南盘江坳陷石炭系层序地层格架及古地理环境   总被引：6，自引：0，他引：6  

赖生华  陈洪德 《云南地质》2004,23(2):233-240

南盘江坳陷石炭系划分为12个三级层序。其中下石炭统、上石炭统分别包含5个和7个三级层序,每个三级层序平均延时6Ma。按界面性质可将三级层序划分为5个Ⅰ型层序和7个Ⅱ型层序。上述十二个三级层序构成二个超层序(二级层序)。超层序内部的三级层序发育齐全,其最顶部的一个三级层序(WQ12)处于石炭系．二叠系过渡层。SS1低水位时期,右江地区为台-盆相间古地理格局,钦防地区的海盆则有所缩小;海侵时期盆地内部成为统一的台地和盆地,而高水位体系域沉积期则台地扩大,台盆缩小。SS2海侵时期,南盘江坳陷再一次分化成台．盆相间地理环境,高水位体系域沉积期则表现为水体变浅,岸线向盆地方向迁移。  相似文献   

中国泥石流形成环境剖析   总被引：2，自引：0，他引：2  

杜榕桓  段金凡 《云南地理环境研究》1990,2(2):8-18

丰富的松散固体物质、充沛的水源和陡峻的地形,作为泥石流形成的三个基本条件,已得到学者们的认同。就本质而言,这三者可归纳为能量和物质两大因素。本文从中国泥石流区域分布着眼,从不同尺度的自然环境因素和人为活动,探讨中国泥石流形成发展的基本规律。研究结果表明,大尺度的区域地质背景、大地貌单元和犬气候系统是控制泥石流形成发育的主导因素;不稳定斜坡因子、小尺度水文气象因子、流域形态因子、森林植被因子等,在大尺度因素的基础上,对泥石流的形成有重要影响;历史上,特别是近期人类经济活动对环境的不良影响,加剧了泥石流的发展。泥石流灾害非单一因子所致,而是诸多因子综合作用的结果,是山地环境退化的产物。泥石流活动具有开放性、内外营力作用的共同性以及自然因素和人为因素的复合性这三大特点。  相似文献   

多媒体技术在新疆地理环境查询系统中的应用     

王建忠 《沙漠与绿洲气象(新疆气象)》2005,28(1):24-26

应用计算机多媒体技术建立的《新疆地理环境》，包括新疆境内气候概况、水文、地貌、植被及交通等内容，它将图形、图像、文字、声音、视频、动画等媒体元素集于一身，实现人机的最佳结合，为有关部门和气象业务人员提供一个多角度、多方位的辅助查询平台。  相似文献   

中甸晚三叠世图姆沟组岩石化学与构造环境   总被引：9，自引：0，他引：9  

黄建国  张留清 《云南地质》2005,24(2):186-192

本文对中甸东部晚三叠世图姆沟组深水浊积岩和弧火山岩、微量和稀土元素进行研究,投点多落入再旋回造山带物源区;微量和稀土元素与图解中多接近大陆岛弧区;常量元素分析与相关图解接近活动大陆边缘和大陆岛弧环境,与火山岩的大地构造环境具有相同的结论。图姆沟组为甘孜—理塘洋盆向西俯冲消减,中甸褶皱带东缘由被动大陆边缘转化为活动大陆边缘过程中形成的岛弧火山—沉积岩系。  相似文献   

Depositional Environments and Diagenesis of the Kuldhar and Keera Dome Carbonates (Late Bathonian–Early Callovian) of Western India     

A.H.M. Ahmad  G.M. Bhat  M. Haris Azim Khan 《Journal of Asian Earth Sciences》2006,27(6):765-778

This paper describes 11 microfacies types in late Bathonian–Early Callovian carbonates of the Kuldhar Member of the Jaisalmer Formation (Rajasthan) and the Keera Golden Oolite Member of the Chari Formation (Kachchh Mainland) western India. The different microfacies associations reported in this study reflect an ideal shallowing upward sequence, representing a system of bioclastic bars developed on the lower ramp, evolving into an oolitic bar-to-bank system separating restricted lagoonal—from lower ramp environment. Four main types of cements, i.e. bladed, fibrous, syntaxial overgrowth and blocky cement (characterized in a few cases by ferroan calcite and anhydrite II) occur in these carbonates. The study also reveals that chemical compaction followed the two phases of early mechanical compaction that largely governed porosity of these limestones. However, micritization and neomorphism also contributed significantly in this respect. Diagenetic signatures in these carbonates suggest that marine phreatic and fresh water phreatic environments dominated, but deep burial diagenesis also played its role in shaping these rocks. The early and late diagenetic changes have been controlled by the depositional facies evolving in a basin riddled with rifting in an extensional tectonic regime forcing regional-scale sea level fluctuations.  相似文献   

Conservation planning in the west, problems, new strategies and entrenched obstacles     

