梯度法在水文地质参数估值中的应用   总被引：7，自引：1，他引：7  

刘立才  陈鸿汉  张达政 《水文地质工程地质》2003,30(3):39-41

根据地下水的抽水试验求含水层的导水系数和储水系数时,传统的计算方法是配线法和直线图解法。这两种方法比较繁琐,且人为误差较大。本文运用数学模型的最优化方法即梯度法,并借助于计算机编程,实现了水文地质参数的数值求解。计算结果能消除人为误差,准确反映含水层的参数特征。  相似文献   

Modelling of groundwater flow in heterogeneous porous media by finite element method     

Hassan Smaoui  Lahcen Zouhri  Abdellatif Ouahsine  Erick Carlier 《水文研究》2012,26(4):558-569

The HySuf‐FEM code (Hydrodynamic of Subsurface Flow by Finite Element Method) is proposed in this article in order to estimate the spatial variability of the transmissivity values of the Berrechid aquifer (Morocco). The calibration of the model is based on the hydraulic head, hydraulic conductivity and recharge. Three numerical tests are used to validate the model and verify its convergence. The first test case consists in using the steady analytical solution of the Poisson equation. In the second, the model has been compared with the hydrogeological system which is characterized by an unconfined monolayer (isotropic layer) and computed by using PMWIN‐MODFLOW software. The third test case is based on the comparison between the results of HySuf‐FEM and the multiple cell balance method in the aquifer system with natural boundaries case. Good agreement between the Hydrodynamic of Subsurface Flow, the numerical tests and the spatial distribution of the thickening of the hydrogeological system is deduced from the analysis and the interpretations of hydrogeological wells. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

论"单位涌水量就是导水系数"   总被引：2，自引：0，他引：2  

兰太权 《地下水》2007,29(5):43-45,68

单位涌水量是井抽水水位降深换算为1 m时的单井出水量;导水系数是含水层宽度为1 m时,地下水水力坡度为1时的单宽流量.二者之间从定义上看毫无关系,但它们的单位(m3/d·m)(m2/d)是相同的.笔者经过多年探讨和初步试验后发现,单位涌水量就是管井抽水所利用含水层的导水系数.  相似文献   

On solution of the inverse problem for confined aquifer flow via maximum likelihood     

Hugo A. Loaiciga  Miguel A. Mariño 《Mathematical Geology》1986,18(7):677-692

Joint estimation of transmissivity (T) and storativity (S) in a confined aquifer is done via maximum likelihood (ML). The differential equation of groundwater flow is discretized by the finite-element method, leading to equation _t+x _t=u _t. Elements of matrices and , as well as estimated covariance matrix of noise termu _t, are functions of T and S. By minimizing the negative loglikelihood function corresponding to discretized groundwater flow equation with respect to T and S, ML estimators are obtained. The ML approach is found to yield accurate estimates of T and S (within 9 and 10% of their actual values, respectively) and showed quadratic convergence in Newton's search technique. Prediction of aquifer response, using ML estimators, results in estimated piezometric heads accurate to ±0.5 m from their actual, exact values. Statistical properties of ML estimators are derived and some basic results for statistical inference are given.  相似文献   

卷云与水云的短波透射与反射特性   总被引：8，自引：1，他引：7  

佟彦超  刘长盛 《大气科学》1998,22(1):32-38

利用矩阵算法计算了对不同太阳天顶角下不同光学厚度的卷云与水云,在4π空间内0～360o的不同方位与0～90o不同天顶角下的波长为1.39 μm太阳短波波段的透射与反射,其天顶角间隔为5.6o,方位角间隔为5.0o。可以看出两种云透射和反射辐射的差别及它们随着光学厚度变化而变化的情况。同时,将其与波长为0.55 μm的可见光波段的透射和反射进行了比较。  相似文献   

Neogene aquifer properties specified through the interpretation of electrical sounding data,Salamiyeh region,central Syria     

