关于马坑铁矿矿床疏干的探讨

马坑矿区水文地质条件复杂,一期生产与二期技改工程开拓中遇到断裂带或溶洞,常会发生突水、突泥等险情,事故频繁的发生,给矿山的安全和生产带来较大的隐患。本文针对马坑铁矿的二期疏干预测工程,在进行大量矿山水文地质基础工作和相关数据统计的基础上,对矿区目前地下水疏干工作进行了一些简要的探讨。     

Groundwater quality degradation as a result of overpumping in the delta Wadi El-Arish area,Sinai Peninsula,Egypt

The delta Wadi El-Arish area of the Sinai Peninsula is one of the most important parts of Egypt for industrial and agricultural expansion projects because of its relatively abundant supply of groundwater. This study focuses on the hydrogeology and hydrochemistry of the Quaternary aquifer in the delta Wadi El-Arish area and on the impacts pumping has had on groundwater quality. The objectives were to determine the relationships between groundwater pumping and water levels and water quality, to estimate the hydraulic parameters of the Quaternary aquifer, and to determine the hydrochemistry of groundwater in the Quaternary aquifer and its suitability for irrigation. The conclusions are: (1) potentiometric surface elevations have declined by an average of about 0.5 m since 1981 in response to an increase in pumping, (2) the transmissivity of the lower Pleistocene calcareous sandstone (kurkar) unit is higher than the transmissivity of the upper Pleistocene alluvium, (3) groundwater in the Pleistocene aquifer is augmented with groundwater leaking from the overlying Holocene sand dune deposits through the intervening sandy clay aquitard, (4) groundwater in the kurkar is of lower quality than groundwater in the alluvium, (5) total dissolved solids (TDS) concentrations have increased by an average of about 1500 ppm since 1962, (6) an increase in saltwater intrusion has occurred in the northern part of the study area, and (7) the irrigation suitability of groundwater pumped from wells in much of the area is limited to salt tolerant crops. Our recommendations are: (1) no new pumping wells should be drilled and no increase in pumping rates should be allowed in the delta Wadi El-Arish area, (2) reliable estimates of the quantity of groundwater recharge should be made, (3) flood irrigation systems should be replaced by either drip or sprinkler     

试论里坝地段某些放射性水文地质特征

本文在初步分析研究里坝地段地质及水文地质条件的基础上,根据该地段1:5000放射性水文地球化学找矿的实际资料,运用数理统计方法,分析计算了地下水中某些化学组分间的相关关系及其与铀矿化的关系,解释评价了该地段部分放射性水文地质异常,并初步提出了该地段的某些放射性水文地球化学找矿的“半定量”指标体系。实践证明,本文的结论对于条件与该地段相似的地区的放射性水化学找矿工作,具有一定的参考指导作用。     

对海河流域地下水开采管理的思考

地下水是海河流域经济社会发展的重要水源 ,长期的过渡开采已造成诸多环境地质问题 ,如地面沉降、地裂缝、塌陷等。本文根据各区域水文地质状况及地下水开采情况的不同 ,对地下水的开采管理提出了一些想法     

东刘家金矿矿区地下水动态与均衡分析

东刘家金矿矿区位于海阳市郭城镇,主要发育3组NE向断裂裂隙,含水岩组主要为第四系冲洪积、坡积孔隙含水岩组,碎屑岩类孔隙裂隙含水岩组,碳酸盐岩类岩溶裂隙含水岩组及基岩风化带裂隙含水岩组。文中在查清水文地质条件的情况下,详细分析了矿区含水层的富水性,地下水补给、径流、排泄及动态特征,矿区地下水开发利用现状。在此基础上,进行了地下水均衡计算,地下水补给来源主要为大气降水入渗和农灌入渗补给,补给方式为地表直接下渗补给、断裂带导水补给以及上覆松散层下渗补给,主要排泄方式为人工开采、矿坑涌水和蒸发,总体上矿区处于地下水均衡状态。研究成果为矿区在今后的开采过程中控制地下水,合理防治与排水,维持区域地下水自然动态等提供了科学的依据。。     

Effects of linking up of discontinuities on fracture growth and groundwater transport

It is proposed that the growth of fractures is the basic process for generating and maintaining permeability in solid rock (bedrock). Many extension fractures grow as hydrofractures, whereas many shear (and extension) fractures grow through the formation of transverse fractures that connect the adjacent tips of existing fractures. In a boundary-element analysis, the hydrofractures are modeled as being driven open by a fluid overpressure that varies linearly from 10 MPa at the fracture centre to 0 MPa at the fracture tip. The host rock has a uniform Young's modulus of 10 GPa, a Poisson's ratio of 0.25, and is dissected by vertical joints and horizontal contacts, each of which is modeled as an internal spring of stiffness 6 MPa m⁻¹. The number of joints and contacts, and their location with respect to the hydrofracture tip are varied in different model runs. The results of the analyses indicate that the tensile stresses generated by overpressured hydrofractures open up joints and contacts out to considerable distances from the fracture tip, so that they tend to link up to form a hydraulic pathway. Using the same Young's modulus, Poisson's ratio, and internal spring constant for joints as in the hydrofracture models, boundary-element models were made to study the interaction stresses that cause neighbouring joints to become interconnected through the growth of linking transverse fractures that, ultimately, may evolve into shear fractures. The models were subjected to tensile stress of 6 MPa acting normal to the joint planes as the only loading. The offset (horizontal distance) and underlap (vertical distance) between the adjacent tips of the joints were varied between model runs. The results show a concentration of tensile and shear stresses in the regions between the neighbouring tips of the joints, but these regions become smaller when the underlap of the joints decreases and changes to overlap. These stress-concentration regions favour the development of transverse (mostly shear) fractures that link up the nearby tips of the joints, so as to form a segmented shear or extension fracture. Analytical results on aperture variation of a hydrofracture in a homogeneous, isotropic rock are compared with boundary-element results for a hydrofracture dissecting layered rocks. The aperture is larger where the hydrofracture dissects soft (low Young's modulus) layers than where it dissects stiff layers. Aperture variation may encourage subsequent groundwater-flow channeling along a pathway generated by a hydrofracture in layered rocks. Electronic Publication     

