太行山南段平顺铁矿成矿地质特征及找矿预测     

张海东  刘建朝  江爱国  刘淑文  戈小红 《地球科学与环境学报》2010,32(3)

通过对太行山南段平顺铁矿矿区构造特征及岩浆岩的动力学分析研究,认为第一岩浆岩带属于被动侵位机制,岩体内部成矿潜力较大;第二岩浆岩带为主动侵位机制,背斜核部及岩体与围岩的接触部位为有利成矿区。同时根据岩石、矿石的稀土元素、微量元素、Pb同位素特征及矿体与岩体的关系,认为晚期闪长岩是主要的成矿母岩,但早期基性—超基性岩间接为铁矿的形成提供了一定的物质来源;矿体的形态明显受到接触面及周边构造形态的控制,呈不规则板状、透镜状、分枝状、羽状分布。最后运用矿体成矿规律、磁异常、电法异常等找矿预测方法,在研究区内圈出了龙降沟岩体南缘、双井、东郊3个找矿预测区。  相似文献   

鲁中南岩溶分区初步研究   总被引：1，自引：0，他引：1  

赵有美  彭凯  李岚 《山东国土资源》2010,26(11)

依据山东省中南部地质、气候环境的差异,划分岩溶区、亚区及岩溶系统。对岩溶区域的岩溶形态,由宏观到微观,由地表到地下,由溶蚀形态特征到堆积形态特征进行了详细论述。该区岩溶形态丰富多彩,既有代表半干旱岩溶区特征的干谷、大泉、常态山含石灰岩角砾的坡麓堆积的组合,也有代表半湿润岩溶区特征的溶丘、溶沟田、溶蚀洼地、地下河、洞内指向流纹、天锅、边槽及红壤土等的组合。  相似文献   

Statistical Analysis of the Dynamic Parameters of Silty Clay in the Beijing Area     

Shi Chunhu  Lü Yuejun  Peng Yanju  Tang Rongyu 《中国地震研究》2010,24(1):117-127

Soil dynamic parameters, including dynamic shear modulus ratio and damping ratio, have important effects on the results of layered soil earthquake response. In this paper, the mean parameter values of silty clay in different depths are obtained after statistical analysis of the experimental soil dynamic data from 20 recent site seismic safety evaluation reports in the Beijing area. Furthermore, based on two typical engineering sites, the influence of four different soil dynamic parameters, the statistic mean values, experimental values, values recommended by Yuan Xiaoming, and the values recommended in the code for seismic safety evaluation of engineering sites ( DB001 -94) are analyzed. The result shows that mean statistical values are applicable to seismic safety evaluation work in the Beijing area, especially for some inter-layered silty clays whose undisturbed soil samples are hard to obtain.  相似文献   

不同应力路径下天津滨海软土强度参数试验研究          下载免费PDF全文

张建新  王沛  李晶 《水文地质工程地质》2011,38(6):56-60

以天津滨海新区地下工程涉及较多的9～18m深度海相软土为研究对象,采用应力应变控制式三轴剪切渗透试验仪,分别进行三轴固结不排水试验(CU)、三轴不固结不排水试验(UU)以及模拟基坑开挖卸荷的减p路径试验(DEP),得到滨海软土在不同应力路径下的力学性状与初始固结状态有关。CU与UU试验应力与应变关系曲线呈硬化特征,CU试验孔隙水压力与应变关系呈先剪缩后剪胀的性质;DEP试验应力与应变关系曲线呈软化特征,在等应力控制条件下,孔隙水压力与应变关系呈剪胀性质,孔压为负。DEP试验对于总应力强度参数有影响,对有效应力强度参数影响较小。在滨海软土基坑支护设计中,选用CU试验参数进行计算,设计偏于安全。  相似文献   