Jamal Asfahani 《水文研究》2007,21(21):2934-2943

Twenty‐nine Schlumberger electrical soundings were carried out in the Salamiyeh region in Syria using a maximum current electrode separation of 1 km. Three soundings were made at existing boreholes for comparison. Aquifer parameters of hydraulic conductivity and transmissivity were obtained by analysing pumping test data from the existing boreholes. An empirical relationship between hydraulic conductivity determined from the pumping test and both resistivity and thickness of the Neogene aquifer has been established for these boreholes in order to calculate the geophysical hydraulic conductivity. A close agreement has been obtained between the computed hydraulic conductivity and that determined from the pumping test. The relationship established has, therefore, been generalized in the study area in order to evaluate hydraulic conductivity and transmissivity at all the points where geoelectrical measurements have been carried out. This generalization allows one to derive maps of the hydraulic conductivity and transmissivity in the study area based on geoelectrical measurements. These maps are important in future modelling processes oriented towards better exploitation of the aquifers. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Aquifer heterogeneity determination through the slope method     

Zekai Şen  Essam Wagdani 《水文研究》2008,22(12):1788-1795

In arid‐region wadis, groundwater storage lies within shallow Quaternary alluvium deposits, which are connected with the present‐day hydrological cycle and, therefore, are replenished due to occasional runoff and flash flood occurrences. The groundwater resources are precious in these environments; therefore, their potentiality must be assessed with care in the best manner. The aquifer potentiality is calculated after the storativity and transmissivity parameter estimations, which require rather long‐duration field tests with restrictive assumptions in the theoretical model developments, such as the homogeneity and isotropy. It is the main purpose of this paper to expose the fundamentals of the slope‐matching procedure (SMP) and its application for short‐duration field tests in arid‐region aquifers. In this manner, the subsurface hydrogeological behaviours of the bored land pieces at and around the well locations are prospected in a detailed and refined manner. It is shown that in many cases the classical techniques are appropriate, inconvenient and inapplicable with conclusive reliable results and conclusions. The application of the SMP is presented for some aquifer tests from the central western part of the Kingdom of Saudi Arabia. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

On the use of the groundwater replenishment periods approach to determining aquifer parameters     

S. Lallahem  J. Mania 《水文研究》2006,20(7):1585-1595

Chalk crops out from a wide belt around the Paris basin, France, covering an area of about 70 000 km². In this region, the chalk presents the most important unconfined aquifer because of its extent and the size of its resources ((11–12) × 10⁹ m³ year^?1). The assessment of underground outflow depends on the vertical feeding, the infiltration and the hydrometry. This paper analyses the regional structural map, interprets the groundwater reaction under rainfall, explains the water circulation in such media where the reservoir geometry plays an essential role on aquifer response, and determines different aquifer physical parameters. Attempts are made to identify the rapid transfer of groundwater at the level of faults and their important fissures. Based on a quantitative study of the seasonal and interannual piezometry fluctuations, it is noted that the mode and the piezometric chronology events are controlled by major parameters of geological and hydrogeologic contexts, aquifer hydraulic characteristics, the position of upstream and downstream basin limits, groundwater depth and replenishment time. This paper ends with determination of groundwater physical parameters of the diffusivity (T/S, T and S) values by examination of the groundwater replenishments periods. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Generalization of TOPMODEL for a power law transmissivity profile     

I. IORGULESCU  A. MUSY 《水文研究》1997,11(9):1353-1355

A generalization of the TOPMODEL equations for a power law vertical profile of hydraulic conductivity is introduced. The exponential profile of TOPMODEL is obtained as a limit case of the new general form. © 1997 John Wiley & Sons, Ltd.  相似文献   

利用不对称的地下水位潮汐波动确定滨海含水层参数     

宋超  周训  赵敬波  陈瑞阁  张欢  李婧玮 《现代地质》2013,27(6):1471

在滨海地区,地下水水位受潮汐波动影响较大,使得传统的抽水试验、水位回复试验等方法确定含水层参数存在困难且花费较大。通过对广西北海市滨海含水层地下水位动态资料进行分析,发现其上升段和下降段是不对称的。基于海岸带承压含水层正弦潮汐波的传播理论,提出了确定含水层参数的分段法,并与振幅衰减法和滞后时间法进行对比,各种方法求出的储水系数与导水系数之比(S/T)很接近,说明分段法是有效的。对于北海市滨海含水层,上升段求出的S/T值比下降段要大,其成因机理还有待进一步分析。  相似文献