Impacts of headcut height on flow energy,sediment yield and surface landform during bank gully erosion processes in the Yuanmou Dry‐hot Valley region,southwest China          下载免费PDF全文

Baojun Zhang  Donghong Xiong  Guanghui Zhang  Su Zhang  Han Wu  Dan Yang  Liang Xiao  Yifan Dong  Zhengan Su  Xiaoning Lu 《地球表面变化过程与地形》2018,43(10):2271-2282

To quantify the changes in flow energy, sediment yield and surface landform impacted by headcut height during bank gully erosion, five experimental platforms were constructed with different headcut heights ranging from 25 to 125 cm within an in situ active bank gully head. A series of scouring experiments were conducted under concentrated flow and the changes in flow energy, sediment yield and surface landform were observed. The results showed that great energy consumption occurred at gully head compared to the upstream area and gully bed. The flow energy consumption at gully heads and their contribution rates increased significantly with headcut height. Gully headcuts also contributed more sediment yield than the upstream area. The mean sediment concentrations at the outlet of plots were 2.3 to 7.3 times greater than those at the end of upstream area. Soil loss volume at gully heads and their contribution rates also increased with headcut height significantly. Furthermore, as headcut height increased, the retreat distance of gully heads increased, which was 1.7 to 8.9 times and 1.1 to 3.2 times greater than the incision depth of upstream area and gully beds. Positive correlations were found between energy consumption and soil loss, indicating that energy consumption could be used to estimate soil loss of headcut erosion. Headcut height had a significant impact on flow energy consumption, and thus influenced the changes in sediment yield and landform during the process of gully headcut erosion. Headcut height was one of the important factors for gully erosion control in this region. Further studies are needed to identify the role of headcut height under a wide condition. Copyright © 2018 John Wiley & Sons, Ltd.  相似文献   

Evaluation of vertical crustal movements and sea level changes around Greenland from GPS and tide gauge observations     

Jiachun An  Baojun Zhang  Songtao Ai  Zemin Wang  Yu Feng 《海洋学报(英文版)》2021,40(1):4-12

To better monitor the vertical crustal movements and sea level changes around Greenland, multiple data sources were used in this paper, including global positioning system(GPS), tide gauge, satellite gravimetry, satellite altimetry, glacial isostatic adjustment(GIA). First, the observations of more than 50 GPS stations from the international GNSS service(IGS) and Greenland network(GNET) in 2007–2018 were processed and the common mode error(CME) was eliminated with using the principal component analysis(PCA). The results show that all GPS stations show an uplift trend and the stations in southern Greenland have a higher vertical speed. Second, by deducting the influence of GIA, the impact of current Gr IS mass changes on GPS stations was analysed, and the GIA-corrected vertical velocity of the GPS is in good agreement with the vertical velocity obtained by gravity recovery and climate experiment(GRACE). Third, the absolute sea level change around Greenland at 4 gauge stations was obtained by combining relative sea level derived from tide gauge observations and crustal uplift rates derived from GPS observations, and was validated by sea level products of satellite altimetry. The results show that although the mass loss of Gr IS can cause considerable global sea level rise, eustatic movements along the coasts of Greenland are quite complex under different mechanisms of sea level changes.  相似文献   

南海北部阳江‒一统暗沙断裂带与新近纪岩浆活动     

蔡国富  张向涛  彭光荣  吴静  柳保军  白海军  李振升  马晓楠  李三忠  索艳慧 《大地构造与成矿学》2021,45(1):40-52

阳江?一统暗沙断裂带是南海北部珠江口盆地极其重要的中?新生代构造带和转换带.基于钻井资料和大范围、高密度的二维、三维地震资料,本文初步揭示阳江?一统暗沙断裂带走向为NW-NWW向、宽约30 km,沿着断裂走向从陆架至洋陆边界断裂带可分为北?中?南三段,断裂在新生代选择性活化,具有多重走滑断裂叠合和基底岩浆底辟强烈等特点...  相似文献   

NCDSN台站地震监测系统实时监视软件   总被引：3，自引：3，他引：0  

马宝君  赵谊  崔东源  马莉  李云龙 《地震地磁观测与研究》2006,27(2):89-92

阐述NCDSN台站连续波形数据断记问题的一种解决办法,软件安装及其使用方法,方法简便易行,便于推广。  相似文献   

深水沉积研究前缘问题   总被引：27，自引：0，他引：27  

庞雄  陈长民朱明何敏  柳保军申俊 连世勇 《地质论评》2007,53(1):36-43

深水沉积研究经历了50年,争论也持续了50年。从浊流及鲍玛序列开始,随着对浊流定义的过分使用,到今天对鲍玛序列作为浊积岩相序及相关的扇模式普遍持否定态度,深水沉积研究经历了一个认识的旋回。主要问题和争论的焦点是：是否所有深水砂岩都是浊流成因,鲍玛序列能否代表浊积岩相序;是否所有的深水扇水道下方都能形成席状的、平行的、加厚的、具有丘状外形的浊积砂岩沉积;是否可以利用地震方法识别深水扇的砂岩储层。对“浊流”概念的过分使用把深水扇模式内几乎所有深水沉积都解释成浊流成因,导致了曾经为之建立模式的学者纷纷撰文抛弃原有扇模式。深水沉积研究面临着对过往认识的否定和如何建立新的理论模式。尽管浊流及相关的深水扇模式研究走向穷途末路,石油工业却从浊流理论和相关模式中获得了许多油气发现,勘探家们仍然希望通过这些模式寻找更多的油气,科学理论和应用出现了分化。对深水沉积过程和流态的认识及沉积模式的建立是当今深水沉积研究的难点,实现深水砂岩储层的有效预测是深水沉积研究的主要目的。我国深海油气勘探在即,深水沉积的科学问题同样不可逾越。  相似文献   

