Ephemeral landform development following rapid coastal uplift in the southern orogen of Taiwan     

Slawomir Jack Giletycz  Andrew Tien-Shun Lin  Katsura Yamada  Liang-Chi Wang  Chih-Wei Chien  Jiann-Yuh Lou  Neng-Wei Huang  Che-Yung Ting  Kuo-Wei Shih 《地球表面变化过程与地形》2021,46(12):2379-2394

Newly emerged landscapes above sea level are characterized by rapidly evolving geomorphic systems where the initial fluvial pattern adapts to a former submarine topography. Such an early formed fluvial system establishes drainage basins and unstable landforms that characterize high topographic asymmetry which are prone to fast removal or reorganization. Transitional landscapes might form depositional systems as lakes or ponds that subsequently are incised, captured and incorporated into drainage basins. In this study we focus on the recently emerged Hengchun Peninsula to survey its paleoenvironment evolution. Three drillings performed in the Gangkou basin with fieldwork revealed several indicators that reconstructed stages of the landscape reorganization. The major finding shows an ephemeral large lake in the central part of the Hengchun Peninsula that was drained to the Pacific c. 6000 bp . The lake belonged to an ephemeral lakeland that was created after the emergence of the peninsula. Currently, several areas as relict landforms indicate this stage of topography evolution that through high rates of incision and subsequent captures, transforms into drainage basins. Furthermore, two drillings show brackish waters at the present estuary of the Gangkou basin. These two different paleoenvironments today build one system – Gangkou catchment. Long-term uplift rates show that a hanging wall of the Hengchun Fault plays a significant role in the creation of a lakeland by tilting the peninsula's surface. The tilt impacts on asymmetrical emergence of the peninsula and catchment development. Our study shows that a new geomorphic system might create depositional ephemeral landforms (lakes) that represent phases of early topography evolution after emergence above a sea level that are subjected to instantaneous rearrangement and evolves through large-scale phases before it reaches a topographic steady-state.  相似文献   

A probabilistic approach for earthquake risk assessment based on an engineering insurance portfolio     

Wen-Ko Hsu  Wei-Ling Chiang  Qiang Xue  Dung-Mou Hung  Pei-Chun Huang  Cheng-Wu Chen  Chung-Hung Tsai 《Natural Hazards》2013,65(3):1559-1571

This paper presents the construction classification of the existing engineering covers in Taiwan. The exposure profile and variable vulnerability during different construction phases are established for some kinds of classes of construction. Finally, we present a method and framework to estimate the probable maximum loss of engineering insurance portfolio during an earthquake with consideration of the dynamic nature of structural changes and exposure values during a construction project.  相似文献   

Simultaneous measurement of humidity and temperature in the lower troposphere over Chung-Li,Taiwan     

Chih-Wei Chiang  Subrata Kumar Das  Jan-Bai Nee  Shun-xing Hu  Huan-ling Hu 《Journal of Atmospheric and Solar》2009,71(12):1389-1396

A combined Raman–Rayleigh lidar has been designed at Chung-Li, Taiwan for the simultaneous measurement of water-vapor mixing ratio, temperature and extinction-to-backscatter ratio of aerosol in the lower troposphere. The technique of Raman–Rayleigh lidar can retrieve correct temperature profile in the lower troposphere where the measurements are underestimated due to the aerosol loading. Two typical cases are discussed under different humidity (dry/wet) conditions. The water vapor and temperature profile have shown a good agreement with radiosonde. Simultaneous measurement of Raman–Rayleigh lidar also illustrates the physical nature of the aerosol and is useful in understanding the effects of humidity on aerosol swelling.  相似文献   

Equivalent series system to model a multiple friction pendulum system with numerous sliding interfaces for seismic analyses     

C. S. Tsai  H. C. Su  T. C. Chiang 《地震工程与工程振动(英文版)》2014,13(1):85-99

Current structural analysis software programs offer few if any applicable device-specifi c hysteresis rules or nonlinear elements to simulate the precise mechanical behavior of a multiple friction pendulum system(MFPS) with numerous sliding interfaces.Based on the concept of subsystems,an equivalent series system that adopts existing nonlinear elements with parameters systematically calculated and mathematically proven through rigorous derivations is proposed.The aim is to simulate the characteristics of sliding motions for an MFPS isolation system with numerous concave sliding interfaces without prior knowledge of detailed information on the mobilized forces at various sliding stages.An MFPS with numerous concave sliding interfaces and one articulated or rigid slider located between these interfaces is divided into two subsystems: the fi rst represents the concave sliding interfaces above the slider,and the second represents those below the slider.The equivalent series system for the entire system is then obtained by connecting those for each subsystem in series.The equivalent series system is validated by comparing numerical results for an MFPS with four sliding interfaces obtained from the proposed method with those from a previous study by Fenz and Constantinou.Furthermore,these numerical results demonstrate that an MFPS isolator with numerous concave sliding interfaces,which may have any number of sliding interfaces,is a good isolation device to protect structures from earthquake damage through appropriate designs with controllable mechanisms.  相似文献   

Spatial and Temporal Changes of Groundwater Level Induced by Thrust Faulting     

Yeeping Chia  Jessie J. Chiu  Yi-Hsuan Chiang  Tsai-Ping Lee  Chen-Wuing Liu 《Pure and Applied Geophysics》2008,165(1):5-16

