高密度电阻率法在金凤煤矿水文地质探测中的应用

煤矿防治水工作对煤矿安全开采非常重要,查明矿井水文地质情况是煤矿防治水工作的重要内容之一.利用高密度电法对金凤煤矿011802工作面进行勘探,提出了高密度电阻率法在解决煤矿含水层富水性划分及地下水通道导水性评价的方法,查明了古近系、基岩风化带的相对富水区,取得了较好的验证效果,说明高密度电阻率法能很好地解决此类水文地质勘查问题.     

多孔介质含水层疏水引起的地表下沉研究

研究含水层疏水及采矿引起的地表下沉对地面建（构）筑物的保护有重要意义。本文以孔隙弹性理论为基础,对多孔介质含水层疏水引起的地表下沉进行了分析,同时应用有限元方法耦合计算了多孔介质含水层疏水及采矿引起的地表下沉。     

Characteristics of water inflow and chemical grouting treatment of a Liu Yuanzi Coal Mine shaft in the Ordos Basin

During shaft constructing, a borehole water inflow of 30 m3/h was encountered in Liu Yuanzi Coal Mine in the southwestern Ordos Basin, whose aquifer is mainly cretaceous. On the basis of regional hydrogeological conditions, a mercury intrusion method and scanning electron microscope were used in this study. We conclude that the loose, porous and easily collapsible clay particles of the cretaceous aquifer rock mass were the major geological cause for water hazards during the construction of the shaft. We propose an approach of chemical grouting from the working surface and in the end succeeded in blocking the water.     

Utilizing SAR imagery and aquatic vegetation to map fresh and brackish lakes in the Brazilian Pantanal wetland

South America's Pantanal, the world's largest tropical wetland, contains hundreds of thousands of geochemically diverse lakes, ranging from dilute to brackish to saline in composition. These lakes form the backbone of the habitat that supports the highly diverse flora and fauna of the Pantanal, yet the natural processes that create and destroy them are largely unknown. The quantities and types of lakes in the Pantanal and their spatial distribution are therefore essential, but missing information required to understand the dynamics of the Pantanal ecosystem.RADARSAT S1 and S7, and JERS-1 imagery were integrated with field measurements of water geochemistry and characteristics of emergent aquatic vegetation for fresh and brackish lakes of the Nhecolândia region of the Brazilian Pantanal. A supervised classification was used to classify forest, pasture, bare soil, and lakes. A mask is then applied to produce an image of only lakes. The radar backscattering values were found to have a strong relationship with the emergent aquatic plant assemblages of the lakes—S1 imagery was the most useful. The plant assemblages, in turn, were observed to be strongly controlled by the total dissolved solids (TDS) and pH of the lakes. The relationships between backscattering values, plant assemblages, and geochemistry were then exploited to map the type and distribution of the lakes in the study area.Threshold rules were used to perform Level 1 and Level 2 classifications of the lakes. For the Level 1 classification, the σ^o values of RADARSAT S1 effectively separated brackish (10,000 > TDS > 1000 mg/kg) from fresh water lakes (TDS < 1000 mg/kg) with a total accuracy of 91%. For the Level 2 classification, the σ^o values of RADARSAT S1 effectively separated lakes into three geochemical groups: brackish (10,000 > TDS > 1000 mg/kg), hard with only Typha (1000 > TDS > 100 mg/kg), and fresh water lakes (TDS mg/kg < 100 mg/kg) with a total accuracy of 83%. Considering that the area is very remote and the lakes are very numerous, this may be the most feasible way to map lake type in the Pantanal.     

Maintaining Groundwater Supplies during Drought Conditions in the Brighton Area

The very low level of recharge to the chalk of the South Downs, which provide Brighton with its water supply, has meant that the groundwater levels are very low. Despite this, no restrictions have been necessary since February 1991. This is perhaps due to the instigation of public information campaigns, together with media coverage of the drought, as well as a successful programme of leakage control. This paper looks at how the growth of public water supply has been accommodated operationally while ensuring that groundwater quality is maintained. Options for the future expansion of supply, and their cost-effectiveness, are also considered.     

