试论黄河下游北岸可能决口地段及其最大淹没范围   总被引：3，自引：1，他引：2  

陆中臣  贾亚非  曹银真  舒晓明 《地理研究》1987,6(4):15-25

鉴于黄河的现状,作者认为黄河决口的潜在危险越来越大。推断北岸决口的可能性为大。根据溃坝原理,采用水力学方法对北岸决口的最大淹没范围作了模拟。指出若从沁河口—原阳段决堤,淹没面积约2.21万平方公里,从原阳—高村段决堤,则约为2.12万平方公里。  相似文献   

应用洞穴考古成果建立辽东地区中、上更新统标准剖面     

高尚华  于本刚 《国土资源》1990,(4)

辽东地区第四系不发育。近年,由于旧石器时期遗迹的发掘,积累了较丰富的古动物、古人类资料,使得我们有可能应用这一成果建立辽东地区中、上更新统的标准剖面。辽东地区中更新统称庙后山组(太子河地区)和牛心山组(丹东—营口区);上更新统称山城子组(太子河地区)和金牛山组(丹东—营口区),代表了0.377—0.017Ma期间的堆积。古生态分析表明,庙后山期(牛心山期)为温暖湿润的森林—疏林草原型自然景观;山城子期(金牛山期)为寒冷的干旱草原—半荒漠型自然景观。  相似文献   

准噶尔盆地四棵树剖面孢粉组合及三叠系-侏罗系界线     

HE Zhen-jian Geological Scientific Research Institute of Shengli Oilfield Company  SINOPEC  Dongying 《地层学杂志》2007,(Z2)

在实测四棵树剖面的基础上,详细研究了其孢粉组合特征,建立了5个孢粉组合:1)Cameratitriletes和Zonotriletes-Protopinus-Cycadopites组合,2)Cyatheaceae-Pinaceae-Cycadopites组合,3)Cyatheaceae-Pinaceae-Quadraeculina-Cycadopites组合,4)Cyatheaceae-Quadraeculina-Piceaepollenites组合和5)Cyatheaceae-Clas-sopollis-Pinaceae组合,分别产于上三叠统的小泉沟群、下侏罗统的八道湾组和三工河组、中侏罗统的西山窑组和头屯河组。根据孢粉组合特征,结合岩性和沉积及区域资料,将三叠系-侏罗系界线定于38层和39层之间。  相似文献   

横断面测图比例尺及断面间距对挖填工程量的精度影响     

耿汉文  徐加东 《现代测绘》2006,29(5):33-33,38

横断面测图比例尺及断面间距的选择，直接影响到挖填工程量的计算精度，本文通过对方量精度估算分析，提出了供设计人员和测绘人员参考的测量方案。  相似文献   

南澜沧江构造岩浆带下侏罗统就康组的建立   总被引：1，自引：0，他引：1  

田应贵  胡鹏  王承平 《云南地质》2006,25(1):63-69

新建就康组为厚度较大的碎屑岩夹陆相火山岩地层。其底以角度不整合覆于三叠系中酸性火山岩之上，顶部被中侏罗统花开左组平行不整合覆盖。化石较丰富，时代归下侏罗统。  相似文献   

Holocene climate variation determined from rubidium and strontium contents and ratios of sediments collected from the BadainJaran Desert,Inner Mongolia,China     

《Chemie der Erde / Geochemistry》2014,74(4):571-576

Rubidium (Rb) and strontium (Sr) contents and ratios were analyzed in 197 sediment samples collected from the CGS1 segment of the Chagelebulu Section in the Badain Jaran Desert of China to study millennial scale climate change during the Holocene. The results showed that the Rb and Sr contents and Rb/Sr ratios were low in the samples of dune sands and loess (Mz < 5.64Φ), and those values were high in the samples of loess (Mz > 5.64Φ) and paleosols, these data displayed 11 changing cycles in alternation of peaks and valleys in the chart. In addition, the Rb contents were positively correlated with Mz (mean particle diameter) and clay contents. While the correlations were weaker, Sr contents also showed a tendency to increase with increases in the Mz and clay contents. Based on a comprehensive analysis of the distribution of Rb and Sr within the CGS1 segment, it appears that the observed Rb and Sr contents and ratios varied in accordance with fluctuations of the East Asian winter and summer monsoons. In terms of timing and climate, low values (C1–C11) resulting from winter monsoons had a strong correlation with cold events in the North Atlantic: the period C1 corresponded to times ranging from 400 a to 1400 a and the periods C2, C3, C4, C7, C9, C10, and C11 corresponded to times of 3000 a, 4000 a, 5900 a, 8200 a, 9400 a, 10,300 a, and 11,000 a, respectively. The cold event C5 (6200 a) was also discovered in the North Atlantic in recent; and C6 (7100 a), C8 (8700 a) were discovered in some other places of China. These cold events indicated by Rb and Sr contents and ratios in the Chagelebulu Section of the Badain Jaran Desert recorded the regional response of global climate change during the Holocene.  相似文献   

黄河流域山东段“三生空间”分类及其时空格局变化分析          下载免费PDF全文

寻妍  马绍伟  王哲  冯海燕  张金盈  王磊 《山东国土资源》2022,38(10)

本文以黄河流域（山东段）为研究区，构建了基于山东省地理省情监测数据的“三生空间”分类体系，运用格网化研究方法分析了2017年以来黄河流域（山东段）“三生空间”时空格局及其演变情况。研究成果表明黄河流域（山东段）“三生空间”以生产空间为主，其次为生态空间，面积最少的为生活空间。近年来，“三生空间”时空演变情况为生活空间、生态空间面积增加，生产空间面积下降。黄河流域（山东段）“三生空间”研究成果可为国土空间优化提供借鉴意义。  相似文献