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41.
在中欧地区的河谷、洪积扇、山坡坡麓及湖底常零星分布着更新世及全新世的碳酸盐沉积物。不少学者把碳酸盐沉积当作气候变化的产物并划分出其在中欧沉积的若干时期。笔者通过德国中部Leine河流域新老石灰泉华的详细研究对泉华沉积与气候直接联系的观点提出了新的见解。运用不同方法测年验证,得知研究区的石灰泉华沉积始于11000aB.P,随后石灰泉华在研究区不同地点连续沉积。岩芯上沉积的变化和石灰泉华层的消失应是由地貌过程所引起的泉水出露位置改变所致。 相似文献
42.
塔里木及邻区晚古生代早期古气候与构造 总被引:2,自引:0,他引:2
影响塔里木及邻区晚古生代早期气候的地球内部因素为古昆仑和南天山两个古洋盆封闭及有关的两条缝合构造带演化,从而形成上述时空段内热带海洋气候、热(亚热)带季风气候、热带沙漠气候以及热带滨岸干湿气候区域的更替,古气候特征的判断主要依据古地磁数据、古生态气候学、沉积环境诸方面。 相似文献
43.
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
44.
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
45.
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
46.
哺乳动物群指示的气候旋回——以周口店早更新世哺乳动物群为例 总被引:2,自引:0,他引:2
文章根据对周口店地区四个哺乳动物群的分析,讨论了该区早更新世气候及生态环境的变迁。第18地点显示了约1.90MaB.P.的干凉气候和森林—草原植被。第12地点指示了1.70MaB.P.的湿热气候和茂密森林生态环境。东洞则记录了1.20MaB.P.的干冷气候和草原景观。到第9地点时(约1.00~0.90MaB.P.),气候炎热,森林和草原植被同时发育 相似文献
47.
Lakes in arid zone are sensitive to climatic changes. The lacustrine sediment sequence in Sogo Nur has well and truly recorded climatic events such as the Sui-Tang Dynasty Warm Period, the Song-Liao Dynasty Cold Period, the Medieval Warm Period, the Little Ice Age and the 20th Century Warm Period. Commonly, the climate in warm Periods was relatively humid,accordingly the lake area extended and water level rose, and vice versa. Apart from climatic change, human activity is also an important factor of influencing lake vicissitude, and they played the dominant role alternatively during different periods; the factor of climatic change predominated in historical period, while since the beginning of the 20th century the utilization of water resources by human has became decisive. 相似文献
48.
最优气候相似法及其在降水预报中的应用 总被引:2,自引:0,他引:2
介绍了一种短期气候预测方法———最优气候相似法 ,并应用于张家界地区 1 999~ 2 0 0 2年 5~ 7月总降水预报中 ,结果显示最优气候相似法能够有效地提高短期气候的预测能力 ,特别对气候异常具有良好的反应能力 ,适合于短期气候业务预报。 相似文献
49.
1IntroductionHighway, as a kind of man-made structure, will become a part of the geographical environment and be impacted by all sorts of natural factors after it is finished. On the other hand, highway also brings some changes to the geographical environment. A highway often passes through different natural regions, so it must be adaptable to any geographical environments. On the basis of deep understanding of the geographical environment, service life and normal level of the highway can be e… 相似文献
50.
The temperature appeared rising trend during the 20th century in China's tropics.Two cooling stages and two warming stages in the process of climatic fluctuation can be recognized.After the 1980s the climate is the warmest which corresponds to the global change,but the warmest period is the 1940s in Kunming.The climate pattern mostly appears contemporaneity of warming and humidity,which is different from the situation of whole China.The natural disasters tend to be aggravated.The number of typhoons increased.Flood damages occurred frequently in the years of more typhoons.The number of droughts and cold damages increased.It was snowed in Guangzhou.There was frost in Haikou and Yaxian.Four years of heavy snow have been recorded in Kunming. 相似文献