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1.
敦煌西土沟沙漠洪水资源开发利用模式及成效分析   总被引:1,自引:0,他引:1  
收集研究区域内雨量站历年降水量资料,水文站历年径流系列资料以及历年最大洪峰流量、洪水总量成果资料及西土沟敦煌沙漠水文实验研究站实测水文资料,调查该区域内洪水沟道的历史最大洪水。用水文学原理和方法对洪峰流量和洪水总量变化规律进行统计分析,结合敦煌西土沟流域灾害综合治理工程实施情况估算区域水资源可利用量,提出沙漠洪水资源开发利用新模式。结果表明:西土沟流域洪水灾害综合治理工程的实施探索出导流+分洪+工程防护的洪水资源开发利用模式、拦蓄洪水产生地下径流利用模式和沙漠冷水虹鳟鱼养殖到葡萄种植的区域水资源重复利用模式;有效遏制了研究区内沙漠的进一步推进并可显著增加流域内可利用水资源量,实现了区域生态治理与经济发展的良性循环。  相似文献   

2.
In the paper we present the procedure for hazard assessment that has been used to prepare the landslide hazard map of the Principality of Andorra at 1:5,000 scale. The main phases of the hazard assessment are discussed. Susceptibility analysis has involved the location of the potential slope failures, and the estimation of both landslide volume and runout distance. In the susceptible areas, landslide magnitude and frequency has been determined in order to produce the Hazard Zoning Map. Data required for hazard assessment have been introduced into a GIS or derived directly from available Digital Terrain Models. Data handling and treatment with the GIS has allowed the performance of the landslide hazard assessment and mapping in a fast and reproducible way.  相似文献   

3.
全球主要火山灾害及其分布特征   总被引:1,自引:0,他引:1  
本文研究了火山灾害各种致灾因子的物理过程和灾害特点,根据文献中记载的全球火山灾害,在进行火山灾害分区研究的基础上,研究了全球火山灾害分布特征.全球主要的火山灾害分布在8个主要区域.有记载的火山灾害在热带占73%,远高于火山喷发分布于热带区的比例.全球两个最强烈的火山灾害分布区都是围绕着位于板块结合部表现为复杂构造结的班达海和加勒比海,而且每一个灾害区都有3条分支.热带区第3个灾害区为中非区,地幔上隆是这里主要的动力学背景.本文还研究了1700年以来火山灾害时间分布特征,以及1993年以来各种火山灾害发生频次.  相似文献   

4.
城市雨洪模拟技术研究进展   总被引:8,自引:1,他引:7       下载免费PDF全文
从对水文过程描述的角度对城市雨洪模拟技术进行了回顾,认为管网汇流阶段算法较为成熟,而产流和坡面汇流阶段还有待深入研究.从模型构建思想的角度回顾其发展历程,阐明了经验性模型和分布式概念性模型的局限性以及分布式物理模型的良好发展前景.通过总结国内外几个具代表性城市雨洪模型的特点,从特定模型的角度进一步分析城市雨洪模型的现状,并指出中国与国外模型研究的差距.对与城市雨洪模拟精度密切相关的基础数据收集与管理技术进行了讨论,并提出了城市雨洪模拟技术的发展方向.  相似文献   

5.
GIS complemented statistical classification techniques yield good result in predicting landslide hazards. Indian standard landslide hazard model follows guidelines formulated by the Bureau of Indian Standards (BIS, 1998), in which the study area is divided into five categories, ranging from very low hazard zone to very high hazard zone on fixed numerical ratings. For land use planners, “moderate hazard zone” proves vague and indecisive. In the present study, BIS based landslide hazard zones are demarcated for 140 sq. km area for a road corridor in East and North Sikkim that shows 21.96%, 53.14%, 22.80% and 2.10% for ‘Low Hazard Zone’, ‘Moderate Hazard Zone’, ‘High Hazard Zone’ and ‘Very High Hazard Zone’ respectively. This classification scheme has been reclassified to binary system based on population distribution and defining the cut-off by evaluation techniques of the ROC. The reclassification eliminates “moderate hazard zone”, minimizing the Type-II error and becomes more acceptable for future land use planning.  相似文献   

6.
酸性污染物欧拉型输送转化模式的研究   总被引:2,自引:0,他引:2  
数值模式是研究酸性污染及其长距离输送特性的一种重要方法。70年代以来,国内外发展了许多欧拉型的输送转化模式,我国在欧拉型酸性污染物长距离输送模式的研究中也取得了重要进展。主要介绍了国内外的欧拉酸性污染物输送转化模式,并就模式的发展方向进行了讨论。  相似文献   

