电导率法在海水入侵监测中的应用

海水入侵是人类不合理开采地下淡水而导致的一种环境恶化的地质灾害，其发生过程是一个可监测和可预报的过程。目前海水入侵的监测方法主要为物探和水化学方法，本文讨论了电导率法在海水入侵实际监测中的原理及应用。     

秦皇岛市海水入侵现状及防治对策研究

海水入侵是一种严重的地质灾害,它可引起机井报废、土壤盐渍化、地下管线腐蚀等一系列生态环境问题。秦皇岛市自20世纪80年代开始,在沿海的石河、汤河、洋河、戴河等入海口以及昌黎县、抚宁县灌区,先后发生了海水入侵现象,且有范围越来越广、程度越来越重的趋势,给当地工农业生产带来了巨大影响。通过分析秦皇岛市海水入侵的原因,提出修建沿海防护工程是治理海水入侵的有效措施,合理开采地下水、节约用水、进行污水和雨水资源化、海水淡化等减少淡水开采或补充地下淡水层是解决海水入侵的根本措施。     

秦皇岛市海水入侵现状及机理浅析

上世纪80年代初,秦皇岛市沿海局部区域发生海水入侵,其中以汤河、洋一戴河下游平原区较为严重,现状调查海侵面积71.75Km2。海水入侵使多眼饮用、农用水井水质变成,也使沿海生态环境受到影响。本文对海水入侵现状,成因机理进行分析,为防治海水入侵灾害发生提供依据。     

基于Visual Modflow的秦皇岛市海水入侵剖面

海水入侵是现代社会所特有的环境问题,已经引起国际社会的广泛关注。秦皇岛的地质环境条件和不合理的人为活动,导致了严重的海水入侵。数值模拟方法目前越来越多应用于各个领域,而由加拿大Waterloo水文地质公司开发的Visual Modflow软件具有系统化和可视化特点以及强大的模拟功能。通过浓度观测井的实测值与模型计算值进行对比,表明模型与实际数据比较切合,因此运用Visual Modflow通过概念模型及边界建立海水入侵剖面,预测评价秦皇岛海水入侵的趋势,能为秦皇岛市的海水入侵治理提供可靠的依据。     

黄渤海沿海地区地下水管理与海水入侵防治研究

正沿海地区人口密集,经济发展迅速。地下水开采等人类活动和海平面上升导致许多地区出现了严重的海水入侵问题,引发地下水水质恶化、土壤退化等一系列生态环境问题,严重制约经济社会的可持续发展。科学管理沿海地区地下水,防止海水入侵加剧,已成为亟需解决的重要问题。为此,2016年7月经科技部批复正式立项"黄渤海沿海地区地下水管理与海水入侵防治研究"(2016YFC0402800),以不同类型海岸带的海水入侵发生、演化、防治与地下     

重视地下水资源开发利用与保护

本文着重介绍了国内外地下水开发利用状况，以及造成水质严重污染，影响人类的生存，提出合理开发利用和保护地下水资源，已成为当今世界上的重要课题，提出了和措施，一，强调地下不和地表水是自然界水循环中两个密切相关的环境，必须统一管理，协调开发，二，应用计算机技术，建立管理模型。三，注意解决地表与地下水联合规划，海水入侵，地面沉降，工农业污染，人工回灌等，四，加强对水质和生态环境的保护。     

对水敏感性的机理与影响因素的研究

通过对咸淡水界面水敏感性机理与影响因素的研究，表明在非反应性微粒的释放迁移、反应性微粒的膨胀和絮凝作用与胶体吸附架桥作用下多孔介质中微粒物质的释放、膨胀、迁移、重沉积等引起的孔喉阻塞是导致水敏感性的机理所在；临界盐浓度、临界盐浓度变化率、临界离子强度、一临界流速和pH值是水敏感性的主要影响因素；指出水敏感性的研究对防止海水入侵具有重要的理论意义和实用价值。     

网络入侵诱骗技术的研究

在介绍基于网络和基于主机的入侵检测系统的基础上，分析了入侵诱骗技术和Hon—eypot技术。基于诱骗技术的网络安全系统是入侵检测的扩充，是网络安全技术中的一个新的研究领域，具有广阔的应用前景。     

我国首家海水烟气脱硫示范工程建成

深圳能源集团投资２．１５亿元建设的深圳西部电厂海水烟气脱硫工程，３月８日２０时，通过了７２小时连续试运行，移交生产。这是国内首家海水烟气脱硫示范工程，在目前世界上已投运的同类装置中也是最大的。海水烟气脱硫工艺是用于燃煤电厂的新型烟气脱硫工艺，利用天然海水作烟气中二氧化硫的吸收剂，无需其他添加剂，也不产生任何废弃物，具有技术成熟、工艺简单、系统可靠、投资省、运行维护费用低运行稳定等特点，适用于燃煤含硫量不高，并以海水为循环冷却水的海边电厂。目前在挪威、西班牙等国家和地区已广泛应用。西部电厂海水烟气…     

