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81.
82.
西藏前冬环流及地温特征与夏季旱涝关系 总被引:1,自引:1,他引:1
选取西藏地区各区域内严重干旱年和严重洪涝年各5年,分析了北半球500hPa高度距平场同期和前冬环流,同时对旱涝年前冬地温距平与当年夏季旱涝的关系也进行了相关分析。结果表明,干旱年和洪涝年前冬(12月~2月)环流距平分布状况和地温距平有明显差异,这些不同特征是预测西藏夏季旱涝的信号和重要因子。夏季伊朗高压位置偏北或偏南,西太平洋高压脊线和西脊点位置都有一定的指示意义。同时,也可根据2月500hPa高度场正、负距平区位置特点,预测了西藏主要农业区沿雅鲁藏布江一线雨季偏迟或偏早。 相似文献
83.
黄锡畴 《中国地理科学(英文版)》1991,1(1):54-61
A mire as an ecosystem, usually is considered as an aquatic ecosystem,or a terrestrial ecosystem. The author thinks that mire is a special ecosystem between these two ecosystems, and proposes the new concept that a mire is a natural ecosystem with transitional nature of semi-water and semi-land formed by water and land interaction. The paper discusses the nature of the mire ecosystem, the exploitation and utilization and ecological construction of a mire. 相似文献
84.
In Korea, a reference disposal system, KRS, was proposed in 2006 after 10 years of research and development. In the KRS, the high-level radioactive waste repository is considered to be located in a crystalline rock likes granite. For a validation of the feasibility, safety, and stability of the KRS, an underground research tunnel, KURT was constructed in Nov. 2006. During the construction of KURT by a controlled blasting, the size and characteristics of an excavation damaged zone(EDZ) were investigated by in situ as well as laboratory tests. The possible influences of an EDZ around a tunnel on the thermal, hydraulic and mechanical behaviors of the near field were investigated by using hydro-mechanical and thermo-mechanical coupling analyses. From this study, it was found that the existence of an EDZ can influence the thermal, hydraulic, and mechanical behaviors of the near field and it was recommended that an EDZ should be considered as an important parameter during the design of underground repositories. 相似文献
85.
Chan-Hee Park Christof Beyer Sebastian Bauer Olaf Kolditz 《Environmental Geology》2008,55(8):1755-1766
Precise and efficient numerical simulation of transport processes in subsurface systems is a prerequisite for many site investigation
or remediation studies. Random walk particle tracking (RWPT) methods have been introduced in the past to overcome numerical
difficulties when simulating propagation processes in porous media such as advection-dominated mass transport. Crucial for
the precision of RWPT methods is the accuracy of the numerically calculated ground water velocity field. In this paper, a
global node-based method for velocity calculation is used, which was originally proposed by Yeh (Water Resour Res 7:1216–1225,
1981). This method is improved in three ways: (1) extension to unstructured grids, (2) significant enhancement of computational
efficiency, and (3) extension to saturated (groundwater) as well as unsaturated systems (soil water). The novel RWPT method
is tested with numerical benchmark examples from the literature and used in two field scale applications of contaminant transport
in saturated and unsaturated ground water. To evaluate advective transport of the model, the accuracy of the velocity field
is demonstrated by comparing several published results of particle pathlines or streamlines. Given the chosen test problem,
the global node-based velocity estimation is found to be as accurate as the CK method (Cordes and Kinzelbach in Water Resour
Res 28(11):2903–2911, 1992) but less accurate than the mixed or mixed-hybrid finite element methods for flow in highly heterogeneous media. To evaluate
advective–diffusive transport, a transport problem studied by Hassan and Mohamed (J Hydrol 275(3–4):242–260, 2003) is investigated here and evaluated using different numbers of particles. The results indicate that the number of particles
required for the given problem is decreased using the proposed method by about two orders of magnitude without losing accuracy
of the concentration contours as compared to the published numbers. 相似文献
86.