Changes of groundwater level, ranging from a fall of 11.10 m to a rise of 7.42 m, induced by thrust faulting during the 1999 M_w 7.6, Chi-Chi earthquake have been recorded in 276 monitoring wells in Taiwan. Most coseismic falls appeared near the seismogenic fault as well as other active faults, while coseismic rises prevailed away from the fault. Coseismic groundwater level rises and falls correlated fairly well with hypocentral distance in the vicinity of the thrust fault. We found a major difference of coseismic changes in wells of different depths at most multiple-well stations. The recovery process of coseismic groundwater level changes is associated with the confining condition of the aquifer. Cross-formational flow is likely to play an important role in groundwater level changes after the earthquake. In the hanging wall of the thrust fault, an abnormal decline of groundwater level was observed immediately before the earthquake. The underlying mechanism of the unique preseismic change warrants further investigation.  相似文献   

An integrated earthquake early warning system and its performance at schools in Taiwan     

Bing-Ru Wu  Nai-Chi Hsiao  Pei-Yang Lin  Ting-Yu Hsu  Chiou-Yun Chen  Shieh-Kung Huang  Hung-Wei Chiang 《Journal of Seismology》2017,21(1):165-180

An earthquake early warning (EEW) system with integration of regional and onsite approaches was installed at nine demonstration stations in several districts of Taiwan for taking advantages of both approaches. The system performance was evaluated by a 3-year experiment at schools, which experienced five major earthquakes during this period. The blind zone of warning was effectively reduced by the integrated EEW system. The predicted intensities from EEW demonstration stations showed acceptable accuracy compared to field observations. The operation experience from an earthquake event proved that students could calmly carry out correct action before the seismic wave arrived using some warning time provided by the EEW system. Through successful operation in practice, the integrated EEW system was verified as an effective tool for disaster prevention at schools.  相似文献   

Trophic coupling between <Emphasis Type="Italic">Synechococcus</Emphasis> and pigmented nanoflagellates in the coastal waters of Taiwan,western subtropical Pacific     

Lin Yun-Chi  Tsai An-Yi  Chiang Kuo-Ping 《Journal of Oceanography》2009,65(6):781-789

In our attempt to characterize the interaction of trophic coupling between Synechococcus and pigmented nanoflagellates (PNFs), successive size-fraction experiments were performed at a coastal station on the northeast coast of Taiwan from June, 2005 to January, 2006. By estimating the growth rate and grazing rate of Synechococcus in the presence of nanoflagellates of different sizes, we truncated the food web by removing organisms with different body sizes (<2 μm, <5 μm, <10 μm, and <20 μm). The growth rates of Synechococcus ranged from −0.016 to 0.051 h⁻¹ during the experimental period, suggesting that temperature was a primary mechanism controlling Synechococcus growth. In addition to size and relative biomass of pigmented nanoflagellates and Synechococcus, it is suggested that community structures played an important role in trophic link. Furthermore, we conclude that the trophic cascading effect in the northeast coast of Taiwan includes: 1) high grazing rates at night in the warm season; 2) the Synechococcus biomass generally exceeds the grazing threshold (6 × 10⁴ cells mL⁻¹); and 3) the biomass ratio of <5 μm PNFs to >5 μm PNFs should be 1:1 to 2:1.  相似文献   

An ANN–RTS smoother scheme for accurate INS/GPS integrated attitude determination     

Kai-Wei Chiang  Yung-Cheng Lin  Yun-Wen Huang  Hsiu-Wen Chang 《GPS Solutions》2009,13(3):199-208

Digital mobile mapping, the method that integrates digital imaging with direct geo-referencing, has developed rapidly over the past 15 years. The Kalman filter (KF) is considered an optimal estimation tool for real-time INS/GPS integrated kinematic positioning and orientation determination. However, the accuracy requirements of general mobile mapping applications cannot be easily achieved even when using the KF scheme. Therefore, this study proposes an intelligent scheme combining ANN and RTS backward smoother to overcome the limitations of KF and to enhance the overall accuracy of attitude determination for tactical grade and MEMS INS/GPS integrated systems.

Yun-Wen Huang (Corresponding author)Email:

  相似文献   

Non-local scaling in two-dimensional gravitational clustering     

Dipak Munshi  Lung-Yih Chiang  Peter Coles  & Adrian L. Melott 《Monthly notices of the Royal Astronomical Society》1998,293(3):L68-L72

Using an ensemble of high-resolution 2D numerical simulations, we explore the scaling properties of cosmological density fluctuations in the non-linear regime. We study the scaling behaviour of the usual N -point volume-averaged correlations, but also examine the scaling of the entire probability density function (PDF) of the fluctuations. We focus on two important issues: (i) whether the scaling behaviour of 2D clustering is consistent with what one infers from radial collapse arguments; and (ii) whether there is any evidence from these high-resolution simulations that a regime of stable clustering is ever entered. We find that the answers are (i) yes and (ii) no. We further find that the behaviour of the highly non-linear regime in these simulations suggests the existence of a regime in which the correlation function is independent of the initial power spectrum.  相似文献   

The influence of faculae on sunspot heat blocking     

Wei-Hwan Chiang  Peter Foukal 《Solar physics》1985,97(1):9-20

We study the influence of faculae on sunspot heat blockage using a thermal model based on eddy heat diffusion through the convection zone. The facula is represented as a localized area of excess emission surrounding the sunspot, which is represented as a thermal plug. Our computations using a range of reasonable combinations of spot and facular depths show no significant influence of the facula on the long storage times of heat blocked by sunspots. However, the local cooling of surface layers produced by excess facular emission in this model propagates globally within the convection zone in a similar way to the heating produced by a spot. The net effect of spots and faculae on L over time scales longer than an active region lifetime should thus be determined by the global sum of sunspot flux deficits and facular excesses.  相似文献