共查询到20条相似文献，搜索用时 62 毫秒
1.
2.
介绍了山东数字地震台网基本情况,计算了40个测震台站台基背景噪声,利用Welch方法计算噪声功率谱密度（PSD）,进而计算地震台台基1—20 Hz地动噪声均方根值（RMS）和有效动态观测范围。根据计算结果,依照《地震台站观测环境技术要求》,对山东测震数字台网40个参评测震台站进行背景噪声级别分类,并分析不同台站背景噪声水平较低的原因,以期为测震台网的优化建设提供数据支持。 相似文献
3.
4.
中国大陆背景噪声成像研究及应用前景 总被引：1，自引：0，他引：1
对长时间序列的背景地震噪声进行互相关计算可以得到台站间的经验格林函数,这种方法不依赖天然地震及人工震源,仅利用台站记录的背景噪声就能得到地下结构,该方法可以更为便捷地获得地震活动性较低地区的地下构造.随着背景噪声层析成像技术的发展应用,该方法会进一步提高地壳上地幔速度模型的分辨率.本文综述了背景噪声成像技术及其在中国大... 相似文献
5.
6.
7.
利用山东数字地震台网的实时记录波形资料,采用在频率域积分方法,计算出各台站背景噪声的位移值。然后进行统计分析,得出了山东地区背景噪声位移值的空间分布和时间变化特征：台站背景噪声幅值与不同地区地质环境、岩性密切相关,位于第四系黄土覆盖层较厚的鲁西聊城、菏泽地区,鲁西北德州地区和鲁北东营、滨州地区各子台的背景噪声位移值较大,鲁中、鲁南山区和胶东半岛地区的基岩台站背景噪声位移值较小;同时,白天噪声值大于夜间噪声值,但深井观测台站的背景噪声值相对稳定。此项研究为绘制台网监测能力图提供基础数据,并为计算各台站的场地响应及震级修正值等测震学研究提供基础资料,促进台网的改建和发展。 相似文献
8.
山西数字遥测地震台网十五勘选子台台址地动噪声分析 总被引：2，自引：1，他引：2
对山西数字遥测台网“十五”勘选的19个子台台址背景噪声进行分析和计算,得出了各台址背景噪声地动速度均方根值(RMS值)、有效测量动态范围、噪声信号功率谱。结果表明,各台址背景噪声水平符合数字地震观测技术规范要求。 相似文献
9.
低频背景噪声是地震数据的重要组成部分,在地下介质成像和地质构造探测等研究中发挥重要作用。区域性背景噪声研究不仅会得出该区域背景噪声特性,还可以针对地域性特征进行更适合的应用。辽宁地区低频背景噪声对本区域背景噪声研究有重要意义,基于辽宁省6个台站连续多年的宽频带地震背景噪声数据,利用地震计观测的位移值研究辽宁地区低频背景噪声特征,并采用数学函数模型构建了辽宁地区低频背景噪声模型。通过计算背景噪声位移分析发现,辽宁地区低频背景噪声（1 Hz以下）具有明显季节性变化,通常在冬季达到最大值,在夏季达到最小值。基于三角函数关系拟合得到辽宁地区背景噪声年变公式,建立辽宁地区低频背景噪声模型,并采用ADF法验证了该模型可靠性。 相似文献
10.
11.
12.
13.
M. N. French R. L. Bras W. F. Krajewski 《Stochastic Environmental Research and Risk Assessment (SERRA)》1992,6(1):27-45
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities. 相似文献
14.
15.
《中国科学:地球科学(英文版)》2014,(3)
正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research. 相似文献
16.
《国际泥沙研究》2014,(4)
正Director:Shangfu Kuang,China Vice-directors:Chunhong Hu,China Duihu Ning,China Guangquan Liu,China The International Research and Training Center on Erosion and Sedimentation(IRTCES)was jointly set up by the Government of China and UNESCO on July 21,1984.It aims at the promotion of international exchange of knowledge and cooperation in the studies of erosion and 相似文献
17.
18.
19.
Richard D. Hey 《地球表面变化过程与地形》1979,4(1):59-72
Feedback mechanisms, which operate upstream through drawdown and backwater effects and downstream through sediment discharge are responsible for channel evolution. By combining these mechanisms with channel processes it euables a dynamic process-response model to be developed to simulate the initial evolution of straight gravel-bed channels. When erosion commences on a land surface, sediment entrained in the headwater reach by hydraulic action is selectively transported, deposited and reworked. This produces a damped oscillation between degradation and aggradation as the channel and valley respond to spatial and temporal variations in sediment calibre and hydraulic conditions. The initial cut and fill phases are responsible for valley incision and floodplain development while secondary and subsequent activity can produce river terraces. Eventually sediment entrainment in the headwaters declines as slopes are reduced. Subsequent channel evolution is relatively insignificant because it is dependent on local weathering activity producing material that can be transported on declining slopes. Therefore landforms produced during the initial phase of development, when local weathering was non-limiting, dominate the landscape. 相似文献