MODFLOW在井灌区地下水数值模拟中的应用

利用地下水数值模拟软件VISUAL MODFLOW,根据三河市的水文地质条件,建立三河市研究区的地下水流动模型,对三河市地下水水位进行分析和预测.模拟结果表明:计算地下水位和实测结果吻合较好,模型可以用来对该区的地下水位和水量进行模拟和预报.利用模型对该区域种植结构优化后的地下水水位进行了模拟和预测.     

三维水流数值模型在地下水允许开采量评价中的应用

为查明赵口引黄灌区中牟境内深层地下水允许可开采量,采用地下水流数值模拟软件GMS建立三维水流数值模型,对地下水资源进行评价计算。将开采井的开采层位根据其具体坐标和开采量加载在模型相应的网格上,在规划开采条件下按运行20年预测模型,得出该水源地2030年末深层地下水预测流场,分析深层采井附近的降落漏斗。     

MODFLOW 在井灌区地下水数值模拟

利用地下水数值模拟软件VISUAL MODFLOW，根据三河市的水文地质条件，建立三河市研究区的地下水流动模型，对三河市地下水水位进行分析和预测。模拟结果表明：计算地下水位和实测结果吻合较好，模型可以用来对该区的地下水位和水量进行模拟和预报。利用模型对该区域种植结构优化后的地下水水位进行模拟和预测。     

大型灌区集中开采条件下地下水数

在对某大型灌区水文地质条件进行分析的基础上，以灌域为基本单位，用Visual Modflow进行参数率定，确定水文地质参数，建立了地下水三维非稳定流模型。利用此模型进行地下水集中开采的数值模拟，确定了合适的开采方案。结果表明，本文分析方法结果合理，具有较高的预测精度和潜在的实用价值。     

基于解析-数值结合法的傍河水源地开采方案与地下水资源量分析

合理设计开采方案对傍河水源地地下水资源开发和避免环境地质问题的发生具有重要意义.以承德市四道河典型傍河地下水水源地为研究区,在明确区域水文地质条件的前提下,建立地下水流数值模型,运用仿泰斯公式和映射叠加原理计算出合理的开采井布局,数值法与解析法相结合得到最优开采方案,确定水源地地下水可开采资源量.结果显示,在研究区4个...     

基于GMS的博兴县南部区域浅层地下水流数值模拟

博兴县南部地区由于常年过量开采地下水致使地下水位持续下降,局部地区形成了一定规模的降落漏斗.运用GMS(Groundwater Modeling System)软件建立博兴县南部浅层地下水流数值模型,并对2020年的地下水流场变化情况进行预测,同时对该区过去、现在和未来的地下水流场进行对照研究,结果表明未来10年该区地下水位依然呈下降趋势.     

GMS软件在静脉产业生态工业产业园地下水质运移中的应用

静脉产业是一种新兴的资源再生产业,将废物转化为可重新利用的能源,达到节约能源和保护环境的目的。主要是研究产业对区域地下水水质的影响,预测产业在生产过程中和储存罐发生泄漏等情况下对地下水水质的影响。以哈尔滨静脉产业生态工业产业园为例,运用GMS模型选用特征指标进行地下水溶质运移模拟,通过数值模拟计算进行溶质运移预测,预测指标在三种工况下,地下水溶质的运移趋势。经过预测,该区三种工况下的地下水水质污染程度较小,从而得到静脉产业在运作时对地下水水质影响很小,为今后研究静脉产业对地下水的影响趋势提供依据。     

卫宁灌区迎水桥水源地地下水均衡变化研究

地下水是重要的生态因子,地下水的均衡状态往往影响着该区域生态系统的天然平衡。地下水均衡计算是区域地下水资源评价的重要环节,是对地下水各均衡要素的定量化研究。应用水均衡法与数值模拟法对卫宁灌区某水源地自然条件与开采条件下的地下水各均衡要素进行计算分析。两种方法互为论证,计算结果接近,表明其具有较好的可信度,可以为合理开采地下水提供科学依据。综合两种计算结果,水源地在开采条件下,地下水补给项与排泄项各要素的量与其所占比例均发生了很大的变化,同时水源地地下水在自然条件下的正均衡变为开采条件下的负均衡,说明人工开采地下水是影响水源地地下水天然均衡状态的重要因素,应提出相应措施保障区域的供水安全。     

基于双响应面法的地下水流数值模拟模型的替代模型研究

以内蒙古金泉工业园区水源地为研究区,在已有地下水水流数值模拟模型基础上,采用拉丁超立方抽样方法,获取输入（抽水量）数据集和输出（地下水位降深）数据集,运用双响应面方法,建立了地下水水流数值模拟模型的替代模型—双响应面模型。经验证,双响应面模型计算出的地下水水位降深均值与地下水水流数值模拟模型计算出的地下水水位降深均值的平均相对拟合误差为0.22%,地下水水位降深剩余标准差的平均相对拟合误差为0.03%,相对拟合误差都比较小,说明所建立的双响应面模型可以有效的替代地下水流数值模拟模型,这为地下水资源优化管理中替代模型的建立提供了有效的科学论证。     

