Temperature and precipitation fluctuations in the Czech Republic during the period of instrumental measurements   总被引：2，自引：0，他引：2  

Rudolf Brázdil  Pavel Zahradní?ek  Petr Pi?oft  Petr ?těpánek  Monika Bělínová  Petr Dobrovolny 《Theoretical and Applied Climatology》2012,110(1-2):17-34

The history of early meteorological observations using instruments in the Czech Lands is described (the longest temperature series for Prague-Klementinum starts in 1775, precipitation series for Brno in 1803). Using the PRODIGE method, long-term monthly temperature and precipitation series from selected secular stations were homogenised (for 10 and 12 stations, respectively). All the seasonal and annual temperature series for the common period 1882–2010 show a significant positive linear trend with accelerated warming from the 1970s onwards. No significant linear trends were disclosed in the series of seasonal and annual precipitation totals. Correlation coefficients between the Czech series analysed decrease as distances between measuring stations increase. A sharper decrease of correlations for precipitation totals displays much weaker spatial relationships than those for mean temperatures. The highest correlations between all stations appeared in 1921–1950, the lowest in 1891–1920 (temperature) and 1981–2010 (precipitation). Wavelet analysis reveals that very distinct annual cycles as well as the slightly weaker semi-annual ones are better expressed for temperature series than for precipitation. Statistically significant cycles longer than 1?year are temporally unstable and sporadic for precipitation, while in the temperature series cycles of 7.4–7.7 and 17.9–18.4?years were recorded as significant by all stations in 1882–2010 (quasi-biennial cycle of 2.1–2.2?years for half the stations). Czech homogenous temperature series correlate best with those of the Northern Hemisphere for annual, spring and summer values (with significant correlation coefficients between 0.60 and 0.70), but this relation is temporally unstable. Circulation indices, such as the North Atlantic Oscillation Index (NAOI) and the Central European Zonal Index (CEZI), may explain the greater part of Czech temperature variability, especially from December to March and for the winter; however, this relationship is much weaker, or even random, for precipitation series. Further, relationships with the Southern Oscillation Index (SOI) are weak and random. Relatively weak coincidences exist between statistically significant cycles in the Czech series and those detected in NAOI, CEZI and SOI series.  相似文献   

塔里木盆地克拉2气田白垩系储层沉积相   总被引：19，自引：6，他引：13  

贾进华  顾家裕  郭庆银  皮学军  王月华  邹义声 《古地理学报》2001,3(3):67-75

克拉2气田是我国陆上勘探发现的最大气田,它的发现奠定了塔里木盆地做为我国 “西气东输” 重要天然气基地的资源基础。克拉2气田产层主要为下白垩统巴什基奇克组砂岩、下第三系库姆格列木群底砂岩和白云岩,其中下白垩统巴什基奇克组砂岩储层厚度为220.3-285.2m,孔隙度为1.1-22.4%,平均12.83%;渗透率为0.004-1770.1×10-3μm2,平均51.46×10-3μm2。砂岩储层以剩余原生粒间孔为主。通过钻井和露头剖面沉积相对比,克拉2气田巴什基奇克组第三段为扇三角洲前缘沉积,主要微相有水下分流河道、水下重力流和浅湖泥等,岩性以砂砾岩、含砾砂岩和褐色泥岩为主;第二段为辫状河三角洲前缘沉积,主要有水下辫状河道、河口砂坝和分流间湾等微相,以棕褐色中细砂岩夹薄层泥岩为主;第一段为辫状河三角洲平原沉积,主要有远端辫状河道和分流间湾微相,以棕褐色中细砂岩为主。巴什基奇克组沉积时期,古气候以干旱炎热为主,北部发育多个扇体,在平面上相互连接、叠置形成多个物源出口,形成了一系列由辫状河道组成的辫状河三角洲,而非单一辫状河流形成的沉积体,从而形成大面积分布的稳定砂体。沉积微相对比表明,巴什基奇克组储层是由互相切割的多个辫状河道砂体叠置而成,各段微相在横向上分布十分稳定,各砂体互相连通、连续性好,泥岩夹层薄、不连续,空间上具有厚度大、分布广、连续性好、物性好和隔夹层少的特点,为一套优质天然气储层。  相似文献   

洞庭盆地第四纪沉积环境演变的初步分析   总被引：15，自引：2，他引：15  

皮建高  张国梁  梁杏  张人权 《地质科技情报》2001,20(2):6-10

利用水流能量指数，分析了洞庭盆地第四纪沉积环境的演变特征。得出洞庭盆地主要为河流－过流型湖泊相互消长的沉积环境。沉积环境的演变及主要水流方向，受差异性构造沉降的控制。历史时期，人为作用对盆地沉积环境影响很大，并且是近代洞庭湖区洪灾加剧的主要原因。  相似文献   

