Late Quaternary Activity of the Chuxiong-Nanhua Fault and the 1680 Chuxiong MS6 ¾ Earthquake     

Chang Zufeng  Chang Hao  Li Jianlin 《中国地震研究》2017,31(3):431-440

In this paper, according to the results of the satellite imagery interpretation and field investigation, we study the active features and the latest active times of the Chuxiong-Nanhua fault, the Quaternary basins formation mechanism, and the relationship between the fault and the 1680 Chuxiong M_S6 ¾ earthquake. Several Quaternary profiles at Lvhe, Nanhua reveal that the fault has offset the late Pleistocene deposits of the T2 and T3 terraces of Longchuan river, indicating that the fault was obviously active in late Quaternary. The Chuxiong-Nanhua fault has been dominated by dextral strike slip motion in the late Quaternary, with an average rate of 1.6-2.0mm/a. Several pull apart Quaternary basins of Chuxiong, Nanhua, and Ziwu etc. have developed along the fault. The 1680 Chuxiong M_S6 ¾ earthquake and several moderate earthquakes have occurred near the fault. The Chuxiong-Nanhua fault are the seismogenic structure of those earthquakes, the latest fault movement was in the late-Pleistocene, and even the Holocene. In large area, the Chuxiong-Nanhua fault and the eastern Qujiang fault and the Shiping fault composed a set of NW-trending oblique orientation active faults, and the motion characteristics are all mainly dextral strike slip. The motion characteristics, like the red river fault of the Sichuan-Yunnan Rhombic Block southwestern boundary, are concerned with the escaping movement of the Sichuan-Yunnan Rhombic Block.  相似文献   

Simulating and mapping the risk of surge floods in multiple typhoon scenarios: a case study of Yuhuan County,Zhejiang Province,China   总被引：1，自引：0，他引：1  

Mengya?Li  Wei?Wu  Jun?WangEmail author  Zhumei?Che  Yali?Xie 《Stochastic Environmental Research and Risk Assessment (SERRA)》2017,31(3):645-659

We propose a scenario-based method for simulating and mapping the risk of surge floods for use by local authorities concerned with public safety and urban planning in coastal areas. Focusing on the triad of hazard, vulnerability and adaptation capability, we estimate the comprehensive risk and display its spatial distribution using the raster calculation tool in ArcGIS. The detailed methodology is introduced via a case study of Yuhuan, an island county in Zhejiang Province, China, which is frequently affected by typhoon storm surges. First, we designed 24 typhoon scenarios and modeled the flood process in each scenario using the hydrodynamic module of MIKE 21. Second, flood depth and area were used for hazard assessment; an authorized indicator system of land use categories and a survey of emergency shelters were used for vulnerability and adaptation capability assessment, respectively; and a quantified model was used for assessment of the comprehensive risk. Lastly, we used the GIS raster calculation tool for mapping the risk of storm surges in multiple typhoon scenarios. Our principal findings are as follows: (1) Seawalls are more likely to be overtopped or destroyed by more severe storm surges with increasing typhoon intensity. (2) Most of the residential areas with inadequate emergency shelters are highly vulnerable to flood events. (3) As projected in the risk mapping, if an exceptional typhoon with a central pressure of 915 or 925 hPa made a landfall in Yuhuan, a wide range of areas would be flooded and at high risk. (4) Determining optimal strategies based on identification of risk-inducing factors is the most effective way of promoting safe and sustainable development in coastal cities.  相似文献   

Simulating Stable Isotope Ratios in Plumes of Groundwater Pollutants with BIOSCREEN‐AT‐ISO          下载免费PDF全文

Patrick Höhener  Zhi M. Li  Maxime Julien  Pierrick Nun  Richard J. Robins  Gérald S. Remaud 《Ground water》2017,55(2):261-267

BIOSCREEN is a well‐known simple tool for evaluating the transport of dissolved contaminants in groundwater, ideal for rapid screening and teaching. This work extends the BIOSCREEN model for the calculation of stable isotope ratios in contaminants. A three‐dimensional exact solution of the reactive transport from a patch source, accounting for fractionation by first‐order decay and/or sorption, is used. The results match those from a previously published isotope model but are much simpler to obtain. Two different isotopes may be computed, and dual isotope plots can be viewed. The dual isotope assessment is a rapidly emerging new approach for identifying process mechanisms in aquifers. Furthermore, deviations of isotope ratios at specific reactive positions with respect to “bulk” ratios in the whole compound can be simulated. This model is named BIOSCREEN‐AT‐ISO and will be downloadable from the journal homepage.  相似文献   

Distribution,potential sources and ecological risks of two persistent organic pollutants in the intertidal sediment at the Shuangtaizi Estuary,Bohai Sea of China     

Xiutang Yuan  Xiaolong Yang  Anguo Zhang  Xindong Ma  Hui Gao  Guangshui Na  Humin Zong  Guize Liu  Yongguang Sun 《Marine pollution bulletin》2017,114(1):419-427

