ASSESSMENT OF HYDRAULIC PROPERTIES IN AN UNCONFINED ALLUVIAL AQUIFER NEAR GRAND ISLAND,NEBRASKA1

ABSTRACT: A method is presented to analyze time-drawdown data from one or more observation wells for the calculation of four hydraulic parameters for unconfined aquifers: vertical hydraulic conductivity, horizontal hydraulic conductivity, storage coefficient, and specific yield. The hydraulic parameter results are further analyzed for reliability and the possible ranges of the actual parameter values. After verification using a theoretical example, the method was used to analyze pumping test data from 22 observation wells in an unconfined alluvial aquifer near Grand Island, Nebraska. Results indicate that this method can be used to efficiently calculate the four hydraulic parameters in this type of aquifer. The method can also identify the impact of measurement errors on the parameter estimates, and provide ranges of the actual parameter values. The parameter values calculated using this method were compared to those determined using other theories. It is found that this method is very useful for calculating the hydraulic properties from pumping test data and for analyzing the parameter reliability.     

加油站安全监控预警系统研发与应用

加油站安全监控系统采用分散监控、集中管理与网络传输的监控策略,不仅可实现传统的视频监控和记录功能,还对加油站进出车辆情况、收费情况、设备运行情况以及加油站工作情况进行实时监视和记录;在可实现加油站现场安全参数(如温度、液位、可燃气体浓度等)的实时采集与处理,对在加油站内部及周边动态安全状况实时分析的基础上,根据警情设定自动作出相应的应急反应,如打开声光报警装置等;同时,对危险源可能发生的事故后果(包括死亡、重伤和轻伤等)进行模拟与分析,进而为事故的应急救援提供决策与支持。     

Modeling a wetland system: The case of Keoladeo National Park (KNP), India

A model for the wetland part of KNP is presented and analyzed. Two-dimensional parameter scans suggest that this minimal model possesses dynamical complexities. Per capita availability of water to “bad” biomass (W₁) is one of the most vital parameters. One can ensure good health of the park by restricting the par capita availability of water to low values. Getting the “bad” biomass removed by granting permits to villagers should go hand in hand with water management and conservation activities. The model presented in this paper may be helpful in designing the timing and nature of human interventions in the form of implementation of well worked out policies in future.     

用总有机碳浓度表达活性污泥反应动力学的研究

本研究对废水活性污泥法处理中常用指标ＣＯＤ、ＢＯＤ５、ＭＬＶＳＳ与总有机磷指标的相关性进行了探讨。     

青海门源地区O3浓度水平及影响因子分析

为研究高原背景地区O_3的浓度水平,于2013年9月13日至2013年10月14日期间,在国家大气背景站青海门源站开展了为期32天的观测。观测结果显示,门源地区O_3小时浓度均值为115.0±22.6μg/m3,低于《环境空气质量标准》(GB3095-2012)中O_3小时平均浓度限值的一级标准(160μg/m3)。通过分析O_3和NOx实时浓度在一天24小时内随时间变化的特征序列,发现在多数观测天内O_3和NOx呈现此消彼长的变化规律,表明O_3主要来自有NOx参与的光化学反应;另有几天NOx和O_3的浓度出现同峰同谷的现象,推测这种变化主要是大气运动传输造成的。相关性分析表明,臭氧浓度与温度、湿度、风速、SO2、NOx以及CO的浓度都显著相关(P0.01);多元线性回归分析表明O_3与温度、湿度、气压、风速的关系近似符合Y=0.630T-0.192H-0.004P-0.091W+196.039,拟合结果与真值误差2.88%。综上分析,门源地区O_3浓度水平较低,但在高温低湿、风速较高、NOx浓度较低的情况下,O_3容易积累,O_3浓度主要受光化学反应和大气运动传输过程两个因素影响。     

