山区年、月平均温度推算方法的研究   总被引：9，自引：0，他引：9  

卢其尧 《地理学报》1988,(3)

本文提出了山区年、月平均温度空间分布的推算方法,并提供了相应的小地形温度订正值。该方法在福建省沙溪流域山区实际应用的结果表明,能有效地揭示山区年、月平均温度空间分布的宏观与微观变化,效果满意,精度较高。  相似文献   

青海湖沉积物中的粘土矿物   总被引：5，自引：0，他引：5       下载免费PDF全文

徐昶  林乐枝 《地质科学》1989,5(4):348-354

本文对青海湖沉积物中的粘土矿物和沉积环境进行了初步研究。沉积物的粒度成分一般以粉砂级为主,湖周沉积物较粗,湖内沉积物较细。湖中粘土矿物以伊利石-绿泥石为主,含少量蒙脱石和高岭石等。沉积物表层未见蒙脱石,粘土中Al₂O₃、K₂O和MgO的相对百分含量的特征与海粘土的化学成分特征相似。  相似文献   

Subfossil and modern diatom plankton and the paleolimnology of Rotsee (Switzerland) since 1850     

André F. Lotter 《Aquatic Sciences - Research Across Boundaries》1989,51(4):338-350

The diatom biostratigraphy of the topmost sediment meter of Rotsee, Central Switzerland, is characterized by a major change fromCyclotella comensis-dominated toStephanodiscus hantzschii/S. parvus-dominated assemblages. A comparison between old phytoplankton samples, taken between 1910–1930, and subfossil diatom assemblages is used for dating the upper 35 cm of the core. There is evidence that the change in dominant diatoms occurred in 1919/20, thus before the opening of an artificial inlet in 1922, and is due to increasing eutrophication. Furthermore, the sedimentary carbonate content can be used as a good indicator for past phytoplankton productivity in Rotsee.  相似文献   

Annual heat balance and equilibrium temperature of Lake Aegeri,Switzerland   总被引：1，自引：0，他引：1  

David M. Livingstone  Dieter M. Imboden 《Aquatic Sciences - Research Across Boundaries》1989,51(4):351-369

The mean heat budget of Lake Aegeri, Switzerland, is 950 MJ·m^–2, comparable to that of neighbouring lakes. The annual variation in the net heat flux can be adequately described using a six-term heat balance equation based on 12 years of monthly mean meteorological and surface temperature data. Although the magnitude of the net heat flux is dominated by the radiative terms of the equation, the one-month backward shift of the net flux and total heat content extrema from the solstices and equinoxes respectively is due to the phase shift of the non-radiative with respect to the radiative terms. A linear approximation was used to express the net heat flux in terms of a heat exchange coefficient and an equilibrium temperature. The former varies from 17 to 28 W·m^–2·K^–1 in the course of a year; fluctuations in the latter are found to depend mainly on fluctuations in cloud cover and relative humidity, whilst the effect of fluctuations in air temperature and wind speed is slight.  相似文献   

漳州地热普查区地球化学异常的讨论     

戴仲鸿  郭永祥  杨金城 《地球科学》1988,(3)

本文以漳州热田为例,通过对该区的地质及构造特征、地下热水分布、水化学特征及土壤地球化学异常的分析对照,论证了化探工作在地热勘查中的应用效果。同时,对热田的化探异常成因进行了初浅的探讨。  相似文献   

Areal extent of the 1988 flood in Bangladesh: How much did the satellite imagery show?     

Harun Rasid  M. A. H. Pramanik 《Natural Hazards》1993,8(2):189-200

This paper presents the methods and results of visual interpretation of satellite imagery for estimating areal extent of the 1988 flood in Bangladesh. The main limitation of this method was that cloud-free images were not available for the peak flood period in the first week of September. Relatively cloud-free images on three selected dates in the last three weeks of September showed that areas of inundation on those dates ranged from 44000 to 60000 km² ± 5% (31 to 42% of Bangladesh). The Government of Bangladesh official estimates of the areal extent of flooding were tentative in nature, since these were based on a choropleth map of relative proportions (percentages) of flooding in different parts of the country. The official estimate of the maximum extent of flooding was 82000 km² (57% of Bangladesh), i.e. 15 to 26% larger than the area shown on satellite imagery. The actual extent of flooding was certainly larger than the estimates from satellite imagery but, perhaps, smaller than the official estimates, since a reduction of 15 to 26% of flood area in one to three weeks seemed unlikely. An alternative method of mapping flood-affected areas by using newspaper-interpreted data was attempted, but the method had limited values because of reporting bias.  相似文献   

宁芜地区三个辉长岩的全岩和矿物Rb-Sr等时线年龄   总被引：9，自引：0，他引：9       下载免费PDF全文

徐祥  邢凤鸣 《地质科学》1994,(3):309

 从南京到芜湖有许多辉长岩体分布,如南京蒋庙岩体、高古山岩体、大栏杆岩体,马鞍山阳湖塘岩体,当涂姑山岩体和芜湖市区的辉长岩体等。  相似文献   

Discussion on the Relation Between the Probabilistic Distribution of Magnitude in a Seismic Province and That in an Area with Potential Seismic Source     

Gao MengtanInstitute of Geophysics  SSB  Beijing  China 《中国地震研究》1994,(3)

According to the joint probabilistic distribution model of magnitude and space,the author discusses the relationship between the probabilistic distribution of magnitude in a seismic province and that in an area with potential seismic sources.The results show that if the magnitude probabilistic distribution follows the truncated exponential form in a seismic province,there must be some potential source in which the magnitude probabilistic distribution does not conform to that form.The result is consistent with the concept of "characteristic earthquake" derived from the study of actual records of seismicity and the study of geology.The author suggests that the relationship between the probabilistic distribution of magnitude in a seismic province and that in a seismic potential area must be considered in the study of the analysis of seismicity,seismic zonation and engineering seismology,for the purpose of the evaluation of the probabilistic distribution of magnitude correctly in every area with potential s  相似文献   

江淮地区北部晚太古宙TTG质片麻岩   总被引：5，自引：1，他引：5  

涂荫玖 《安徽地质》1994,(4)

江淮地区北部的灰色片麻岩是深成侵入的英云闪长岩－奥长花岗岩－花岗闪长岩，以高铝型为主，具弱的负Ｅｕ异常或不明显。从英云闪长岩到奥长花岗岩，ＴｉＯ＿２、ＦｅＯ、Ｃａ０、ＭｇＯ减少，而稀土元素分馏程度增加。形成于晚太古宙华北陆台南东大陆边缘挤压的构造环境下，由斜长角闪岩部分熔融而成。  相似文献   

桐城桐山－庐江大化下古生界飞来峰及其地质意义     

汪来利  刘贻灿  石永红 《安徽地质》1994,(Z1)

桐城桐山－庐江大化的飞来峰位于早白垩世杨湾组（Ｋ＿１ｙ）弱变形的紫红色陆相碎屑岩之上，由下古生界的硅化粗晶灰岩，白云质灰岩及硅质岩组成，岩层强烈碎裂。其中伴生的张裂隙及剪切石香肠指示岩层由南东向北西逆冲。这一飞来峰的形成与郊庐断裂南段平移作用产生的次级逆冲有关。是由此产生的推覆体差异剥蚀的结果，这种次级逆冲推覆作用发生在扬子板块前陆褶冲带的变形之后。  相似文献