基于升降轨D-InSAR获取台湾美浓MW6.7地震同震形变场     

刘增伟  陶秋香  王峰  李兴远 《华南地震》2020,40(3):63-69

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The effect of storm movement on infiltration,runoff and soil erosion in a semi-arid catchment     

Qihua Ran  Feng Wang  Jihui Gao 《水文研究》2020,34(23):4526-4540

Rainfall characteristics are key factors influencing infiltration and runoff generation in catchment hydrology, particularly for arid and semiarid catchments. Although the effect of storm movement on rainfall-runoff processes has been evaluated and emphasized since the 1960s, the effect on the infiltration process has barely been considered. In this study, a physically based distributed hydrological model (InHM) was applied to a typical semi-arid catchment (Shejiagou, 4.26 km²) located in the Loess Plateau, China, to investigate the effect of storm movement on infiltration, runoff and soil erosion at the catchment scale. Simulations of 84 scenarios of storm movement were conducted, including storms moving across the catchment in both the upstream and downstream directions along the main channel, while in each direction considering four storm moving speeds, three rainfall depths and two storm ranges. The simulation results showed that, on both the hillslopes facing downstream (facing south) and in the main channel, the duration of the overland flow process under the upstream-moving storms was longer than that under the downstream-moving storms. Thus, the duration and volume of infiltration under upstream-moving storms were larger in these areas. For the Shejiagou catchment, as there are more hillslopes facing downstream, more infiltration occurred under the upstream-moving storms than the downstream-moving storms. Therefore, downstream-moving storms generated up to 69% larger total runoff and up to 351% more soil loss in the catchment than upstream-moving storms. The difference in infiltration between the storms moving upstream and downstream decreased as the storm moving speed increased. The relative difference in total runoff and sediment yield between the storms moving upstream and downstream decreased with increasing rainfall depth and storm speed. The results of this study revealed that the infiltration differences under moving storms largely influenced the total runoff and sediment yield at the catchment scale, which is of importance in runoff prediction and flood management. The infiltration differences may be a potential factor leading to different groundwater, vegetation cover and ecology conditions for the different sides of the hillslopes.  相似文献   

Terrestrial heat flow and lithospheric thermal structure in the Chagan Depression of the Yingen-Ejinaqi Basin,north central China     

Yinhui Zuo  Shu Jiang  Shihu Wu  Wei Xu  Jiong Zhang  Renpeng Feng  Meihua Yang  Yongshui Zhou  M. Santosh 《Basin Research》2020,32(6):1328-1346

The Chagan Depression in the Yingen-Ejinaqi Basin, located at the intersection of the Paleo-Asian Ocean and the Tethys Ocean domains is an important region to gain insights on terrestrial heat flow, lithospheric thermal structure and deep geodynamic processes. Here, we compute terrestrial heat flow values in the Chagan Depression using a large set of system steady-state temperature data from four representative wells and rock thermal conductivity. We also estimate the “thermal” lithospheric thickness, mantle heat flow, ratio of mantle heat flow to surface heat flow and Moho temperature to evaluate the regional tectonic framework and deep dynamics. The results show that the heat flow in the Chagan Depression ranges from 66.5 to 69.8 mW/m², with an average value of 68.3 ± 1.2 mW/m². The Chagan Depression is characterized by a thin “thermal” lithosphere, high mantle heat flow, and high Moho temperature, corresponding to the lithospheric thermal structure of “cold mantle and hot crust” type. We correlate the formation of the Yingen-Ejinaqi Basin to the Early Cretaceous and Cenozoic subduction of the western Pacific Plate and the Cenozoic multiple extrusions. Our results provide new insights into the thermal structure and dynamics of the lithospheric evolution in central China.  相似文献   

