珠江三角洲地区风暴潮重现期及增水与环境要素的关系   总被引：2，自引：0，他引：2  

李阔  李国胜 《地理科学进展》2010,29(4)

珠江三角洲地区是我国海岸中台风暴潮最严重的区域之一,受全球变暖和海平面上升影响,该地区风暴潮增水重现值将出现显著的变化。本文采用耿贝尔方法和皮尔逊Ⅲ型分布法,分别计算了珠江三角洲地区11个潮位站的最大增水值的重现期,并对计算结果进行了比较,绘制了风暴潮增水重现值分布曲线。结果表明大部分潮位站的耿贝尔分布曲线与经验频率点吻合程度较好,少数潮位站的皮尔逊Ⅲ型分布曲线与经验频率点吻合程度较好,两种方法结合起来效果最佳;分析了该地区风暴潮重现期的基本特征;最后总结了风暴潮与台风路径、天文潮以及地形之间的关系。该计算结果将为政府规划设计部门决策提供参考,对风暴潮预报、海岸工程设计和估计风暴潮造成的损失提供科学依据。  相似文献   

APN技术在地震前兆观测系统中的应用     

刘爱春  王秀英  周振安  李阔 《地震地磁观测与研究》2010,31(6):51-54

介绍基于GPRS的APN无线网络通讯技术,并应用于地震前兆观测系统。实际运行结果表明,应用该技术系统可提高数据传输的稳定性、可靠性、安全性和实时性,是地震前兆观测数据传输的有效通讯手段。  相似文献   

The Effect of Toluene-Substrate Concentration on Biological Clogging and Sloughing in Porous Media     

W.C. Cheng  M.C. Tom Kuo 《Ground Water Monitoring & Remediation》2010,30(4):73-80

One-dimensional flow experiments on biological clogging were carried out by biostimulating columns packed with glass beads, sterilized, and inoculated with toluene-utilizing bacteria. Biostimulation consisted of continuously injecting toluene at four concentrations (3.0 ± 0.9, 6.1 ± 0.8, 8.7 ± 1.6, and 11.3 ± 0.8 mg/L). The results of column flow experiments indicated that a threshold concentration of toluene exists below which the total biomass in the column can be kept at a steady-state level. The column cores were extruded and segmented to determine the biomass distribution throughout the column at clogging. Clogging resulted in a significant buildup of filamentous bacteria close to the inlet end. Based on the nucleotide sequence of 16S rRNA genes, the dominant filamentous bacteria were identified as Nocardia farcinica. A 235-d column experiment demonstrated that the clogging near injection points can be controlled by keeping the influent concentration of toluene below the threshold.  相似文献   

Copula‐based joint probability function for PGA and CAV: a case study from Taiwan          下载免费PDF全文

Yun Xu  Xiao‐Song Tang  J. P. Wang  H. Kuo‐Chen 《地震工程与结构动力学》2016,45(13):2123-2136

This study aims to develop a joint probability function of peak ground acceleration (PGA) and cumulative absolute velocity (CAV) for the strong ground motion data from Taiwan. First, a total of 40,385 earthquake time histories are collected from the Taiwan Strong Motion Instrumentation Program. Then, the copula approach is introduced and applied to model the joint probability distribution of PGA and CAV. Finally, the correlation results using the PGA‐CAV empirical data and the normalized residuals are compared. The results indicate that there exists a strong positive correlation between PGA and CAV. For both the PGA and CAV empirical data and the normalized residuals, the multivariate lognormal distribution composed of two lognormal marginal distributions and the Gaussian copula provides adequate characterization of the PGA‐CAV joint distribution observed in Taiwan. This finding demonstrates the validity of the conventional two‐step approach for developing empirical ground motion prediction equations (GMPEs) of multiple ground motion parameters from the copula viewpoint. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Evaluating the effect of the global ionospheric map on aiding retrieval of radio occultation electron density profiles   总被引：1，自引：0，他引：1  

