格尔木河流域河流地貌演化的研究进展          下载免费PDF全文

郑长远  安福元  张啟兴 《盐湖研究》2016,24(4)

位于柴达木盆地南缘的格尔木河发源于东昆仑山脉,末端注入盆地中东部的察尔汗盐湖,是该盐湖最主要的补给河流,极大地影响着该盐湖的成盐演化过程。格尔木河的主要支流——昆仑河和雪水河都是由冰川融水形成,因此,该流域内的冰川进退对河流径流量变化和谷地填充地层物源有着重要影响。该河流域内主要的填充地层为昆仑河砾岩(河流相)、纳赤台沟组(冲洪积相)和三岔河组(河湖相)。在三岔河组之上,发育了四/五级阶地,除最高的T₅之外,其他均为以三岔河组为基底的内叠基座阶地。根据前人的研究,昆仑河砾岩沉积的年代为1269至1042 ka(ESR年龄);纳赤台沟组堆积于482至642 ka之间(ESR和TL年龄);三岔河组形成于355-95 ka(ESR和U系年龄)、90-16 ka(OSL年龄),T₅-T₁阶地基本形成于16- 4.6 ka之间。由于采用的测年方法不同,不同学者对三岔河组的形成时代存在争议,对阶地的划分也有所不同(四级或五级阶地)。但是对T₅-T₁阶地形成时代有较一致的观点,即末次冰消期和全新世早中期。对于格尔木河河流地貌过程的驱动因素,目前尚存在争论,大部分学者认为是气候变化驱动了该区域河流地貌的形成,但也有学者认为构造活动是主导因素。  相似文献   

Geologically constrained changes to landforms caused by human activities in the 20th century: A case study from Fukuoka Prefecture,Japan     

《Applied geography (Sevenoaks, England)》2017

Human activity has been recognized to be an important geomorphic agent, and the resulting changes to landforms and land cover are regarded as a global problem. Although there has been much research into the relationships between geomorphic processes and types of land use such as agriculture, mining, and urbanization, it is important to clarify spatiotemporal human impacts on topography on a regional scale when predicting future changes in land cover.This study examined changes in land use to clarify the distribution and impact of anthropogenic changes to landforms, as well as the influence of geology on the extent of these changes. In a case study from Fukuoka Prefecture, Japan, changes in land use over the last century were analyzed using a geographic information system (GIS). The study area, which covers approximately 4930 km², has experienced urban development since 1950 and has a current population of over 5 million. Land use data were prepared using paper-based early editions of topographic maps. Subsequently, the distribution of anthropogenic landforms was evaluated by comparing landforms with regional geological data.GIS analysis using our prepared land use data, landform data, and regional geological data has clarified the following characteristics of the study area. (1) Land uses prior to 1950 were constrained by topographic relief. After 1950, land use was characterized by urban sprawl. Urban areas expanded and contained both higher elevations and steeper slopes at their margins. The relationships between land uses and landforms during this urbanization are unclear. (2) The area of urban land increased in the geological regions with Paleogene sedimentary rocks (PSD) and Mesozoic granitic rocks (GR) during the 20th century. The largest coal mining area in Japan was located in the PSD geological regions, and ancient iron working was common in the GR geological regions, particularly during the 7th century. This result indicates that the land use distribution, especially urban areas in sloping terrain, is related to the regional geology. (3) Deforestation related to land use resulted in steeper terrain in forest land in the PSD and GR geological regions. These changes to landforms in forest areas occurred as a result of rapid urban sprawl and have created many new boundaries between forest areas with steeper slopes and urban areas with gentler slopes. This phenomenon may have caused an increase in the frequency of sediment-related disasters.This case study indicates that predictions of anthropogenic changes to landform, which are important for the assessment of global climate change and natural hazards, must clarify the relationships between land uses, landforms, and regional geology.  相似文献   

日照市地质地貌景观旅游资源类型与开发利用          下载免费PDF全文

王申 《山东国土资源》2007,23(3):7-10

日照市濒临黄海,腹地宽广,内陆和沿海地质地貌景观资源丰富,构成日照市旅游资源的主体。内陆地质地貌景观以山体、河流和人工湖泊为主,沿海地质地貌景观以岬角、岛礁、沙滩、澙湖为主。目前,内陆景点开发利用较少,沿海景观利用深度不够。在开发利用地质地貌景观时,应科学规划,减少人类活动对生态环境的破坏,保持地质地貌的原生态。  相似文献   