豫西南中新生代古地理环境变迁     

冯祖杰  周旗  王军  谷保俊 《河南国土资源》1997,(4)

豫西南地区曾经是恐龙生活的“家园”。本文根据区内地层发育和出露特点，结合地壳（构造）活动规律，对豫西南中、新生代自然古地理环境（古地理、古环境、古气候、古生态）进行初步研究。这一研究结果对展示中生代恐龙的自然生态、生活环境，揭示恐龙演化规律和灭绝原因，具有一定的理论和实际意义。  相似文献   

崤山地区隐伏花岗岩体及其找金前景     

陈铁华  赵保军  张天义  朱嘉伟 《河南国土资源》1997,(1)

航磁、重力异常和遥感影像证实，在崤山太华群之下有一隐伏花岗岩体存在，其规模可与小秦岭文峪岩体相比，岩体从南西（深处）向北东（浅处）侵入，在申家窑以北又转向北西。岩体的发现，深化了基础地质的研究程度，解决了金矿成矿的热源问题。研究表明，崤山地区金矿成矿条件优越，具备找到大型金矿的前景。经综合分析，预测了三个有希望的成矿区  相似文献   

雅鲁藏布中新生代深水沉积盆地形成和演化(Ⅲ)——喜马拉雅被动大陆边缘构造沉降分析          下载免费PDF全文

徐强  刘宝珺  余光明  G. Einsele  W. Frisch  刘光华  J. Wendt  A. Wetzel  L. Ratschbacher  H. P. Luterbacher 《沉积与特提斯地质》1993,(1):58-65

喜马拉雅特提斯中、新生代属印度板块北部被动大陆边缘。对充填这个被动大陆边缘的沉积物用“反剥法”(backstrippiog)进行研究,恢复了从被动大陆边缘到前陆盆地的抓降史。对分离出的盆地构造沉降曲线与McKenzie模式图版进行对比相关性分析,判断认为被动大陆边缘成熟期主要为热耗散沉降,前陆盆地时逆冲推覆动力为主要影响因素。  相似文献   

鲁西隆起与歧口凹陷耦合机制     

牛树银  王金忠  孙爱群  马宝军  陈超  王宝德  张建珍  胡华斌 《大地构造与成矿学》2012,36(1):1-7

山区固体矿产地质研究和盆地油气地质研究是地质学两个重要的研究领域,但是由于部门的划分而导致两者研究各有侧重,从而使两者研究的结合和借鉴远远不够。鲁西隆起由南至北分别展布有尼堒山-母子山、蒙山、徂莱山-新甫山-孟良岗、泰山-鲁山-沂山等四个隆起,而隆起之间则分布有泗平、汶蒙、肥城、莱芜等四个相邻的断陷,断陷与隆起之间均发育典型的铲状断裂,并控制着中新世的箕状断陷沉积;而歧口凹陷则以南大港和北大港潜山构造带为界划分为歧南、歧北、板桥三个次级凹陷,它们均呈北侧陡且深、南侧缓而浅的箕状不对称形态,具有"北断南超"的特点。其形态特征完全可以与鲁西隆起区的隆坳构造进行对比。笔者从幔枝构造的视角研究认为它们是鲁西隆起与歧口凹陷之山盆耦合形成的主要构造形迹。  相似文献   

哈达门沟金矿床构造应力场演化及控矿规律分析     

马宝军  牛树银  陈超  王宝德  孙爱群  张建珍 《大地构造与成矿学》2012,36(4)

以矿区构造节理统计分析为基础,结合矿区地质特征及区域构造演化,分析了哈达门沟金矿区构造控矿特征及应力场演化。认为山前"钾化带"与矿体就位直接相关,它沟通了复式褶皱核部的隐伏岩体与浅部节理,并成为流体运移的主要通道。与成矿控矿有关的构造应力场可分为四期:第一期变形在新太古代的乌拉山旋回,最大主应力σ1方位15°～195°,共轭节理为NNW和NE向;在成岩、变质作用同时进行下除形成了区内透入性的强塑性叠加小褶皱外还有整体上的大型复背斜。第二期构造应力场作用时间在晚古生代,σ1方位约在160°～340°,形成近SN和NE向共轭节理和西侧的大桦背岩体,这一期有局部的矿化现象;前两期应力场形成了轴向近EW向的叠加褶皱、断裂和两期共轭剪节理等成矿前主要构造。第三期应力场处于主成矿期,变形为燕山运动中、晚期构造,σ1在290°方位近水平扭压,形成EW和NW向共轭剪节理;张扭性应力场使近EW向的节理弯曲变形,并形成追踪张节理,这两类裂隙成为主要的矿液通道及容矿空间。第四期构造应力场应在晚燕山运动及以后,为成矿后构造变形,σ1近直立,整体抬升使矿脉遭受剥蚀而出露地表。  相似文献