Xinan Yue  William S. Schreiner  Ying-Hwa Kuo 《GPS Solutions》2013,17(3):327-335

Radio occultation (RO) has been proven to be a powerful technique for ionospheric electron density profile (EDP) retrieval. The Abel inversion currently used in RO EDP retrieval has degraded performance in regions with large horizontal gradients because of an assumption of spherical symmetry as indicated by many studies. Some alternative methods have been proposed in the past; the global ionospheric map (GIM)-aided Abel inversion is most frequently studied. Since the number of RO observations will likely increase rapidly in the near future, it is worthwhile to continue to improve retrieval method. In this study, both the simulations and the real data test have been done to evaluate the GIM-aided Abel inversion method. It is found that the GIM-aided Abel inversion can significantly improve upon the standard Abel inversion in either the F or the E region if an accurate GIM is available. However, the current IGS GIM does not appear accurate enough to improve retrieval results significantly, because of the spherical symmetry assumption and sparse global navigation satellite system (GNSS) stations used in its creation. Generating accurate GIM based on dense GNSS network to aid the Abel inversion might be an alternative method.  相似文献   

地形追随垂直运动方程在南疆极端暴雨中的诊断分析     

周括  冉令坤  蔡仁  屈涛  陈蕾 《大气科学》2022,46(3):745-761

针对2021年6月15～17日发生在昆仑山脉北坡的南疆极端暴雨过程,本文综合考虑地形对暴雨发生、发展的作用后,利用地形追随坐标控制方程并采用Boussinesq近似推导建立了地形追随坐标的非静力平衡广义垂直运动方程。诊断结果表明,经向气压梯度力耦合经向散度项（项一）、垂直气压梯度力耦合纬向散度项（项二）和非绝热加热经向梯度项（项三）是激发暴雨垂直运动发展演变的三个主要强迫项。项一体现了偏北风逐渐增强,在昆仑山脉的阻挡下导致经向辐合增强,触发了垂直上升运动。经向气流辐合始终是对流活动最主要的强迫过程,其次为纬向气流辐合。在地形追随坐标形式下,经向和垂直气压梯度能够增强项一和项二。对流发展阶段,水汽辐合与非绝热加热过程增强了非绝热加热经向梯度,促进了垂直上升运动发展。在地形的影响下,对流层中高层西风过山气流波动特征明显。重力波活动导致的高层辐散进一步促进了山脉迎风坡对流活动。经向和纬向气流辐合、非绝热加热过程以及重力波活动等多个因素共同造成了此次南疆极端暴雨。  相似文献   

一次暴雨中尺度涡旋发展机制诊断分析研究     

焦宝峰  冉令坤  李舒文  周括 《大气科学》2022,46(3):762-774

中尺度涡旋可以持续激发新对流,是造成局地持续性降水的重要系统。基于经典涡度方程的诊断无法描述热力信息对于涡旋发展的贡献。本文采用Boussinesq近似对涡度方程进行整理,将方程唯一强迫项定义为垂直速度位涡,其形式与位涡类似,利用垂直速度替换位温。进一步在垂直速度位涡倾向方程中,以气压水平梯度的形式引入热力过程的间接作用,定量描述动热力配置的贡献。以2021年6月15日发生在南疆的一次极端暴雨为例,利用高分辨率数值模拟资料,初步分析了低层动热力强迫作用向垂直涡度的传递。结果表明,垂直速度位涡的局地变化主要来自热力强迫项中低层垂直风切变与低层冷池的耦合作用,两者在降水区前侧产生大范围的正值区。该区域与垂直速度位涡的正值区重叠,促进垂直速度位涡的增长,进而维持降水前缘的正涡度,有利于产生较强的上升运动,触发新对流并造成持续性降水。  相似文献   

Effects of flow rate and chemical oxygen demand removal characteristics on power generation performance of microbial fuel cells     