青藏高原（格尔木-亚东）冰缘现象及其气候意义     

刘擎  李宜垠  孙才奇  聂振宇  杨玮琳  崔之久  刘耕年 《冰川冻土》2021,43(3):690-700

冰缘地貌与沉积是冰冻圈环境变化的载体,对其开展深入研究对了解青藏高原地表过程与过去气候变化,具有重要意义。基于青藏高原（格尔木-亚东）冰缘地貌和沉积野外记录和实验分析,获得以下认识：格尔木在LGM时多年冻土至少下限到达海拔2 900 m,年均气温降至< -4 ℃,比现在至少低9 ℃,气候寒冷干燥;冰消期和全新世存在极端干冷的气候事件,可能存在地面温度< -10 ℃的冬季迅速降温气候期。楚玛尔、那曲谷露和纳木错的冰楔假型分别记录了末次冰期冷期多年冻土扩张,亚东古砂楔记录了早全新世冷事件。西藏羊八井泥炭沉积剖面孢粉和测年揭示,该区自新仙女木事件以来经历了严寒（12.8~9.8 ka）、暖湿（9.8~5.0 ka）、干冷（5.0 ka至今）的气候阶段。青藏高原（格尔木-亚东）广泛发育的冻融褶皱、成层坡积、风沙沉积等,是古环境重建的重要佐证,具有刻画冷暖-干湿的意义。  相似文献   

喀斯特地貌SAR影像多级配准方法   总被引：2，自引：0，他引：2  

杨海兰  张利恒  韦春桃 《测绘科学》2015,40(1):72-76

文章针对现有SAR影像配准方法对喀斯特地貌低相干区域配准的局限性,在阴影区域提取的基础上提出一种SAR影像多级配准方法。通过对喀斯特地貌阴影区域的分析,逐级提取阴影区域质点和位于山峰位置的高相干点作为特征点。在进行像元级和亚像元级的配准时分别采用几何特征参数和相干系数作为自动配准的测度。实验验证了喀斯特地貌SAR影像采用此方法进行配准的可行性,配准精度有所提高。  相似文献   

实验地貌的观测方法讨论     

王书芳  徐向舟  徐飞龙 《测绘科学》2012,(2):149-151,178

实验地貌观测方法的选择直接影响试验观测的精度和效率。数字近景摄影测量技术具有较高的观测精度和效率,其设备简单易操作且成本相对较低,但观测精度仍需结合传统手段进行率定和校核;点云式激光扫描技术使用范围广、精度高,但设备制作成本高、数据处理量大,等值线式激光扫描技术克服了上述缺点;超声波地形仪多用于水下地形观测,应用范围及效率精度有待改进。实验地貌观测技术未来的研究趋势应朝着高精度、高效率、操作简便的方向发展。  相似文献   

浙江省江山市江郎山地质遗迹资源特征及成景机制探讨   总被引：5，自引：1，他引：4  

田毓仁  刘成东  严兆彬  何国锦 《地球学报》2010,31(4):585-592

江郎山俗称“三爿石”, 素有“雄奇冠天下, 秀丽甲东南”之誉, 还拥有“中国丹霞第一奇峰”、“全国一线天之最”的称号。本文对江郎山地质遗迹资源特征进行了比较详细的描述, 并将江郎山丹霞地貌及其成因机制从地层、岩性、构造及外动力作用等方面进行了较深入的研究。研究表明, 江郎山地质遗迹具有独特的成景机制, 是地质构造演化、岩浆作用以及外动力共同作用的结果。该研究无论对旅游资源的开发保护还是对该地区地质演化的研究都有所裨益。  相似文献   

福建沿海第四纪地质调查中钻探布置及质量控制     

柳文广 《福建地质》2010,29(2):139-145

福建沿海经济区陆续开展以滨海平原、山间盆地、冲积平原、丘陵台地等为主的1∶5万第四纪地质调查,根据各地貌单元发育规律,结合1∶5万福清幅第四纪专题调查,总结了浅覆盖层勘探线的布置方法、钻孔密度、技术要求、质量控制等要点。  相似文献   

鲜水河—安宁河断裂带磨西—冕宁段的滑动速率与强震位错   总被引：10，自引：1，他引：10  

周荣军  何玉林  杨涛  何强  黎小刚 《中国地震》2001,17(3):253-262

航片解译及野外地震地质考察结果表明，鲜水河－安宁河断裂带磨西－冕宁段存在明显的晚第四纪活动性，其以左旋走滑运动为主，并伴有显著的垂直滑动分量。晚第四纪以来的平均水平滑动速率在鲜水河断裂磨西以南段为6．0－9．9mm/a，安宁河断裂冕宁以北段为4．7－5．3mm/a。同震位错及地震地表破裂研究表明，A．D．1786年康定－泸定磨西73／4级地震的地表破裂可能南延至田湾以南；安宁河断裂冕宁以北段则具有蕴育71／2级左右地震的构造背景，最晚一次强震的地质记录极有可能是史料记载不全的A．D．1327年一次6级或6级以上地震的证据。  相似文献   

Automated mapping of land components from digital elevation data     

J. R. Dymond  R. C. Derose  G. R. Harmsworth 《地球表面变化过程与地形》1995,20(2):131-137

An algorithm for automating the mapping of land components from digital elevation data is described. Land components are areas of relatively uniform slope and aspect and often correspond with ridge crests, shoulders, head slopes, back slopes or foot slopes. Aspect regions, which generally span from stream to ridge, are first identified by generalizing an aspect map derived from digital elevation data. The aspect regions are then split successively into land components by grouping pixels above or below an automatically determined contour of elevation or ‘distance from stream’. The contour approximates a slope break. The land components mapped in this way give a complete polygonization of a hilly landscape and are a reasonable approximation of manually mapped land components.  相似文献