7.
The pterosaur collection at the Natural History Museum is of great historical importance. Most of the material is figured or cited, and several specimens are types or casts of types. Pterosaurs from UK localities are well represented, but foreign material is also present as original specimens and as high quality casts. The entire collection has been recorded in a database and curatorial improvements have been made, which has improved physical and virtual access to the collection. Although many of the specimens were collected as long ago as the early 1800s, they are still useful today. A full list of Natural History Museum pterosaur specimens is published, for the first time since 1888.  相似文献   

8.
帕米尔高原是由喜马拉雅山脉、喀喇昆仑山脉、昆仑山脉、天山山脉、兴都库什山脉交汇于此形成的一个巨大的山结。由于其特殊的地质构造位置和复杂的构造演化历史,形成了良好的成矿地质背景条件。依据中塔两国政府“双方地学领域科技合作谅解备忘录”精神,中塔两国合作组织实施了“塔吉克帕米尔成矿带地球化学调查”工作。完成3万km2地球化学填图任务,建立了工作区地球化学数据库,编制了系列地球化学图件。应用地球化学分析方法回答了测区资源潜力评价有关的地学问题,在此基础上编制了Ag、Au、Pb-Zn等8个元素(组)找矿预测图,共圈定各类找矿预测区136个。同时,也从地球化学角度解决了许多地质问题。为开展塔吉克帕米尔地区地质科学研究,了解帕米尔地区优势资源种类、分布地域、资源潜力等评价信息,快速缩小找矿靶区,实现找矿突破,改变地区资源分布格局等工作提供了可靠而丰富的地球化学基础资料。  相似文献   

9.
The chemical factors affecting the accuracy of Wilson's procedure for determination of ferrous iron in silicates have been investigated. This procedure utilizes pentavalent vanadium to oxidize ferrous iron as it is set free from the silicate by hydrofluoric acid. The quadrivalent vanadium produced is more resistant to oxidation by oxygen than ferrous iron, and conserves the reducing power of the silicate. The procedure is done at room temperature.Recovery of ferrous iron under various conditions has been studied to elucidate the chemical mechanisms of loss in the procedure. Some improvements have been made. The studies indicate that the procedure is of high accuracy.An effect resulting in loss of ferrous iron titre has been found, involving the chemical attack of solids by solutions containing oxygen and pentavalent vanadium. This loss does not appear to take place if all ion species are in solution.  相似文献   

10.
ABSTRACT

Hazard analysis is a crucial step in flood risk management, and for large rivers, the effects of breaches need to be taken into account. Hazard analyses that incorporate this overall “system behaviour” have become increasingly popular in flood risk assessment. Methods to perform such analyses often focus on high water levels as a trigger for dike breaching. However, the duration of high water levels is known to be another important failure criterion. This study aims to investigate the effect of including this duration dependency in system behaviour analyses, using a computational framework in which two dike breach triggering methods are compared. The first triggers dike breaches based on water levels, and the second one based on both water-level and duration. The comparison is made for the Dutch Rhine system, where the dike failure probabilities are assumed to conform to the new Dutch standards of protection. The results show that including the duration as a breach triggering variable has an effect on the hydraulic loads and overall behaviour in the system, therefore influencing the risk. Although further work is required to fully understand the potential impact, the study suggests that including this duration dependency is important for future hazard risk analyses.  相似文献   

11.
Semarang is one of the biggest cities in Indonesia and is nowadays suffering from coastal flooding. Land subsidences, high water tide, and inadequate structural measures play important roles in the coastal inundations. Structural and non-structural methods for controlling coastal flooding including dykes, drainage systems, pump stations, polder systems, coastal-land reclamations, coastal planning and management, public education, as well as the establishment of an institutional framework for disaster management have been implemented in the Semarang coastal area. Although some improvements have been made, the current flood management system has generally failed to address a wide range of coastal inundation problems. Some improvement actions have been proposed including stakeholders involvement on the disaster mitigation. For a long period coastal management, accelerated sea level rises due to global warming should also be taken into account.  相似文献   

12.
The first 7 years of the National Tsunami Hazard Mitigation Program (NTHMP) have had a significant positive impact on operations of the Richard H. Hagemeyer Pacific Tsunami Warning Center (PTWC). As a result of its seismic project, the amount and quality of real-time seismic data flowing into PTWC has increased dramatically, enabling more rapid, accurate, and detailed analyses of seismic events with tsunamigenic potential. Its tsunameter project is now providing real-time tsunameter data from seven strategic locations in the deep ocean to more accurately measure tsunami waves as they propagate from likely source regions toward shorelines at risk. These data have already been used operationally to help evaluate potential tsunami threats. A new type of tsunami run-up gauge has been deployed in Hawaii to more rapidly assess local tsunamis. Lastly, numerical modeling of tsunamis done with support from the NTHMP is beginning to provide tools for real-time tsunami forecasting that should reduce the incidence of unnecessary warnings and provide more accurate forecasts for destructive tsunamis.  相似文献   

