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1.
地震地下流体井水位、水温观测是地震地球物理台网主要观测手段,其数据集包含水位、水温测项的原始数据、预处理数据、产品数据和均值类数据,可为地震监测预报研究提供重要的数据支撑,用于前兆异常、同震响应、区域应力变化特征、含水层参数反演、观测机理等研究。地下流体井水位、水温数据集不仅可为地震预测预报和科学研究提供服务,而且在国民经济建设领域具有重要的应用价值。  相似文献   

2.
Forest restoration policies are often implemented without the assessment of their full environmental impact. In this study, we investigated the challenges of vegetation greening resulted from forest restoration on water resource sustainability, using a model‐based simulation in northwestern China. Four different vegetation scenarios and 25 future climate scenarios were employed using the Soil and Water Assessment Tool model. Results suggest that (a) the mean annual evapotranspiration changes from only 7.2% in the barren case to 100% in the forest case; however, it produced a 35.2% reduction in average annual streamflow and a 157% increase in soil water storage. The upstream vegetation greening caused the enhancement of water retention, while also creating great challenges for future downstream water resource sustainability; (b) seasonal effect was significant in that 100% forest case increased evapotranspiration (+40%) but it also reduced the streamflow (?73%) compared to the barren case in growing season, which may exacerbate spring and summer drought; (c) changes of evapotranspiration and streamflow were only 0.3% and ?0.9% at T + 3.9 °C when compared to the historic scenario in barren cases, while for all forest cases, variations were 3% and ?21.8%, respectively; (d) vegetation greening induced more remarkable changes in hydrological components than those resulting from climate change. Our “what if” research provides new insights for promoting sustainable management of water resources and ecosystems in mountainous water source areas.  相似文献   

3.
月球探测计划中影像数据的格式   总被引:1,自引:1,他引:0       下载免费PDF全文
月球影像数据是研究月球的地貌、地表形态,绘制全月地形图以及进行各种相关科学研究的基础.早期的Lunar orbiter,Apollo,Surveyor基本是以模拟影像格式传回地球,经过扫描后以照片形式发布.Clementine 的数据是通过PDS中心,以PDS的形式发布的.影像数据的保存与发布格式应遵循以下原则:数据格式要便于经常更新和补充;能够在各种平台和各不同目的使用人群中方便地使用;要符合国际标准,方便处理,能够与以前多次探测计划得到的数据结合使用.为中国嫦娥工程的影像数据格式提出建议.  相似文献   

4.
三维数据的二维可视化方法综述   总被引:1,自引:0,他引:1       下载免费PDF全文
等高线图、晕渲图和分层设色图等作为传统的三维数据的二维可视化方法,有各自的优点并被广泛地应用于屏幕显示和平面制图中。随着三维数据分辨率的不断提高,传统可视化方法已不能完全满足显示、挖掘隐含信息的要求。一种新的地形参数(openness)以及由此而产生的新的可视化方法(RRIM)被提出,这在很大程度上增强了二维显示的立体感和直观性。同时,在构造地貌研究的应用中,对细微构造的识别有着其他可视化方法无法比拟的优越性。良好的室内地貌解译工作不仅能够提高工作效率而且能够在一定程度上减少野外工作量。同时,对于森林覆盖严重、自然条件恶劣、不易到达而又具有研究价值的区域,RRIM提供了一种更好的工作方法,有着非常重要的实用价值。  相似文献   

5.
JointsolutionoflevelingandgravitydataincrustaldeformationmonitoringZUSHENGZHANG1)(张祖胜)YUANXIYANG2)(杨元喜)HANRONGSUN1)(孙汉荣)Z...  相似文献   

6.
Introduction When seismic waves propagate in a medium of complex geometry,such as a dam,it pro-duces stress concentration area at some spots of the dam because of the interface reflection and refraction of the waves,resulting in serious safety risk.Understanding seismic wave propagation in complex mediums becomes very important.In order to reduce the damage from natural earth-quakes,precaution measures should be designed on the basis of the seismic propagation charac-teristics.Experimental geo…  相似文献   

7.
沈建国  张宏敏 《地震学报》2006,28(6):622-628
给出了一种声波在固体和液体中传播过程的显示方法.该方法能够显示声波在二维平面内的动态传播过程.与动态光弹法、施利仑(Schlieren)法等声传播显示方法相比,该方法不仅能够同时显示不同时刻固体、液体中的声场,而且还适应于非透明固体;另外,对样品的残余应力没有要求,制作比较容易;但是,测量的声场是间接的,受接收换能器余震和液体直达波影响.将铝板放在液体里,记录到了在铝板中传播的纵波、横波和面波,在液体中传播的直达波以及3种首波,它们分别与铝板中传播的纵波、横波和面波相耦合,并且直观地显示了铝板与液体界面上所传播声波之间的耦合关系;将有机玻璃放在液体中,记录了有机玻璃中传播的声波及其与液体中所传播声波的耦合关系.   相似文献   