浊积岩和砂质碎屑流岩关键识别标志及辽河盆地岩心实例^*          下载免费PDF全文

杨棵  朱筱敏  刘宇  刘兴周  郭峰 《古地理学报》2020,22(3):483-492

重力流是自然界中广泛存在的一种流体形式,不同学者基于不同切入点往往会提出多种重力流的划分方案。采用浊流和碎屑流的二分方案,对浊积岩和砂质碎屑流岩的沉积特征展开综述和探讨,旨在进一步概括这2类岩石的沉积特征,明确具有指示意义的最典型相标志。研究表明,在野外露头和钻井岩心中,可以通过以下典型特征鉴别浊积岩和砂质碎屑流岩: 砂岩内若发育以正粒序为特征的递变层理,则应该将其认定为浊积岩;若砂岩内发育泥岩撕裂屑、漂浮状泥砾或不含任何层理构造(块状砂岩),则应该将其认定为砂质碎屑流岩。这些特征是鉴别浊积岩和砂质碎屑流岩最可靠的标志。此外,变形层理、爬升波纹交错层理、波状层理、平行纹层、冲刷侵蚀界面、岩性突变界面和槽模等沉积构造也具有一定指示意义,出现这些特征时需要结合沉积背景、岩相的垂向组合关系和地球物理等资料进行综合判断。  相似文献   

Barium Isotopic Compositions in Thirty‐Four Geological Reference Materials Analysed by MC‐ICP‐MS     

Ya‐Jun An  Xin Li  Zhao‐Feng Zhang 《Geostandards and Geoanalytical Research》2020,44(1):183-199

Measurement of Ba isotope ratios of widely available reference materials is required for interlaboratory comparison of data. Here, we present new Ba isotope data for thirty‐four geological reference materials, including silicates, carbonates, river/marine sediments and soils. These reference materials (RMs) cover a wide range of compositions, with Ba mass fractions ranging from 6.4 to 1900 µg g^?1, SiO₂ from 0.62% to 90.36% m/m and MgO from 0.08% to 41.03% m/m. Accuracy and precision of our data were assessed by the analyses of duplicate samples and USGS rock RMs. Barium isotopic compositions for all RMs were in agreement with each other within uncertainty. The variation of δ^138/134Ba in these RMs was up to 0.7‰. The shale reference sample, affected by a high degree of chemical weathering, had the highest δ^138/134Ba (0.37 ± 0.03‰), while the stream sediment obtained from a tributary draining carbonate rocks was characterised by the lowest δ^138/134Ba (?0.30 ± 0.05‰). Geochemical RMs play a fundamental role in the high‐precision and accurate determination of Ba isotopic compositions for natural samples with similar matrices. Analyses of these RMs could provide universal comparability for Ba isotope data and enable assessment of accuracy for interlaboratory data.  相似文献   

广西合浦盆地干热岩资源成热条件及潜力评价     

康志强  张起钻  管彦武  冯波  袁金福  孙明行  刘德民  王新宇  杨志强  陆济璞  张勤军  冯民豪 《吉林大学学报(地球科学版)》2020,50(4):1151-1160

为了对广西合浦盆地干热岩资源成热条件及其潜力进行评价，利用广西航磁勘查数据，采用Parker-Oldenburg法反演计算了居里面深度。在此基础上进行大地热流密度值和不同埋深地温计算，发现计算结果与现有测温资料吻合，合浦盆地内西场凹陷和常乐凹陷具有干热岩资源成生条件。结合合浦盆地内基础地质调查资料和油气钻孔资料，分析了合浦盆地干热岩资源的储层和盖层条件。初步圈出2个位于西场凹陷和常乐凹陷的干热岩勘查靶区C1和C2，面积分别为167.10和72.90 km²，干热岩资源量分别为182.48×10¹⁵、77.59×10¹⁵ J。按20%的采收率，合浦盆地干热岩资源量可开采量为52.01×10¹⁵ J，折合标准煤177.48×10⁴ t，占2018年广西全区能源生产总量3 756.69×10⁴ t标准煤的4.72%。在资源量评价基础上，可优先考虑位于合浦盆地西场凹陷的C1靶区开展进一步的勘探工作。  相似文献   

Weakening laws of slip zone soils during wetting–drying cycles based on fractal theory: a case study in the Three Gorges Reservoir (China)     

