选取川滇地区西昌地震实验场的3个勘察试验点。采用能量测试仪实测标准贯入试验能量传递率,研究我国常规SPT试验装置锤击效率,并评价其稳定性。试验实测结果显示,现场标准贯入试验的锤击能量传递率均值基本超过75%。能量传递率随着贯入深度的增加稍有增加,地表下20 m范围内增长幅值为10%左右。试验结果可为评价我国常规SPT试验设备的锤击效率提供依据。     

计算横向非均匀介质体波理论地震图的Maslov渐近法

本文运用Maslov渐近理论编写的二维横向非均匀介质中的理论地震图程序,与其它类型算法作了精确对比,结果表明,在层状介质模型中,本程序的结果无论振幅还是波形对比都与反射率法基本相同。对于二维横向非均匀模型,在射线理论的非奇点处,本算法与射线方法基本一致,在射线理论的奇异点处,Maslov方法消除了射线理论所固有奇点,提高了计算精度。