共查询到18条相似文献，搜索用时 35 毫秒
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应用信息熵方法对地下水观测网的层次分类——以河北平原地下水观测网为例 总被引：3，自引：0，他引：3
陈植华 《水文地质工程地质》2002,29(3):24-28
本文主要针对目前地下水观测网存在的层次不清问题，提出了基于信息熵理论新的分类方法。文章列举了观测网层次问题的表现，原因和可能造成的后果，提出地下水观测网的层次性应该对应地下水流动系统的层次性。认为地下水观测网就是一种信号通讯网，水位信号具有可传递性、差异性以及衰减性等特征，可以运用信息熵理论中的互信息概念，定量刻画观测孔之间的信息联系，并以这种信息联系程度作为观测孔层次分类的主要依据。作者以河北平原地下水观测网为实例，研究了区域尺度观测网的分类，结果表明信息熵方法可以很好地解决此类问题。 相似文献
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地下水观测网的若干问题与基于信息熵的研究方法 总被引：5，自引：0，他引：5
观测站点分布的任意性、随意性和层次不清以及观测数据的冗余性等是中国地下水观测网普遍存在的问题 ,这些问题制约着观测网提供可靠和有效数据信息的能力。文章以河北平原地下水观测网为例 ,分析了观测网几个问题的表现和原因 ,并对国内外观测网优化设计的指导思想、技术方法的现状和进展作了简要介绍。在参考大量国内外研究成果的基础上 ,主要介绍了基于信息熵原理研究观测网优化设计的方法 ,包括基本概念、原理和解决观测孔层次分类、信息冗余以及空间优化布局的技术思想。笔者认为 ,信息熵方法是一种能够评价地下水观测网信息 (而不是数据 )收集能力和优化观测网布局的很具发展潜力的技术方法。 相似文献
3.
应用信息熵方法对区域地下水观测网的优化研究 总被引：9，自引：0，他引：9
数据冗余是观测网优化需要解决的主要问题之一, 冗余数据既造成数据噪音又增加观测网运行成本.减少数据冗余的主要手段是减少观测孔的数量, 但前提是不影响原有观测网提供信息的能力.作者基于信息熵概念和随机技术的结合, 提出了一种优化观测孔数量的方法, 这种方法的基本原理是利用信息熵理论来评价每一个观测孔数据信息含量大小, 计算观测网中每一对观测孔之间的信息流交换, 并建立观测孔之间信息传递与距离的统计关系, 这种关系是判断冗余性观测孔的基础.这种方法被用来优化河北平原区域地下水观测网, 不仅解决了数量问题, 同时也可确定具体冗余性观测孔.最后结果对比证明, 将河北平原地下水观测孔的数量减少2 6%, 几乎没有影响现有观测网提供数据信息的能力. 相似文献
4.
地下水动态观测网优化设计研究 总被引：4，自引：0，他引：4
仵彦卿 《地质灾害与环境保护》1994,5(3):56-64
本文采用状态空间分析法,通过对地下水流系统输入变量、输出变量及地下水动态测量值的研究,提出了地下水流系统确定一随机性数值模型。运用该模型的模拟解,进行地下水动态观测网优化设计。该方法把地下水动态观测网密度、位置及观测频率优化与地下水流系统结合起来研究。为了克服该模型计算量大的缺陷,本文提出了一种改进算法,使这一观测网优化方法适于在微机上实现,减少了计算工作量。该方法曾用于陕西某地区地下水位动态观测网的优化设计,取得了显著经济效益。 相似文献
5.
仵彦卿 《地质灾害与环境保护》1994,5(2):16-27
地下水观测网优化设计,包括观测孔空间位置及时域上观测频率的优化设计。本文从地下水动态特征出发,提出了地下水观测频率优化设计的时间克立金方法、谱分析方法以及统计学分析方法。在观测频率优化设计中,各种方法研究的角度各有特点和差异。 相似文献
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本文旨在探讨复杂自然．技术系统（生态—地质，生态．水文地质，等）的监测问题。监测概念包括用于研究和预报目标状态的观测系统和信息搜集系统，其目的作出调整这种状态到最佳的管理决议。此外，赞成В．H．IIIecTaXOB的观点，即地下水监测的模拟定位是组织地下水监测的主要方法原理之一。该方法是指观测网的最佳布局，它可以不断确定和校正预报模型，提高其可靠性和精度。[第一段] 相似文献
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本文介绍一种新的地下水位观测多优化设计方法－－孔位离散游移式单纯形优化设计法。该方法不仅优化速度快，自动化程度高，而且衡量观测网质量的标准全面客观，是一种适合广泛使用的观测网优化设计法。文章还对与观测网优化设计有关的最优观测网使用时限及观测精度问题进行了讨论。 相似文献
10.