云南省生物多样性与生态安全形势研究

云南省以其得天独厚的自然条件孕育了丰富而又脆弱的生物多样性资源，然而外来物种入侵破坏了云南的生物多样性，威胁到国家的生态安全。分析了外来物种入侵、生物多样性及生态安全三者之间的关系，提出生物多样性资源是我国的核心竞争力所在，要将维护生态安全提升到国家战略高度予以重视，同时采取多种措施防范外来物种入侵。     

Using a Mass Balance Model to Evaluate Groundwater Budget of Seawater‐Intruded Island Aquifers1

Jang, Cheng‐Shin, Chen‐Wuing Liu, Shih‐Kai Chen, and Wen‐Sheng Lin, 2011. Using a Mass Balance Model to Evaluate Groundwater Budget of Seawater‐Intruded Island Aquifers. Journal of the American Water Resources Association (JAWRA) 48(1): 61‐73. DOI: 10.1111/j.1752‐1688.2011.00593.x Abstract: The study developed a mass balance model to evaluate the groundwater budget of seawater‐intruded island aquifers using limited available data. The Penghu islands were selected as a study area. As sparse observed data were available in the islands, methods of combining water and chloride balances were used to determine the amounts of groundwater pumping, seawater intrusion, aquifer storages, and safe yields in the shallow and deep aquifers. The groundwater budget shows that seawater intrusion to freshwater aquifers was 1.38 × 10⁶ and 0.29 × 10⁶ m³/year in the shallow and deep aquifers, respectively, indicating that the seawater intrusion is severe in the both aquifers. The safe yield of the shallow aquifer was 14.56 × 10⁶ m³/year in 2005 which was four times higher than that of the deep aquifer (3.70 × 10⁶ m³/year). However, the annual pumping amounts in the shallow and deep aquifers were 4.77 × 10⁶ and 3.63 × 10⁶ m³/year, respectively. Although the safe yield of the shallow aquifer is enough for all water resources demands, only 55% of exploitation amount was extracted from the shallow aquifer due to its poor water quality. Groundwater exploitation in the deep aquifer should be significantly reduced and regulated by a dynamic management of pumping scheme because the annual pumping amounts are close to the safe yield and seawater intrusion occurs continually. Additionally, to alleviate further aquifer salination, at least half of the current annual groundwater abstraction should be reduced.     

Seawater Intrusion and Sustainable Yield of Basal Aquifers1

Liu, Clark C.K. and John J. Dai, 2012. Seawater Intrusion and Sustainable Yield of Basal Aquifers. Journal of the American Water Resources Association (JAWRA) 48(5): 861‐870. DOI: 10.1111/j.1752‐1688.2012.00659.x Abstract: Basal aquifers, in which freshwater floats on top of saltwater, are the major freshwater supply for the Hawaiian Islands, as well as many other coastal regions around the world. Under unexploited or natural conditions, freshwater and the underlying seawater are separated by a relatively sharp interface located below mean sea level at a depth of about 40 times the hydraulic head. With forced draft, the hydraulic head of a basal aquifer would decline and the sharp interface would move up. It is a serious problem of seawater intrusion as huge amounts of freshwater storage is replaced by saltwater. Also, with forced draft, the sharp interface is replaced by a transition zone in which the salinity increases downward from freshwater to saltwater. As pumping continues, the transition zone expands. The desirable source‐water salinity in Hawaii is about 2% of the seawater salinity. Therefore, the transition zone expansion is another serious problem of seawater intrusion. In this study, a robust analytical groundwater flow and salinity transport model (RAM2) was developed. RAM2 has a simple mathematical structure and its model parameters can be determined satisfactorily with the available field monitoring data. The usefulness of RAM2 as a viable management tool for coastal ground water management is demonstrated by applying it to determine the sustainable yield of the Pearl Harbor aquifer, a principal water supply source in Hawaii.     

秦皇岛海岸线资源利用与保护对策

伴随着人类对近海资源开发活动的加剧,海岸线遭受破坏的问题日益凸出。通过对秦皇岛海岸线资源利用现状进行分析,总结出秦皇岛海岸线资源利用存在缺少合理规划、海水入侵严重、排污入海缺乏严格监控、跟踪管理不到位等问题,提出规划先行、分区开发、生态保护、加强管理、公众参与等秦皇岛海岸线资源保护与可持续发展利用的对策。     

