渭北旱塬区地下水动态研究

渭北旱塬区地表水资源短缺,地下水成为城市和农村的重要供水水源,为了掌握该区地下水动态变化特征,本文以渭北旱塬区2000-2009年间水文气象和地下水浅层监测井实测资料为依据,根据地下水补给排泄条件及自然、人为影响因素之间的关系,将研究区地下水动态成因分为灌溉-开采、渗入-蒸发、渗入-开采和径流-开采4种类型,对各类型地下水变化特征进行分析,并运用差分自回归移动平均(ARIMA)模型对地下水位埋深进行模拟预测。结果表明:拟合程度较高,预测效果较好。     

基于Modflow水文数值模型确定察汗淖尔流域地下水适宜生态水位的研究

文章以察汗淖尔流域为例，利用Modflow水文模型软件，建立地下水动态水文模型，研究其地下水资源在不同规划开采方案对地下水环境的影响，提出地下水适宜生态水位，并对整体流域地下水水位恢复时限进行预测。定量分析表明，不同压采指标对应的方案优劣次序有所差异，对地下水恢复至适宜生态水位年限有不同影响。     

控制排水对宁夏银南灌区水稻田盐分动态变化的影响

本文结合2004～2005年在宁夏银南灌区水稻田进行的一项控制排水大田试验，研究分析了控制排水措施对田间盐分动态变化的影响。结果表明：控制排水条件下0.3m深度地下水盐分的平均浓度略高于常规排水，并且该深度地下水盐分浓度在总体上比较稳定；在0.8m和1.2m深度，控制排水条件下的地下水盐分浓度明显大于常规排水条件下盐分的浓度，而且盐分受灌溉的影响程度要小于常规排水；最后，控制排水措施减小了田间浅层地下水盐分浓度的差异，而对深层地下水盐分浓度的空间差异影响较小。两年的试验研究结果说明控制排水措施对水稻田地下水盐分动态产生了一定程度的影响，但是并没有出现明显的积盐现象。因此，具有环保意义的农田控制排水措施可以在当地进行推广使用。     

GMS在地下水污染质运移数值模拟预测中的应用

利用地下水模型系统软件GMS,对研究区污染物在地下水中污染运移进行数值模拟.根据模拟结果,规划基地的防渗减小了对地下水的污染影响.建议加强监测,在做好防渗的同时,开展水力调控措施研究,降低地下水污染应急处理的技术难度.     

基于作物水盐生产函数的咸水灌溉制度确定方法

本文在作物水盐生产函数和农田水盐动态模型基础上，以单位面积纯收益最大为目标函数提出了制定咸水灌溉制度的模型。以山西省永济市试区进行的棉花咸水灌溉试验资料为依据，求得了有关模型的参数；利用该试区35年系列的旬降雨、旬蒸发量资料，对3种不同灌水时间和灌水次数、7种灌溉咸水浓度，共计49种可能组合的农田土壤盐分和产量进行了模拟，并与该试区大田试验数据进行了比较。结果表明该模型合理可靠。以模拟产量为依据，在对当地深井和浅井灌溉效益分析的基础上，提出了咸水灌溉制度及其相应的地下水开发利用策略。     

吴忠市金积地下水饮用水源地保护区划分

对以地下水为主要供水水源的城市进行地下水饮用水源地保护区划分将提高饮用水的安全保障程度。在总结地下水水源地划分的原则和方法基础上,利用FEFLOW软件建立了吴忠市金积傍河型地下水水源地的地下水数值模型,模拟了规划的三种地下水开采情景下地下水的运动,并利用反向粒子跟踪技术和水源地划分原则和标准确定了三级保护区范围。该研究可为吴忠市和其他类似地区地下水资源管理和有效保护提供科学依据和参考。     

酒泉盆地地下水资源演变规律研究

以酒泉盆地为研究区,在已有观测(井)资料的基础上,采用地下水数值模拟软件Feflow,建立研究区地下水数值模拟模型,分析酒泉盆地地下水均衡和地下水动态,得到酒泉盆地区域地下水在灌区之间的空间数量构成,得出酒泉盆地地下水年代尺度的动态特征。     

