土工织物加筋体在提高路堤稳定性方面的应用

加筋技术在地基处理过程中的应用已经广泛应用,加筋作用原理、应力传递和加筋作用机理的研究与工程应用已经日趋成熟,就路基填筑的填筑材料特性、路基碾压施工特点及路基的断面形式,结合土工织物的筋材性状,对路基填筑中的加筋技术进行了设计与检算,并且提出了施工坡面防护措施。     

矿山环境中苔藓植物重金属元素的地球化学特征——以大冶铜绿山为例

通过系统的野外采样并结合室内分析,将研究区分为3个区域:靠近污染源的铜绿山矿区附近、受矿区影响明显的大冶市区以及相对清洁的武汉市中国地质大学校园,研究了苔藓中和降尘中重金属元素质量分数分布特征和来源,进而进行了对应性分析,最后将研究区域与国内外其他地区进行了对比,结果表明:①铜、铁等元素的污染受矿源的影响较大,而铅、锌的污染则与交通等人类活动有较大关系;②苔藓植物对Cu和Zn有较强的吸附能力;③与其他地区相比,铜污染是大冶市有别于其他地区的首要污染特征;④苔藓植物可以较好地指示大气中的污染物来源.     

RADARSAT影像在土地利用动态监测中的应用

为了改变以往土地管理部门对土地管理的传统方式,节省在常规管理中耗费的大量人力和物力,遥感技术作为新兴发展的科学技术,已应用于动态监测土地利用的变化。本文将具体论述如何利用微波遥感技术监测土地利用的动态变化。     

土地利用动态遥感监测数据库标准探讨

为了将土地利用动态遥感监测技术和成果进一步普及和应用,规范土地利用动态遥感监测数据库建设,依据国土资源信息化标准建设的总体部署和要求,参考相关标准和规程,结合土地利用动态遥感监测业务特点,制定了土地利用动态遥感监测数据库标准草案。     

基于通量均衡基准的地壳垂直形变场逼近的Fourier分析法

本文根据地壳运动的全球通量均衡假说建立了地壳垂直形变场的分析模型,分析了以往作者所研究的球谐函数和球冠谐函数模型的优缺点,着重推导了在密切平面坐标系下该模型的Fourier级数解,该模型一方面可以简单地应用于地壳垂直形变场的逼近,另一方面为采用谱分析法提取地壳垂直形变场信息提供了理论依据。     

近16年暖季青藏高原东部两类中尺度对流系统（MCS）的统计特征

利用日本高知大学提供的逐小时分辨率静止卫星云顶黑体亮温（TBB）资料,使用模式匹配算法对2000～2016年（2005年除外）暖季（5～9月）青藏高原东部的两类中尺度对流系统（MCS）进行了识别和追踪,并利用人工验证订正了结果。基于此,利用NOAA的CMORPH（Climate Prediction Center Morphing）降水资料和NCEP的CFSR（Climate Forecast System Reanalysis）再分析资料对高原东部两类MCS进行了统计和对比研究。研究发现,7月和8月是高原东部MCS生成最活跃的季节,然而,此两个月能够东移出高原MCS的比例最小;5月虽然MCS生成数最少,但是移出率高达近40%。对比表明,能够东移出高原的MCS（V-MCS）比不能移出的MCS（N-MCS）生命史更长,触发更早,短生命史个例占比更低。暖季各个月份,相比于N-MCS,V-MCS的对流更旺盛且发展更快,然而,由于其发生频数远低于N-MCS,总体而言,V-MCS对高原东部的降水贡献率仅为15%左右,是N-MCS相应数值的一半左右。高原东部两类MCS的环流特征差异显著,有利于V-MCS发生、维持和东移的因子主要位于对流层中低层（西风带短波槽、西风引导气流、低层风场切变）,而在对流层高层,N-MCS拥有更好的高空辐散条件（其对应的南亚高压更强）。     

An adaptive approach to selecting a flow‐partition exponent for a multiple‐flow‐direction algorithm