北部湾经济区南康盆地地下水资源应急潜力评价

针对滨海盆地地下水的复杂性,以南康盆地地下水资源应急潜力评价为例,通过概化出南康盆地水文地质概念模型的基础上,采用Visual-MODFLOW软件中SEAWAT模块建立了南康盆地变密度地下水流与溶质运移的数值模拟耦合模型,假设2025年10月出现极端干旱,在保证不发生海水入侵条件下,按那时规划的需水量进行应急供水预测,获得了度过整个枯水季节各集中开采区地下水应急潜力。该方法将滨海水源地地下水应急供水预测和盆地的水文地质结构及当地发展规划紧密结合起来,具有较高的精度。     

On-farm water management in saline groundwater area under scarce canal water supply condition in the Northwest India

The study investigates the possibility of enhancing crop water productivity in the parts of Northwest India where groundwater quality is marginal and canal water supply is severely scarce. Soil, Water, Atmosphere and Plant (SWAP) model was calibrated and validated in three farmers’ fields with varying canal water availability and groundwater quality in the Kaithal Irrigation Circle of the Bhakra Canal system, Haryana. On the basis of predicted and observed soil water content, pressure heads, salt concentration at 2 week intervals and crop yields, the model was found suitable for use in the region. A few nomographs were prepared to provide a graphical method to predict the effect of different combinations of water quality and depth of water application on crop yield and soil salinity and to help develop some guidelines to the farming community. Water management alternatives at the field level were suggested to increase the yield and to maintain soil salinity below threshold level. The application of frequent irrigation in precisely leveled field would help in achieving 10% higher yield even when saline groundwater of 11 dS/m is used for irrigation.     

Assessment of groundwater storage depletion by overexploitation using simple indicators in an irrigated closed aquifer basin in Iran

In arid and semi-arid regions irrigation is usually needed to provide enough water for crop growth in cultivated areas. As surface waters are scarce, especially in summertime when the water is needed, groundwater is heavily used to supply the water demand. Overexploitation of the aquifer in dry years causes depletion of the groundwater storage and systematical lowering of the piezometric levels. This is a particular problem in aquifers developed in closed basins where lateral inflow is nearly absent and replenishment is constrained by rainfall recharge. In this paper, simple indicators derived from meteorological data, abstraction rates and piezometric time series are compared with the groundwater storage depletion as obtained from a calibrated groundwater flow model. Application of the method to the overexploited Shahrekord basin in Iran shows that for the simulated period 1989-2003 an accumulative index of the difference of aquifer recharge, as calculated by a soil moisture balance method, and groundwater abstraction has a correlation coefficient of nearly one with model calculated storage. Indicators based on the filling index derived from piezometric time series or on the ratio of aquifer discharge to recharge have slightly lower correlations. The accumulated index indicator can be used to follow aquifer storage in the future without the need to run the full groundwater flow model. This simple approximation is restricted to aquifer systems with a limited lateral inflow and outflow.     

Development and application of a modeling approach for surface water and groundwater interaction

Investigation of the interaction of surface water (SW) and groundwater (GW) is critical in order to determine the effects of best management practices (BMPs) on the entire system of water resources. The objective of this research was to develop a modeling system for considering SW–GW interactions and to demonstrate the applicability of the developed system. A linked modeling approach was selected to consider SW–GW interaction. The dual-simulation scheme was developed to consider different time scales between a newly developed surface model: Dynamic Agricultural Non-point Source Assessment Tool (DANSAT), and existing groundwater models; a three-dimensional finite-difference groundwater flow model (MODFLOW) and a modular three-dimensional transport model (MT3D). A distributed and physically based DANSAT predicts the movement of water and pesticides in runoff and in leachate at a watershed scale. MODFLOW and MT3D simulate groundwater and pesticide movement in the saturated zone. Only the hydrology component of the linked system was evaluated on the QN2 subwatershed in the Nomini Creek watershed located in the Coastal Plain of Virginia mainly due to lack of observed data for MT3D calibration. The same spatial scale was used for both surface and groundwater models while different time scales were used because surface runoff occurs more quickly than groundwater flow. DANSAT and MODFLOW were separately calibrated using the integrated GW approach which uses own lumped baseflow components in DANSAT, and using the steady-state mode in MODFLOW, respectively. Then the linked system was applied to QN2 based on the parameters selected for DANSAT and MODFLOW to simulate time-dependent interactions on the entire system. The linked approach was better than the integrated approach for predicting the temporal trends of monthly runoff by improving the monthly Nash–Sutcliffe efficiency index from 0.53 to 0.60. The proposed linked approach will be useful for evaluating the impacts of agricultural BMPs on the entire SW–GW system by providing spatial distribution and temporal changes in groundwater table elevation and enhancing the reliability of calibrated parameter sets.     

