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狄樑 《地震地磁观测与研究》2012,33(1):57-60
对常熟地震台DSQ水管倾斜仪3年多的资料进行初步分析,雷电降雨、气温突变、气压变化会使观测数据发生畸变,雷电干扰时观测数据产生台阶、脉冲,甚至仪器故障、水管换水会使观测数据产生较大幅度漂移,伸缩仪标定时的检修也会对水管仪产生干扰,停电后恢复供电会使数据产生漂移现象. 相似文献
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包头地震台形变干扰分析 总被引:2,自引:2,他引:0
整理包头地震台伸缩仪、水管倾斜仪和水平摆倾斜仪观测资料,依据干扰类型分析发现,风扰、雷电降雨、温度与气压、标定与地震,仪器故障与停电是影响3台仪器观测的主要因素,干扰特征主要表现为缺记断记、数据突跳、尖脉冲、高频干扰、台阶、毛刺,大幅度变化、曲线加粗和趋势性变化等。不同类型观测仪器对干扰的响应不同,识别并剔除干扰,有利于地震观测数据应用,对地震异常判定具有参考价值。 相似文献
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降雨对地电阻率干扰的分析 总被引:8,自引:0,他引:8
在一些地电阻率观测台站受本身台址条件的限制,观测深度较浅,因此,观测值受到降雨等气象因素的影响。本文选取昌黎台EW向1983-1994年观测资料月均值,用褶积滤波和多元回归方法对ρs进行了降雨校正,将将之作为一个灰箱系统,将资料外推至19954上,然后与原始观测值作残差分析,取得了一定效果。 相似文献
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本文通过四分量自检、相对标定内精度分析对东平地震台YRY-4钻孔分量应变观测资料进行可靠性分析,并结合滑动相关性计算、潮汐因子内精度对2套仪器数据进行了对比,证明YRY-4钻孔分量应变2面应变相关性高,相关系数接近1,相对标定内精度高,与体应变数据整体趋势一致。2套仪器观测环境一致,运行稳定,数据正常可靠,但也存在降雨、场地干扰特殊时段曲线表现不一致的情况。针对2种特殊情况结合相关性计算、S变换进行了对比分析。结果表明,降雨时段,因钻孔条件差别较大,2套仪器数据相关性较差,接近0;场地干扰时段,2套仪器观测系统均受到影响,频率域同步出现干扰信号,影响数据曲线形态及潮汐因子精度,但2套仪器面应变相关性达0.91。综合分析,东平台钻孔应变仪与体应变2套仪器观测系统是可靠稳定的。 相似文献
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洞体形变数字化观测干扰分析 总被引:3,自引:2,他引:1
对山东省洞体形变数字化观测资料的干扰进行了分析讨论.分析认为:①山东省泰安,马陵山和烟台3个台形变观测资料的主要干扰是气象因子变化,观测环境变化和仪器故障;②气压,大风,降雨是导致观测资料出现异常变化的主要因素;气压的短周期突变可导致固体潮曲线畸变,大风引起固体潮曲线出现毛刺;降雨导致观测曲线趋势变化;③马陵山地震台垂直摆倾斜仪NS向能够清晰记录到附近地区塌方,爆破和小震引起的弹性形变波;④供电系统,传感器和数采器故障是导致观测数据丢失的最主要原因. 相似文献
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Yuan-FanTSAI Huai-KuangTSAI Cheng-YanKAO 《国际泥沙研究》2004,19(1):37-46
The Chi-Chi earthquake in 1999 caused disastrous landslides, which triggered numerous debris flows and killed hundreds of people, A critical rainfall intensity line for each debris-flow stream is studied to prevent such a disaster. However, setting rainfall lines from incomplete data is difficult, so this study considered eight critical factors to group streams, such that streams within a cluster have similar rainfall lines. A genetic algorithm is applied to group 377 debris-flow streams selected from the center of an area affected by the Chi-Chi earthquake, These streams are grouped into seven clusters with different characteristics, The results reveal that the proposed method effectively groups debris-flow streams. 相似文献
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Shen Ping Zheng ZhizhenInstitute of Geophysics SSB Beijing ChinaCenter for Seismic Data Information SSB Beijing China 《中国地震研究》1998,(1)
Ground deformation may be caused by crustal movement and non-crustal movement.The non-crustal movements include those caused by temperature,rainfall,ground water,etc.Deformation caused by crustal movement includes seismogenic deformation(that appearing in the process of earthquake preparation and that directly caused by the earthquake)and general tectonic activities.The key point in the study of the relationship between ground deformation and earthquakes is how to eliminate information of deformation caused by non-crustal movement and permanent(or slow)tectonic deformation in observed data.In this paper an analysis is made on the short leveling data recorded at Dahuichang Deformation-Observing Station,Beijing,for 22 years(1970-1991)by using the LMS algorithm method after lateral adaptive filtering of the modern digital signal processing technique.Eliminating the approximate annual variation in deformation caused by non-crustal movement such as temperature,rainfall,ground water,etc.,a unified standard is 相似文献