The Italian National Geothermal Database (BDNG), is the largest collection of Italian Geothermal data and was set up in the 1980s. It has since been updated both in terms of content and management tools: information on deep wells and thermal springs (with temperature > 30 °C) are currently organized and stored in a PostgreSQL relational database management system, which guarantees high performance, data security and easy access through different client applications. The BDNG is the core of the Geothopica web site, whose webGIS tool allows different types of user to access geothermal data, to visualize multiple types of datasets, and to perform integrated analyses. The webGIS tool has been recently improved by two specially designed, programmed and implemented visualization tools to display data on well lithology and underground temperatures.This paper describes the contents of the database and its software and data update, as well as the webGIS tool including the new tools for data lithology and temperature visualization. The geoinformation organized in the database and accessible through Geothopica is of use not only for geothermal purposes, but also for any kind of georesource and CO2 storage project requiring the organization of, and access to, deep underground data. Geothopica also supports project developers, researchers, and decision makers in the assessment, management and sustainable deployment of georesources. 相似文献
87.
地下工程施工或地下采矿导致地表沉陷,甚至造成突然坍塌或沿层面滑移等灾害事故。文中根据概率积分法的基本原理,基于褶曲构造地层,任意形状空间开挖条件下地表点在任意方向的移动与变形值预计方法,并顾及复杂地质和开挖等因素,推导出不规则形状地下空间开挖条件下地表移动与变形预计公式。由于地表沉陷预计公式都是不可积重积分式,因此,采用数值积分方法解算这些不能求出原函数的方程式和变积分限问题。 相似文献
88.
盐碱地中华绒螯蟹育苗水质调配技术的研究 总被引:2,自引:0,他引:2
研究了地下卤水中Na^ /K^ 对中华绒螫蟹(Eriocheir sinensis)幼体生长发育的影响以及幼体对人工海水盐度的适应性。结果表明:随着地下卤水中Na^ /K^ 的降低,中华绒螫蟹幼体存活率、变态率和体质量增长率逐渐升高,当地下卤水中的Na^ /K^ 低于18、6时,中华绒螯蟹幼体的存活率、变态率和体质量增长率与海水对照相比差异不显著;人工海水盐度梯度设置为18~26,Z1→Z2、Z3→Z4、Z5→M各阶段不同处理组幼体存活率和体质量增长率差异显著,而变态率差异基本不显著,各阶段的最适盐度分别为20,22和20。 相似文献
89.
火山学研究有了长足的进步。本文总结近些年全球火山学研究各个方面的成果,包括对火山基本概念的新的认识、火山机构、火山的各种分类、火山岩石学和地球化学、火山岩相学、评估火山爆发大小的火山爆发指数、岩石和地球化学分类、各种常量和微量元素区分图、活火山分布与板块构造理论的关系、活火山给人类带来的灾害与利益和活火山的监测、曾经的火山活动与生物毁灭、单成因火山研究等。火山—构造是未来火山学研究的一个方向,通过火山与构造关系的研究以揭示火山的分布和地球的演化。火山喷出的岩浆是其通过地下以岩墙或管道形式为通道运移到地表的结果。中朝边境上的长白山的位置是个特例,应当值得深入的研究。中国分布有许多新生代火山,它们是否为单成因火山、这些火山在成分上是否有演化规律、它们的分布与大地构造的关系等都有待深入和系统的研究。 相似文献
90.
地下空间资源是地表基质层中宝贵的自然资源之一,其作为城市有机体的重要组成部分,在未来城市建设中起着举足轻重的作用。苏南都市圈城市地下空间资源开发在全国处在领先地位,地下空间规划管理方面已形成较为完善的体系,城市地质调查也在全国率先实现全覆盖。依据地下空间资源开发现状和地质结构 “软硬”两个方面条件对苏南都市圈城市地下空间资源进行分类,划分为宁镇丘陵岗地型、苏锡常平原型和长江中下游冲积平原型三种类型。不同类型城市地下空间资源开发的地质背景和城市需求不尽相同,需根据实际情况定制不同的地下空间调查、规划、建设、管理体系。城市地下空间资源地质调查作为城市地质调查工作的延伸,需要提出更高的要求。本文从城市地下空间资源地质调查精度和深度、多参数多尺度一体化建模、地下空间资源评价、多种地下资源协同利用、地质资料信息数据库与平台建设等方面提出对策建议,用于指导未来城市地下空间资源调查的工程实践,为地质调查成果支撑城市地下空间全生命周期发展提供借鉴意义。 相似文献