天然气水合物系统的环境效应

环境效应是天然气水合物科学体系中重要一环,同时,有关该领域的调查研究也是人类安全、环保、经济、科学地利用水合物资源的可靠保证。海底天然气水合物所孕育的独特的生态系统、与之关联的重大地学、环境问题以及资源的勘探开发均是充满魅力而又富有挑战的科学新领域。梳理了当前全球范围内有关水合物环境效应的大部分研究工作,综述了与天然气水合物环境有关的生物效应、化学效应和物理效应的研究现状及内容,着重强调了与该领域相关的基础问题和焦点问题,展望了该领域未来发展的趋势,希望藉此为我国的水合物环境效应调查与评价工作向纵深推进提供参考依据,并能引起广大研究者的兴趣与重视。     

半封闭海湾固有振动周期的数值计算

用二维数值模式,根据芝罘湾的实测水深和形状,计算了该湾的固有振动周期,与实测资料吻合较好。计算结果同时给出了当节点N=1,2,...,6时,湾内的振幅分布（合波长、波节线分布）,以及纵振动和横振动分布情况。     

自然延伸概念及相关地质要素在海域划界中的影响效力分析

The United Nations Convention on the Law of the Sea entitled the coastal States to naturally extend the continental shelf, which has caused more drastic disputes of maritime delimitation. This paper devotes to clarifying the significant concept of natural prolongation through an effect method combing the legal principles and technical analysis. Firstly, the classic samples with respect of the development of geological features are traced. Based on these samples, the classification with a model is proposed in order to affirm the concept''s significance under certain geomorphologic situations. Lastly, scientific analysis is used to present two potential prolongation situations and emphasize that all the technical analysis on maritime delimitation should be complied with international law and protect the common interest of all the mankind.     

Mapping of climatic parameters under climate change impacts in Iran

ABSTRACT

This research aims to provide a comprehensive evaluation of climate change effects on temperature, precipitation and potential evapotranspiration over the country of Iran for the time periods 2010–2039, 2040–2069 and 2070–2099, and under scenarios A2 and B2. After preparation of measured temperature and precipitation data and calculation of potential evapotranspiration for the base time period of 1960–1990 for 46 meteorological stations (with a nationwide distribution), initial zoning of these three parameters over the country was attempted. Maximum and minimum temperatures and values of precipitation were obtained from the HadCM3 model under scenarios A2 and B2 for the three time periods, and these data were downscaled. Corresponding maps were prepared for the three parameters in the three time periods, and spatial and temporal variations of these climatic parameters under scenarios A2 and B2 were extracted and interpreted. Results showed that the highest increase in temperature would occur in western parts of the country, but the highest increase of potential evapotranspiration would occur in the central region of Iran. However, precipitation would vary temporally and spatially in different parts of the country depending on the scenario used and the time period selected.

Editor Z. W. Kundzewicz; Associate editor not assigned     

Delineating groundwater potential zones in a hard-rock terrain using geospatial tool

Abstract

Geospatial techniques have become one of the leading tools in the field of natural sciences for assessment, monitoring and management of natural resources, particularly in groundwater research. The paper discusses the demarcation and assessment of groundwater potential zones using geospatial techniques in the Deccan Volcanic Province of Maharashtra, India, using multi-criteria analyses. The study incorporates integration of thematic information (geomorphology, lithology, drainage density, slope and lineaments) in a GIS environment in order to identify groundwater potential zones. The methodology adopted can be used as a rapid assessment tool in groundwater exploration and is helpful in predictive groundwater resource management. Multi-criteria evaluation techniques were used to integrate all the thematic layers. Individual themes and their corresponding categories were assigned a knowledge base ranking from 1 to 5, depending on their importance for groundwater potential. Using the Raster calculator tool in Arc GIS software, all thematic maps were integrated to produce a composite groundwater potential map of the study area. The identified groundwater potential zones were classified into four classes, from excellent to poor. The generated groundwater potential zones were validated with field checks and borewell/dugwell yield data, and showed consistency with the observations.

Citation Singh, P., Thakur, J. K., and Kumar, S. (2013) Delineating groundwater potential zones in a hard-rock terrain using geospatial tools. Hydrological Sciences Journal, 58 (1), 1–11.     

