Defining the range of ecological shelter zones in the shore zone of Three Gorges Reservoir,China

To maintaining a health ecological environment in Three Gorges Reservoir (TGR) area, ecological shelter zones (ESZ) need to be built in the TGR shore zone urgently. Based on the implication and function of ESZ, this study first analyzed the relationships amongst three subsystems of the TGR area, including the upstream production-living land, the downstream reservoir water body, and the ESZ. Then a simple and practical hydrological environment model for controlling the eutrophication of the TGR water body was constructed to determine ESZ range of TGR. Additionally, based on the pollutant degradation efficiency of ESZ and the assimilative capacity of reservoir water body, a raster reverse tracking method was proposed to determine the range of ESZ. Thirdly, take Yangdu town in Zhongxian county as a typical region, the ESZ range under three scenarios of different rainfall intensity, degradation efficiency and inflow water quality that corresponding to the three decisive factors of defining ESZ range were discussed. Finally, the statistical laws of the ESZ’s width at each boundary points were discussed to facilitate the ESZ construction projects, and selected standardized rate at 70, 90, and 99 % were labelled as “General”, “Good” and “Excellent” level to represent the performance of the width of the ESZ range. In conclusion, it suggest “Good” level width as basic width of ESZ, and additionally a special protection zone should be put on upstream environment for the extreme large width at the boundary points.     

Delineation of Potential Seismic Source Regions of Moderately Strong Earthquakes Without Seismogenic Tectonics

In this paper,approaches are developed to delineate the potential seismic source regions of moderately strong earthquakes that do not have clear seismotectonic settings.Based on comprehensive analysis of regional tectonic backgrounds and seismicity,the data,such as isoseisrnals,spatial distribution of after shocks,regional tectonic stress field,and focal mechanisms,are employed for the delineation of the potential seismic source regions.The reliability of such potential seismic source regions is also discussed.     

通化集安群石榴子石和黑云母微区化学成分特征及其对变质作用p-T-t轨迹的指示意义

集安群片麻岩中石榴子石和黑云母接触带两侧边缘广泛发育Fe－Mg交换反应所形成的扩散环带,但晶体内部各自保持变质峰期的成分,中温带石榴子石可保留生长环带。经微区化学成分详细研究后,正确运用Grt－Bt温度计获得进变质阶段,变质高峰期和修期后Fe－Mg交换反应停止时的温度条件。按石榴子石和斜长石的微区钙含量变化确定了峰期和退变质阶段压力。据此建立起逆时针形式的变质作用p－T－t轨迹,反映该区早元古代陆壳内裂陷带的闭合过程。     

马尼希基海底高原重力均衡及其构造意义研究

采用三维导纳分析技术,联合海底地形和重力异常数据,对马尼希基海底高原重力均衡状况进行了分析研究,并结合地震学等研究成果,分析其构造意义。马尼希基海底高原海底地形与重力异常相干性在长波部分(大于100 km)相对较小,说明高原地壳底部存在低密度异常,并且,根据Airy均衡分析,这种低密度异常并非完全由洋壳对海底地形的均衡调整引起,推测高原地壳底部存在由岩装“板垫作用”(crustal under-plating)形成的低密度异常体,即“底部载荷”。马尼希基海底高原短波海底地形符合Airy均衡,据此分析获得高原地区洋壳厚度为22. 7 km,与地震研究结果一致。岩石圈挠曲均衡分析表明,马尼希基海底高原岩石圈有效弹性厚度为2.5-5.5 km,较优拟合值为3.5km,可能意味着高原形成时岩石圈年龄较小。根据顾及底部载荷的挠曲均衡模型进行分析,定量计算了底部载荷规模,约为地形载荷的30%,其体积约为9.3 X 105km3,平均深度为18 km,是整个高原洋壳的重要组成部分,表明洋壳底部板垫作用在马尼希基海底高原形成和演化过程中产生过重要影响。     

地震红外长波辐射短期异常特征分析

利用NOAA卫星资料反演的地震长波辐射值OLR对黑龙江及其周边2003年以来8次中强地震进行了追踪研究.结果显示,震前2个月左右OLR场值存在明显的高值异常区,未来震中距离高值区中心点250km(优势距离为160km).该方法对黑龙江及其周边4级以上地震短期判定可能具有一定的指示价值,也为利用卫星遥感技术预测未来可能发震区域并及时做出短期预测预警提供了新途径.     

济南市一次大雾天气过程的诊断分析

利用济南地区地面气象观测资料和探空观测资料以及NCEP1°×1°再分析资料，对2007年1月2-4日济南地区大雾形成及持续原因进行了初步分析，发现：稳定的经向大气环流、较弱的地面气压场是大雾形成的主要天气形势，较弱而持续的偏北风、源源不断的水汽补充及明显的逆温层是这次大雾形成并维持的必要条件。在实际气象预报工作中，不仅要注意天气形势、水汽等条件的分析，在冬季更要注重逆温层对大雾形成的分析。     

Distribution and source of heavy metals in the surface sediments from the near-shore area,north Jiangsu Province,China

Samples of surface sediment and vibrocore were collected in the near-shore area of north Jiangsu Province for grain size, elements, ²¹⁰Pb_excess and ¹³⁷Cs analyses. In our study area, the diversity of metal concentration was controlled not by the grain size, but by the source. The element content of the old Yellow River Delta was used as baseline for our study area. Geoaccumulation indexes indicate that no station was polluted by Cu, Pb, Zn and As, but the I_geo values of As were close to zero in some stations. Slight pollution caused by Cd was observed in some stations. Correlation and enrichment factors suggest that Cu, Pb and Zn are lithogenic in origin, while As and Cd are mixed in origin. Especially, in some polluted stations Cd was obviously anthropogenic in origin.     

Variations of methane stable isotopic values from an Alpine peatland on the eastern Qinghai-Tibetan Plateau

Acta Geochimica - Isotopic signature is a powerful tool to discriminate methane (CH4) source types and constrain regional and global scale CH4 budgets. Peatlands on the Qinghai-Tibetan Plateau are...     

辽河盆地东部凹陷热历史及构造—热演化特征

根据辽河盆地东部凹陷大地热流测量和镜质体反射率数据,恢复了该区的热历史,结果表明:东部凹陷热流呈现古热流高现今热流低的变化特征,沙河街组三段沉积期到东营组沉积期(距今43～25Ma)盆地热流为66～82mWm2,现今热流值为47～70mWm2。构造沉降史分析显示,盆地经历了早期的裂谷阶段(距今43～25Ma)和后期的热沉降阶段,裂谷阶段包含了两个裂谷亚旋回。盆地现今较低的大地热流和较高的古热流及典型的裂谷型构造沉降样式为东部凹陷的构造—热演化提供了重要认识。     

西安市地震应急指挥技术系统设计与实现

本文从系统总体架构设计、系统功能设计与应用成果、系统特色4个方面简要介绍了西安市地震应急指挥技术系统设计与实现情况.本系统是首个应用于省会城市地震应急工作,并基于国产Server GIS软件平台研制开发出的地震应急指挥技术系统,可为大城市地震应急指挥技术系统的建设与发展提供可借鉴的经验.