民乐、山丹6.1级地震异常及台站实现短临预报的思考

在综合分析了民乐-山丹6.1级地震前张掖中心台范围内震兆异常特征的基础上,总结了本次地震前该台的短临预报过程及存在的问题,对今后台站如何搞好地震短临预报工作进行了探讨.     

中国大陆地区中强地震前加卸载响应比异常时间尺度的统计研究

加卸载响应比理论是近年来提出的地震预测方法。本文进行了加卸载响应比异常时间尺度的统计研究，其中包括中国大陆地区5．0～8．1级的部分中强地震共30个震例，并得出加卸载响应比异常的时间尺度与未来地震震级之间的拟合函数。结果表明，地震前加卸载响应比异常的时间尺度与未来地震的震级具有正变关系，即震级越高，地震前加卸载响应比异常的时间尺度越长。根据加卸载响应比异常的时间尺度与震级之间的关系可以估计未来地震的发震时间，同时，可以确定加卸载响应比时空扫描过程中时问长度的大小。     

关于数字化记录中前兆信号的分析

介绍了如何用MATLAB工具软件—小波分析的基本理论对数字信号进行数字滤波,着重分析和研究了呼和浩特地震台形变观测资料出现各种信号,提出了小波分析理论对台站实际工作的重要性。     

Green''''s functions for uniformly distributed loads acting on an inclined line in a poroelastic layered site

Based on one type of practical Biot's equation and the dynamic-stiffness matrices of a poroelastic soil layer and half-space, Green's functions were derived for uniformly distributed loads acting on an inclined line in a poroelastic layered site. This analysis overcomes significant problems in wave scattering due to local soil conditions and dynamic soil-structure interaction. The Green's functions can be reduced to the case of an elastic layered site developed by Wolf in 1985. Parametric studies are then carried out through two example problems.     

Geochemical Information Indicating the Water Recharge to Lakes and Immovable Megadunes in the Badain Jaran Desert

1 Introduction The Badain Jaran Desert, located in western Inner Mongolia, China, has a unique landscape containing 144 lakes (72 of which are still watery) with a total water area of about 23 km2, and the world’s highest stationary sand dunes with a height between 200 m and 500 m. Much attention has been paid to the water recharge of the desert in the past decade. Investigations on the resources of water system there have been performed continuously since the early 1990s, which lead to th…     

福州市土地利用景观格局分析

以福州市土地利用现状图为基本图件，在GIS支持下编制了福州市土地利用景现图，进而选取几种主要指数，通过Excel软件计算，定量分析了福州市土地利用的景观格局及破碎化特征。结果表明：林地为基质景观，优势度指数最高，分离度指数最低；耕地、园地、城镇村及工矿用地和水域的均匀度较高，多样性指数较大，但破碎化程度较深；未利用地破碎度最低。从总体上看，土地利用的景观比较单调、多样性指数较小、破碎化程度也较低，景观异质性不高。     

广西南丹地区有色金属尾砂型人工矿床地质特征及其资源化

广西南丹地区尾矿分布于大厂、车河、芒场等矿区。尾砂来自以锡石为主的多金属矿床，尾砂中除Sn，Pb，Zn，Ag，Sb的质量分数达到工业指标外，Au亦达到综合利用指标。通过试验证明，对尾矿中的细微粒锡石可采用风力分级选矿、磁选和化学选矿等方法回收；尾砂中的非金属资源可作为填充材料、水泥原料利用，使尾砂型人工矿床充分的资源化。     

体绘制技术在地学3D GIS 可视化中的应用研究

体绘制技术是目前科学计算可视化研究的一个重要组成部分，对地质体内部属性分布的可视化有重要意义。该文针对地学研究中几何建模和属性建模同样重要的特点，基于一种矢栅一体化的混合数据模型，对地质体表面采用三角面片描述几何形状，对地质体内部采用基于八叉树的自适应网格剖分技术描述内部属性特征。对网格剖分后的体数据，采用体元投射的体绘制技术进行地质体内部属性可视化，显示出很好的效果，具有实际应用意义。     

Development of a soil moisture‐based distributed hydrologic model for determining hydrologically based critical source areas

A simple grid cell‐based distributed hydrologic model was developed to provide spatial information on hydrologic components for determining hydrologically based critical source areas. The model represents the critical process (soil moisture variation) to run‐off generation accounting for both local and global water balance. In this way, it simulates both infiltration excess run‐off and saturation excess run‐off. The model was tested by multisite and multivariable evaluation on the 50‐km² Little River Experimental Watershed I in Georgia, U.S. and 2 smaller nested subwatersheds. Water balance, hydrograph, and soil moisture were simulated and compared to observed data. For streamflow calibration, the daily Nash‐Sutcliffe coefficient was 0.78 at the watershed outlet and 0.56 and 0.75 at the 2 nested subwatersheds. For the validation period, the Nash‐Sutcliffe coefficients were 0.79 at the watershed outlet and 0.85 and 0.83 at the 2 subwatersheds. The per cent bias was less than 15% for all sites. For soil moisture, the model also predicted the rising and declining trends at 4 of the 5 measurement sites. The spatial distribution of surface run‐off simulated by the model was mainly controlled by local characteristics (precipitation, soil properties, and land cover) on dry days and by global watershed characteristics (relative position within the watershed and hydrologic connectivity) on wet days when saturation excess run‐off was simulated. The spatial details of run‐off generation and travel time along flow paths provided by the model are helpful for watershed managers to further identify critical source areas of non‐point source pollution and develop best management practices.