Miao  Fasheng  Wu  Yiping  Li  Linwei  Tang  Huiming  Xiong  Feng 《Acta Geotechnica》2020,15(7):1909-1923

Acta Geotechnica - Slip zone soils play a crucial role in the evolution of landslides. In this paper, slip zone soils of the Huangtupo Landslide in the Three Gorges Reservoir area, which is an...  相似文献   

Study of subsurface eddy properties in northwestern Pacific Ocean based on an eddy-resolving OGCM     

Xu  Anqi  Yu  Fei  Nan  Feng 《Ocean Dynamics》2019,69(4):463-474

Ocean Dynamics - A method based on the Okubo–Weiss parameter was used to detect subsurface eddies (SSEs) with an eddy-resolving ocean general circulation model. Statistical analyses showed...  相似文献   

Seismic responses of postyield hardening single–degree-of-freedom systems incorporating high-strength elastic material     

Hanlin Qiang  Peng Feng  Zhe Qu 《地震工程与结构动力学》2019,48(6):611-633

It is widely accepted that ductility design improves the seismic capacity of structures worldwide. Nevertheless, inelastic deformation allows serious damage to occur in structures. Previous studies have shown that a certain level of postyield stiffness may reduce both the peak displacement and residual deformation of a structure. In recent years, several high-strength elastic materials, such as fiber-reinforced polymer (FRP) and high-strength steel bars, have been developed. Application of these materials can easily provide a structure with a much higher and more stable postyield stiffness. Many materials, members, and structures that incorporate both high-strength elastic materials and conventional materials show significant postyield hardening (PYH) behaviors. The significant postyield stiffness of PYH structures can help effectively reduce both peak and residual deformations, providing a choice when designing resilient structures. However, the findings of previous studies of structures with elastic-perfectly plastic (EPP) behavior or small postyield stiffness may not be accurate for PYH structures. The postyield stiffness of a structure must be considered an important primary structural parameter, in addition to initial stiffness, yielding strength, and ductility. In this paper, extensive time history and statistical analyses are carried out for PYH single–degree-of-freedom (SDOF) systems. The mean values and coefficients of variation of the peak displacement and residual deformation are obtained and discussed. A new R-μ_p-T-α relationship and damage index for PYH structures are proposed. A theoretical model for the calculation of residual deformation is also established. These models provide a basis for developing the appropriate seismic design and performance evaluation procedures for PYH structures.  相似文献   

How changes of groundwater level affect the desert riparian forest ecosystem in the Ejina Oasis,Northwest China     

HaiYang Xi  JingTian Zhang  Qi Feng  Lu Zhang  JianHua Si  TengFei Yu 《寒旱区科学》2019,11(1):62-80

Groundwater is a key factor controlling the growth of vegetation in desert riparian systems. It is important to recognise how groundwater changes affect the riparian forest ecosystem. This information will not only help us to understand the ecological and hydrological process of the riparian forest but also provide support for ecological recovery of riparian forests and water-resources management of arid inland river basins. This study aims to estimate the suitability of the Water Vegetation Energy and Solute Modelling(WAVES) model to simulate the Ejina Desert riparian forest ecosystem changes,China, to assess effects of groundwater-depth change on the canopy leaf area index(LAI) and water budgets, and to ascertain the suitable groundwater depth for preserving the stability and structure of desert riparian forest. Results demonstrated that the WAVES model can simulate changes to ecological and hydrological processes. The annual mean water consumption of a Tamarix chinensis riparian forest was less than that of a Populus euphratica riparian forest, and the canopy LAI of the desert riparian forest should increase as groundwater depth decreases. Groundwater changes could significantly influence water budgets for T. chinensis and P. euphratica riparian forests and show the positive and negative effects on vegetation growth and water budgets of riparian forests. Maintaining the annual mean groundwater depth at around 1.7-2.7 m is critical for healthy riparian forest growth. This study highlights the importance of considering groundwater-change impacts on desert riparian vegetation and water-balance applications in ecological restoration and efficient water-resource management in the Heihe River Basin.  相似文献