Biodegradation of monoaromatic hydrocarbons in aquifer columns amended with hydrogen peroxide and nitrate

The ability of indigenous microorganisms to degrade benzene, toluene, ethylbenzene and xylenes (BTEX) in laboratory scale flow-through aquifer columns was tested separately with hydrogen peroxide (110 mg/l) and nitrate (330 mg/l as NO₃⁻) amendments to air-saturated influent nutrient solution. The continuous removal of individual components from all columns relative to the sterile controls provided evidence for biodegradation. In the presence of hydrogen peroxide, the indigeneous microorganisms degraded benzene and toluene (> 95%), meta- plus para-xylene (80%) and ortho-xylene (70%). Nitrate addition resulted in 90% removal of toluene and 25% removal of ortho-xylene. However, benzene, ethylbenzene, meta- and para-xylene concentrations were not significantly reduced after 42 days of operation. Following this experiment, low dissolved oxygen (< 1 mg/l) conditions were initiated with the nitrate-amended column influent in order to mimic contaminated groundwater conditions distal from a nutrient injection well. Toluene continued to be effectively degraded (> 90%), and more than 25% of the benzene, 40% of the ethylbenzene, 50% of the meta- plus para-xylenes and 60% of the ortho-xylene were removed after several months of operation.     

The Effect of Borehole Sealing on the Southern Lincolnshire Limestone Catchment

The Southern Lincolnshire Limestone is an important groundwater resource; however, for many years water has been lost from the aquifer system through uncontrolled artesian flow from wild-bores in the Fenland area. During 1991–92, there was an extensive programme of sealing or controlling the wild-bores, and compensation flows for ecological and farming purposes were provided at some sites.
This paper describes a field study which was designed to identify the important features of part of the catchment; this was followed by the development of an existing groundwater model to provide an improved representation of the uncontrolled and controlled wild-bores. The model is used to assess the consequences of controlling or sealing the wild-bores.     

近距离顶板灰岩富水性探测与突水危险性研究

针对某矿1102工作面近距离顶板灰岩含水层是否具有突水危险性,采用瞬变电磁探测和UDEC数值模拟的方法,就顶板灰岩富水性分区及覆岩结构稳定性、导水裂隙发育特征进行了深入研究。研究结果表明:1顶板灰岩含水层有2处含水较强区,1处含水中等区,2处含水中等偏弱区。21煤上覆岩层裂隙发育集中在采空区后方、前方煤壁处及工作面中部离层区。裂隙发育高度随采空区跨度增加而增大,两者呈非线性关系。开挖40~120 m时,裂隙发育高度突增;开挖70 m、裂隙高度为22 m时发展至灰岩含水层。315 m厚砂岩充当了隔水层,工作面突水危险性较小。4采用新型化学注浆堵水材料——改性脲醛树脂,成功进行了工作面防治水试验,效果显著。     

三山岛北部海域金矿区水文地质特征分析

通过开展水文地质测绘、水文地质钻探、钻孔综合水文测井及钻孔抽水试验,结合区域地质、水文和气象资料,基本查明了三山岛北部海域金矿区水文地质条件。区内主要含水岩层划分为第四系松散岩类孔隙含水层、花岗岩风化裂隙含水层和构造碎裂岩裂隙含水层,研究表明,矿坑充水直接因素为构造裂隙水,间接因素为风化裂隙水和第四系松散岩类孔隙水。采用比拟法、大井法和水平廊道法对矿坑涌水量进行了预测,除比拟法之外,其余2种方法是根据水文钻孔抽水试验结果计算的,抽水试验严格按照有关规范规程要求进行,试验数据可靠。矿坑涌水量预测结果显示:大井法和水平廊道法计算出的涌水量接近,而比拟法预测结果略微偏大,说明本次预测工作所采用方法和数据较为合理,间接证明渗透参数分析工作是合理的。     

Theory of Seepage into an Auger Hole in a Confined Aquifer Overlying a Gravel Substratum

An analytical solution is presented to the problem of steady groundwater flow seeping into a pumped cylindrical hole partially penetrating a homogeneous and anisotropic confined aquifer overlying a gravel substratum. Solutions are obtained for two general cases of the problem: (1) when the level of the pumped hole is below the confining layer; (2) when it is above it. The validity of the proposed theory is tested by comparing analytical predictions obtained for a few flow situations with corresponding results obtained by numerical means. The theory presented here can be utilized to convert the rate of rise of water in a pumped auger hole into directional conductivities of soil, in areas where water is found to be in a confined state overlying a gravel substratum. The study shows that the conductivity values calculated by neglecting the confining pressure of an artesian aquifer with a gravel base [i.e., by applying the existing (Boast and Kirkham in 1971), auger hole seepage theory for a phreatic aquifer with a gravel base to confined situations] may result in serious error; hence, the artesian head of an aquifer must be accounted for while computing the conductivity values. Further, it is observed that the area contributing flow to a pumped auger hole/well with a gravel base is mostly restricted to a short radial distance from the center of the hole, particularly for situations where the gravel substratum is located close to the bottom of the hole. This is in contrast to auger hole flow situations overlying an impervious substratum, where the domain contributing flow is mostly spread out to a considerable distance from the center of the hole.