8.
地磁观测中干扰抑制方法的发展及展望   总被引:1,自引:0,他引:1  
地磁观测数据不仅具有学术研究意义,也是不可或缺的国家基础战略资源.但是,目前我国地磁台网中近1/3地磁台站正日益受到由外界人工电磁干扰源的干扰,产出的地磁观测数据质量下降.如何选用合适的技术方法对干扰进行辨识是目前地磁台网运行中数据处理的热点和难点.基于此本文从地磁观测数据中分析及抑制方法中遇到的主要问题入手,对现代信号处理技术在地磁数据分析及干扰抑制方面的应用进行归纳总结,作为现代信号处理的演化的新方向,介绍了智能信息处理理论中数据融合、数据挖掘等技术在地磁数据分析方法的发展及展望中谈及.研究发现,智能信息处理是地磁数据中干扰辨识及抑制领域有效技术和今后发展趋势,也是地磁观测数据综合处理中值得借鉴和学习的有效技术之一.  相似文献   

9.
Methodology for credibility assessment of historical global LUCC datasets   总被引:1,自引:0,他引:1  
Fang  Xiuqi  Zhao  Wanyi  Zhang  Chengpeng  Zhang  Diyang  Wei  Xueqiong  Qiu  Weili  Ye  Yu 《中国科学:地球科学(英文版)》2020,63(7):1013-1025
Land use-induced land cover change(LUCC) is an important anthropogenic driving force of global change that has influenced, and is still influencing, many aspects of regional and global environments. Accurate historical global land use/cover datasets are essential for a better understanding of the impacts of LUCC on global change. However, there are not only evident inconsistencies in current historical global land use/cover datasets, but inaccuracies in the data in these global dataset revealed by historical record-based reconstructed regional data throughout the world. A focus in historical LUCC and global change research relates to how the accuracy of historical global land cover datasets can be improved. A methodology for assessing the credibility of existing historical global land cover datasets that addresses temporal as well as spatial changes in the amount and distribution of land cover is therefore needed. Theoretically, the credibility of a global land cover dataset could be assessed by comparing similarities or differences in the data according to actual land cover data(the "true value"). However, it is extremely difficult to obtain historical evidence for assessing the credibility of historical global land cover datasets, which cannot be verified through field sampling like contemporary global land cover datasets. We proposed a methodological framework for assessing the credibility of global land cover datasets. Considering the types and characteristics of the available evidence used for assessments,we outlined four methodological approaches:(1) accuracy assessment based on regional quantitative reconstructed land cover data,(2) rationality assessment based on regional historical facts,(3) rationality assessment based on expertise, and(4) likelihood assessment based on the consistency of multiple datasets. These methods were illustrated through five case studies of credibility assessments of historical cropland cover data. This framework can also be applied in assessments of other land cover types, such as forest and grassland.  相似文献   

10.
地震孕育过程中的前兆地声   总被引:7,自引:0,他引:7  
郑治真 《地震研究》1992,15(2):193-204
本文介绍了有关地声观测技术和前兆地声机制的综合研究结果,为了获得连续可靠的地声信息,研制了四路慢速磁带仪等地声极微震记录仪。经过四年连续野外观测记录证明了它的稳定性和实用性;为了解决地声源定位问题,在山东莒县及云南洱源建立了标准地声台网,进行了连续四年记录,取得了可靠的资料;为了解决地声信号处理问题,建立了全国地声数据处理中心,及相应的时间序列和地声资料处理程序库。在上述工作基础上进行了长期连续观测和全面的基础研究。通过观测,获得了可靠的前兆地声信息,特别是第一次用仪器记录到了可听前兆地声,提前时间为3—15分钟。观测研究表明前兆地声确实存在,地声可以作为地震预报的一种重要方法。  相似文献   

11.
Politics, economics and science interpret the concept of sustainability differently. The discussion distinguishes between economic, environmental and social sustainability. While advocates of economic sustainability assume that natural capital is substitutable by humanmade capital, policies for a sustainable development are questionable. The paper therefore highlights a regional case to show that sustainability is indivisible. Moreover, economics and policies serving Baltic sustainability need a new institutional network to manage the multispecies resource with participation of the social players and by addressing targets step by step. The findings are based on a simple ecological-economic model providing insights for the negotiation game for all players. In addition, multispecies resource management shows a strong hierarchy in both social actions and targets. Since sustainable development is an on-going, dynamic process, policy implementation and funding must also be continuous. Sustainable development therefore challenges the institutional sets for the process and its relations to local, regional and national policies.  相似文献   