Hydrogeology and sustainable agriculture

 The world's population continues to grow and to require more and more food. Attempts by modern high output agriculture to meet this need have led to serious environmental problems. A more sustainable balance is now required and is being sought in a variety of ways. Hydrogeologists should continue to highlight the threat posed by agriculture to groundwater, particularly since groundwater is a hidden resource and its degradation and rehabilitation often take place slowly. But the time has come for groundwater specialists to go further and become actively involved in helping to provide practical and sustainable solutions. The agriculture of the future requires a holistic approach which balances the essential economics of food production with equally valid environmental needs, including those of groundwater. Such an approach demands cross-sectoral collaboration involving multidisciplinary research and action within an integrated policy framework. This paper reviews the current groundwater/agriculture interface and some of the attempts being made to achieve a more truly sustainable agriculture with particular emphasis on European experience. It aims to stimulate greater interest and involvement by hydrogeologists in helping to bring about realistic solutions that will enable future generations to enjoy adequate good quality food and water. Received: 9 August 1996 / Accepted: 11 November 1996     

Hydrological and hydrogeological characteristics of Wadi el Mujib catchment area,Jordan

Hydrological and hydrogeological data in the area have been verified to evaluate the availability and the potentiality of the water resources for the proposed damsites in the Wadi el Mujib catchment area, which is considered a semiarid to arid region. The quantity of the surface waters is very small compared with the surface area of the basin, however, due to the shortage of precipitation in the country and the necessity to attain socioeconomic objectives, the investigation of these waters has become more vital. The most reliable exploitation can be essentially achieved by constructing small storage dams on the suitable sites in order to benefit from the flood waters coming from the main wadis. For the above purpose, the hydrogeological and hydrological study of Wadi el Mujib catchment area was carried out, where the Wadi Mujib dam site will be constructed. The hydrogeological investigation of the groundwater was performed by constructing a groundwater contour map of the Amman-Wadi Es Sir aquifer (B2/A7) so as to verify the groundwater flow system and to determine the potentiality of the aquifer from the hydraulic parameters obtained from the pumping test analysis. The hydrological feasibility study of the dam was carried out by evaluating the water balance for a long-term period (1970 to 1990) in order to obtain reliable data that can be used to estimate the recharge to B2/A7 aquifer. In addition, a frequency analysis was performed to estimate the flood design of the reservoir area as well as the spillway at the proposed dam site.     

即墨市宝龙泉水文地质条件调查与分析

通过资料收集、专项地质测量、水文地质调查与测绘、水文地质物探、水文地质钻探、钻孔抽水试验、水质分析试验和综合研究等技术方法对宝龙泉区域水文地质条件进行了勘查,对泉的成因、汇水面积、补给量和流量进行了初步的分析和探索,结果显示:泉区内发育的7条近南北和近东西向的断裂异常构成了宝龙泉泉脉的构造格局,经钻探验证,3条断裂透水性好,含水丰富,其中DF1-3和DF3-4断裂为宝龙泉的主要泉脉通道;在水位标高53. 07 m时,泉水自流的流量为296. 76 m^3/d;泉水的矿化度为0. 582 g/L,水化学类型HCO3·SO4-Ca型。地下水水质主要类型分类为Ⅱ~Ⅲ类,均受不同程度的污染,主要适用于集中式生活饮用水水源及工、农业用水。按地表汇水面积和断裂形成的区域面积分别计算,可估算出宝龙泉流量平均为303. 78 m^3/d和337. 14 m^3/d。研究结果可为宝龙泉区域泉水的保护和开发利用提供依据。     

Hydrogeology of the Ordos Basin,China

The Ordos Basin is located in the east of NW China that is composed of different aquifer systems. Karst groundwater is stored in the Carmbrian-Ordovician carbonates along the margins of the basin. Fissured-pore water is present in the Cretaceous strata in the central-western basin and pore water is stored in the overlying Quaternary deposits discontinuously. The main origin of groundwater in the basin is direct or indirect infiltration of precipitation. Groundwater flows from recharge areas to adjacent local discharge areas. Besides evaporation and abstraction, groundwater feeds springs and rivers, such as the Yellow River and its tributaries. According to the karst aquifer lithologic structure, the features of karst development and circulation, the karst aquifer is divided into three structural and circulation patterns. Based on the control of Cretaceous sedimentary environment, lithologic structure, lithofacies, and palaeogeographic characteristics, the Cretaceous system is divided into the northern desert simple plateau aquifer system and the southern loess plateau aquifer system. PACKER was used to obtain temperature, hydrogeochemical and isotope data at specific depths. Groundwater circulation is studied using hydrodynamic fields, temperature fields, isotopes, hydrogeochemical data and numerical simulations. According to the result, it is divided into local, intermediate and regional systems.