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Hydrological modelling often implies the use of rainfall data. Its quality and resolution directly affect the accuracy of the simulation results. This study illustrates that a simple approach of incorporating rainfall intensity information in daily rainfall records significantly improves the simulation of surface runoff and rainfall infiltration into soil profiles. The procedure is developed using a frequency analysis on rainfall data of the Royal Meteorological Institute of Belgium, collected with a resolution of 10 min and for a consecutive period of 61 years. The frequency analysis of the data allowed the incorporation of rainfall intensity information into daily rainfall records. To test the effect of this approach the surface runoff and water flow into three different soil types was simulated using the HYDRUS‐1D model for a typical dry, normal and wet year. The simulation results whereby the observed 10‐min rainfall data was used as input were considered as the reference. Comparative analysis revealed that the simulations using the 10 min rainfall data deducted from the incorporation of rainfall intensity into daily rainfall records, deviate a maximum 1·2% from the reference and produce much better results than the Soil Conservation Service (SCS) runoff curve‐number method because rainfall intensity is considered in the procedure presented. The SCS curve‐number method typical overestimates surface runoff during periods of low rainfall intensity (winter) and underestimate runoff during periods of high rainfall intensities (summer). Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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L. Guenni A. Bárdossy 《Stochastic Environmental Research and Risk Assessment (SERRA)》2002,16(3):188-206
The need for high resolution rainfall data at temporal scales varying from daily to hourly or even minutes is a very important
problem in hydrology. For many locations of the world, rainfall data quality is very poor and reliable measurements are only
available at a coarse time resolution such as monthly. The purpose of this work is to apply a stochastic disaggregation method
of monthly to daily precipitation in two steps: 1. Initialization of the daily rainfall series by using the truncated normal
model as a reference distribution. 2.␣Restructuring of the series according to various time series statistics (autocorrelation
function, scaling properties, seasonality) by using a Markov chain Monte Carlo based algorithm. The method was applied to
a data set from a rainfall network of the central plains of Venezuela, in where rainfall is highly seasonal and data availability
at a daily time scale or even higher temporal resolution is very limited. A detailed analysis was carried out to study the
seasonal and spatial variability of many properties of the daily rainfall as scaling properties and autocorrelation function
in order to incorporate the selected statistics and their annual cycle into an objective function to be minimized in the simulation
procedure. Comparisons between the observed and simulated data suggest the adequacy of the technique in providing rainfall
sequences with consistent statistical properties at a daily time scale given the monthly totals. The methodology, although
highly computationally intensive, needs a moderate number of statistical properties of the daily rainfall. Regionalization
of these statistical properties is an important next step for the application of this technique to regions in where daily
data is not available. 相似文献
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BELLIE SIVAKUMAR 《水文科学杂志》2013,58(5):727-738
Abstract The importance of high-resolution rainfall data to understand the intricacies of the dynamics of hydrological processes and describe them in a sophisticated and accurate way has been increasingly realized. The present study investigates the general suitability of fractal (or scaling) theory for understanding the rainfall behaviour and transforming rainfall data from one time scale to another. The study, employing a multi-fractal approach, follows the research undertaken earlier by the author (Sivakumar, 2000) employing a mono-fractal approach in which some preliminary indication as to the possibility of existence of (multi-) fractals was obtained. Rainfall data of three different resolutions, six-hourly, daily, and weekly, observed over a period of 25 years in two different climatic regions: a subtropical climatic region (Leaf River basin, Mississippi, USA); and an equatorial climatic region (Singapore) are analysed. The existence of multi-fractal behaviour in the rainfall data is