FeFlow和MODFlow在地下水动态模拟中的应用对比

地下水作为我国城市发展和工农业发展的重要物质基础,对地下水流动进行动态模拟分析是地下水合理利用和科学管理的重要内容。本综述将FeFlow和MODFlow地下水模拟软件在地下水动态模拟预测的应用作对比,分析比较两者之间的优缺点以及存在的局限性,为在地下水研究领域中选取应用适当的模拟软件提供理论参考。     

基于HYDRUS模型不同灌水模式下土壤水盐运移模拟

以田间试验为基础,应用饱和-非饱和土壤水分及溶质运动理论,利用HYDRUS-1D/2D数值模型对内蒙古河套灌区不同灌水模式下土壤水分、盐分运移规律进行数值模拟,分析了不同灌溉条件下的水盐运移状态,并将模拟结果与田间试验实测结果进行对比分析。研究结果表明,在相同灌水定额下,100cm土体内沟灌条件下生育期土壤盐分含量平均值比畦灌条件下土壤盐分含量平均值降低24.4%,沟灌可以有效控制土壤盐分的累积。利用HYDRUS模型对土壤水盐运移的模拟结果能够为灌区的水盐管理提供科学依据。     

考虑地下水入渗的洪水演进模型构建及应用

近年来我国北方地下水埋深逐渐增加,在洪水演进中,地下水渗漏的可能性较大,从而对洪水演进可能产生较大影响。针对此问题,以小清河分洪区及其西部为研究对象,建立了考虑地下水入渗的洪水演进模型。利用该模型对小清河分洪区的设计标准洪水进行了模拟,分析了地下水渗漏对小清河分洪区、河北省部分区域的水位以及出口东茨村的水位和泄量的影响。模拟结果表明:地下水渗漏对小清河分洪区的洪水演进有较大影响。因此在小清河分洪区的调度运用以及治理规划时,需要充分考虑地下水渗漏这一重要因素。     

Stochastic Goal Programming Model for Optimal Blending of Desalinated Water with Groundwater

A stochastic goal programming (GP) model is developed in orderto determine the daily production of desalination plants to meet the requirements of water blending stations (WBS) for major cities in the Eastern Province of the Kingdom of SaudiArabia. The WBS is assumed to be a control point in the systemwhere water is blended to satisfy the desired water quality, downstream of the control point. The desalinated water is blended with brackish groundwater extracted from several groundwater wells. The objective of the model is to minimize the goal deviations from the following priority levels: demand for blended water, control of salinity levels, depletion of groundwater and maximize the use of brackish water, demand forbrackish water at WBS, and production of desalinated water. Anessential element of the model is the input data; unfortunately,available data are not accurate due to the inherent uncertaintyassociated with it. This uncertainty will generate uncertainty in the model output, which affects reliability and confidence associated with the decisions. Thus, reliable planning should consider uncertainties associated with model input parameters.The developed stochastic model shows how Goal Programming (GP)modeling can be used to plan the water resources in the EasternProvince of Saudi Arabia, assuming that both supply and demandare uncertain.     

Modeling of Ground Water Salinity on the Caspian Southern Coasts

Water salinity is one of the main restrictive factors in water exploiting. Also, unsuitable management and exploitation of water resources has led to an increase of surface and groundwater salinity. Thus, in view of human needs to water resources, it is necessary to study and define water salinity factors in order to weaken these factors. This research has been conducted to investigate the factors of groundwater salinity and also, to provide a model for estimating groundwater salinity on the Caspian southern coasts. Data included in the model are: water qualitative examinations in the area, annual precipitation and evaporation, water table depth, surface water salinity, aquifer formation (Transmissivity) and distance from Caspian Sea. Surface and groundwater salinity was estimated by sampling in different sites on the Caspian southern coasts. Then, Multivariate Regression method was used by using SPSS software. In this stage, groundwater EC has been used as a variable for water salinity or dependent variable and groundwater salinity factors have been used as independent variables. A linear model and a non-linear model were presented. The models efficiency was evaluated by applying them in the sites that their data were not used for presenting the models. Finally, groundwater EC average map was provided by using the presented non-linear model and Geographic Information System in the Eastern part of Mazandaran province. In view of salinity hazard increases in the coastal terrains and agricultural areas, the places with high hazard salinity must be defined and managed to decrease water resources salinity.     