中国-东盟自贸区城市群空间经济关联研究——基于社会网络分析法的视角   总被引：2，自引：1，他引：1  

梁经伟  文淑惠  方俊智 《地理科学》2015,35(5):521-528

从城市群的角度运用社会网络分析法对中国-东盟自贸区空间经济联系进行研究,首先从度、入度、出度3个角度对自贸区内的44个城市建立网络模型分析城市之间的复杂关系。其次对网络图进行中心度分析,判断城市的经济辐射范围,基于核心-边缘理论对自贸区内44个城市划分。最后利用派系过滤算法对城市网络图进行社团结构分析,利用K-plex算法进行凝聚子群分析。分析结果表明自贸区内城市之间存在密切的联系,核心城市群与边缘城市群圈层明显;同时中国在自贸区内扮演着重要角色,带动国家经济关系建设,促进区域经济的繁荣发展。  相似文献   

游客生态旅游认知及其对环境管理措施的态度——以井冈山风景区为例   总被引：3，自引：1，他引：2  

钟林生  宋增文 《地理研究》2010,29(10):1814-1821

以井冈山风景区为例,采用问卷调查和统计分析方法,研究了游客的生态旅游认知及其对环境管理措施的态度,并分析两者之间的相关性。结果表明:游客对生态旅游"基于自然"、"旅游对象受到保护"、"环境教育"认知率较高,对"社区利益"的认知率尚低,且不同类型游客对生态旅游认知不同。游客对"对环境负责任"、"保护环境资源"、"注意环境影响"、"重视环境教育"、"尊重地方文化"五类旅游环境管理措施持积极态度,但对"加强游客管理"的措施持消极态度。而且生态旅游的认知与某些生态旅游环境管理态度也直接相关,认识到生态旅游"基于自然"、"旅游对象受到保护"以及"社区利益"的游客更认同"重视环境教育"的环境管理措施。最后,还就提高生态旅游认知和加强生态旅游区环境管理提出了具体建议。  相似文献   

A framework for karst ecohydrology   总被引：7，自引：0，他引：7  

Ognjen Bonacci  Tanja Pipan  David C. Culver 《Environmental Geology》2009,56(5):891-900

Ecohydrology can be defined as the science of integrating hydrological and biological processes over varied spatial and temporal scales. There exists in karst a strong and direct interaction between the circulation and storage of groundwater and surface water. These fluxes in turn affect the spatial distribution of organisms in these habitats. Because of the fact that the appearance, storage and circulation of water in karstified areas is significantly different from other more homogenous and isotropic terrains, karst ecohydrology should develop original methods and approaches. At the same time, traditional approaches are also very useful. Large karst underground geomorphological patterns occur in many sizes and varieties, ranging from a few meters long or deep to very large, the deepest being deeper than 1 km and longer than hundreds of kilometres. In this article, special attention is paid to ecohydrological functions of karst underground features (caves, pits, conduits, etc.), which play a crucial dual role in (1) hydrology and hydrogeology of water circulation and storage and (2) ecology of many rare and endangered species. Differences in morphology, hydrology, hydrogeology and climate have resulted in a range of different environments, which provide the opportunity for the coexistence of different species. The role of the epikarst and vadose zones, as well as caves in ecohydrological processes, is discussed. The importance of the flood factor in karst ecology is analysed. The aim of this article is to move forward the discussion among different disciplines to promote and develop a conceptual framework for karst ecohydrology.  相似文献   

Geomorphological,pedological, and hydrological characteristics of karst lakes at Conversano (Apulia,southern Italy) as a basis for environmental protection     

