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121.
水位随机气压效率的地震前兆异常研究   总被引:1,自引:0,他引:1  
对在大气压力的随机气压变化作用下深井水位变化特点进行分析研究,在前人工作的基础上,提出可以利用大气压力的随机气压变化进行水位气压效率的计算。该方法较以往各种计算方法排除干扰能力强,计算方便,地震前兆异常突出,是水位气压效率地震前兆预报方法中能够应用于日常地震监测的方法之一。  相似文献   
122.
地震前兆综合加权信息量是在地震综合信息量的基础上,改进了地震前兆异常出现概率的计算方法后,得出的一种综合预报新方法。其特点是:1.所有的异常都取自每年年底的山东省地震会商报告,而不是取自地震后的震例总结或论文;2.利用“地震预报专家系统”的思想对每一异常事件进行综合评估。考虑到异常的可靠性、有效性、显著性及相互关联性给予不同的权重,以每一异常的最可能发震时来估算异常出现的概率,计算了山东地区1990年以来地震前兆综合加权信息量,分析了1995年9月20日苍山Ms5.2级地震前这种信息量变化的特点。  相似文献   
123.
Research on carrying capacity, aiming at maintaining the limited ability of the Earth's life supporting system to sustain human development, requires a comprehensive and ecosystem-based approach to monitor and assess the localized sustainability of coupled social and ecological systems. A definition termed the ecosystem-based carrying capacity of island (EBCCI) was developed in this paper of which the indices of fundamental and realized carrying capacities of island (FCCI and RCCI) were highlighted to emphasize the inter-dependencies between social systems and ecological systems. In order to avoid the difficulties and uncertainties of direct assessment, the related assessment model was established on the basis of synthetic evaluation of inherent and external factors affecting the EBCCI. The southern Miaodao Archipelago (SMA) located in the intersection of the Bohai Sea and the Yellow Sea, China, was taken as a typical example to acquire integrated recognition of the island ecosystem and its carrying capacity so as to discuss its sustainable development. The index scores of FCCI and RCCI in the SMA were 0.818 5 and 0.712 9 out of 1.0, respectively, with acceptable uncertainties. The results showed a relatively well capacity to sustain progress and relatively well realization of the carrying capacity of island ecosystem, owing to a well capacity of ecologically regulating, general performance of both ecologically supporting and resource provisioning, and a relatively high level of social supporting system. The study implied that it was critical to optimize the inter-dependencies and to sustain the relative balance between social systems and ecological systems so as to improve the RCCI and further facilitate the sustainability of SMA. The approach proposed in this paper provides a powerful tool which is well applicative to the regional level of an oceanic island or archipelago to study the sustainable development and can be further popularized to the coastal zone.  相似文献   
124.
为了进一步研究利用水文水力学模型和GIS结合的多情景模拟方法进行洪涝灾害风险评估,该文以台州市路桥区为研究对象,首先选取路桥区典型雨量站长序列降雨资料,采用年最大值法取样,根据暴雨强度频率适线效果确定耿贝尔型分布曲线为其理论频率曲线,采用高斯-牛顿法推求暴雨强度总公式;然后基于GIS生成路桥区的真实地表格栅,进行两类汇水区的划分;最后概化排水管网系统,基于GIS并结合SWMM模拟出不同暴雨重现期的城市内涝结果;将其与调查后的路桥区历史涝情对比可知,计算模型和参数选取较准确,在城市暴雨内涝情景模拟方面有一定的应用价值。  相似文献   
125.
本文给出一种用褶积滤波处理井水位对气压响应滞后的新方法,考虑了气压对井水位“记忆”影响的特点,对水位的气压改正采用了非线性的处理方法。用新方法对鲁03井进行气压改正后的平均中误差为0.65cm,而用一般相关方法则为1.96cm。最后讨论了褶积滤波积分区间长度与水井含水层系统性质的关系。含水层的导水系数越小,井孔截面积越大,则这个区间越长。  相似文献   
126.
由承压井水位动态反演水井含水层的应力变化   总被引:5,自引:0,他引:5  
分析了承压井含水层应力场与地壳应力应变之间以及含水层应力应变与井水位之间的定量关系,给出了利用承压不位变化反演含水层应力变化的三种新方法,通过含水层的参数,固体潮效应以及气压效应反演水井含水层的应力变化,讨论了承压井水位反映含水层应力应变的稳定性,并将该反演结果与其它方法的结果进行了比较。  相似文献   
127.
