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121.
122.
The paper gives the distributions of the daily mean temperature of black body of satellite infrared
images from June 7 to 10, 1998 during HUAMEX and examines 14 meso-α-scale convective systems and a
number of meso-b-scale convective systems using the satellite infrared images at 1-h intervals. The mesoscale
convective systems on June 7 and 9, which resulted in severe rainstorm over the middle of Taiwan and the
estuary region of the Pearl River (Zhujiang R.), are emphatically analyzed. The serial development of mesoscale
convective systems is revealed by the distributions of the black body temperature of satellite infrared images. The
environmental conditions in which many mesoscale convective systems continuously occurred are diagnosed.
The visualizing tool, LiveView, displays the link between the upper and lower horizontal wind fields and the
vertical circulations and 3-dimensional trajectories of moist air motions, based on the data of objective analyses. 相似文献
123.
卫星遥感技术应用在公路选线中,具有常规方法无可比拟的优势。在国道314线焉耆盆地段高速公路前期选线研究中,以Landsat-5 TM457数字图象为主要信息源,通过数据处理和遥感判释并综合分析常规资料,对恶煮盆地段第四纪堆积平原土体工程地质区进一步划分亚区,探讨分析了不良地质现象分布规律、形态背景及发展演化趋势,在此基础上比较各设计线路之优缺点,并提出科学合理的建议线路方案。 相似文献
124.
125.
四川省青川断裂的特征及形成的物理条件 总被引:3,自引:0,他引:3
本文详细地讨论了四川省青川断裂的断裂特征及形成的物理条件。对断裂构造岩的微构造和宏观构造进行了细致的描述分析,将断裂岩分为四个带。结合区域资料,讨论了断裂的形成时代及与邻区的关系。 相似文献
126.
石榴石是研究区内暗色镁铁质岩、麻粒岩及片麻岩的主要造岩矿物之一。成分分
析表明,它们是含钙铝榴石分子较多的镁铝一铁铝系列石榴石,红外光谱测定其近于铁铝榴石;
穆斯堡尔谱分析表明,Fe3+含量增多将引起石榴石内六配位多面体变形程度增大;:是胞参数ao
与Ca2+含量呈正相关。本区石榴石是麻粒岩相变质作用的产物,形成的温压条件为780-840℃.
0.85-1.10 GPa。形成石榴石的反应是复杂的,其中包括角闪石与斜长石的增温脱水反应以及
紫苏辉石+斜长石组合向石榴石+革斜辉石组合转化的滑动反应。 相似文献
127.
Xu Jiongxin 《地球表面变化过程与地形》1993,18(8):687-702
This paper describes meandering alluvial rivers with mean annual suspended-sediment concentrations of more than 100 kgm?3 on the Loess Plateau, China, and explains their formation as caused by the effect of hyperconcentrated water flow. When the river is dominated by hyperconcentrated flow, the rate of energy expenditure required for sediment transport declines significantly. Accordingly, the river channel adjusts itself to a lower channel gradient by increasing the river length, resulting in a meandering channel. Since the stable transportation of sediment by hyperconcentrated flow is dependent on river channel boundary conditions, the latter play an important role in the formation of meanders of this kind. The paper also discusses the conditions for the discrimination of meandering and braided rivers in this area. 相似文献
128.
Diego Gómez Pablo Salvador Julia Sanz Mikhail Urbazaev José Luis Casanova 《地理信息系统科学与遥感》2020,57(6):813-829
ABSTRACT The climate in southern Iceland has warmed over the last 70 years, resulting in accelerated glacier dynamics at the Solheimajoküll glacier. In this study, we compare glacier terminus locations from 1973 to 2018, to changes in climate across the study area, and we derive ice-surface velocities (2015–2018) from satellite remote-sensing imagery (Sentinel-1) using the offset-tracking method. There have been two regional temperature trends in the study period: cooling (1973–1979) and warming (1980–2018). Our results indicate a time lag of about 20 years between the onset of glacier retreat (?53 m/year since 2000) and the inception of the warming period. Seasonally, the velocity time series suggest acceleration during the summer melt season since 2016, whereas glacier velocities during accumulation months were constant. The highest velocities were observed at high elevations where the ice-surface slope is the steepest. We tested several scenarios to assess the hydrological time response to glacier accelerations, with the highest correlations being found between one and 30 days after the velocity estimates. Monthly correlation analyses indicated inter-annual and intra-annual variability in the glacier dynamics. Additionally, we investigate the linkage between glacier velocities and meltwater outflow parameters as they provide useful information about internal processes in the glacier. Velocity estimates positively correlate with water level and negatively correlate with water conductivity between April and August. There is also a disruption in the correlation trend between water conductivity and ice velocity in June, potentially due to a seasonal release of geothermal water. 相似文献
129.
作者首次在该区找到了硅灰石矿。在专题研究基础上,分析了区域地层、构造、岩浆活动和硅灰石矿床地质特征等,提出该硅灰石矿主要产于康古尔断裂带内的花岗岩与碳酸盐地层接触带,属矽卡岩型硅灰石矿。对区内花岗岩、碳酸盐地层、矽卡岩、大地构造等硅灰石成矿条件作了分析,初步提出了该矿主要应用领域为建筑陶瓷工业。 相似文献
130.
Conditioning mean steady state flow on hydraulic head and conductivity through geostatistical inversion 总被引:5,自引:2,他引:3
A. F.?Hernandez S. P.?NeumanEmail author A.?Guadagnini J.?Carrera 《Stochastic Environmental Research and Risk Assessment (SERRA)》2003,17(5):329-338
Nonlocal moment equations allow one to render deterministically optimum predictions of flow in randomly heterogeneous media and to assess predictive uncertainty conditional on measured values of medium properties. We present a geostatistical inverse algorithm for steady-state flow that makes it possible to further condition such predictions and assessments on measured values of hydraulic head (and/or flux). Our algorithm is based on recursive finite-element approximations of exact first and second conditional moment equations. Hydraulic conductivity is parameterized via universal kriging based on unknown values at pilot points and (optionally) measured values at other discrete locations. Optimum unbiased inverse estimates of natural log hydraulic conductivity, head and flux are obtained by minimizing a residual criterion using the Levenberg-Marquardt algorithm. We illustrate the method for superimposed mean uniform and convergent flows in a bounded two-dimensional domain. Our examples illustrate how conductivity and head data act separately or jointly to reduce parameter estimation errors and model predictive uncertainty.This work is supported in part by NSF/ITR Grant EAR-0110289. The first author was additionally supported by scholarships from CONACYT and Instituto de Investigaciones Electricas of Mexico. Additional support was provided by the European Commission under Contract EVK1-CT-1999-00041 (W-SAHaRA-Stochastic Analysis of Well Head Protection and Risk Assessment). 相似文献