环境与灾害中的流体力学问题

本文从流体力学角度简要介绍了洪水灾害、风灾、火灾、环境污染及环境生态方面的情况,叙述了减轻灾害的措施和效果,谈到了有关的研究课题.     

青海滑坡初探

青海是我国滑坡灾害比较严重的地区之一。本文简要阐述了青海滑坡灾害的地质环境、类型、分布、影响因素等,并分析了滑坡灾害的发展趋势。对青海滑坡的治理提供借鉴。     

矿产资源开发与泥石流灾害及其防治对策

由于掠夺式开采以及环境保护滞后于经济发展,我国矿产资源开发利用产生了比较严重的环境问题。本文在分析我国矿山人为泥石流灾害状况的基础上,提出了改善生态环境保护与重建的法治建设环境,加大矿山生态环境保护的监督管理力度,并具体提出了矿山人为泥石流灾害预防和工程治理的措施。     

滚石灾害防治方法浅析

随着人类活动的广度和力度不断加大,多山地带的滚石问题越来越突出,致使有关滚石灾害及其防治方法的研究也逐步得到重视。总体而言,滚石灾害的防治方法可分为主动防护和被动防护两大类,可应用于不同的滚石灾害环境。对各类滚石灾害防治方法进行简单介绍之后,作者分析了各方法的应用范围和适用条件。     

工程地质学发展趋势刍议

环境工程地质学是工程地质学发展的新阶段,它囊括并发展了工程地质学的所有问题。作为研究工程建设与地质环境相互作用的环境工程地质学,有待于进一步发展为工程环境灾害学──一方面,由于各种自然环境恶化和灾害间的相关性和因果性（环境恶化链、灾害链）,研究似宜不限于地质环境和灾害（当然后者仍是重点）,而适当扩大至土地环境、水环境和社会环境。作为一门应用地质学的环境工程地质学及其母学科工程环境灾害学将具有力学、地理、经济三大支柱,首先力求地质学与地理学的相互渗透和融合。另一方面,由于各种人类活动间的相关性和因果性（活动链）,所研究的人类活动似宜不限于工程建设和运行,而适当扩大至采矿和水事活动,包括开采地下水和排污。后者引起的环境恶化和灾害尤为严重,正酿成危机。其根本出路不仅在于科技进步,而且在于文化调节,力求科技与文化的相互渗透和融合。     

水库地区的水岩作用及其地质环境影响

本文综述了水库地区水环境系统的变化及水岩作用类型和机制, 在此基础上讨论了水库区地质环境的变化和环境灾害的发生, 提出以水环境变化和水岩作用为中心的水库地质环境评价和灾害预测的研究方向。     

中国沿海地质环境与区域持续发展的若干问题探讨

本文分析了中国沿海岩石圈动力学的基础特征, 指出中国东部沿海地质环境与灾害存在南北分异的格局, 阐述了沿海区域工程地质环境的基本规律, 并通过全球及中国近百年海平面变化, 以及人类工程活动对河口海岸地质环境影响的分析, 对沿海地区未来的地质环境与灾害趋向做了初步评估, 并认为中国沿海21世纪的环境与发展将面临严峻的挑战, 特别是环渤海地区。最后, 对影响沿海区域发展的若干问题进行了初步探讨并提出了几点建议。     

陕西泾阳南塬黄土滑坡灾害与引水灌溉的关系

陕西泾阳南塬塬边黄土滑坡频繁发生，造成的经济损失和人员伤亡极为惨重。本文讨论了区内黄土滑坡灾害形成的地貌地形及地质环境特征，着重分析了人类不合理的引用地表水灌溉，改变了地下水文条件，从而降低了土体的抗剪强度，导致黄土滑坡形成的过程和机制。通过研究认为，合理进行灌溉，控制地下水位是改善塬边地质环境和防治滑坡灾害的关键措施。     

环境与灾害力学研讨会

为促进数学、力学与地学的结合,更好地为国土整治、环境保护和灾害防治贡献力量,充分发挥中国科学院多学科综合性优势,中国科学院数理化局组织召开“环境与灾害力学研讨会”,得到了中国科学院地学方面各有关研究所的热情支持,由中国科学院力学研究所主办      

四川华蓥山地重力灾害类型及成因分析

从华蓥山所处的地理位置出发,全面的介绍了华蓥山地区近些年来的重力灾害发生的情况,可以看到重力灾害在本地区的影响之大,已经成为了本地区主要的灾害类型。通过各方面的调查研究,采用科学分析和经验指导相结合的方法,分析了引起重力灾害发生的各种因素,并重点从地质因素、水体因素、人为因素等3方面分析了华蓥山地重力灾害发生的成因,总结了可以引起重力灾害发生的外因和内因,可以看到重力灾害不单是某一个因素导致,而是由于众多的因素相互的影响所导致的。采取各种措施来预防灾害的发生,减少灾害给人类的生产和生活带来的危害。     