N. Lopez  V. Spizzico  M. Parise 《Environmental Geology》2009,58(2):327-337

The land around Conversano (Apulia, southern Italy) is part of the Murge karst, interesting limestones and dolomitic limestones of Upper Cretaceous age, in a flat environment with sub-horizontal setting. Dolines and karst depressions are the most typical landforms in the area. Filling of these landforms with eluvial deposits locally created the possibility of water stagnancy at the surface. The Conversano territory presents ten karst lakes that represented, until some decades ago, the only water resource available for the local people, who built the typical bell-shaped wells to collect water volumes satisfying local needs during the dry season. Currently, these lakes have no great importance as water supplies, but represent habitats of great naturalistic value that are still able to support the ecological functionality and the wet environments with self-vegetation. Hydrological and hydrogeological studies have been carried out with the aim to fully estimate the related environmental problems. For this purpose, the hydrogeologic data of historical time series have been collected and compared to those of the last 5 years; successively, according to the Thornthwaite method, a hydrological monthly balance has been evaluated to quantify the distribution of water volumes interacting annually between the surface water bodies and the underlying carbonate groundwater. This evaluation has highlighted the need to carefully consider all the parameters concurring to a right definition of water balance for a karst environment, where pedological features, climatic conditions and anthropogenic modifications to the environment represent the elements of a very delicate system. Particularly, on the basis of recent soil map and field surveys, a re-evaluation of the available water capacity, estimated in some 40 mm, has been carried out. The studies have highlighted the need to extend the environmental protection rules to larger areas around the lakes, e.g. at the catchment scale, with definition of buffer zones; in this manner, it will be possible to constantly monitor the protected land and the local anthropogenic activities, that represent real polluting sources for both the surface water resources and the underlying carbonate groundwaters.  相似文献   

Evaluating disturbance on mediterranean karst areas: the example of Sardinia (Italy)     

Jo De Waele 《Environmental Geology》2009,58(2):239-255

Evaluating the human disturbance on karst areas is a difficult task because of the complexity of these peculiar and unique environments. The human impact on karstic geo-ecosystems is increasingly important and there is an increasing need for multidisciplinary tools to assess the environmental changes in karst areas. Many disciplines, such as biology, geomorphology, hydrology and social-economical sciences are to be considered to sufficiently evaluate the impact on these intrinsically vulnerable areas. This article gives an overview of the evolution of environmental impact on karst areas of the island Sardinia (Italy). For this particular case, the most important impacts in the past 50 years are derived from the following activities, in decreasing importance: (1) mining and quarrying; (2) deforestation, agriculture and grazing; (3) building (widespread urbanisation, isolated homes, etc.) and related infrastructures (roads, sewer systems, aqueducts, waste dumps, etc.); (4) tourism; (5) military activities. To evaluate the present environmental state of these areas the Disturbance Index for Karst environments [Van Beynen and Townsend (Environ Manage 36:101–116)] is applied in a slightly modified version. Instead of considering the indicators of environmental disturbances used in the original method, this slightly modified index evaluates the disturbances causing the deterioration of the environmental attributes. In the Sardinian case study, 27 disturbances have been evaluated, giving rise to the definition of a Disturbance Index ranging between 0 (Pristine) and 1 (highly disturbed). This Disturbance Index simplifies the original KDI method, appears to adequately measure disturbance on Mediterranean karst areas and could be applied with success to other similar regions.  相似文献   

Establishing a monitoring network for an impoundment-induced landslide in Three Gorges Reservoir Area, China   总被引：2，自引：1，他引：1  

Xianqi Luo  Fawu Wang  Zhenhua Zhang  Ailan Che 《Landslides》2009,6(1):27-37

A methodology for monitoring system of an impoundment-induced landslide in Three Gorges Reservoir Area, China is introduced. Currently, based on landslide geological classification, the monitoring regions and methods which include types of monitoring instruments, placement and calibration precision of instruments, and appropriate periods for instrumental placement is confirmed. To optimize the monitoring system, sensitivity analysis of displacements and the water table in landslides affected by reservoir surface fluctuation is completed to determine the layout of the monitoring cross sections and the monitoring points. As a case study, the behavior of displacements and the potential fluctuation of the water table in the Shiliushubao landslide, produced by the gradual water impoundment at Three Gorges Reservoir, has been simulated using 3D finite element method analysis. The sensitivity analysis of Shiliushubao landslide is investigated by the fuzzy set evaluation method. As a result, the monitoring network of Shiliushubao landslide is established.  相似文献