investigated using (a) the power spectrum method; (b) the empirical probability distribution function (PDF) method; (c) the statistical moment scaling method; and (d) the probability distribution multiple scaling (PDMS) method. The results achieved from all these methods for the six different rainfall data sets considered indicate the existence of multi-fractal behaviour of rainfall observed in Leaf River basin and Singapore, providing further support to the results obtained using the mono-fractal approach (Sivakumar, 2000). The suitability of a multi-fractal framework to characterize the behaviour of rainfall observed in the above two significantly different climatic regions, subtropical and equatorial, seems to suggest the general suitability of the fractal theory for transforming rainfall from one time scale to another. Investigations with rainfall data from several other climatic regions are underway with a view to strengthening the above conclusions. 相似文献
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A criterion is developed for determining the validity of the Soil Conservation Service curve number (SCS‐CN) method. According to this criterion, the existing SCS‐CN method is found to be applicable when the potential maximum retention, S, is less than or equal to twice the total rainfall amount. The criterion is tested using published data of two watersheds. Separating the steady infiltration from capillary infiltration, the method is extended for predicting infiltration and rainfall‐excess rates. The extended SCS‐CN method is tested using 55 sets of laboratory infiltration data on soils varying from Plainfield sand to Yolo light clay, and the computed and observed infiltration and rainfall‐excess rates are found to be in good agreement. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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Abdullah Gokhan Yilmaz 《水文科学杂志》2013,58(12):2148-2162
AbstractThere is increasing concern that flood risk will be exacerbated in Antalya, Turkey as a result of global-warming-induced, more frequent and intensive, heavy rainfalls. In this paper, first, trends in extreme rainfall indices in the Antalya region were analysed using daily rainfall data. All stations in the study area showed statistically significant increasing trends for at least one extreme rainfall index. Extreme rainfall datasets for current (1970–1989) and future periods (2080–2099) were then constructed for frequency analysis using the peaks-over-threshold method. Frequency analysis of extreme rainfall data was performed using generalized Pareto distribution for current and future periods in order to estimate rainfall intensities for various return periods. Rainfall intensities for the future period were found to increase by up to 23% more than the current period. This study contributed to better understanding of climate change effects on extreme rainfalls in Antalya, Turkey. 相似文献
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Many landslides are triggered by rainfall. Previous studies of the relationship between landslides and rainfall have concentrated on deriving minimum rainfall thresholds that are likely to trigger landslides. Though useful, these minimum thresholds derived from a log–log plot do not offer any measure of confidence in a landslide monitoring or warning system. This study presents a new and innovative method for incorporating rainfall into landslide modelling and prediction. The method involves three steps: compiling radar reflectivity data in a QPESUMS (quantitative precipitation estimation and segregation using multiple sensors) system during a typhoon (tropical hurricane) event, estimating rainfall from radar data and using rainfall intensity and rainfall duration as explanatory variables to develop a landslide logit model. Given the logit model, this paper discusses ways in which the model can be used for computing probabilities of landslide occurrence for a real‐time monitoring system or a warning system, and for delineating and mapping landslides. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献