福建海岸带地质环境背景与海水入侵的形成条件探讨

提出一种新的网格自适应方法：在需要加密的网格单元中心加入新结点,并对加密后的相邻 三角形网格单元进行公共边变换, 构成新的网格单元. 与传统的在网格边界中点加入新节点的自 适应方法相比,新方法可以更加灵活地控制网格密度,加密后的网格继承原先的网格质量不 发生畸变,并且算法编程简便,容易实现. 将自适应网格生成方法和基于特征线方程的分离 算法相结合,对空腔内不可压缩黏性流动进行了计算. 在特征线方向上进行时间步离散,动 量方程求解过程中采用非增量型分离算法. 计算中,把求解变量梯度值作为判定准则,在 变化剧烈的区域进行网格局部加密. 计算结果表明该组合算法有很好的计算精度,并有效减 少了计算时间和存储量.     

丰、枯水年磨刀门水道盐水上溯运动规律对比

通过一维纵向逐时咸界图的方法, 得到了磨刀门水道丰、枯水年的盐水运动规律图.对比分析了不同年份不同上游径流对磨刀门水道盐水上溯运动规律的影响. 分析表明, 丰、枯水年不同的上游径流量将改变磨刀门水道盐水入侵的上溯距离和上溯速度的快慢, 造成程度不同的咸潮灾害. 磨刀门水道中盐水运动的半月及日周期性变化规律不受上游径流的影响,均为小潮期间盐水逐步上溯, 大潮期间盐水逐步退出. 上游径流量的大小只影响磨刀门水道盐水上溯运动的速度和距离远近, 不改变磨刀门水道中盐水上溯运动的半月周期规律.      

大屯孔庄矿副井井筒破裂与底部含水层水文地质条件

本文从水动力和水化学两方面讨论了大屯孔庄矿副井井筒破裂与第四系底部含水层水文地质条件的关系, 详细分析了底部含水层水文地质条件变化可能对底部含水层及其周围岩土体以及井筒受力状态和强度特征产生的影响。首次指出了底部含水层水动力变化在井筒外部受力环境分析中的重要性和水化学作用对井壁混凝土强度的损害性。     

Modeling and Analysis of Seawater Intrusion in the Coastal Aquifer of Eastern Cap-Bon, Tunisia

A numerical model that treats density-dependent variably saturated flow and miscible salt transport is used to investigate the occurrence of seawater intrusion in the Korba aquifer of the eastern coast of Cap-Bon in northern Tunisia. We examine the interplay between pumping regimes and recharge scenarios and its effect on the saline water distribution. More localized simulations are used to examine, in vertical cross sections, the effects of well location and soil type and the role of the vadose zone in possible remediation actions. The exploratory simulations suggest interesting interactions between the unsaturated zone and the saltwater–freshwater interface with possible implications for groundwater exploitation from shallow unconfined coastal aquifers, involving in one case feedback between seawater intrusion and the high pressure head gradients around the pumping-induced drawdown cone and in another case threshold-like interface displacement for tight soils such as clays. The data processing steps undertaken in this GIS and modeling study are described in some detail, and a critical assessment is given of the data availability and of the requirements for successful monitoring and modeling of seawater intrusion risks in heavily exploited coastal aquifers such as those found in the semi-arid regions of the Mediterranean basin. It is shown how, with the aid of GIS, reasonably reliable information can be assembled from maps, surveys, and other sources of geospatial and hydrogeological data, an approach that is necessary in the many regions of the world with acute water resource problems but with limited means for undertaking systematic data acquisition and environmental monitoring actions. Nonetheless the need for more concerted monitoring of relevant parameters and processes and of closer coordination between monitoring and modeling is stressed. An idea of the extent of over-exploitation of the Korba aquifer is obtained by examining the pumping and rainfall/infiltration data, and the simulation results support groundwater pumping as the mechanism for and seawater intrusion as the origin of the salt contamination observed in the soils and subsurface waters of the Korba plain.     

三山岛金矿F3断裂带的水文地质工程地质特征及灾害防治

本文对三山岛金矿F3断裂带的构造、岩性和水动力学特征进行了研究,对矿坑开挖中的突水和坑道碎屑流的成因做了探讨,并在水文地质结构、水化学、水同位素及水文地热学的综合研究基础上,对未来的二期井下工程开挖中可能出现的工程地质问题进行了预测,提出了防治方案。     

Fundamental study on underwater trafficability for tracked vehicle

In recent years, water disasters have increased in Japan. In water disaster, remote controlled vehicles which work for disaster recovery must run in water environment. Since underwater ground is likely to be soft, the vehicle has a risk of stuck. If a vehicle gets stuck at disaster sites, rescue work is difficult because it is not easily to access to that area. We must make a method for judging whether to run or not. For this purpose, we must quantitatively clarify the relationship between the trafficability and the strength, bearing capacity, etc. of underwater ground. We measured the cone index of underwater ground. From results, we confirmed that fragile layer was formed on the surface layer in underwater ground. We measured drawbar pull of a tracked carrier in test field. As a result, maximum drawbar pull of underwater ground was lower than on the ground. After slip occurs, drawbar pull of underwater ground was smaller than ground significantly.     