The aim of this study is to understand the canopy interception of Qinghai spruce forest under conditions of different precipitation characteristics and canopy structures in the upper reach of Heihe River basin, northwestern China. On the basis of a continuous record covering our investigating period by an automatic throughfall‐collecting system, we analysed the relationships between the canopy interception and the precipitation characteristics. Our results support the well‐established exponential decay relationship between the gross precipitation and the interception percentage after the canopy is saturated. But our results sufficiently illustrate a notable point that the variations in the interception percentage are almost independent from the variations in the gross precipitation before the canopy is saturated. Our examination into the relationship between the interception and the 10‐min average intensity of precipitation demonstrates a divergent relationship, and the divergent relationship is bracketed by an upper ‘dry line’ indicating that 100% of gross precipitation was intercepted before saturation and by a lower ‘wet line’ suggesting that the actual canopy storage capacity reached the maximum and evaporation was the only component of the interception. To search for the relationship between canopy structures and interception, we grouped the canopy covers over the 90 throughfall‐collecting tanks into ten categories ranging from 0 (no cover) to 0.9 (nearly completely covered), and the corresponding canopy interception was calculated by subtracting the averaged throughfall of each canopy‐cover category from the gross precipitation. The results show that the interception percentage increases faster with increasing canopy cover under intermediate rainfall conditions than that under heavy rainfall conditions. Unexpectedly, under light rainfall conditions the increasing rate of interception percentage with increasing canopy cover and also with increasing plant area index is not faster than that under the intermediate rainfall conditions simply because the tank‐measured percentage of interception was extremely high at near‐zero canopy cover conditions. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
128.
江苏沿江地区一次强冰雹天气的中尺度特征分析   总被引:9,自引:2,他引:9  
徐芬  郑媛媛  肖卉  慕熙昱 《气象》2016,42(5):567-577
利用常规气象资料、卫星、多普勒天气雷达、风廓线雷达等资料,对发生在江苏沿江地区一次强冰雹天气形势背景、环境热动力条件、强冰雹发生前地区环境场变化、超级单体雷达回波中尺度特征等进行了详细分析。结果表明:(1)在东北冷涡槽后干冷气流影响下,中高层干冷、低层暖湿的不稳定层结,高低空急流以及地面辐合系统的配置为此次强对流天气的产生提供了有利热动力条件;高CAPE值、逆温层、低层适当水汽条件及较强的深层垂直风切变有利于强冰雹天气的发生。(2)利用多普勒天气雷达、风廓线仪数据反演垂直分布的物理量场(平均散度、平均垂直速度、相对风暴螺旋度、垂直风切变)能够反映本站上空环境场的快速变化情况:强对流系统移入本站前雷达站上空逐渐调整为低层辐合、中高层辐散的风场配置结构,螺旋度和垂直风切变数值逐渐增加,表明环境场有利于强对流系统的维持发展。(3)强降雹超级单体除具有三体散射现象、入流缺口等雷达回波中尺度特征外,持久深厚的中气旋存在造成了显著的有界弱回波区和高悬垂强回波区。应用双多普勒雷达风场反演技术揭示了超级单体内部环流结构:低层气旋性旋转,中层旋转加强,高层风场辐散。超级单体内部涡旋特征的出现和维持有利于支撑空中大冰雹的增长。  相似文献   
129.
The spaceborne precipitation radar onboard the Tropical Rainfall Measuring Mission satellite(TRMM PR) can provide good measurement of the vertical structure of reflectivity, while ground radar(GR) has a relatively high horizontal resolution and greater sensitivity. Fusion of TRMM PR and GR reflectivity data may maximize the advantages from both instruments.In this paper, TRMM PR and GR reflectivity data are fused using a neural network(NN)–based approach. The main steps included are: quality control of TRMM PR and GR reflectivity data; spatiotemporal matchup; GR calibration bias correction;conversion of TRMM PR data from Ku to S band; fusion of TRMM PR and GR reflectivity data with an NN method;interpolation of reflectivity data that are below PR's sensitivity; blind areas compensation with a distance weighting–based merging approach; combination of three types of data: data with the NN method, data below PR's sensitivity and data within compensated blind areas. During the NN fusion step, the TRMM PR data are taken as targets of the training NNs, and gridded GR data after horizontal downsampling at different heights are used as the input. The trained NNs are then used to obtain 3D high-resolution reflectivity from the original GR gridded data. After 3 D fusion of the TRMM PR and GR reflectivity data, a more complete and finer-scale 3D radar reflectivity dataset incorporating characteristics from both the TRMM PR and GR observations can be obtained. The fused reflectivity data are evaluated based on a convective precipitation event through comparison with the high resolution TRMM PR and GR data with an interpolation algorithm.  相似文献   
130.
2003年8月渭河洪灾成因分析及对策   总被引:2,自引:0,他引:2       下载免费PDF全文
本文介绍了手机短信目前的发展前景,阐明气象部门对气象信息的管理应高度重视,不能简单地将气象信息廉价地批发给其它信息提供商,从而造成气象信息的严重贬值。  相似文献   
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