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701.
702.
Delta channels are important landforms at the interface of sediment transfer from terrestrial to oceanic realms and affect large, and often vulnerable, human populations. Understanding these dynamics is pressing because delta processes are sensitive to climate change and human activity via adjustments in, for example, mean sea level and water/sediment regimes. Data collected over a 40-year period along a 110-km distributary channel of the Yellow River Delta offer an ideal opportunity to investigate morphological responses to changing water and sediment regimes and intensive human activity. Complementary data from the delta front provide an opportunity to explore the interaction between delta channel geomorphology and delta-front erosion–accretion patterns. Cross-section dimensions and shape, longitudinal gradation and a sediment budget are used to quantify spatial and temporal morphological change along the Qingshuigou channel. Distinctive periods of channel change are identified, and analysis provides a detailed understanding of the temporal and spatial adjustments of the channel to specific human interventions, including two artificial channel diversions and changes in water and sediment supply driven by river management, and downstream delta-front development. Adjustments to the diversions included a short-lived period of erosion upstream and significant erosion in the newly activated channel, which progressed downstream. Channel geomorphology widened and deepened during periods when management increased water yield and decreased sediment supply, and narrowed and shallowed during periods when management reduced water yield and the sediment load. Changes along the channel are driven by both upstream and downstream forcing. Finally, there is some evidence that changing delta-front erosion–accretion patterns played an important role in the geomorphic evolution of the deltaic channel; an area that requires further investigation. © 2020 John Wiley & Sons, Ltd. 相似文献
703.
基于VR技术的多尺度地质数据3D沉浸式可视化与交互方法 总被引:1,自引:0,他引:1
随着科技的飞速发展,地质大数据正在呈爆炸式增长,地质大数据可视化与交互方法成为研究的新方向。如何通过可视化方法将巨大的、复杂的、潜逻辑的地质数据展现与交互是需要进一步探索的。本文提出基于VR技术的多尺度地质数据3D沉浸式可视化与交互方法,该方法既符合计算思维又符合地质专业理论。首先,从理论上提出多尺度地质数据可视化理论模型;其次,基于VR技术实现多尺度、多分辨率地质数据的可视化;最后,构建了3D沉浸式虚拟现实平台,采用实际数据验证方法的有效性。该方法适用于地质数据的可视化与交互,为科学的定量评价、分析和教学提供新思路,是未来的必然发展趋势。 相似文献
704.
基于PS-InSAR技术的断裂带地壳形变实验研究 总被引:1,自引:1,他引:1
PS-InSAR技术克服了常规D-InSAR技术的空间、时间失相干和大气相位延迟等影响,对高相干点的差分干涉相位采用二维线性(或非线性)回归分析模型获取微小形变。概述PS-InSAR技术的相位组成、技术处理流程,以位于祁连山海原断裂带北盘的海原县为实验区,采用2003—2009年的21景ENVISAT ASAR数据,以GAMMA软件IPTA模块为软件平台处理得出实验区位移速率为-7~-9 mm/a,运动方向为自东向西,断裂带表现为左旋走滑,实验结果与GPS、库仑应力和地质学方法结果有较好的一致性。 相似文献
705.
