追忆李四光对防震减灾的贡献，以系统整体观指导防震应急

笔者在追忆李四光地震科学和防震减灾指导思想的基础上,提出了以系统整体观指导防震应急的新论点,包括:运用地壳运动整体观研究地震规律;应用地震预测整体观进行地震预测;划分活动性构造体系,研究构造活动性;加强综合监测,研究各种地震前兆和相关的自然变异的发展趋势;圈定地震风险区,制定防震应急预案等。并结合中国的实际情况进行了论述。

Risk Assessment of Highways Affected by Debris Flows in Wenchuan Earthquake Area

Since the Wenchuan earthquake in China on May 12th, 2008, highways in earthquake-affected areas have been frequently interrupted by debris flows. We analyzed the hazard effect modes and damage processes along highways and developed three key indexes, scale of debris flows, deposits on highways and river blockage, to describe quantitatively the highway disasters. By combining the empirical methods and the actual terrain conditions, we proposed new methods to determine the value of hazard indexes. In addition, we used the economic value and resistance of highway as vulnerability assessment indexes, then determined the specific subindexes for the subgrade, bridges and culverts, and developed a way for the quantified vulnerability zoning. Moreover, we proposed the assessment and mapping methods for highway risk. The risk is described into 5 grades： extremely low risk, low risk, middle risk, high risk and extremely high risk. We applied these methods in a case study carried out on provincial highway S3o3 from Yingxiu Town to Wolong Town, in Wenchuan County. Analysis of debris flow risk for the whole highway, showed that the total length of highway in extremely low risk area was 28.26 km, 4.83 km in low risk area, 8.0 km in middle risk area, 3.65 km in high risk area, and 3.06 km in extremely high risk area. The assessment results are consistent with the field survey data which reflected the disaster situation. This risk method can be used objectively to evaluate the debris-flow risk along highways, and is useful for highway reconstruction in mountainous areas suffering from active debris flows.

Discussion on Deep Tectonic Background of Moderately Strong Earthquake in Anhui Province and Its Neighboring Areas Using Results of Seismic Tomography

Using the latest results of seismic tomography, we studied the deep tectonic settings of the moderate and strong earthquakes in Anhul Province and its neighboring areas （28° - 39°N, 112°- 124°E）. The results are as follows： （1） There exists a certain correlation between the location of moderate-strong earthquake, the geologic structure of the surface and the partitioning of active tectonic elements with the upper-crust velocity structure. Most earthquakes recording M ≥ 6.0 occur in high-velocity zones or in the transitional areas between high-velocity and low-velocity zones in the upper crust. Seismicity in the low-velocity zone has a lesser impact. Earthquakes occuring in the high-velocity zone are distributed mainly in the velocity variation area. The boundary belts and the interior of the North China plain fault block are the main active sites of moderate-strong earthquakes. Beneath the fault basins in the western and northern sides of the block, the upper crust is characterized by a wide discontinuous distribution in the low-velocity zone, and in the transition zone from the low- to high velocities, the moderate strong seismicity shows a zonal distribution where active faults are developed. The NW-extension Zhoukou-Hefei-Xuancheng low-velocity zone separates the highvelocity zones of Dabieshan Mountains and west Shandong-Anhul, and moderate-strong earthquakes on its northern side bordering the high-velocity zones are relatively frequent. This low-velocity zone is probably an important and deeply structured boundary between the North China and the South China tectonic provinces. （2） The frequent moderate-strong earthquake recorded in the past and the recent small earthquake activities in the Huoshan-Lu＇ an area are the result of a low-velocity zone in the middle crust beneath the central part of Dabieshan and the two sets of deep faults that cut through the crust. （3） In terms of deep structures, the distribution of moderate-strong earthquake in Anhui Province has an obvious regional feature. Based on historical earthquake recurrence intervals and analogue principles of deep seismogenic tectonics, the potential earthquake risk zones recording Ms5.0 in Anhui Province are determined.

The Role of the National Significant Seismic Monitoring and Protection Regions Institution:From the Perspective of the RiskSociety Theory

Earthquake disaster risk,as a typical social disaster risk,is one of the most important risks in modern Chinese society.This study gives definitions of the institution,describes the formation history,the connotations and development and analyzes its role in the control of major social risks caused by earthquakes.Finally,the paper presents recommendations for continuous improvement of this institution under the guidance of risk society theory,and for its application to the government reform and social governance.

The Policies of Seismic Risk Management： Case of the Protected Areas of Dellys and Tenes Cities, Algeria

The greater part of urban heritage, especially of the medium and small Algerian cities, is subject to a major seismic risk. The probability of a happening earthquake is strong, and the territories vulnerability is great. Legislative procedures are implemented to support urban heritage and managing natural disasters. In fact, the PPSMVSS （permanent plan of safeguard and enhancement of saved sectors） as an instrument of protection, preservation and enhancement of this heritage, in its content, does not guide decision makers on how to manage the vulnerability of preserved areas from the earthquake. After the disaster of the earthquake that hit the Algerian Centre （wilaya of Boumerdes） in 2003. A legislative framework was created while other texts have been adapted. Emergency measures operations are launched to preserve the under threat monuments and protected areas. Saved sectors of Dellys, in the wilaya of Boumerdes and T6n^s in the wilaya of Chlef, are all the time subjected to seismic risk. This article presents a comparative study of two PPSMVSS, Dellys and T6n6s, and the management of the vulnerability of their two safeguarded areas. As a result of this study, some indicators were identified to allow the development of plans for the protection and management natural risks of these protected areas.

典型建筑物震害防御投资标准研究

震害防御投资是减轻震害损失的必要条件,投资标准应是考虑震害防御目标与整个社会利益权衡下的决策结果,但以往尚少研究。文中通过对具有广泛性、代表性和权威性的调查分析,得到了我国专业群体对典型建筑物震害防御投资可接受能力的认识,阐明了地震风险区、建筑抗震类别和设防目标对抗震投资决策的影响规律。采用综合分析,提出了典型建筑物震害防御投资推荐标准,可供制定相关政策法规与工程建设参考。