12.
Quality Assurance in Environmental Monitoring   总被引:1,自引:0,他引:1  
Over the past decade, there has been a growing awareness of the need for accountable quality assurance (QA) and control in chemical analysis. In environmental monitoring programs, especially those studying metal contaminants at trace and ultratrace concentrations in natural waters, the sampling, sample storage and sample preparation stages prior to analysis, represent potentially greater sources of error than the chemical analysis. The improvements in data reliability and detection limits when appropriate QA is employed, allow meaningful relationships between the measured concentrations and other physical and chemical parameters to be more reliably interpreted. Published data generated from both field and laboratory studies, frequently show no evidence of QA, yet such data are being used to formulate quality guidelines and as the basis for expensive management actions. So that only quality data forms the basis of regulatory action, it is essential that monitoring data not be published without demonstrable evidence of quality practices in all aspects of the monitoring exercise.  相似文献   

13.
本文是科学数据共享政策法规体系研究系列文章的收笔之作.撰写本文的目的,就是为说明科学数据共享政策法规体系的研究是建立在大量的基础调研之上.调查研究是谋事之基、成事之道.从实践中寻求解决现实问题的方法,才能制定出切实可行的政策、法规,调查研究是制定政策、法规的客观依据.为使制订政策、 规章制度适应社会经济发展和变化的新情况,就深入开展调查研究,认真听取各方面的意见,深入研究相应的管理规律和运行机制.本文详述了调查过程、调查方法,以佐证政策法规研究不能脱离实际.  相似文献   

14.
Professional conduct of scientists during volcanic crises   总被引:1,自引:0,他引:1  
Stress during volcanic crises is high, and any friction between scientists can distract seriously from both humanitarian and scientific effort. Friction can arise, for example, if team members do not share all of their data, if differences in scientific interpretation erupt into public controversy, or if one scientist begins work on a prime research topic while a colleague with longer-standing investment is still busy with public safety work. Some problems arise within existing scientific teams; others are brought on by visiting scientists. Friction can also arise between volcanologists and public officials. Two general measures may avert or reduce friction: (a) National volcanologic surveys and other scientific groups that advise civil authorities in times of volcanic crisis should prepare, in advance of crises, a written plan that details crisis team policies, procedures, leadership and other roles of team members, and other matters pertinent to crisis conduct. A copy of this plan should be given to all current and prospective team members. (b) Each participant in a crisis team should examine his or her own actions and contribution to the crisis effort. A personal checklist is provided to aid this examination. Questions fall generally in two categories: Are my presence and actions for the public good? Are my words and actions collegial, i.e., courteous, respectful, and fair? Numerous specific solutions to common crisis problems are also offered. Among these suggestions are: (a) choose scientific team leaders primarily for their leadership skills; (b) speak publicly with a single scientific voice, especially when forecasts, warnings, or scientific disagreements are involved; (c) if you are a would-be visitor, inquire from the primary scientific team whether your help would be welcomed, and, in general, proceed only if the reply is genuinely positive; (d) in publications, personnel evaluations, and funding, reward rather than discourage teamwork. Models are available from the fields of particle physics and human genetics, among others.  相似文献   

15.
South America is experiencing rapid change in forest cover, of both native and planted forest. Forest cover loss is primarily attributable to fire, logging, and conversion of native forest to agriculture, pasture, and forest plantations, and types of change vary within and among the many diverse types of forests in South America. Major changes in forest cover and growing policy concerns underscore an urgent need for research on sustainable forest management and water ecosystem services in South America. Differences in land ownership and management objectives create trade‐offs between wood production and water ecosystem services from forests. Work is needed to quantify how forest change and management affect ecosystem services, such as wood production versus water provision. Current scientific understanding of forest management effects on water ecosystem services in South America has important limitations, including a scarcity of long‐term records and few long‐term integrated watershed studies. Industry, government, universities, and local communities should collaborate on integrated applied studies of forests and water. Data archiving and publically available data are required. The creation of national networks and a multi‐country South America network to identify and implement common water research protocols, share results, and explore their implications would promote common and well‐supported policies. Hydrologists working in South America are well placed to tackle the challenges and opportunities for collaborative research that will maintain the intrinsic values and water ecosystem services provided by South America's forests.  相似文献   

