基于自动气象站资料的宜昌城市热岛分析     

毛成忠  张明  刘云鹏  张丽文  肖刚 《沙漠与绿洲气象(新疆气象)》2021,15(1):103-110

利用23个自动气象站2009—2018年逐小时气温资料,分析了宜昌城市热岛效应的时空演变,结果显示:(1)近10 a平均热岛强度为1.4℃,呈-0.172℃/10 a的缓慢减弱趋势.近10 a夏季平均热岛强度为1.5℃,呈0.017℃/10 a的缓慢增强趋势.(2)热岛强度日变化是早晨到中午迅速减弱,午后至傍晚逐渐加强...  相似文献   

浅析宜昌磷矿开发中存在的问题及对策   总被引：5，自引：0，他引：5  

李锦文 《化工矿产地质》2000,22(3):183-187

宜昌磷矿资源量大、品位高。经过 30余年的发展 ,已成为该地区经济收入的重要来源之一。但在开发中仍存在矿山规模过小过滥 ,设备利用率低 ,建设资金浪费 ,采富弃贫 ,资源严重浪费 ;产品附加值低 ,可持续发展后劲泛力 ;矿业秩序混乱 ,安全陷患多 ;生态环境严重被破坏等问题。针对存在问题应采取的对策为缩小开采规模 ,提高产品附加值 ;减少矿山生活服务设施投入 ,增加矿山企业的生产规模 ;减少村办、个体小矿山 ,坚持国有矿山的主导地位以及加强区域间合作 ,走矿肥集合与矿化集合的道路等。  相似文献   

Paleoecology of Early Ordovician Reefs in the Yichang Area, Hubei: a Correlation of Organic Reefs Between Early Ordovician and Jurassic     

XIAO Chuantao  LI Meng  YANG Wei  HU Mingyi  LI Chao 《《地质学报》英文版》2011,85(5):1003-1015

The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the research area. The reefs have different thicknesses ranging from 0.5 m to 11.5 m and lengths varying from 1 m to 130 m. The reef-building organisms include Archaeoscyphia, Recepthaculitids, Batostoma, Cyanobacteria and Pulchrilamina. Through the research of characteristics of the reef-bearing strata of the Early Ordovician in the Yichang area, four sorts of biofacies are recognized, which are (1) shelly biofacies: containing Tritoechia-Pelmatozans community and Tritoechia-Pomatotrema community; (2) reef biofacies: including the Batostoma, Calathium-Archaeoscyphia, Pelmatozoa-Batostoma, Archeoscyphia and Calathium-Cyanobacteria communities; (3) standing-water biofacies: including the Acanthograptus-Dendrogptus and Yichangopora communities; and (4) allochthonous biofacies: containing Nanorthis-Psilocephlina taphocoense community. The analysis of sea-level changes indicates that there are four cycles of sea-level changes during the period when reef-bearing strata were formed in this area, and the development of reefs is obviously controlled by the velocity of sea-level changes and the growth of accommodation space. The authors hold that reefs were mostly formed in the high sea level periods. Because of the development of several subordinate cycles during the sea-level rising, the reefs are characterized by great quantity, wide distribution, thin thickness and small scale, which are similar to that of Juassic reefs in northern Tibet. The research on the evolution of communities shows that succession and replacement are the main forms. The former is favorable to the development of reefs and the latter indicates the disappearance of reefs.  相似文献   

长江三峡黄陵花岗岩与莲沱组凝灰岩的锆石SHRIMPU—Pb年龄及其构造地层意义     

高维  张传恒 《中国区域地质》2009,(1):45-50

华南古陆普遍发育新元古代花岗岩,其时代、成因及其对华南新元古代的构造演化具有标识意义。该类型的花岗岩与华南克拉通的破坏及雪球事件的启动相关,其年代学研究一直备受关注,高质量的锆石SHRIMPU—Pb定年是确定其相互关系的基础。黄陵花岗岩体中的岩浆锆石的SHRIMPU—Pb加权平均年龄为837Ma±7Ma,另获得莲沱组顶部层凝灰岩较年轻的一组岩浆锆石SHRIMPU—Pb加权平均年龄724Ma±12Ma。前者表明黄陵花岗岩与桂北的三防、元宝山和云南的峨山花岗岩体侵位的时间相同,后者确定了莲沱组顶界的时代。这为确定南华系的年代地层学框架提供了重要的科学依据。  相似文献   

宜昌地区砾石层的磁性特征与物源分析   总被引：6，自引：3，他引：3       下载免费PDF全文

张勇  张玉芬  李长安  李庭  雷文大 《第四纪研究》2009,29(2):380-386

分布于宜昌-宜都-鸦鹊岭-枝江一带的宜昌砾石层,是江汉平原边缘丘陵区厚度最大的第四纪沉积物,对地层划分、环境演化及长江形成等研究具有十分重要意义。通过对代表该砾石层完整沉积序列的善溪窑剖面（上段）、云池剖面（中段）与李家院剖面（下段）的磁学特征分析发现,从云池剖面距底部9m处向上,磁化率和磁化参数F_300mT等均明显高于其下部分,具体为：  1）下部磁化率平均值为28×10^-8 m³/kg,而上部磁化率平均达到17010^-8 m³/kg;   2）云池剖面距底部9m处以上主导砾石层剖面磁性特征的物质以低矫顽力的亚磁铁性矿物为主,而以下却含有更多的高矫顽力磁性矿物(如赤铁矿);   3）善溪窑和云池砾石层的亚磁性物质颗粒要粗于李家院样品。初步分析认为,上述磁性差异主要是物源变化引起的,距云池剖面底部9m以下的砾石层物源主要为鄂西山地,从云池剖面9m开始有四川以西的物质进入江汉平原,表明此时三峡已经贯通。根据已有的测年资料,推测长江贯通三峡的时间大约为1.0～1.1MaB.P.。  相似文献   