ESTIMATION OF OPTIMAL YIELD IN YUN-LIN AREA OF TAIWAN USING DECISION ANALYSIS1

ABSTRACT: Ground water is a vital resource in the Yun-Lin area of Taiwan. A substantial amount is continuously extracted, creating adverse effects such as land subsidence and seawater intrusion. Minimizing these negative impacts depends on regulating the rate of groundwater withdrawal. An optimal yield must be determined to establish a sound water management policy. A wide range of safe yields for Yun-Lin have already been proposed based on constant hydrological and hydrogeological parameters. By extending the results of those investigations, this study presents a decision analysis model. The optimal yield concept is introduced as well. The proposed model incorporates a probability density function for rainfall recharge and a loss function, derived from fluctuations in the ground water table. Through decision analysis, the optimum yield is obtained by minimizing the expected value of the loss function. The optimal yield varies monthly because the probability density function is time dependent. Analysis results suggest that the cumulative optimum yield of ground water in the area is 1.26 × 10⁸ m³/year. If the probability distribution function for rainfall recharge is modified as new precipitation data become available, the above suggested yield may require revision in the future.     

The utilization of brackish water, protecting the quality of the upper fresh water layer in coastal aquifers

Increasing salinity is one of the most significant and widespread forms of groundwater pollution in coastal areas. This paper presents the causes and impacts of saline water intrusion in coastal areas. Various causes of salt water intrusion, and approaches for the determination of its extent and various measures to control the salt water intrusion are described. An aquifer performance test (APT) approach is presented to identify the extent of existing salt water intrusion in the study area located in the southwest coastal region of Gujarat State (India). A resistivity based experimental technique is used to identify the quality of the groundwater available at different depths. A methodology is presented to assess the extent of available fresh and saline groundwater and to find out the limit up to which lower saline groundwater can be withdrawn for industrial purposes without affecting the upper fresh water layer which can be made available for domestic purposes.     

ADVANCES IN THE BOUNDARY INTEGRAL EQUATION METHOD IN SUBSURFACE FLOW1

ABSTRACT: This paper explores some of the advances of the boundary element method, as applied to ground-water problems, during the last five years. Although the method is still somewhat limited compared to solution by finite elements, the range of solutions has increased considerably. Diffusion and advection-diffusion solutions are done efficiently. These include the incorporation of inhomogeneity, anisotropy, and nonlinear diffusion. The difficult problem of stream-aquifer interaction is an important application as it is much easier to follow a free surface with its multiple configurations. The application must be able to cycle between ground-water connection and disconnection with the stream and include seepage surfaces. Flow in fractured media is a natural application where the flow in fractures can usually be treated without a computational exception in spite of extremely high aspect ratios. The case of seawater intrusion forms a type of free surface problem and thus is a case for which the method has special advantages. For these and other applications the boundary element method provides an inexpensive technique for calculation where the data preparation and setup time is minimal. In most of these cases, programs can and have been written on microcomputers.     

流动注射—光度法联用测定海水中PO4-P

本法针对海水分析时严重的盐度和基体干扰,以监测的海水试样为载流,并在流动注射进样阀前流路上首次引入自制全容量阴离子交换柱,去除载流中的磷酸盐,使进入系统的载流盐度与试样一致,消除了基体干扰,并通过阴柱在线再生条件试验和工作曲线优化试验,建立了流动注射磷锑钼蓝(还原剂为抗坏血酸)光度法直接测定PO4-P浓度为Ⅰ类～Ⅳ类海水的新方法,能分辨海水类别。结果表明,在最适合条件下,该方法在PO4-P浓度5～80μg/L范围内峰高与浓度成线性关系,方法检出限为0.73μg/L,空白海水加10μg/L、30μg/L和60μg/L PO4-P标准物质连续进样,RSD分别为4.57%(n=5)、4.72%(n=4)和5.76%(n=4)。进行实际样品分析时,加标回收率为101%～102%,具有很好的准确性,与国家标准方法———磷钼蓝分光光度法比对,结果吻合,令人满意。     

DECISION SUPPORT SYSTEM FOR MANAGING GROUND WATER RESOURCES IN THE CHOUSHUI RIVER ALLUVIAL IN TAIWAN1

ABSTRACT: Ground water is a vital water resource in the Choushui River alluvial fan in Taiwan. A significantly increased demand for water, resulting from rapid economic development, has led to large scale ground water extraction. Overdraft of ground water has considerably lowered the ground water level, and caused seawater intrusion, land subsidence, and other environmental damage. Sound ground water management thus is essential. This study presents a decision support system (DSS) for managing ground water resources in the Choushui River alluvial fan. This DSS integrates geographic information, ground water simulation, and expert systems. The geographic information system effectively analyzes and displays the spatially varied data and interfaces with the ground water simulation system to compute the dynamic behavior of ground water flow and solute transport in the aquifer. Meanwhile, a ground water model, MODFLOW‐96, is used to determine the permissible yield in the Choushui River alluvial fan. Additionally, an expert system of DSS employs the determined aquifer permissible yield to assist local government agencies in issuing water rights permits and managing ground water resources in the Choushui River alluvial fan.