Stephanie Pincetl 《Geoforum》2006,37(2):246-255

The United States is often considered the progenitor of conservation planning in the world, the first to establish a vast public domain, for example. But with continued population growth, conservation planning on private lands—rural and at the urban fringe—continues to be a substantial challenge due to a tradition of local home rule in land use planning and strong private property protection afforded by the US Constitution. New “bottom-up” collaborative approaches, as well as other innovative strategies seem to be emerging. How effective these will be given pressures for growth and high property values remain to be seen without a rethinking of ideas of nature, a rebalancing of the role of property in American local fiscal regimes, and of private property rights.  相似文献   

杭嘉湖平原全新世沉积环境的演变   总被引：24，自引：1，他引：24  

严钦尚  黄山 《地理学报》1987,(1)

通过分析钻孔资料了解,杭嘉湖平原全新世沉积之下,有两层硬土层。上层硬土层的顶板为本区全新世沉积的下限。晚更新世末,本区为缓起伏的丘陵、台地。南缘为古钱江谷地;西侧(湖州至杭州之间)为古钱江的一条支谷,呈南北向。在这个基础上,全新世早、中期海侵时南缘成为海湾,西侧为河口湾。海侵最盛期时,全区除小块区域外,多属潮坪或潟湖。全新世晚期,西侧的河口湾淤浅阻塞,全区被淤积为淡水湖沼平原。  相似文献   

湘江水系河水的地球化学特征   总被引：14，自引：1，他引：14  

张立成  赵桂久  董文江  李健  曾北危 《地理学报》1987,(3)

本文讨论了湘江水系河水一些主要水化学指标的特征及其环境化学效应,计算了河水的化学稳定性指数和化学侵蚀速率,讨论了该水系重碳酸盐型河水的侵蚀及沉积平衡与总盐量的相关关系,还论证了河水的地球化学特征与水热条件和地质因素的关系。  相似文献   

全球环境基金第七增资期政策分析与预测     

陈兰  王文涛  李亦欣  朱留财 《气候变化研究进展》2018,14(2):201-209

根据全球环境基金(GEF)已公布的改革方案和增资谈判进程,结合当前国际政治经济形势,分析预测了GEF第七增资期(2018年7月至2022年6月)资金规模与规划改革方向。预计GEF-7资金规模较大可能在41亿~44亿美元之间,比上期减少0~7.5%。同时,GEF改革将继续向实现全球环境效益最大化、降低新兴发展中国家受援资金量、提高对最不发达国家资金支持、吸引私营部门参与及完善治理结构等方向纵深推进。作为GEF最大受援国和发展捐资国,尽管中国在GEF-7仍将保持受援国地位,但受GEF政策改革影响,即使在GEF-7增资规模与上期持平的情景下,中国国别资金分配量预计也将在GEF-6的基础上下调至1.43亿~1.59亿美元,同时未来中国在GEF资金规划、项目设计、捐资规模等方面亦须做出相应调整。为不断提升与GEF合作水平及效果,当前阶段中国宜在密切跟踪并积极参与GEF-7增资谈判进程的基础上,统筹考虑、提前谋划、综合研究,推动GEF改革向符合中国及广大发展中国家利益的方向发展。  相似文献   

A typology of adaptation actions: A global look at climate adaptation actions financed through the Global Environment Facility     

《Global Environmental Change》2014

Climate change impacts threaten existing development efforts and achieving future sustainability goals. To build resilience and societal preparedness towards climate change, integration of adaptation into development is being increasingly emphasized. To date, much of the adaptation literature has been theoretical, reflecting the absence of empirical data from activities on the ground. However, the Funds established under the United Nations Framework Convention on Climate Change and managed by the Global Environment Facility, the Least Developed Countries Fund, the Special Climate Change Fund and the Strategic Priority for Adaptation, have approved financing for 133 adaptation projects in 70 countries with sufficient documented experience to allow for initial categorization and evaluation. This article provides the first substantial compendium of adaptation actions identified through the allocation and disbursement of these Funds and organizes these actions into a generalized typology of adaptation activities. The information obtained sheds new insight into what adaptation is, in practice, and suggests some next steps to strengthen the empirical database. Ten types of overarching adaptation activities were identified through an analysis of 92 projects financed through these Funds. This paper analyzes these adaptation activities and compares them with theoretical constructs of adaptation typologies. We find that many of the early ideas and concepts advanced by theoreticians are consistent with results from the field. The adaptation categories that recur the most in Global Environment Facility projects are enabling and relatively inexpensive measures, such as those related to capacity building, policy reform, and planning and management. However, a rich panoply of technical actions ranging from information and communications technology, to early warning systems, to new or improved infrastructure, are also identified as common project goals. Future refinements of the costs of various adaptation actions, the mixture of technical and management options, and evaluating the efficacy of actions implemented, will be key to informing the future global adaptation agenda.  相似文献