Most multiple‐flow‐direction algorithms (MFDs) use a flow‐partition coefficient (exponent) to determine the fractions draining to all downslope neighbours. The commonly used MFD often employs a fixed exponent over an entire watershed. The fixed coefficient strategy cannot effectively model the impact of local terrain conditions on the dispersion of local flow. This paper addresses this problem based on the idea that dispersion of local flow varies over space due to the spatial variation of local terrain conditions. Thus, the flow‐partition exponent of an MFD should also vary over space. We present an adaptive approach for determining the flow‐partition exponent based on local topographic attribute which controls local flow partitioning. In our approach, the influence of local terrain on flow partition is modelled by a flow‐partition function which is based on local maximum downslope gradient (we refer to this approach as MFD based on maximum downslope gradient, MFD‐md for short). With this new approach, a steep terrain which induces a convergent flow condition can be modelled using a large value for the flow‐partition exponent. Similarly, a gentle terrain can be modelled using a small value for the flow‐partition exponent. MFD‐md is quantitatively evaluated using four types of mathematical surfaces and their theoretical ‘true’ value of Specific Catchment Area (SCA). The Root Mean Square Error (RMSE) shows that the error of SCA computed by MFD‐md is lower than that of SCA computed by the widely used SFD and MFD algorithms. Application of the new approach using a real DEM of a watershed in Northeast China shows that the flow accumulation computed by MFD‐md is better adapted to terrain conditions based on visual judgement.     

Windowed nearest neighbour method for mining spatio-temporal clusters in the presence of noise

In a spatio-temporal data set, identifying spatio-temporal clusters is difficult because of the coupling of time and space and the interference of noise. Previous methods employ either the window scanning technique or the spatio-temporal distance technique to identify spatio-temporal clusters. Although easily implemented, they suffer from the subjectivity in the choice of parameters for classification. In this article, we use the windowed kth nearest (WKN) distance (the geographic distance between an event and its kth geographical nearest neighbour among those events from which to the event the temporal distances are no larger than the half of a specified time window width [TWW]) to differentiate clusters from noise in spatio-temporal data. The windowed nearest neighbour (WNN) method is composed of four steps. The first is to construct a sequence of TWW factors, with which the WKN distances of events can be computed at different temporal scales. Second, the appropriate values of TWW (i.e. the appropriate temporal scales, at which the number of false positives may reach the lowest value when classifying the events) are indicated by the local maximum values of densities of identified clustered events, which are calculated over varying TWW by using the expectation-maximization algorithm. Third, the thresholds of the WKN distance for classification are then derived with the determined TWW. In the fourth step, clustered events identified at the determined TWW are connected into clusters according to their density connectivity in geographic–temporal space. Results of simulated data and a seismic case study showed that the WNN method is efficient in identifying spatio-temporal clusters. The novelty of WNN is that it can not only identify spatio-temporal clusters with arbitrary shapes and different spatio-temporal densities but also significantly reduce the subjectivity in the classification process.     

浅谈山东省防震减灾重点项目档案的管理

山东省防震减灾“十一五”规划项目建设期间,山东省地震局加强对重点项目建设档案的管理工作,保证档案的完整、准确和安全,使项目顺利通过验收,为项目建设后的运行维护留下了完整翔实的宝贵资料。文章对强化全员档案管理意识,建立健全档案管理机构和制度,规范档案工作流程及注重验收时档案的质量等方面进行介绍,进一步阐明如何加强重点项目的档案管理工作。     

安宁河—则木河断裂带1993～2012年重力动态变化

利用安宁河—则木河断裂带区域1993～2012年的流动重力观测数据,作出重力场动态图像和部分重力点值时序变化图,总结在这20年里安宁河—则木河断裂带的活动规律,分析研究安宁河—则木河断裂带区域及其临近区域较大震级的地震孕育过程中区域的重力变化情况,为安宁河—则木河断裂带区域地震预测预报提供经验和参考资料.