16.
Marine seismic surveys produce high intensity, low-frequency impulsive sounds at regular intervals, with most sound produced between 10 and 300 Hz. Offshore seismic surveys have long been considered to be disruptive to fisheries, but there are few ecological studies that target commercially important species, particularly invertebrates. This review aims to summarise scientific studies investigating the impacts of low-frequency sound on marine fish and invertebrates, as well as to critically evaluate how such studies may apply to field populations exposed to seismic operations. We focus on marine seismic surveys due to their associated unique sound properties (i.e. acute, low-frequency, mobile source locations), as well as fish and invertebrates due to the commercial value of many species in these groups. The main challenges of seismic impact research are the translation of laboratory results to field populations over a range of sound exposure scenarios and the lack of sound exposure standardisation which hinders the identification of response thresholds. An integrated multidisciplinary approach to manipulative and in situ studies is the most effective way to establish impact thresholds in the context of realistic exposure levels, but if that is not practical the limitations of each approach must be carefully considered.  相似文献   

17.
The Turkey Lakes Watershed (TLW) study is a federal, interdepartmental study established in 1979 to investigate the effects of acid rain on terrestrial and aquatic ecosystems. The 10.5 km2 watershed, located in the Eastern Temperate Mixed Forest on the Canadian Shield, has been the site of multidisciplinary studies on biogeochemical and ecological processes conducted across plot to catchment scales. The whole-ecosystem investigative approach was adopted from the outset and has allowed research to evolve from its original (and continuing) acidification focus to include investigations on the effects of climate change, forest harvesting and other forest ecosystem perturbations. The extensive scientific and support infrastructure allows for collection of a comprehensive data record essential for understanding long-term environmental trends. Data include atmospheric deposition, meteorology, stream hydrology and chemistry, soil, pore and ground water properties, understory and overstory vegetation, lake and outflow physical and chemical properties, and aquatic macroinvertebrate and fish community composition and abundance. These data have contributed to over 400 published research papers and graduate theses. The watershed has also figured prominently in many continent-wide comparisons advancing fundamental watershed theory. The knowledge gained at TLW has influenced pollutant emission and natural resource management policies provincially, nationally and internationally.  相似文献   

18.
Reliable field data for all hydrologic parameters are often unavailable for watersheds even for those intensively monitored.In the absence of reliable such data,verified mathematical relations for an area can be used for other areas with same hydrologic and climatic regimes.The objectives of this research were:1) to assess the total runoff and sediment loss,and 2) to develop rainfall,runoff and soil loss relations for four prominent landuses(including degraded,pasture,forest and agriculture lands) in the Hilkot watershed(Pakistan).Four experimental natural runoff plots were established on the landuses (degraded,pasture,forest and agriculture land).The field study and data collection were conducted in the Hilkot watershed from 1999 to 2005.Regression analysis was conducted to establish relations among rainfall,runoff and soil loss for all landuses using.Regression analysis indicated good correlation with field data.  相似文献   

19.
The oceans have a major influence on world climate and are an important source of food, most of which comes from the coastal zones. These zones, and the traditional, sustainable, life-styles of the fishing communities that live there, are under immense and growing pressure. Urbanization, pollution, sea level rise, and the destruction of natural coast defences and fish nursery grounds are undermining sustainability. Although chemical pollution in some areas, with some substances, is falling it remains a serious problem over the world as a whole.

The United Nations Conference on the Human Environment, held at Rio de Janeiro in June 1992, recognized the need for more effective protection of the resources of the coastal seas, and a number of specific actions are set out in Agenda 21. But action is still not being taken on a scale which matches the problem. There are four probable reasons: first, the sea is still assumed to be too big to damage; second, jurisdiction is inadequate; third, serious national and international conflicts of interest remain; and fourth, economic distortions hamper sound judgement. The northern seas, which suffer less from these problems, should be demonstration areas for sound marine resource management.  相似文献   


20.
鄂霍茨克海的地球物理场与地质构造   总被引:1,自引:0,他引:1  
鄂霍茨克海位于西太平泮边缘海最北部,受欧亚大陆板块和太平洋板块的作用,有十分复杂的地质地球物理特征,鄂霍茨克海不仅有海隆,还有三个著名的盆地,其中的千岛盆地,是研究鄂霍茨克海的一个窗口,本文通过对大量相关资料的二次开发,详细地讨论了鄂霍茨克海的地球物理场特征,沉积特点、热流分及深部结构特点,并对该边缘海的形成演化进行了初步的探讨,我们认为,对鄂霍茨克海研究的结果,将对中国边缘海地质特征的研究起到帮助和借鉴作用。  相似文献   

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