Spatial distribution, source apportionment, and potential ecological risks of sixteen polycyclic aromatic hydrocarbons (PAHs) and seven endocrine disrupting compounds (EDCs) in the intertidal sediment at the Shuangtaizi Estuary, Bohai Sea of China were analyzed. Results showed that the total PAH concentrations ranged from 28.79 ng g^? 1 dw to 281.97 ng g^? 1 dw (mean: 115.92 ng g^? 1 dw) and the total EDC concentrations from 0.52 ng g^? 1 dw to 126.73 ng g^? 1 dw (mean: 37.49 ng g^? 1 dw). The distribution pattern for the PAHs was generally different from that of the EDCs possibly due to their distinct sources and n-octanol-/water partition coefficients (K_OW). Qualitative and quantitative analytical results showed that PAH sources were mainly from a mixture of pyrogenic and petrogenic contributions. The higher levels at the southeast of Geligang indicated that the EDC pollutants may have mainly originated from the plastic industry and other chemical plants located along the Liao River. Ecological risk assessment revealed that PAHs exhibited low ecotoxicological effects, whereas EDCs, especially 4-tert-octylphenol and bisphenol A, had high ecological hazard to the estuarine biota.  相似文献   

The Co-seismic Response of Underground Fluid in Yunnan to the Nepal MS8.1 Earthquake     

Zhang Li  Su Youjin  Luo Ruijie  Gao Wenfei  Zhang Ping 《中国地震研究》2017,31(2):201-212

In this paper, statistics are taken on the co-seismic response of underground fluid in Yunnan to the Nepal M_S8.1 earthquake, and the co-seismic response characteristics of the water level and water temperature are analyzed and summarized with the digital data. The results show that the Nepal M_S8.1 earthquake had greater impact on the Yunnan region, and the macro and micro dynamics of fluids showed significant co-seismic response. The earthquake recording capacity of water level and temperature measurement is significantly higher than that of water radon and water quality to this large earthquake; the maximum amplitude and duration of co-seismic response of water level and water temperature vary greatly in different wells. The changing forms are dominated by fluctuation and step rise in water level, and a rising or falling restoration in water temperature. From the records of the main shock and the maximum strong aftershock,we can see that the greater magnitude of earthquake, the higher ratio of the occurrence of co-seismic response, and in the same well, the larger the response amplitude, as well as the longer the duration. The amplitude and duration of co-seismic response recorded by different instruments in a same well are different.Water temperature co-seismic response almost occurred in wells with water level response, indicating that the well water level and water temperature are closely related in co-seismic response, and the well water temperature seismic response was caused mainly by well water level seismic response.  相似文献   

Generation of continuous surface soil moisture dataset using combined optical and thermal infrared images          下载免费PDF全文

Pei Leng  Xiaoning Song  Si‐Bo Duan  Zhao‐Liang Li 《水文研究》2017,31(6):1398-1407

Surface soil moisture (SSM) is a critical variable for understanding water and energy flux between the atmosphere and the Earth's surface. An easy to apply algorithm for deriving SSM time series that primarily uses temporal parameters derived from simulated and in situ datasets has recently been reported. This algorithm must be assessed for different biophysical and atmospheric conditions by using actual geostationary satellite images. In this study, two currently available coarse‐scale SSM datasets (microwave and reanalysis product) and aggregated in situ SSM measurements were implemented to calibrate the time‐invariable coefficients of the SSM retrieval algorithm for conditions in which conventional observations are rare. These coefficients were subsequently used to obtain SSM time series directly from Meteosat Second Generation (MSG) images over the study area of a well‐organized soil moisture network named REMEDHUS in Spain. The results show a high degree of consistency between the estimated and actual SSM time series values when using the three SSM dataset‐calibrated time‐invariable coefficients to retrieve SSM, with coefficients of determination (R²) varying from 0.304 to 0.534 and root mean square errors ranging from 0.020 m³/m³ to 0.029 m³/m³. Further evaluation with different land use types results in acceptable debiased root mean square errors between 0.021 m³/m³ and 0.048 m³/m³ when comparing the estimated MSG pixel‐scale SSM with in situ measurements. These results indicate that the investigated method is practical for deriving time‐invariable coefficients when using publicly accessed coarse‐scale SSM datasets, which is beneficial for generating continuous SSM dataset at the MSG pixel scale.  相似文献   

龙门山地区历史强震数值模拟     

刘盼  马世虎  李平恩  韩晓飞 《地震地磁观测与研究》2017,38(6):1-9

考虑区域地质构造差异、主要活动断裂分布特征和地表附加重力影响,建立反映龙门山地区地表起伏和岩石圈分层的三维粘弹性有限元模型。以GPS为约束重建研究区现今构造应力场,依次模拟龙门山地区1900年以来发生的5次M_S 7.0以上地震,从库仑应力和等效应力角度,分析应力场演化对强震的影响以及强震间的相互作用关系。研究结果表明:从库仑应力角度,有3次地震对后续地震有促进作用,其中汶川地震对芦山地震有触发作用;从等效应力角度,有4次地震对后续地震的发生具有加速作用。  相似文献   

2014年8月云南鲁甸M_S 6.5地震典型地表破裂特征     

李晓  裴向军  刘洋 《震灾防御技术》2017,12(2):338-345

北京时间2014年8月3日16时30分，云南省鲁甸县发生了M_S 6.5地震，本次地震的发震构造为包谷垴-小河断裂。野外调查发现，王家坡不稳定斜坡上的地表破裂在整个破裂带中比较具有代表性，其地表破裂带整体走向N45°W-N50°W，并且由剪切破裂、张剪切破裂、压剪切破裂、张性破裂以及鼓包等典型地表破裂组成。其中左、右地表破裂边界与发震断层的出露位置一致，由断层错动造成；而部分地表破裂与断层的位置不重合，其成因分为2种，一种是发震断层导致的一些次级地表破裂，另一种是地震引发的滑坡后缘破裂。地表破裂类型和基本组合特征显示出王家坡潜在不稳定斜坡上的地表破裂带具有左旋走滑的性质。  相似文献