仵彦卿 《西安地质学院学报》1995,17(1):82-89
本文推导出普通二变量及泛二变量组合克立金方程式，同时，给出了两种方法的估计误差标准差求解方程，可用于地下水动态观测的密度优化；该方法还可用于地下水位，水中离子浓度的最优估计。 相似文献
11.
An entropy-based approach is applied to identify redundant wells in the network. In the process of this research, groundwater-monitoring network is considered as a communication system with a capability to transfer information, and monitoring wells are taken as information receivers. The concepts of entropy and mutual information are then applied to measure the information content of individual monitoring well and information relationship between monitoring well pairs. The efficiency of information transfer among monitoring wells is the basis to judge the redundancy in the network. And the capacity of the monitoring wells to provide information on groundwater is the point of evaluation to identify redundant monitoring wells. This approach is demonstrated using the data from a regional-scale groundwater network in Hebei plain, China. The result shows that the entropy-based method is recommendable in optimizing groundwater networks, especially for those within media of higher heterogeneities and anisotropies. 相似文献
12.
Spatial assessment and redesign of a groundwater quality monitoring network using entropy theory, Gaza Strip, Palestine 总被引：3，自引：0，他引：3
Using entropy theory, a methodology was developed for the evaluation and redesign of groundwater quality monitoring wells in the Gaza Strip in Palestine. Essential to the methodology is the development of a Transinformation Model (TM) which yields the amount of information transfer and the dependency between the wells as a function of distance. The TM parameters, such as the minimum transinformation and the range, were employed for evaluating the network which revealed that most of the distances between wells were less than the range. It also indicated that a high percentage of redundant information existed in the network. Therefore, the network was reduced by superimposing a square pattern over the monitored area and selecting one well per square block in a stratified pattern. The methodology was tested using the chloride data collected from 1972–2000 from 417 groundwater quality monitoring wells in the Gaza Strip. The number of the groundwater quality monitoring wells in the Gaza Strip was reduced by 53%, while there was 26% redundant information based on the minimum existing distance between wells. This methodology is meant to help monitor the groundwater quality (salinity) in the Gaza Strip. 相似文献
13.
Monitoring of regional groundwater levels provides important information for quantifying groundwater depletion and assessing impacts on the environment Historically,groundwater level monitoring wells in Beijing Plain,China,were installed for assessing groundwater resources and for monitoring the cone of depression.Monitoring wells are clustered around well fields and urban areas.There is urgent need to upgrade the existing monitoring wells to a regional groundwater level monitoring network to acquire information for integrated water resources management.A new method was proposed for designing a regional groundwater level monitoring network.The method is based on groundwater regime zone mapping.Groundwater regime zone map delineates distinct areas of possible different groundwater level variations and is useful for locating groundwater monitoring wells.This method was applied to Beijing Plain to upgrade a regional groundwater level monitoring network. 相似文献
14.
A discrete entropy-based approach is used to assess the groundwater monitoring network that exists in Kodaganar River basin
of Southern India. Since any monitoring system is essentially an information collection system, its technical design and evaluation
require a quantifiable measure of information and this measure can be derived using entropy. The use of information-based
measures of groundwater table shows that the existing monitoring network contains a sufficient number of wells but is not
well designed for the measurement of groundwater level. Entropy-based results show that 15 wells are vital to measure regional
groundwater level, not 28 wells which are being monitored effectively in this basin. 相似文献
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区域地下水位监测网优化设计方法 总被引：8，自引：4，他引：8
区域地下水位监测提供了定量评价含水层地下水位持续下降及其对环境影响必不可少的信息。历史上的地下水位监测网是为了评价地下水资源或监测水源地降落漏斗而设立的,目前它们已经不能适应为流域水资源综合管理提供必需的信息。本文在综述国际地下水位监测现状的基础上,介绍了区域地下水位监测网优化设计的方法。采用地理信息系统编制的地下水动态类型图为地下水位监测井位置的选择提供了坚实的水文地质基础;克里金插值法能定量评价监测网观测值绘制的地下水位等高线的精度,因而可以用来定量设计地下水位监测网;时间序列分析和统计检验提供了优化地下水位监测频率的定量标准。这些方法已被应用于北京平原、乌鲁木齐河流域和济南岩溶泉域,其成果将在本刊分期发表。 相似文献
16.