Quaternary sediment in the Yichang area: Implications for the formation of the Three Gorges of the Yangtze River   总被引：8，自引：0，他引：8  

Fang Xiang  Lidong Zhu  Chengshan Wang  Xixi Zhao  Hongde Chen  Wenguang Yang 《Geomorphology》2007,85(3-4):249

Sediment data from the Yichang area in the Jianghan Basin of Hubei Province in China suggest deposition in a lacustrine environment prior to 0.75 Ma, B.P., followed by incision of the Yangtze River. The earliest Quaternary Yunchi Formation accumulated in an alluvial fan to fan-delta environment. The subsequent Shanxiyao Formation was deposited in an environment that changed from fan-delta to lacustrine. The distribution of sedimentary facies suggests the presence of a lake in the Yichang area prior to 0.75 Ma, B.P. The lack of sediments contemporaneous with the Yunchi and Shanxiyao Formations in other areas of the Jianghan Basin, suggests that this ancient lake was limited to the Yichang area. This lake predates the present Yangtze River in the Yichang area and the Jianghan basin. Provenance studies of gravels in the Yunchi and Shanxiyao Formations, as well as gravels in terraces and the channel of the Yangtze River indicate a variety of sediment sources, but suggest that no material from the area west of the Three Gorges had been carried into the Yichang area prior to 0.75 Ma, B.P. The Yangtze River cut through Three Gorges area only after 0.75 Ma, B.P.  相似文献   

三峡宜昌地区降水、土壤水、地表水的酸化研究   总被引：2，自引：0，他引：2  

翁建华  黄连芬  朱渝生 《水文》2002,22(4):11-14

研究了三峡宜昌地区降水、土壤水、地表水的水质,从土壤的酸中和能力、水体的酸中和能力、主要离子组分着手,研究了受酸雨影响的土壤的酸化、水体的酸化。研究结果表明,宜昌地区的酸雨比较严重,土壤和水体都有轻微酸化的迹象。  相似文献   

湖北省宜昌县震旦系南沱组成因的新认识   总被引：5，自引：0，他引：5       下载免费PDF全文

张启锐 《地质科学》1995,30(2):147-152

在峡东王丰岗南沱组剖面上有一些杂砾岩透镜体和一些水道砂岩透镜体。这些是冰水环境的产物。在南沱组与莲沱组的界线上,见到了几个骑线砾石。这是冰陆环境的有力证据。由此可见,早期主要是冰陆环境,冰川刨蚀和剥蚀作用占主导,沉积作用是次要的。随着气温的回升,冰盖逐渐后退。当冰盖前沿退到研究区内,或刚退出本区时,就形成了本区冰期的主要沉积。因此,可以认为,本区南沱组杂砾岩主要是近源冰海相沉积。  相似文献   

湖北宜昌和南漳奥陶系大湾组笔石生物地层   总被引：4，自引：4，他引：0  

骆天天  张元动 《地层学杂志》2008,32(3)

根据宜昌陈家河剖面大湾组的笔石标本,确立笔石序列自下而上为:Didymograptellus eobifidus带、Corymbograptus deflexus带和Azygograptus suecicus带(大湾组下段),Exigraptus clavus带和Undulogr aptusaustrodentatus带(大湾组上段)。对湖北南漳的全家湾和李家湾两剖面的大湾组进行了详细采集测量,其中全家湾剖面大湾组下段自下而上识别出D.eobifidus带、C.deflexus带和A.suecicus带;李家湾剖面大湾组下段自下而上识别出D.eobifidus带和A.suecicus带,证实南漳大湾组的底界与宜昌地区基本一致。  相似文献   

宜昌第四纪砾石层钾长石主、微量元素物源研究及其地质意义     

林旭  刘海金  吴中海  刘维明  张洋  陈济鑫 《地质力学学报》2021,27(6):1024-1034

位于长江三峡出口的宜昌地区分布着一套第四纪砂砾石层,详细记录了区域内古环境变迁以及长江的形成与演化,但这些砾石层何时与长江上游物质建立物源关系一直存在较大争议。而钾长石是河流沉积物中常见的矿物,其地球化学元素组成在不同区域内存在显著差异,是进行河流物源对比研究的理想矿物。基于此,利用激光剥蚀电感耦合等离子质谱仪（LA-ICP-MS）对宜昌第四纪砾石层和宜昌以上长江流域开展碎屑钾长石原位主微量元素和主成分（PCA）分析,结合砾石层已发表的地层沉积年龄,综合区域内已发表的研究结果,系统对比分析宜昌砾石层与长江上游物质建立物源联系的时间,结果表明在1.15 Ma时宜昌砾石层和长江流域存在物源关系;在0.75 Ma时随着长江上游水系的拓展与调整,有新物源区的物质进入长江。这些物源变化现象,主要体现了1.2~0.7 Ma期间长江流域受东亚和南亚夏季风的气候影响出现的沉积过程。   相似文献