军队参与国际重大自然灾害救援行动工作机制建设的思考

向遭受严重自然灾害的国家或地区提供人道主义紧急支援,是各国军队在和平时期的重要使命。目前中国军队还没有成建制地出国参加过重大自然灾害的国际救援。本文介绍了联合国重大自然灾害国际救援行动协调工作机制、联合国框架下的军队资源参与灾害救援的工作机制。结合印尼地震海啸、海地地震等灾害中各国军队救援的情况,对我国军队将来参与国际重大自然灾害救援,在法律、预案和工作机制准备方面进行了分析,并提出了建议。     

Probability-consistent spectrum and code spectrum

IntroductionInChina,thecombinationofseismicdesigncodewithzoningmapofseismicintensityorgroundmotionparametersisusuallyadoptedtodeterminetheseismicfortificationcriterionforthegeneralindustryandcivilbuildings.Thepresentproceduresareasfollows.Accordingtothepro-jectlocation,thedesignbasicaccelerationofgroundmotionandthedesigncharacteristicperiodofresponsespectrumareobtainedfromthezoningmapofseismicgroundmotionparameters(GeneralAdministrationofQualitySupervision,InspectionandQuarantineofthePeople…     

中国油气页岩分布与存储潜能和前景分析

基于当今化石油气能源的需求还在扩展,它的紧缺势态波及全球,而我国的确需要更多的页岩油气.为此,非常规油气能源,特别是页岩油气的勘探、开发和利用就必然地提到社会进步和经济发展的议程上,并得到世界各个国家的高度重视.因此,页岩油气现已成为我国能源界和科技界及政府部门的热门话题.在经过了一段时间的"热炒"和依据尚不充分的评估后,本文通过对中外有关资料的分析和讨论认为:1)必须在了解世界各国、特别是北美页岩油气赋存与开发的条件下,认识我国页岩的分布状态和页岩油气潜能;2)在理解其它国家页岩属性、页岩油气的前景和勘查及储存背景下,在我国较全面的进行页岩和页岩油气存储的勘探和对其进行要素匹配,并选择远景好的典型地区进行示范研究与探索;3)集理念与实践综合研究制定页岩油气在我国的发展方案和路线图.     

Spatial and temporal controls on historical channel responses – study of an atypical case: Someşu Mic River,Romania

In this paper the spatial and temporal responses of the Some?u Mic River (Romania) to natural and anthropogenic controls over the past 150 years are analysed, based on a series of morphometric parameters extracted from five successive sets of topographic maps and one set of orthophotos. Prior to the intensive hydrotechnical interventions of the last four decades, the river was characterized by a complex alternation of different channel types, resulting in a mixture of alluvial and mixed sinuous – meandering – sinuous anabranched – meandering anabranched reaches, each a few hundred metres to a few kilometres long. The main cause for this spatial behaviour was the local geology. Its effects were intensified by a larger scale slope, slightly higher than along a longitudinal profile with normal concavity, as a consequence of the presence of a 400 m elevation knick‐point located in the catchment area. A generalized maintenance of river in the floodplain perimeter during the entire interval of study (centennial scale), with local planform adjustments and lack of median scale avulsion in lateral tilting areas and along the anabranched reaches, channel lengthening and meander development during hydrological stable periods and channel shortening and increasing of natural cutoffs during periods with higher incidence of floods (decadal scale), and the incapacity of local morphologic changes resulted from human interventions to completely counterbalance general trends (decadal scale), supports the idea of decreasing the amplitude and frequency of important floods, after the end of the Little Ice Age. Channel metamorphosis by canalization, diminishing/elimination of overflows and medium‐scale avulsions by changes in flow regimes (dams) and the presence of dykes in the floodplain perimeter, channel narrowing (43%) and incision (at least after 1945) downstream from dams, and probably because of in‐channel gravel mining are the main anthropically induced changes along the Some?u Mic River. Even if human impact is important, both at the drainage basin scale and along the Some?u Mic River, it has only local impacts, subordinated to climate. The low level of human impact on this river could be the consequence of the higher general slope downstream from 400 m elevation knick‐point, which probably forces the positioning of its effects under an important internal threshold of the fluvial system. This boundary condition defines Some?u Mic River as an atypical river. This study supports the idea that climate has a more important role in the post‐Little Ice Age (LIA) rivers' behaviour than currently accepted. Copyright © 2011 John Wiley & Sons, Ltd.