洞庭盆地第四纪构造活动特征   总被引：17，自引：0，他引：17  

梁杏  张人权  皮建高  张国梁  孙锡良 《地质科技情报》2001,20(2):11-14

利用沉积等厚线图，分析得出的洞庭盆地第四纪构造活动特征如下：北北东及近东西向两组断裂将盆地切割为一系列断块；盆地西部为箕状断块，东部为箕状凹陷、早、中更新世为盆地的断陷阶段，晚更新世以来进入坳陷阶段；第四纪以来构造沉降速率呈加速度增强；构造活动的时空变化控制着洞庭湖的演变。  相似文献   

MgO活性及其在MgCl2溶液中溶度的研究   总被引：6，自引：0，他引：6       下载免费PDF全文

朱黎霞  夏树屏  邢丕峰  高世扬 《盐湖研究》2002,10(2):18-23

测定了不同MgO的碘值和比表面积 ,给出了MgO活性与煅烧温度之间的关系式。研究了MgO活性、煅烧温度、溶解温度和MgCl2 浓度等对MgO溶解的影响。并讨论了活性MgO在含不同硼碱比 [n(B2 O3) :n(MgO) =n]的MgCl2 溶液中形成硼酸镁盐过饱和溶液与增溶的MgO关系。  相似文献   

模糊综合评判在洞庭湖区工程地质环境质量评价中的应用     

皮建高 《湖南地质》1992,11(2):157-162

基本地震烈度、饱和砂土振动液化的可能性、土体允许承载力和压缩模量及洪水威胁性等,是影响洞庭湖区工程地质环境质量的5个主要参评因子,据此本文运用模糊综合评判方法,对洞庭湖区的工程地质环境质量进行了综合评价。  相似文献   

黑龙江省季节冻土形成发育规律及特征   总被引：2，自引：0，他引：2  

石剑  王育光  杜春英  王萍  杨晓强 《黑龙江气象》2003,(3):35-38

在黑龙江省均有季节冻结和季节融化现象发生，多年冻土区有季节融化层，季节冻结层主要分布在多年冻土区以外的地区。按季节冻结类型可把黑龙江省季节冻土分为过渡型、半过渡型、长期稳定型和稳定型等类型。季节冻结和融化深度在年际间有很大的差异，在多年冻土区南界附近，季节冻深年际间变化最大。土季节冻结和融化的影响因素主要有雪盖、植被、土壤成分及含水量、地表状况和地形等。  相似文献   

Summer Floods in Central Europe – Climate Change Track?     

Zbigniew W. Kundzewicz  Uwe Ulbrich  Tim brücher  Dariusz Graczyk  Andreas Krüger  Gregor C. Leckebusch  Lucas Menzel  Iwona Pińskwar  Maciej Radziejewski  Małgorzata Szwed 《Natural Hazards》2005,36(1-2):165-189

In Central Europe, river flooding has been recently recognized as a major hazard, in particular after the 1997 Odra /Oder flood, the 2001 Vistula flood, and the most destructive 2002 deluge on the Labe/Elbe. Major recent floods in central Europe are put in perspective and their common elements are identified. Having observed that flood risk and vulnerability are likely to have grown in many areas, one is curious to understand the reasons for growth. These can be sought in socio-economic domain (humans encroaching into floodplain areas), terrestrial systems (land-cover changes – urbanization, deforestation, reduction of wetlands, river regulation), and climate system. The atmospheric capacity to absorb moisture, its potential water content, and thus potential for intense precipitation, are likely to increase in a warmer climate. The changes in intense precipitation and high flows are examined, based on observations and projections. Study of projected changes in intense precipitation, using climate models, for several areas of central Europe, and in particular, for drainage basins of the upper Labe/Elbe, Odra/Oder, and Vistula is reported. Significant changes have been identified between future projections and the reference period, of relevance to flood hazard in areas, which have experienced severe recent floodings.  相似文献   

Longitudinal effects of ionospheric responses to substorms at middle and lower latitudes: a case study     

Xiaoqing Pi  Michael Mendillo  Paolo Spalla  David N. Anderson 《Annales Geophysicae》1995,13(8):863-870

An ionospheric model is used to simulate total electron content (TEC) disturbance events observed at middle and lower latitude sites near 75○W and 7○E longitudes. Within this longitudinal range, daytime TEC disturbances show patterns that are correlated with substrom activity seen in both auroral electrojet and ring current behavior. In modeling studies of the observed ionospheric effects, both electric field and neutral wind perturbations are examined as possible mechanisms. The morphological features of the required electric field perturbations near drawn and dusk are compared with those at other times to examine the local time characteristics of magnetospheric influence. Large-scale traveling atmospheric disturbances (TADs), an alternative candidate for the disturbance source, are also characterized and compared with known thermospheric behavior.  相似文献   

    

Teresa Pi  Jesús Solé  Yuri Taran 《Mineralium Deposita》2006,41(3):300

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