D. F. Juang  P. C. Yang  T. H. Kuo 《International Journal of Environmental Science and Technology》2012,9(2):267-280

Two microbial fuel cells with different oxygen supplies in the cathodic chamber were constructed. Electrogenic capabilities of both cells were compared under the same operational conditions. Results showed that binary quadratic equations can express the relationships between chemical oxygen demand degradation rate and chemical oxygen demand loading and between chemical oxygen demand removal rate and chemical oxygen demand loading in both cells. Good linear relationships between power output (voltage or power density) and flow rate and between power output and chemical oxygen demand degradation rate were only found on the cell with mechanical aeration in the cathodic chamber, but not on the cell with algal photosynthesis in the cathodic chamber. The relationships between power output and chemical oxygen demand removal rate and between power output and effluent chemical oxygen demand concentration on both cells can be expressed as binary quadratic equations. The optimum flow rates to obtain higher power density and higher Coulombic efficiency in the cell with mechanical aeration in the cathodic chamber (=0.85?mW/m² and 0.063%) and in the cell with algal photosynthesis in the cathodic chamber (=0.65?mW/m² and 0.05%) are about 1000 and 1460???L/min, respectively. The optimum chemical oxygen demand removal rates to obtain higher power density and higher Coulombic efficiency in the cell with mechanical aeration in the cathodic chamber (=1.2?mW/m² and 0.064%) and in the cell with algal photosynthesis in the cathodic chamber (=0.81?mW/m² and 0.051%) are about 40.5 and 36.5%, respectively.  相似文献   

Numerical study of upper ocean response to a typhoon moving zonally across the Luzon Strait   总被引：1，自引：0，他引：1  

Yi-Chun Kuo  Ching-Sheng Chern  Joe Wang  Ya-Ling Tsai 《Ocean Dynamics》2011,61(11):1783-1795

The Luzon Strait (LS) is a wide channel between Taiwan and the Luzon islands. Eastward of the LS, the Kuroshio Current (KC) flows northward along the eastern coasts of Luzon and Taiwan. A typhoon is a strong and localized low-pressure weather system that occurs frequently in the vicinity of the Taiwan area. One typical typhoon track, passing through the seas surrounding Taiwan, is a zonal path across the LS. The satellite measured SST, corresponding to typhoons Pabuk (5 Aug. 2007–12 Aug. 2007) and Dujuan (29 Aug. 2003–5 Sep. 2003), which both moved along this path, demonstrated that a classic right bias cooling occurs to the north of the storm track, during the typhoon forced period. However, some cold anomaly water also present toward left (south) of the storm track east of the LS in the relaxation period. This paper adopted a three-dimensional hydrostatic primitive equation model to study the possible causes of this southward transport of cold waters. Both model results and the observed SST anomaly revealed that the strength of the upper ocean cooling depends on whether a resonant regime between the typhoon winds and the near-inertial currents can be excited. To the east of the LS, the convergence between the warm Kuroshio water and the cold wakes in the poststorm period will enhance the southward spreading of cold anomaly water. The enhanced vertical mixing, induced by the southward propagation of nearly inertial waves associated with the cold wakes, can also produce some cold anomaly to the south of a storm track in the poststorm period. Both mechanisms can contribute to the occurrence of some cold anomaly water to the south of the storm track east of the KC. To the west of the LS, the convergence between the warm Kuroshio water and the cold upwelling water from the northern South China Sea can further strengthen the Kuroshio front in the LS.  相似文献   

A laboratory study on the undrained strength of a silty sand from Central Western Taiwan   总被引：2，自引：0，他引：2  

Yao-Tao Huang  An-Bin Huang  Yu-Chen Kuo  Ming-Dou Tsai 《Soil Dynamics and Earthquake Engineering》2004,24(9-10):733

The sand deposit in Central Western Taiwan typically contained significant amounts of fines. The assessment of liquefaction potential using the simplified procedure often involved adjustment in field test results to account for the effects of fines. The available fines content (FC) adjustment methods are highly empirical and may lead to very different conclusions. The need and/or level of FC adjustment should be justified based on cyclic behavior of sand and its relationship with fines. This study made an attempt to provide that reference information for a silty sand commonly found in Central Western Taiwan. A series of isotropic consolidation, undrained monotonic and cyclic triaxial tests were conducted on reconstituted Mai Liao Sand (MLS) with various FCs and densities. Concurrent shear wave velocities were measured using bender elements in some of the cyclic triaxial tests. This paper describes the geological background, the laboratory tests and their implications in the assessment of liquefaction potential for MLS.  相似文献