Development and Implementation of Support Vector Machine Regression Surrogate Models for Predicting Groundwater Pumping-Induced Saltwater Intrusion into Coastal Aquifers

Predicting the extent of saltwater intrusion (SWI) into coastal aquifers in response to changing pumping patterns is a prerequisite of any groundwater management framework. This study investigates the feasibility of using support vector machine regression (SVMr), an innovative artificial intelligence-based machine learning algorithm for predicting salinity concentrations at selected monitoring wells in an illustrative aquifer under variable groundwater pumping conditions. For evaluation purpose, the prediction results of SVMr are compared with well-established genetic programming (GP) based surrogate models. SVMr and GP models are trained and validated using identical sets of input (pumping) and output (salinity concentration) datasets. The trained and validated models are then used to predict salinity concentrations at specified monitoring wells in response to new pumping datasets. Prediction capabilities of the two learning machines are evaluated using different proficiency measures to ensure their practicality and generalisation ability. The performance evaluation results suggest that the prediction capability of SVMr is superior to GP models. Also, a sensitivity analysis methodology is proposed for assessing the impact of pumping rates on salt concentrations at monitoring locations. This sensitivity analysis provides a subset of most influential pumping rates, which is used to construct new SVMr surrogate models with improved predictive capabilities. The improved prediction capability and the generalisation ability of the SVMr models together with the ability to improve the accuracy of prediction by refining the input set for training makes the use of proposed SVMr models more attractive. Prediction models with more accurate prediction capability makes it potentially very useful for designing large scale coastal aquifer management strategies.     

基于EMD-LSTM耦合模型的趵突泉岩溶地下水水位预测应用

由于岩溶地下水具有强烈的非线性及非平稳波动特征,水位预测结果容易产生较大误差。针对岩溶地下水水位预测精度较差的问题,提出一种EMD-LSTM耦合模型,首先采用经验模态分解（EMD）将趵突泉岩溶地下水水位分解为5个分量（4个本征模函数项和1个残余项）,以此消除水位数据的非平稳波动性;同时构建长短期记忆（LSTM）神经网络模型,并将与地下水水位动态变化密切相关的降水量（表征含水层补给项）和月平均气温值、月最高气温值、月最低气温值、水汽压值（表征含水层排泄项）作为输入项分别对5个分量进行预测,最终将分量预测结果累加获得地下水水位预测值。结果表明：EMD能够显著消除岩溶地下水水位的非平稳波动特征;EMD-LSTM耦合模型可有效提高岩溶地下水水位的预测精度,其均方根误差相比于LSTM神经网络模型、ARIMA模型分别减小了27.86%和59.94%。总体来说,本文所提出的EMD-LSTM耦合模型具有较强的可靠性和稳定性,可为岩溶地下水水位的精确预测提供借鉴。     

Coupled water and salt balance models for Lake Urmia: Salt precipitation and dissolution effects

Investigating the dynamic evolution of storage volume and salinity of Lake Urmia (LU), which is crucial to present more reliable estimations of water balance components, needs to be furthur studied. We aimed to fill this gap by developing a coupled lumped mathematical model that considered the two-way effect of salt and water balance components on each other. Through the coupled water and salt balance model, salt precipitation and dissolution components were incorporated, and vaporation was calculated dynamically based on the lake’s salinity. The final model was then used as a tool to estimate the groundwater flux. Results indicated that during the lake shrinkage period (2009–2015), substantial salt precipitation with an average rate of 6.79 g/100 g/year (6.79 g of salt per 100 g water per year) occurred. In this period, the lake’s salinity increased to more than 450 g/l, and a negative trend of −0.200 km³/year in evaporation was detected. From 2016 to 2019, LU’s water level rose, and although great salt dissolution with an average rate of 4.27 g/100 g/year occurred, the lake’s salinity decreased. In 2019, with the least lake's salinity values (annual average of 266.1 g/l), the evaporation rate was 1.45 times greater than the average evaporation rate through the rest of the simulation period. While LU’s connection with groundwater resources varied temporally, the average groundwater flux (-0.203 km³/year) was higher than it could be neglected. Results of this study are expected to enhance the understanding of LU crisis and to improve the plan to prevent further shrinkage of the lake.     

