Theoretical analysis and field evidence of reciprocity gaps during interference pumping tests     

Frederick Delay  Philippe AckererAlberto Guadagnini 《Advances in water resources》2011,34(5):592-606

We address the question of the reciprocity of drawdowns observed during a sequence of interference pumping tests performed within a porous medium, in the context of different conceptual models of subsurface flow. We provide a generalization of the work by Bruggeman (1972) [5], extending his results obtained in 1972 for Darcian flows in an unbounded, heterogeneous porous medium. We then analyze reciprocity within a dual-continuum conceptualization, where the medium is viewed as being composed of two overlapping continua, representing the porous matrix and embedded fractures, respectively. We show theoretically, and demonstrate numerically, that only drawdowns associated with the fracture continuum display reciprocity under transient flow conditions. Conversely, non-flowing matrix and fracture continua display reciprocity behavior under steady-state conditions. We then provide field evidence of the insurgence of reciprocity gaps by analyzing interference test data from the karstic limestone aquifer of the Hydrogeological Experimental Site (HES) in Poitiers, France. On the basis of our theoretical results and experimental observations, we discuss different interpretations of the observed reciprocity gaps. These include (a) non-linear dependencies of local hydraulic parameters, (b) occurrence of internal boundaries within the domain, (c) inertial effects that develop through open conduits within the rock matrix, (d) modifications of the aquifer properties between subsequent pumping tests, and (e) significant contribution of the matrix pressure in monitored wells when the behavior of the aquifer is conceptualized by a dual-continuum approach.  相似文献   

库尔勒铁门关钻孔应变震前固体潮畸变现象分析   总被引：2，自引：1，他引：1  

王在华  徐长银  李尚伟  祖丽菲亚·尼亚孜 《内陆地震》2011,25(3):229-238

通过对库尔勒铁门关体应变3年的观测资料进行可靠性分析认为本台站资料达到了Ⅰ类台精度,干扰主要为气压效应和水位干扰,观测资料记录到的固体潮清晰.利用低通滤波和一阶差分的方法,可以识别出固体潮畸变.对识别出的48次固体潮畸变现象进行了统计,统计结果表明,6次畸变为干扰,13次近震前存在固体潮畸变现象,其余畸变发生在强远震前...  相似文献   

一种地电场观测环境干扰的分析和试验研究   总被引：1，自引：0，他引：1  

蒋延林  赵卫红  王福才  张骞  朱晔 《中国地震》2015,31(1):158-164

对2009年10月~2010年5月高邮地震台地电场观测中出现的一种不明原因的大幅度扰动干扰进行了分析讨论。经过初步分析、干扰源模拟定位、干扰源测试、干扰源现场调查等途径,确定了干扰源位置和干扰产生的原因,并对该干扰现象进行了排除处理。  相似文献   

Politics and independent scientific advice in RFMO processes: A case study of crossing boundaries   总被引：1，自引：0，他引：1  

Tom Polacheck 《Marine Policy》2012,36(1):132-141

Provision of independent scientific advice is central to the operation of regional fisheries management organizations (RFMOs) even though RFMOs are largely policy (and political) instruments. Political pressures and intervention in science and crossing of the boundaries between scientific and political processes, however, appear to be relatively common. A case study is presented to illustrate some ways in which this occurs. It involves a paper that was withdrawn from scientific meetings of two RFMOs as a result of largely political (rather than scientific) concerns. The details involved in this incident are important for understanding the ways in which political intervention in independent scientific process can and does occur. Moreover, unless one is directly involved in actions of this kind, it is impossible from the reports of RFMOs' scientific bodies to assess whether, and the extent to which, there has been political intervention in the scientific process. It is argued that the nature of the working arrangements in these scientific committees can engender deliberate or inadvertent crossing of the boundaries between scientific independence and the political processes of RFMOs, both of which are important components of RFMO operation. Further, there is very little documentation or assessment of the generic extent of such problems. No simple solutions or reforms exist for isolating scientific advice from political agenda in the processes of RFMOs but it is suggested that increased discussion of the problem along with better understanding and clarity of the role of science in the management process may lead to improved recognition of the importance of independent scientific analyses and advice.  相似文献   