北京平原地下水水位监测网优化 总被引：10，自引：0，他引：10
文章在北京市地下水水位监测现状基础上,分潜水和承压水对北京平原地下水监测网的监测密度和监测频率进行了优化设计。主要采用编制地下水动态类型图的方法进行了地下水水位监测网的优化,克里金插值法能定量评价依据监测网观测值绘制的地下水水位等高线的精度,因而可以用来评价监测优化结果。并根据时间序列分析和统计检验提供的定量标准优化了地下水水位监测频率。优化后,北京平原共有监测孔400眼,其中利用原有监测孔300眼,新设计监测孔100眼,手工监测频率由原来的每月6次优化为每月1次,专项高频率监测可以由地下水自动监测仪实现。文中还对地下水自动监测仪(DIVER)的监测结果和手工监测结果进行了对比评价,提出了地下水水位监测网的维护、管理措施和信息发布方式。 相似文献
17.
Venkatesh Uddameri Sreeram Singaraju E. Annette Hernandez 《Environmental Earth Sciences》2014,71(6):2629-2640
Hydraulic gradient is a fundamental aquifer characteristic required to estimate groundwater flow and quantify advective fluxes of pollutants. Graphical and local estimation schemes using potentiometric head information from three or four wells are used to compute hydraulic gradients but suffer from imprecision and subjectivity. The use of linear regression is recommended when hydraulic head data from a groundwater monitoring network consisting of several wells are available. In such cases, statistical influence analysis can be carried out to evaluate how each well within the network impacts the gradient estimate. A suite of five metrics, namely—(1) the hat-values, (2) studentized residuals, (3) Cook’s distance, (4) DFBETAs and (5) Covariance ratio (COVRATIO) are used in this study to identify influential wells within a regional groundwater monitoring network in Kleberg County, TX. The hat-values indicated that the groundwater network was reasonably well balanced and no well exerted an undue influence on the regression. The studentized residuals and Cook’s distance indicated the wells with the highest influence on the regression predictions were those that were close to high groundwater production centers or affected by coastal-aquifer interactions. However, the wells in the proximity of the production centers had the highest impact on the estimated gradient values as ascertained using DFBETAs. The covariance ratio which indicates the sensitivity of a monitoring well on the estimated standard error of regression was noted to be significant at most wells within the network. Therefore, networks seeking to address changes in groundwater gradients due to climate and anthropogenic influences need to be denser than those used to ascertain synoptic gradient estimates alone. The magnitude of the groundwater velocity was greatly underestimated when the influential wells were excluded from the network. The direction of flow was affected to a lesser extent, but a complete gradient reversal was noted when the network consisted of only four peripheral wells. The influence analysis therefore provides a valuable tool to assess the importance of individual wells within a monitoring network and can therefore be useful when existing networks are to be pruned due to fiscal constraints. 相似文献
18.
In the Daqing region of China there are 34 groundwater well fields with a groundwater withdrawal of 81.9×104 m3/d. Due to over-abstraction of the groundwater resources from the 1960s to present, a cone of depression up to 4,000 km2 has formed in the area. To monitor the change in the groundwater environment, it is necessary to design an effective groundwater-monitoring network. The sites for monitoring groundwater level were selected by applying the finite-element method coupled with Kalman filtering to the area in which the groundwater resources have been extensively exploited. The criterion is a threshold value of the standard deviation of estimation error. This threshold value is determined by the tradeoff between maximum information and minimum cost, in which the maximum information is characterized by the standard deviation and the minimum cost is equivalent to the number of observation wells. The groundwater flow model was calibrated by an optimal algorithm coupled the finite-element method with Kalman filtering by using the data from 16 observation wells from 1986 to 1993. A simulation algorithm coupled with the finite-element method with Kalman filtering analyzed the location data obtained from the existing 38 observation wells in the same region. The spatial distribution of standard deviation of estimation error is computed and the locations that have the maximum standard deviation are selected as additional sites for augmenting the existing observational well network at a given threshold value of the standard deviation surface. Based on the proposed method for selecting a groundwater level monitoring network, an optimal monitoring network with 88 observation wells with the measurement frequency of 12 times per year is selected in the Daqing region of China. 相似文献