Numerical Simulation of the Movement of Saltwater under Skimming and Scavenger Pumping in the Pleistocene Aquifer of Gaza and Jericho Areas, Palestine

The Pleistocene aquifers are important sources of water supply in both the Gaza and Jericho areas of Palestine. The aquifers are saline with freshwater lenses floating on saline bodies of water. It is important to investigate how to exploit these freshwater lenses without causing unnecessary mixing of the fresh and saline waters. The objective of this research is to investigate the feasibility of applying skimming and scavenger pumping as a means to exploit the freshwater lenses and to control saline water upconing in the aquifers. This study is the first to examine the movement of fresh and saline waters underneath skimming and scavenger wells in the aquifers of Gaza and Jericho. Two simulation models that couple density-dependent fluid flow and solute transport have been used to simulate and predict the movement of saltwater under different hydrogeological and operational conditions of skimming and scavenger wells in the two aquifers. The results show (for the Jericho Aquifer) that: the location of well screen has a strong control on the steady-state position of the fresh/saline water transition zone; the upconing mechanism appears to continue under skimming pumping until saline water enters the well screen even when the pumping rate is reduced; and for better salinity control it is necessary to place well screen against the gravel layers only and locate one screen segment in the saline water zone. The study shows (for the Gaza coastal aquifer) that the most important parameters affecting the movement of saline water under scavenger pumping are the relationship between recharge and pumping rates, the location of the well screen within the saturated thickness, the vertical permeability; and the transverse dispersivity. This study shows that saltwater upconing in Gaza aquifer can be controlled by operating a second well in the saline water zone so that the optimal ratio between saline water and freshwater pumping is 1:2 respectively.     

人为地质灾害和地质环境

本文论述了人为地质灾害的概念, 典型事例以及人为地质灾害与地质环境的相互关系。指出, 人为地质灾害是由于人类的工程经济活动而引起的地质灾害。人为地质灾害可导致地质环境恶化, 使环境质量下降；而地质环境恶化又可导致地质灾害的加重, 使灾害频度增大, 强度增高。     

Improved Interpretation of Mercury Intrusion and Soil Water Retention Percolation Characteristics by Inverse Modelling and Void Cluster Analysis

This work addresses two continuing fallacies in the interpretation of percolation characteristics of porous solids. The first is that the first derivative (slope) of the intrusion characteristic of the non-wetting fluid or drainage characteristic of the wetting fluid corresponds to the void size distribution, and the second is that the sizes of all voids can be measured. The fallacies are illustrated with the aid of the PoreXpert^® inverse modelling package. A new void analysis method is then described, which is an add-on to the inverse modelling package and addresses the second fallacy. It is applied to three widely contrasting and challenging porous media. The first comprises two fine-grain graphites for use in the next-generation nuclear reactors. Their larger void sizes were measured by mercury intrusion, and the smallest by using a grand canonical Monte Carlo interpretation of surface area measurement down to nanometre scale. The second application is to the mercury intrusion of a series of mixtures of ground calcium carbonate with powdered microporous calcium carbonate known as functionalised calcium carbonate (FCC). The third is the water retention/drainage characteristic of a soil sample which undergoes naturally occurring hydrophilic/hydrophobic transitions. The first-derivative approximation is shown to be reasonable in the interpretation of the mercury intrusion porosimetry of the two graphites, which differ only at low mercury intrusion pressures, but false for FCC and the transiently hydrophobic soil. The findings are supported by other experimental characterisations, in particular electron and atomic force microscopy.     

Numerical Simulations of the Thermal Impact of Supercritical CO<Subscript>2</Subscript> Injection on Chemical Reactivity in a Carbonate Saline Reservoir

Geological sequestration of CO₂ offers a promising solution for reducing net emissions of greenhouse gases into the atmosphere. This emerging technology must make it possible to inject CO₂ into deep saline aquifers or oil- and gas-depleted reservoirs in the supercritical state (P > 7.4MPa and T > 31.1°C) to achieve a higher density and therefore occupy less volume underground. Previous experimental and numerical simulations have demonstrated that massive CO₂ injection in saline reservoirs causes a major disequilibrium of the physical and geochemical characteristics of the host aquifer. The near-well injection zone seems to constitute an underground hydrogeological system particularly impacted by supercritical CO₂ injection and the most sensitive area, where chemical phenomena (e.g. mineral dissolution/precipitation) can have a major impact on the porosity and permeability. Furthermore, these phenomena are highly sensitive to temperature. This study, based on numerical multi-phase simulations, investigates thermal effects during CO₂ injection into a deep carbonate formation. Different thermal processes and their influence on the chemical and mineral reactivity of the saline reservoir are discussed. This study underlines both the minor effects of intrinsic thermal and thermodynamic processes on mineral reactivity in carbonate aquifers, and the influence of anthropic thermal processes (e.g. injection temperature) on the carbonates’ behaviour.