13.
稳定同位素地球化学研究新况   总被引:6,自引:0,他引:6  
近年来稳定同位素地球化学进展显著。同位素测试方面的主要进展表现为:①离子探针质谱及激光制样系统的迅速发展和在同位素分析中广泛应用;②同位素测量仪器的自动化和电脑化;③分析方法和结果标准化;④新的同位素分析方法的开拓。同位素分馏机制方面最突出的进展是对与质量无关的同位素分馏的研究。已发现这种分馏在大气化学反应中和前太阳系阶段起重要作用。同时对热力学和动力学同位素分馏研究正进一步系统化。同位素应用方面,地球表面圈层研究受到更多注意。与资源与环境问题直接相关的研究更受到特别重视。对硼、硅、氯和锂等同位素新方法的地质应用也进展突出。  相似文献   

14.
Flood hazard evaluation is an important input for Nuclear Power Plants external events safety studies. In the present study, flood hazard at various nuclear sites in India due to rainfall has been evaluated. Hazard estimation is a statistical procedure by which rainfall intensity versus occurrence frequency is estimated from historical records of rainfall data and extrapolated with asymptotic extreme value distribution. Rainfall data needed for flood hazard assessment are daily annual maximum rainfall (24?h data). The observed data points have been fitted using Gumbel, power law and exponential distribution, and return period has been estimated. To study the stationarity of rainfall data, a moving window estimate of the parameters has been performed. The rainfall pattern is stationary in both coastal and inland regions over the period of observation. The coastal regions show intense rainfall and higher variability than inland regions. Based on the plant layout, catchment area and drainage capacity, the prototype fast breeder reactor (PFBR) site is unlikely to be flooded.  相似文献   

15.
继顾琅和鲁迅1906年出版《中国矿产志》以来的100多年中,中国社会发生了根本性改变,中华民族由半殖民地半封建国家逐步走上了康庄大道,矿产资源功不可没。根据《国土资源"十三五"规划纲要》"总结百年勘查成果和成矿规律"的要求,《中国矿产地质志》的各项研编工作全面部署,并取得实质性进展,截止目前共完成59部成果报告,取得了一系列重要成果:制定了统一的研编技术要求,清理出全国已发现矿产地近6.5万处,划分出18种矿床类型;修订和统一了部分省区的岩石地层划分方案和地层系统;划分或修正了大地构造单元和成矿区带,探讨了大地构造格局、演化与成矿作用,总结了重点Ⅲ级成矿区带成矿规律,建立了区域成矿模式和成矿谱系;完成了部分全国性、省级(单矿种)志书和普及本,获得了一批地球化学/年代学数据,深化了典型矿床和成矿规律研究,在钨、锡、锰、镍、银、锑矿等重要矿产矿床成因与成矿规律、华南洋构造演化与成矿、前寒武纪成矿等方面取得了一些创新性成果,不仅提升了矿床学理论研究水平,还指导了成矿预测和找矿勘查,普及了矿产知识,实现了边研编、边服务,取得了显著的社会效益。  相似文献   

16.
《China Geology》2020,3(1):173-181
The Beijing-Tianjin-Hebei region boasts rich geothermal resources and new achievements have been made in the exploration and development of geothermal resources in this region based on previous regional investigation. In detail, geothermal reservoirs of Gaoyuzhuang Formation of Jixian System and Changcheng System in Xiongan New Area have been recently discovered, opening up the second space of geothermal resources; the calculation method of the recoverable resources of geothermal fluid with reinjection being considered has been improved in Beijing-Tianjin-Hebei region, and uniform comprehensive assessment of shallow geothermal energy, hydrothermal geothermal resources, and hot dry rocks (HDR) geothermal resources in the whole Beijing-Tianjin-Shijiazhuang region has been completed. The scientific research base for cascade development and utilization of geothermal resources in Beijing-Tianjin-Hebei region has applied hydraulic fracturing technology to the geothermal reservoirs in Gaoyuzhuang Formation. As a result, the production capacity doubled and two-stage cascade utilization composed of geothermal power generation and geothermal heating were realized, with the first-phase installed capacity of 280 kW and the geothermal hearing is 30000 m2. In this way, a model of the exploration, development, and utilization of geothermal resources formed. Large-scale utilization has become the future trend of geothermal resource development in Beijing-Tianjin-Hebei region, and great efforts shall be made to achieve breakthroughs in reinjection technology, geothermal reservoir reconstruction technology, thermoelectric technology and underground heat exchange technology.  相似文献   

