Recharge and salinization in the Madrid Basin     

A. S. Issar  R. M. Llamas  I. Herraez 《Environmental Geology》1993,21(1-2):55-61

The purpose of this work was to reinvestigate the existing hydrogeological conceptual model of the basin of Madrid, Spain. A cumulative chemical isotopic diagram which enabled the distinction between different groups of water as well as calculation of the mode of their blending was used for this investigation. It was found that the groups of discharge were lighter in their isotopic composition than that of recharge. The previous explanation of this fact, backed by carbon-14 dating, was the long residence time due to flow lines going down to depths of more than 1000 m. This flow model assumes homogenous conditions to these depths. This assumption can not be supported by evidence from deep wells. Thus a modified model is suggested which maintains homogenous conditions only to about 300 m and a deep confined aquifer below containing paleowater. The higher degree of depletion of this water has been explained by a colder climate on top of an altitude effect. Another interesting observation was the correlation between the isotopic composition of the rains, the month of the rain event and the composition of the recharge group groundwater. It could be seen that the winter rains resemble the groundwater composition, which shows that practically all the spring and summer rains were evapotranspirated.  相似文献   

充分利用生产坑道排水资料预测矿坑涌水量   总被引：1，自引：0，他引：1  

邓安云  张兴恒  任玉芬  吕永增 《云南地质》2008,27(2):239-244

利用生产坑道排水资料,选择比拟法、曲线方程法,对黄家山矿区进行矿坑涌水量预测,取得较好效果,对相邻类似矿区有指导意义。  相似文献   

东营凹陷地下水动力场的形成与演化   总被引：10，自引：5，他引：10  

楼章华  朱蓉  金爱民  武恒志  郑和荣  王宁 《地质科学》2003,38(1):85-96

沉积盆地地下水动力场的理想模式可以归纳为对称型和不对称型两种,其中局部地下水动力单元可以划分为泥岩压榨水离心流,大气水下渗向心流,越流、越流蒸发泄水和滞流4种类型。地下水动力场的演化具有旋回性,每个旋回可以分为两个阶段:盆地沉降沉积时期的泥岩压榨水离心流阶段和盆地抬升剥蚀时期的大气水下渗向心流阶段。随沉积盆地的形成与演化,水动力场也有形成、发展和消亡的过程。东营凹陷地下水动力场在平面上呈对称性:总体上大气水由凹陷边缘向凹陷中心渗入,凹陷内部各洼陷为压榨水形成的离心流区,凹陷边缘南部斜坡带和北部断阶带以及凹陷内部中央断裂带为越流泄水区。纵向上,局部水动力单元强度及演化规律与地层的埋藏深度有关。随着埋藏深度的增加,水动力单元强度逐渐减弱。  相似文献   

山东荣成沽河流域水资源系统分析     

许模  费美高 《地质灾害与环境保护》1996,7(3):50-55,63

流域水资源系统由降水产流，以及通过水文下垫面的转换，形成的地表径流和地下水流流组成。本文将复杂的沽河流域水 资源系统分解成多个子系统，利用频谱分析方法对各个水资源子系统的转换功能进行定量的分析刻画，并利用地下含水介质子系统的转换特征函数－频率响应函数求取水文地质参数，丰富了水文地质参数的获取途径。  相似文献   

Porewater pressure increases in soil and rock from underground chemical and nuclear explosions   总被引：3，自引：0，他引：3  

Wayne A. Charlie  George E. Veyera  Deanna S. Durnford  Donald O. Doehring 《Engineering Geology》1996,43(4):225-236

A review and analysis of chemical and nuclear explosive-induced porewater pressure increases and induced rise in groundwater table elevations (groundwater mounding) is presented. Our analysis indicates that residual pore pressure increases and groundwater mounding can be induced by underground chemical and nuclear explosions to scaled distances of 879 m/(kt)^1/3. This relationship is linear over seven orders of magnitude of explosive energy ranging from a 0.01 kg chemical explosion to a 100 kt nuclear explosion and is valid for a wide variety of saturated geological profiles. Underground chemical explosions, and probably underground nuclear explosions have the potential to induce liquefaction of water-saturated soils to scaled distances of about 260 m/(kt)^1/3.  相似文献   

Groundwater characteristics and climate and ecological evolution in the Badain Jaran Desert in the southwest Mongolian Plateau     

《China Geology》2021,4(3):421-432

The Badain Jaran Desert is the third largest desert in China, covering an area of 50000 km². It lies in Northwest China, where the arid and rainless natural environment has a great impact on the climate, environment, and human living conditions. Based on the results of 1∶250000 regional hydrogeological surveys and previous researches, this study systematically investigates the circulation characteristics and resource properties of the groundwater as well as the evolution of the climate and ecological environment since the Quaternary in the Badain Jaran Desert by means of geophysical exploration, hydrogeological drilling, hydrogeochemistry, and isotopic tracing. The results are as follows. (1) The groundwater in the Badain Jaran Desert is mainly recharged through the infiltration of local precipitation and has poor renewability. The groundwater recharge in the desert was calculated to be 1.8684×10⁸ m³/a using the water balance method. (2) The Badain Jaran Desert has experienced four humid stages since the Quaternary, namely MIS 13-15, MIS 5, MIS 3, and the Early–Middle Holocene, but the climate in the desert has shown a trend towards aridity overall. The average annual temperature in the Badain Jaran Desert has significantly increased in the past 50 years. In detail, it has increased by about 2.5°C, with a higher rate in the south than in the north. Meanwhile, the precipitation amount has shown high spatial variability and the climate has shown a warming-drying trend in the past 50 years. (3) The lakes in the hinterland of the Badain Jaran Desert continuously shrank during 1973–2015. However, the vegetation communities maintained a highly natural distribution during 2000–2016, with the vegetation cover has increased overall. Accordingly, the Badain Jaran Desert did not show any notable expansion in that period. This study deepens the understanding of groundwater circulation and the climate and ecological evolution in the Badain Jaran Desert. It will provide a scientific basis for the rational exploitation of the groundwater resources and the ecological protection and restoration in the Badain Jaran Desert.© 2021 China Geology Editorial Office.  相似文献   