养分(磷)吸收机理模型的应用研究──Ⅱ.模型参数的敏感性分析

采用Claassen的养分吸收机理模型探讨了玉米与大豆幼苗磷吸收过程中的参数敏感性，结果表明：在一般土壤与施肥条件下，玉米与大豆幼苗吸收磷的高度敏感性参数或重要限制因素为根系伸长速率与根半径；在相同土壤供磷条件下，供试大豆幼苗根系的磷摄取能力远低于玉米幼苗根系的磷摄取能力，其原因归结于两者在根系最大养分流Imax与根系伸长速率K两个敏感性参数上的差异；玉米与大豆幼苗磷吸收过程中三种根毛参数的敏感性均较低，这主要与土壤供磷水平较高有关；土壤含水量在玉米幼苗磷吸收过程中表现了极高的敏感性,当土壤含水量降低时，土壤养分供应参数对玉米幼苗磷吸收的敏感性与限制作用均增大。     

影子价格─自然灾害经济评价中合理的价格

着重说明自然灾害经济评价中利用影子价格的原因，简要说明我国目前在投资项目评价中采用的影子价格及计算方法，以及在自然灾害经济评价中如何利用影子价格进行计算．     

西台盐湖水文地质参数动态变化研究

为了建立卤水水位和水化学动态数学模型，这就需要掌握盐湖的水文地质参数的动态变化。分别选取西台吉乃尔盐湖（简称西台盐湖，下同）枯水期（4～5月）和丰水期（8～9月）两个时段开展野外流速流向测试工作，对测试的实验数据进行分析，归纳出西台盐湖水文地质参数动态变化的规律：枯水期流速相对丰水期小，但是随着卤水的开采规模和开采条件不同以及自然气候、水文条件的改变，卤水的渗流场也随之改变，卤水的渗透流速呈现多变性。两次测试的流向结果与测试期间同期的卤水等水位线显示的流向基本一致，由于持续抽卤的影响，9月的流向与5月的流向有很大的差异，流向方向大致相反。     

Hydro-chemical Survey of Groundwater of Hisar City and Assessment of Defluoridation Methods Used in India

Ground water quality of Hisar city was assessed for its suitability for drinking purposes. Samples collected from the Bore-wells (forms a part of municipal water supply) and handpumps (direct consumption) were analyzed for the various physico-chemical parameters including pH, electrical conductivity, total dissolved salts, total hardness, total alkalinity, sodium, potassium, calcium, magnesium, carbonate, bicarbonate, chloride and sulfate. The concentrations of magnesium, sodium, potassium, sulfate and especially of chloride were found moderately higher than the WHO standards for the drinking water. Further a comparison of fluoride (F⁻) levels in groundwater of various cities and towns of Haryana state was performed. The relatively higher concentrations of F⁻ in groundwater of Haryana raise the risk of fluorosis and hence groundwater must be used with proper treatment. Promising defluoridation methods using locally available materials and technologies are discussed for the prevention and control of fluorosis. Data were assessed statistically to find the suitable markers of ground water quality as an aid to monitoring groundwater quality.     

市政污泥厌氧发酵渗沥液污染物释放与热效应

为了研究污泥厌氧发酵过程中渗沥液水质污染指标随温度和时间的变化规律,以及污泥的热效应变化,分别测定30,45,60℃下厌氧发酵不同时间后污泥渗沥液的p H值、DO、TN和TOC含量,分析厌氧发酵对渗沥液污染指标的影响,通过热重-差热试验绘制45℃下不同时间的TG-DTA曲线,研究厌氧发酵对污泥热效应的影响。结果表明:新鲜污泥渗沥液p H值为7.50,随着厌氧发酵的进行,30℃下p H值上升25.7%,DO、TN与TOC含量分别下降90.0%、90.4%、74.9%,且初期外界温度越高反应速率越快;由TG-DTA曲线可知:水分散失和有机物燃烧分解致使质量损失,并分别伴随吸热和放热现象。