17.
膨胀土是具有较大胀缩变形能力的特殊性粘土,膨胀土斜坡地区极易发生滑坡等地质灾害,本文根据安康汉江二号桥南侧滑坡勘察资料,较全面地介绍了该膨胀土滑坡特征,为滑坡根治提供了充分的地质依据。  相似文献   

18.
The survey of Messenia by the University of Minnesota Messenia Expedition (UMME) was recently followed by the Pylos Regional Archaeological Project (PRAP). Despite improvements in survey methodology, problems remain, particularly with the interpretation of field data and with extrapolation, especially when this is made based on survey results alone, without excavation. In addition, the work of the archaeologists has not yet been fully integrated with that of the earth scientists. Some examples are given of the difficulties encountered in this survey, especially concerning retrodictions (predictions about the past) of ancient settlement patterns and numbers. Suggestions are made here for further survey and selective excavation, especially in eastern Messenia, where fieldwork has been far less extensive than in western Messenia. More fieldwork is needed to determine the pattern of geomorphic changes in the region, especially in relation to the varying degrees of visibility and/or preservation of the ancient sites. Meanwhile, increased recent human activity is rapidly destroying or endangering those remains that have hitherto survived, so that survey is often de facto of a rescue nature. © 2007 Wiley Periodicals, Inc.  相似文献   

19.
Conclusion The sporadic application of ‘slum clearance’ programmes served only to exacerbate the already intransigent problem of urban housing shortage, as the example of Lagos has demonstrated. The continued application of Western assumptions in urban development (whereas they have since been modified in those countries) has inhibited a reassessment of issues in the Nigerian context. Some of the issues at stake have been considered in this paper. Conventional Western concepts have not only proved inappropriate to the realities of rapid urban growth and limited resources in Nigeria and most of tropical Africa, but have intensified the problems still further. In the context of Maroko slum clearance exercise as contained in this paper, they must be seen as an unsuccessful attempt to control rather than resolve the housing problems of the urban poor. I terms of planning five procedural steps are necessary to be followed to accomplish a desirable urban renewal exercise for the community. They are (1) to acquire land in accordance with the plan, consisting of purchase of land and the structures on it. (2) Relocation of residents from the acquired buildings into satisfactory quarters. The relocation exercise must be made not only mandatory on the government (local or state) undertaking renewal but made a legal requirement. (3) Site clearance — the razing of the structures on the land may be carried out only after the quality of such structures have been determined. This exercise also assumes that a process of data collection and analysis have been accomplished (social and physical). (4) Site improvements and supporting facilities and services are undertaken by the agency. Site improvements include streets, sewers, lightiing etc. Others may include parks, play ground, schools etc. (5) Land may be built upon by agency or sold to original owners if compensations have been paid. They may also be given back to owners with loans to rebuild either through self-help or cooperative venture. Amortization and interest on such loans should be made generous for the poor. Since demolition of housing must precede new construction in the project area, the existing stock of housing is decreased, forcing the displacees to seek shelter in the remaining housing in the city or erect squatter housing. This is especially likely at the low-quality end of the housing market, since the greatest reduction in the housing stock occurs there. The condition may remain depending on government’s degree of responsiveness. Perhaps the only way to avoid the problem of a reduced housing stock in any urban renewal project, thus curbing the incidence of the spiral process of slums among the poor, as the Maroko example has demonstrated in Lagos, is by building new dwelling units for relocatees before demolishing their present homes. Such policy would merge with general attempts to relocate the poor in suburbs, seeking a reduction in the concentrations of poverty in central cities of Nigeria.  相似文献   

20.
The site of Mansehra is located seismically in an active regime, known as the Crystalline Nappe Zone and Hazara-Kashmir Syntaxis in NW Himalayas, Pakistan. Seismic Hazard Assessment (SHA) for the site has been carried out by considering the earthquake source zones, selection of appropriate attenuation equations, near fault effects and maximum potential magnitude estimation. The Mansehra Thrust, Oghi Fault, Banna Thrust, Balakot Shear Zone, Main Boundary Thrust, Panjal Thrust, Jhelum Fault and Muzaffarabad Fault and, further to the south, the Sanghargali, Nathiagali, and Thandiani Thrusts are the most critical tectonic features within the 50 km radius of Mansehra. Using the available instrumental seismological data from 1904 to 2007, SHA has been carried out. Other reactivated critical tectonic features in the area have been investigated. Among them the Balakot-Bagh fault, with the fault length of 120 km from Balakot to Poonch, has been considered as the most critical tectonic feature on the basis of geological/structural/seismological data. The potential earthquake of maximum magnitude 7.8 has been assigned to the Balakot-Bagh fault using four regression relations. The peak ground acceleration value of 0.25 g (10% probability of exceedance for 50 years) and 0.5 g has been calculated with the help of the attenuation equation using probabilistic and deterministic approaches.  相似文献   

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