我国铀矿床水文地质分类的探讨     

熊世伦 《铀矿地质》1985,(1)

本文总结了近三十年来所取得的各类铀矿床的水文地质勘探资料和部分矿床开采验证的结果。根据铀矿床围岩特征和含水条件,归纳出坚硬裂隙岩层、半坚硬孔隙岩层、岩溶和赋存温热水岩层四种含水特点。总结出了引起矿床充水的三个主要因素,即矿体与当地侵蚀基准面的相对位置、地表水体(主要是河流)的影响程度和地质构造发育程度及形态特征。在此基础上,将矿床水文地员条件共分为十六种不同情况,得出一个比较简单、直观的分类表,进一步划分出水文地质条件简单、中等、复杂和极复杂四种类型,并作了简要阐述,列举了典型矿床实例。最后得出铀矿床水文地质条件多数不复杂,而复杂和极复杂类型仅占矿床总数的20％,河水、岩溶和温热水是造成矿床水文地质条件复杂的三个主要因素等结论。  相似文献   

Coastal processes and environmental hazards: the Buenos Aires (Argentina) and Venetian (Italy) littorals   总被引：1，自引：0，他引：1  

Jorge Pousa  Luigi Tosi  Eduardo Kruse  Dardo Guaraglia  Maurizio Bonardi  Andrea Mazzoldi  Federica Rizzetto  Enrique Schnack 《Environmental Geology》2007,51(8):1307-1316

The Buenos Aires (Argentina) and Venice (Italy) coastlands have experienced significant saltwater contamination of the phreatic aquifer, coastal erosion, hydrodynamic changes and relative sea level rise processes due to natural and man-induced factors. These factors expose coastal areas to morpho-hydro-geological hazards, such as soil desertification, frequency and degree of flooding, littoral erosion, and the silting of river mouths and channels. Man-made interventions and actions, such as beach mining, construction of coastal structures and exploitation of aquifers without an adequate knowledge of the hydrology setting and an adequate management program, worsen these natural hazards. Uncontrolled human activity induces environmental damage to the overall coastal plains. The coastal plains play an important role in the social/economic development of the two regions based on land use, such as agriculture, horticulture, breeding, and tourism, as well as industry. Results of investigations on saltwater contamination, sea level rise and morphological changes recently performed in these two coastal areas are presented here.  相似文献   

Groundwater quality monitoring system in zones of infrastructure facilities     

G. Rasula  M. Rasula   《Engineering Geology》2001,60(1-4):351-360

Protection of groundwater already is and will also be in the future, a particularly important environmental, socio-economic, social welfare and political task. The fact that the costs of preventive measures are 10–20 times lower than the funds needed to clean up and revitalize polluted aquifers, as well as the fact that the area to be occupied with transport communications and other infrastructure facilities will aggravate protection, both call for an urgent introduction of modern methods of monitoring and preserving all the existing and potential groundwater resources. The basic principle of groundwater protection against pollution means constant control and preventive measures of protection, namely prevention of incidental and other kinds of pollution. The very construction of communications and all accompanying facilities changes and degrades the existent natural geological environment, and when in use they may become structures in whose immediate surrounds surface and ground waters may be polluted by the toxic and waste substances transported. The experience gained through the following activities: the ‘pilot model’ for groundwater monitoring in the zone of Makis, the investigations and monitoring of critical sites polluted with xylene (CIP, Belgrade, 1994/95), and information on the latest achievements in this field in the world (obtained while working on the study of methodology of hydrogeological investigations needed for groundwater quality monitoring system — Jaroslav Cerni Institute for the Development of Water Resources, Belgrade, 1998), stresses a necessity to obligatory design and construct operational systems for groundwater quality monitoring, particularly in the zones of infrastructure facilities (roads, railway, gas pipelines, oil pipelines), which can be considered as potential linear polluters. In that light, this paper is a contribution to developing hydrogeological investigation methodology for designing and operating a monitoring system in the zones of roads, and its legal and practical incorporation in the technical documents of each project. Besides, an emphasis is put on multidisciplinary approach to system implementation, its full automation, rational management, and effective and optimal measures for groundwater protection.  相似文献   

Performing cluster analysis and discrimination analysis of hydrological factors in one step     

Gwo-Fong Lin  Chun-Ming Wang 《Advances in water resources》2006

Based on self-organizing map, a method that can perform cluster analysis and discrimination analysis in one step is proposed in this paper. Using the proposed method, one can view the relative topological relationships of input patterns, determine the proper number of clusters, and assign unknown patterns to known clusters without losing any information of input patterns. Regarding the capability of determining the proper number of clusters, the proposed method is superior to conventional cluster analysis. The discrimination results also show that the assignments of unknown patterns to known clusters are reasonable using the proposed method. The advantages of the proposed method are also demonstrated by an application to the hydrological factors affecting low-flow duration curves in southern Taiwan.  相似文献