THE OPTIMAL STEADY-STATE IN GROUNDWATER MANAGEMENT1

Groundwater use is likely to be inefficient in the absence of regulation and hence there is substantial interest in optimal groundwater withdrawals over time. Under an optimal regime withdrawals, pumping lifts, and profits converge to steady-state levels. In this paper we show that optimal steady-state lifts, withdrawals, and marginal user costs can be readily calculated for multi-cell models of confined aquifers. Applications to the design of economically efficient groundwater management policies are discussed, comparisons to previous work and to the safe yield concept are made, and an illustrative example is given.     

IRRIGATION AND GROUNDWATER DEPLETION IN CADDO COUNTY,OKLAHOMA1

ABSTRACT: Similar groundwater problems associated with the Ogallala in western Oklahoma are beginning to affect aquifers much farther east. A rapid decline in the water table has been detected in Caddo County, Oklahoma. Ninety-six percent of the groundwater resources used in Caddo County are used for irrigation. Severe consequences for farmers, especially peanut growers, are possible in the near future.     

秦皇岛沿海地下水脆弱性评价

在介绍地下水脆弱性及其评价方法的基础上，分析了秦皇岛沿海地区地下水脆弱性的影响因素。应用DRASTIC方法与GIS技术耦合的模型，对该区地下水脆弱性进行评价，并进行了脆弱性分区。     

铁细菌在水处理方面的应用及影响其生长的因素

随着人们对铁细菌认识的突破，其应用也发生了巨大的变化。本文主要介绍了铁细菌在水处理方面的两个主要应用方向——酸性矿山废水的处理和城市用水的处理。同时综述了影响铁细菌生长的几个主要因素。     

人类活动对城市地下水影响的探讨

通过对城市地下水包气带特征、地下水的排泄和补给特征、雨水排泄特征的系统分析，认为由于城市地下水系统受自然条件和人为因素双重作用的控制使之表现出与自然状态下完全不同的特征：由于地表的硬化，城市包气带由三层结构变为四层结构，即地表硬化层、土壤水带、中间带和毛细水带；城市地区的人文历史沉积也会对包气带造成影响；雨水主要通过城市的排水系统排泄。地下水主要通过人工开采排泄，都表现出集中排泄的特点。文中还对酸沉降对城市地区地下水水质和包气带性质可能受到的影响进行了初步的分析。     

地下水回灌补源防治咸水入侵技术研究 --以山东省广绕县为例

山东省广绕县井灌区由于长期超采地下水，引起区域地下水位持续下降、咸水入侵和地裂缝等一系列环境地质问题，成为区域社会和经济持续发展的制约因素。采用地下水回灌补源和调蓄技术是防治咸水入侵的有效途径。探讨了地下水回灌补源系列技术方法，涉及试验研究、数学模拟与优化技术等。室内、野外试验研究为地下水回灌规划和设计以及建立数值模拟模型提供了基本数据和参数。为了优化调整地下水开采量和回灌补源，建立了管理模型。管理模型预测表明，引用黄河水和汛期雨洪水回灌补源，以及通过节水减少漏斗区地下水开采量等系列措施可以有效地阻止咸水入侵，逐步改善区内的地下水环境。     

COMBINED SURFACE WATER-GROUNDWATER ANALYSIS OF HYDROLOGICAL SYSTEMS WITH THE AID OF THE HYBRID COMPUTER1

The solution with the aid of the hybrid computer of the partial and total differential equations for an integrated surface water groundwater system is described. A versatile computing technique has been developed to make a rapid and accurate study of the groundwater response due to varying inputs (deep percolation) or outputs (evapotranspiration) from the groundwater system. Spatial variations in basic vegetation phenomena, such as pattern, and hydrological parameters, are represented by means of a grid network which also allows the input of variable boundary conditions. The model is applied to an area in Columbia, South America which is subject to high water-table conditions. Various reclamation schemes and management practices under conditions of irrigated agriculture are assessed.     

Application of stimulating agents on the immobilized bioluminescence strain Pseudomonas putida mt-2 KG1206, preserved by deep-freezing, for the convenient biomonitoring

This study was conducted to develop methods for the application of an immobilized bioluminescence strain(KG1206),preserved by deep-freezing(DF),for the monitoring of contaminated environments.The immobilized cells,preserved by DF,required approximately 2 hr for reconstitution of their activity.A large reduction in bioluminescence was observed due to the DF process;0.07-0.58 times that of the non deep-frozen(NDF) immobilized strain.The decreased bioluminescence activity induced by the DF process was enhanced by the stimulants,sodium lactate(SL) and KNO 3.However,regardless of the inducer chemical tested,the immobilized strain modified with KNO 3 consistently produced greater bioluminescence than that treated with SL,in the range of 3.0-10.7(avg.6.7 ± 3.69) and 1.2-4.2(avg.2.4 ± 1.47) times that of control,respectively.All KNO 3 treatments of contaminated groundwater samples also resulted in an increase in bioluminescence activity,but the rate of stimulation varied for each sample.Also,no strong linear correlation was observed between the bioluminescence and the total concentration of an inducer,which may related to the complex characteristics of the environmental samples.Overall,the results demonstrated the ability of immobilized genetically engineered bacteria,preserved by DF,to measure a specific group of environmental contaminants using a stimulating agent(KNO 3),suggesting the potential for its preliminary application in a field-ready bioassay.     

液压振动台试验系统中的控制系统集成设计

根据液压振动台试验系统的功能特点,采用Labview软件将液压振动台试验系统的主要控制部件的软、硬件开发和系统集成优化,大大降低了试验系统的人力成本,提高了工作效率,操作简单便捷。     

东川因民矿区地下水-选厂水水化学特征及资源化影响因素

矿区水质分析结果表明,地下水属弱碱性淡水软水-微硬水。泉水水化学类型为HCO3-Ca·Mg。坑道水水化学类型为HCO3-Mg·Ca、HCO3·SO4-Mg·Ca、SO4·HCO3-Mg·Ca和SO4-Mg·Ca。地下水水化学成分的变化与(SO42-)浓度相关。泉水与坑道水具有一定的水力联系。选厂排放水中Pb、As含量高于坑道水。坑道水、选厂排放水具有弱侵蚀性。采矿活动和选矿过程对地下水-选厂水水质有较大影响,地下水水化学演变受控于矿业活动和矿区地球化学背景。