强震动台站与干扰源最小距离的初步研究          下载免费PDF全文

李佐唐  潘颖凌  田秀丰  姚凯  何新社 《地震工程学报》2012,34(1):88-92

为了在强震台址勘选、台站观测环境保护工作中对泵房、火车站、采石场爆破这三类干扰源的避让提供定量参考依据,通过实地测试,探讨了这三种干扰源的振动衰减关系.研究认为预警与固定观测台站离开11 kW泵房的距离应不小于69 m;离开(客货低速)铁路线的距离应不小于228m;离开采石场的距离应不小于723 m.烈度速报台站离开泵房的距离应不小于19m;离开铁路线的距离应不小于156 m,离开采石场的距离应不小于428 m.  相似文献   

基于极值特征尺度的干扰辨识技术在地磁观测中的应用研究     

郑江蓉  谢凡  张秀霞  鲍海英 《地球物理学进展》2012,27(2):528-536

在地震前兆观测台网中,地磁和地电同台观测是较为常见的,地电测量时的供电干扰会引起同台地磁观测数据的变化,造成地磁观测精度下降.本文在分析产生地电供电干扰的机理及特点基础上,提出了采用噪声辅助的基于极值特征尺度的干扰辨识,对采用线性差值辨识出的干扰区间利用这种技术进行填充.并将该方法应用到成都、洛阳、徐庄子和蒙城四个磁电同台观测数据的分析处理中.结果表明:该方法在地电供电对地磁资料的干扰辨识精确度方面和干扰抑制损失上有较好的效果和较高的稳定性,辨识精确高,抑制损失相对与传统滤波器达到最小程度.在抑制地电供电干扰,提高地磁观测精度方面有较好的应用价值.  相似文献   

西安基准地震台钻孔体应变观测干扰分析   总被引：1，自引：0，他引：1  

陈冬柏  罗词建  李媛嫒  任隽  张璐 《高原地震》2012,24(2):50-54

通过对西安地震台钻孔体应变观测资料的干扰因素进行分析,认为西安钻孔体应变观测资料不同程度地受降雨、气压、钻孔水位、石砭峪水库水位（库容）的影响,并对之间的相关关系及其变化特征进行了分析总结。  相似文献   

山丹多极距与单极距电阻率对比分析及干扰因素研究     

石航  尹亮  邹小波 《高原地震》2012,(4):50-57

利用山丹地震台2年多的多极距观测资料,并结合该台单一极距的观测资料,对比分析了2种观测方法的结果。结果显示,多极距观测在干扰排除和异常落实方面具备一定的优势;同一场地不同极距电阻率测值的相互佐证,可以为识别干扰和判定地震前兆异常的真实性提供帮助。  相似文献   

SMAP卫星辐射计在中国近海及沿岸的RFI特征分析     

周玮辰  韩震  王艺晴  罗志鲜  付定甜 《海洋通报》2017,36(6):706-714

射频干扰RFI(Radio-Frequency Interference)的校正和抑制一直是微波遥感研究领域的重要问题之一。本文基于SMAP卫星2015年5月1日至5日L波段辐射计亮温数据对中国近海及沿岸的射频干扰进行了特征分析。研究发现RFI分布不均匀,主要集中在城市群及其周边地区;通过对比辐射计天线接收的亮温数据与射频干扰校正和抑制后的数据,发现研究区域主要的射频干扰(95%)的平均值为1.4 K,整体射频干扰平均值为2.5 K,标准差为6.5;研究区域中不同波段和极化的数据受到射频干扰影响较为相似,受射频干扰影响最大的是升轨的垂直极化数据,受影响最小的是升轨的水平极化数据。  相似文献   

山东水管倾斜仪观测运行分析   总被引：1，自引：0，他引：1  

李希亮  陆汉鹏  孟建国  胡尊迎  田凤东 《山西地震》2014,(1):5-9

文章介绍了山东地区3个地震台站安装的水管倾斜仪的基本概况,并选取各台2007年—2011年的观测数据,从资料的完整性、观测质量及受干扰情况等方面进行了分析和探讨。结果表明:3个台站的观测资料均有很好的连续性和完整性,仪器稳定性较高,观测系统运转正常,可为地震研究提供数据支持。同时发现,在日常观测中,水管仪地倾斜观测主要受气压、降雨、观测环境变化和仪器调修等因素的干扰。  相似文献