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131.
阿合勒-冲乎尔火山沉积盆地是一个以火山岩并伴有陆源和内源沉积物的堆积场所,即该区泥盆纪地层是以事件作用的产物为其主要成分特点。显然,对其古地理的恢复、相的划分采用传统的相序分析方法是不合适的。作者认为要阐明该区泥盆纪的古地理面貌,必须在区域地层研究基础上,综合分析各种相标志和沉积物的特点,寻求它们的物理成因和地质成因解。在这一过程中,相的动力学分析显得尤为重要。本文在上述学术思想指导下,把本区泥盆纪的相分为成因相和环境相两大类,并对其中的微相进行了详细的阐述,从而为把沉积学的原理和方法应用了火山岩的搬运机制和堆积环境研究中提供了先期研究实例,同时为研究和恢复该区以至整个新疆北部泥盆纪的古地理格局打下了坚实的基础。 相似文献
132.
133.
Geostatistical regionalization of glacial aquitard thickness in northwestern Germany, based on fuzzy kriging 总被引:1,自引:0,他引:1
In many instances hydrogeological parameters obtained by conventional methods for selected localities within an aquifer or an aquitard are not sufficient for adequate regionalization at the scale of the entire layer. Here, we demonstrate an application of the fuzzy kriging method in regionalization of hydrogeological data, in which the set of conventional, crisp values is supplemented by imprecise information subjectively estimated by an expert. It is believed that such an approach eventually may reflect the real-world conditions more closely than a traditional crisp-value approach, because the former does not impose exactness artificially on phenomena which are diffuse by their nature. Spatial interpolation was done for the thickness of one of the major aquitards (till and glaciolacustrine clay) in northwestern Germany. The dataset consists of 329 crisp values from boreholes supplemented by 172 imprecise values defined as fuzzy numbers. It is demonstrated that the reliability of regionalization was higher, compared to regionalization performed with the crisp dataset only. Fuzzy kriging was performed with FUZZEKS (Fuzzy Evaluation and Kriging System) developed at the Ecosystem Research Center at the University of Kiel. 相似文献
134.
浙江杭嘉湖平原区环境地球化学研究 总被引:3,自引:1,他引:3
根据杭嘉湖平原区区域地球化学调查结果,对本区开展了区域和城市(杭州市)环境质量评价的环境地球化学研究。研究结果表明,杭嘉湖平原区区域环境质量和杭州市区环境质量良好,各环境质量区较好的反映各区内工业生产水平、人口密集程度、历史长短。通过对杭州市不同环境质量区内蔬菜的分析研究证明,杭州市区污染区内有害元素尚未对人体健康产生影响,但为防止今后出现超标现象,应当高度重视,加强土壤环境保护。 相似文献
135.
地质雷达及其在环境地质中的应用 总被引:24,自引:2,他引:24
本文结合近几年联邦德国在环境地质方面的研究工作对地质雷达在环境工程领域中的应用范围及其局限性作了简要总结,文中并介绍了地质雷达技术的方法原理及存在问题。 相似文献
136.
西昆仑山南侧甜水海湖岩芯铁变化的环境记录 总被引:11,自引:0,他引:11
阐述了青藏高原西昆仑山南侧甜水海湖岩芯沉积物中氧化铁的丰度、频率分布和富集系数的变化规律。其丰度值范围FeO0.39%-3.95%,平均值为1.25%;Fe2O30.44%-8.09%,平均值为2.60%;Fe2O3/FeO0.21-3.60,平均比值1.12。说明该彻岩芯沉积物中铁平均丰度值较低,但其变化幅度较宽且清楚,在一定程度上反映了古气候环境具有较大幅度的波动。变异系数值表明,该湖岩芯沉积物中FeO的离散程度较Fe2O3大。大约距今23万年来氧化铁的沉积地球化学特征可划分出7个环境演化阶段,并基本上可与深海氧同位索阶段对比。揭示了甜水海湖演化与青藏高原强烈隆升引起的气候环境改变的密切关系。在距今23一15万年,沉积以河流相或冲积、洪积相为主,沉积环境以氧化环境为主导,气候以温干型波动;在距今15-7.4万年,沉积以湖相为主,沉积环境以还原环境为主导,气候以温湿型为主;在距今74万年以来,湖盆沉积环境多样化,沉积物以湖相和近源冲积、洪积相交替出现。气候出现冷湿、冷干、温湿和温干多种波动模式。这些资料分析初步认为甜水海古湖大约形成于距今15万年,即青藏高原第三成湖期,这也与青藏高原在距今15万年左右的再次构造隆升有关。 相似文献
137.
Y. -K. Tung K. -C. Yeh J. -C. Yang 《Stochastic Environmental Research and Risk Assessment (SERRA)》1997,11(2):145-171
Hydrologic regionalization is a useful tool that allows for the transfer of hydrological information from gaged sites to ungaged
sites. This study developed regional regression equations that relate the two parameters in Nash's IUH model to the basin
characteristics for 42 major watersheds in Taiwan. In the process of developing the regional equations, different regression
procedures including the conventional univariate regression, multivariate regression, and seemingly unrelated regression were
used. Multivariate regression and seeming unrelated regression were applied because there exists a rather strong correlation
between the Nash's IUH parameters. Furthermore, a validation study was conducted to examine the predictability of regional
equations derived by different regression procedures. The study indicates that hydrologic regionalization involving several
dependent variables should consider their correlations in the process of establishing the regional equations. The consideration
of such correlation will enhance the predictability of resulting regional equations as compared with the ones from the conventional
univariate regression procedure. 相似文献
138.
The Zoige Basin is located in the eastern margin of the Qinghai-Xizang Plateau, in which two cores, RH and RM, have been drilled,
with the depths of 120 m and 310 m respectively. The former with the bottom age of 826 kaB. P. has been divided into 21 stages
according to the multi-proxy analysis, which could be basically compared with the oxygen isotope record of deep-sea core.
The palaeoclimatic and palaeoenvironmental process of the Zoigê Basin over the past 900 kaB. P. is reconstructed, and the
comparison of core RH with the Luochuan Loess record is made. 相似文献
139.
Evolution of Quaternary groundwater system in North China Plain 总被引:4,自引:0,他引:4
Zonghu Zhang Dehong Shi Fuhong Ren Zhengzhou Yin Jichao Sun Cuiyun Zhang 《中国科学D辑(英文版)》1997,40(3):276-283
The Quaternary groundwater system in the North China Plain is formed mainly through the terrestrial water flow action on the
united geological and tectonic backgrounds. The analysis of groundwater dynamic field, simulation of groundwater geochemistry,
and the14C dating and extraction of isotope information have provided more evidence for recognizing and assessing the evolution of
groundwater circulation system and studying the past global changes. The exploitation and utilization of groundwater on a
large scale and overexploitation have given rise to the decline of regional groundwater level, change of flow field, decrease
of water resources and downward movement of saline water body. The water environment has entered a new evolution stage in
which it is intensely disturbed by the mankind’s activities.
Project supported by the National Natural Science Foundation of China. 相似文献
140.
陕西关中晚更新世黄土—古土壤序列特征及其记录的古环境变迁 总被引:7,自引:1,他引:7
陕西关中盆地的泾阳南塬和西安东郊席王晚更新世黄土剖面底部的S1古生境是由4层古土壤及与其相间的两层古土壤构成。这是目前发现的黄土高原晚更新世黄土,古土壤序列保存较好的剖面。两剖面的地层结构,磁化率曲线和地球化学组分反映出了12个温湿,冷干气候变化阶段可以归纳为6个气候变化旋回。 相似文献