基于时间序列模型的济南趵突泉地下水位预测

本文对2012年5月至2017年12月济南泉域趵突泉的地下水位波动规律进行了分析,并采用3种灰色时间序列模型,评价了保泉形势,通过模型的拟合效果检验可知:对于存在周期性波动趋势的地下水位观测值,GM(1,1)模型优势未能得到充分体现,ARIMA与Holt-Winters模型的预测结果较为接近,整体精度较高,表现出明显的预测优势。深入比选ARIMA与Holt-Winters模型的8项拟合优度指标,最终确定利用预测效果最优的Holt-Winters模型,从时间序列的角度对趵突泉地下水位进行分析,并预测2018—2019年趵突泉的年平均水位分别为27.734m和27.605m,泉水位波动的峰值为28.215 m,谷值将出现于2019年的6月份,数值仅为27.124m,逼近27.01m的泉水停喷线,为近7年来的最低水位。预测结果表明:现状降雨与开采条件下,2019年6月趵突泉将面临潜在的停喷的危机,保泉形势不容乐观。     

关中盆地浅层地下水水文地球化学分布特征研究

以揭示地下水化学场的形成机理为研究目的,在了解关中盆地水文地质的基础上,分析了地下水的水化学特征,讨论了其形成机理。结果表明:水化学类型、矿化度、硬度均具有明显的水平分带特征,但由于受到地质地貌和水文地质不同的制约,又各有特点;离子含量的分布与pH值、矿化度、硬度和水化学类型的分布规律有着一定的联系;离子的变化趋势的大小明显受到矿化度大小的约束,且地下水动力场对化学场起着控制性作用。     

Brackish groundwater resources in Bahrain: Current exploitation,numerical evaluation and prospect for utilization

In Bahrain, where water resources available for direct use are finite and the best of its quality has a salinity of over 2.5 g L^–1, utilization of brackish groundwater is an essential part in the management of the country's water resources. Bahrain's brackish water occurs in the Rus-Umm Er Radhuma formations in the form of a lens of a finite lateral extent, with a salinity ranges between 8 and 15 g L^–1. Planning for utilization of brackish groundwater for desalination purposes in Bahrain was based on simulation modeling of the aquifer system using a mixing cell model developed originally in 1983. The model was used to predict the aquifer response to pumping from the proposed wellfield in terms of changes of TDS over a period of 20 years. Construction and operation of the wellfield in 1984 was based on the predicted salinity changes. Over the past 9 uears of wellfield operation (1984–1993), and through continuous monitoring of the aquifer response to pumping, the collected data is used to post-audit the original model by history matching. The calibration process adopted has resulted in a statisfactory agreement between the model output and the observed data. The model is then used to predict the wellfield salinity changes and the aquifer potentiometric levels. The expected life span for the brackish groundwater utilization by the wellfield is redefined through constrained utilization that takes into account salinity deterioration coupled with the effect of head decline on hydraulic interaction between the brackish water and the upper fresh water aquifer. The results suggest that the operation of the wellfield should cease by the year 2007. Construction of a new model that enables testing and evaluating different development scenarios is recommended to aid future management decisions regarding the utilization of brackish groundwater.     

关中盆地潜水水文地球化学演化机理

在分析关中盆地水文地质背景的基础上,根据地下水的水文地球化学特征,讨论了研究区潜水的形成机理。结果表明:地下水水动力和水化学类型具有明显的水平分带特征,水动力场对水化学类型的分布起着控制性作用;Cl-浓度与TDS的大小可用来表征研究区的蒸发强度;研究区内地下水离子交换作用主要发生在高矿化度的地下水中。PHREEQC模拟结果显示,沿地下水流向,路径1、2以方解石和石膏的沉淀为主,离子交换方式主要是Na+-Ca2+交换;而路径3则以方解石沉淀、白云石和石膏溶解为主,除发生Na+-Ca2+离子交换外,还存在着Ca2+-Mg2+交换现象。