Hong-Lin Yuan Shan Gao Meng-Ning Dai Chun-Lei Zong Detlef Günther Gisela Helene Fontaine Xiao-Ming Liu ChunRong Diwu 《Chemical Geology》2008,247(1-2):100-118
We describe an in situ method for simultaneous measurement of U–Pb–Hf isotopes and trace element compositions of zircons using a quadrupole and multiple-collector inductively-coupled-plasma mass spectrometer (Q-ICP-MS and MC-ICP-MS, respectively) connected to a single excimer laser-ablation system. A laser-generated zircon aerosol was split behind the ablation cell into two transport tubes via a Y-shaped connector and simultaneously introduced into the two mass spectrometers. Hafnium isotopes were measured on the MC-ICP-MS instrument, while U–Pb ages and trace element compositions were determined using the Q-ICP-MS. The precision and accuracy of this method was evaluated using six well-known and widely used zircon standards (91500, Temora-2, GJ-1, Mud Tank, BR266 and Monastery). Analyses were carried out using spot sizes of 32, 44 and 60 μm. For the 44 and 60 μm spot, the resulting U–Pb ages, Hf isotopic and rare earth element (REE) compositions of these six zircons agree with recommended/reported values within 2σ error. The difference in relative standard deviations (RSD) of 206Pb/238U ages between split-flow measurements and those obtained separately on the Q-ICP-MS is within ~ 20% for 91500, Temora-2 and GJ-1, and ~ 60% for Mud Tank (due to its lower U and Pb concentrations). Our method provides a precise approach for determining the U–Pb age and the Hf isotopic and trace element compositions of zircon within a single ablation event. This is in particular important for analysis of zircons that are small or contain complicated zoning patterns. Finally, the REE composition of zircon BR266 is more homogeneous than other zircons and could be a suitable standard by which to benchmark new standards for microprobe analyses of zircons. 相似文献
706.
<正>1 Introduction Athabasca oil sands are large deposits of heavy crude oil,located in northeastern Alberta Basin,Canada.Those oil sands,hosted primarily in upper and middle of McM urray Formation,is in 18m in thickness and 160m-180m in buried depth.The average liquid saturation is 相似文献
707.
TANG Mingming LU Shuangfang LIANG Hongru YAN Bihui MA Huifang SHEN Shan 《《地质学报》英文版》2015,89(Z1):412-414
<正>1 Introduction Lattice Boltzmann Method(LBM)have a remarkable ability to simulate single,multiphase and multicomponent fluids(MichaelDaniel,2007).Ludwig Boltzmann’s work is based on a simple idea that a gas is composed of interacting particles which could be analysed by Newton’s laws.So the flowing property of gas could be give out by 相似文献
708.
岩溶地面塌陷、区域地下水位下降、采空区地面塌(沉)陷、矿坑突水等是广西矿山在开采过程中产生的最主要环境水文地质问题.从武宣盘龙铅锌矿矿区的地层岩性分布、地质构造条件、岩溶发育特征、水文地质特征、开采工程活动、矿坑疏干地下水影响等方面综合分析,揭示盘龙矿区存在的主要环境水文地质问题,并结合开采工程活动提出帷幕灌浆、回填灌浆加固、充填采空区、加强地面变形监测、先探水再掘进等防治措施与对策,为矿山有序开采及安全经济高效运行、矿床疏干排水方案及矿山深部开采设计提供科学依据. 相似文献
709.
710.
Effects of Activated Irrigation Water on Soil Physicochemical Properties and Crop Growth and Analysis of the Probable Pathway 总被引:2,自引:0,他引:2
Quanjiu Wang Yan Sun Songrui Ning Jihong Zhang Beibei Zhou Lijun Su Yuyang Shan 《地球科学进展》2019,34(6):660-670
With the problem of shortage of water resources becoming increasingly prominent, the improvement of production efficiency of agricultural water resources in China has become an important research content of modern irrigated agriculture. The technology of activated irrigation water provides a new way to excavate the physiological production potential of irrigation water and improve the comprehensive efficacy of irrigation water in agro-ecosystems. In this study, the research progress of the variable characteristics of physicochemical properties of activated irrigation water, the transport and transformation of soil material by activated irrigation water, and the promotion of crop growth by activated irrigation water were comprehensively analyzed. On this basis, according to the basic theories of soil physics, crop physiology, and material transport dynamics, the effects of activated irrigation water on soil material transport, soil material transformation, water and nutrition uptake by root, and crop yield formation and the probable pathway were analyzed. The key problems of basic science and applied technology in the future research are put forward to provide reference for the scientific and reasonable utilization of activated irrigation water technology. 相似文献