Simulation of land use impacts on groundwater levels and streamflow in a Virginia watershed

Increase in withdrawal and decrease in recharge of groundwater due to urbanization influences subsurface flow regimes. The overall objective of this study was to determine the impact of land development activities on the subsurface flow regime in the Upper Roanoke River Watershed (URRW). A regional groundwater model of the URRW was constructed using Modular Three-Dimensional Ground-Water Flow Model (MODFLOW) and calibrated for steady-state conditions. Then, eight land use management scenarios were simulated on the Back Creek (BC) subwatershed to assess the impacts of residential density, residential location, and land-cover on hydraulic head of groundwater and streamflow. The average recharge output from the Hydrological Simulation Program, FORTRAN (HSPF) simulation was used as the direct input to MODFLOW to take changes in land use into account in the BC watershed. Development of agriculture and forest areas with low-population density on larger area (low-density scenario), near the middle of the watershed (mid-section scenario), and with changes all open space to lawn (lawn scenario) had greatest overall impact on the BC watershed for both hydraulic head and streamflow among density, location, and land-cover scenarios, respectively. The simulated scenarios indicated that decreases in both hydraulic head and streamflow coincided with the increases in impervious land. The reductions in hydraulic head and streamflow were restricted to the subwatershed where land use changes occurred. The urbanization impacts on both surface and subsurface regimes were very local with 20.8 cm of maximum difference in local hydraulic head and 0.532% of maximum percent difference in local streamflow at lawn scenario while average corresponding values through BC watershed was 4.3 cm and 0.153%, respectively. Use of a fully distributed surface model in a dynamic manner was recommended to solve the inconsistencies in the spatial and temporal scale of surface and groundwater models. However, the proposed approach can be used as a management and planning tool for evaluating the local and overall impacts of land use management on the surface and subsurface flow regimes.     

Drip irrigation water and salt flow model for table grapes in Coachella Valley,California

Unlike annual crops where reclamation leaching of salts can be readily conducted between cropping, leaching of salts in permanent crops that are drip irrigated pose challenges. A need exists to formulate and test a management-type of salinity model for drip irrigation of table grapes. The model reported herein predicts the distribution of salts along the vine row and between the rows during the growing season, as affected by reactivity of salts of the applied irrigation water as well as rate and duration of drip application. The calibrated model reproduced the initial field salinity profiles after repeated irrigation cycles by adjusting only the routing factor α which is the ratio of horizontal to vertical water flow. After eight cycles the profiles stabilized and the calibrated horizontal to vertical flow routing ratio was 0.6. There is remarkable agreement between measured and simulated salinity. Corresponding soil moisture profiles show the expected high water content with depth at the emitter, the decrease in surface water content with radial distance and the increase with depth, at the distal end of the wedge. Although the model is location specific it can be applied knowing soil, initial and boundary conditions, as well as irrigation application quantity and quality and as such can be applied location by location in order to assess flow and quality of deep percolation recharging the groundwater system. With this capacity the model can predict soil water quantity and quality outcomes for possible land and water management scenarios.     

农业节水措施对地下水涵养的作用及其敏感性分析

以北京市大兴区为研究区,利用经校验的水平衡模型,通过调整灌溉满足率和灌溉水利用系数,探讨了不同农业节水措施对增加地下水补给量和减少地下水开采量的作用及其敏感性。结果表明,不同水文年型下,降低灌溉满足率及提高灌溉水利用系数都能减少地下水开采量,且降低灌溉满足率对减少地下净开采量的作用更为显著,有利于区域地下水涵养。在参数取值范围内,地下水净开采量对灌溉满足率的敏感性较大,而地下水补给量对灌溉水利用系数的敏感性较高。与提高灌溉水利用系数相比,对资源性缺水区域,采用先进节水技术,适度降低区域灌溉满足率,对促进水资源持续有效利用及加大地下水涵养具有更显著的效果。     

长潭河流域水文模型的建立和应用

结合时变增益非线性产流模型与水箱模型的概念，建立了一个两层结构的水文模型。上层采用时变增益产流模型模拟地表产流，下层采用水箱模型综合模拟壤中流与地下径流，上下两层分别应用Nash单位线和线性水库调蓄方法进行汇流计算。该模型共有6个参数（产流模型与汇流模型分别包含3个参数）。产流模型参数采用SCEUA全局优化算法自动率定，汇流模型参数采用主观优化方法（即实测资料推求及人工调试）确定。以湖南省长潭河流域为对象进行水文模拟应用研究，结果表明尽管模型结构简单，但是能够取得比较好的模拟效果，说明模型比较可靠。     

The Viejo Retamo secondary canal

The intended operation of the Rio Tunuyan irrigation scheme in the province of Mendoza, Argentina, is to divide flow proportionately over the entire area in accordance with registered water-rights. The main division of flow is by regulators at the heads of the lateral canals, which serve areas of appr. 15,000 ha. Taking the sub-lateral or secondary canal Viejo Retamo as an example, this paper discusses the flow division downstream of these regulators. The operation of the canal is evaluated with two performance indicators:

-the ratio of volume of water intended to be supplied to the tertiary units over the volume of water actually supplied, and

-the misallocation of water in volume.

In the Rio Tunuyan scheme, there is also a relation between the evapotranspiration of crops and the groundwater level: if less than 60% of the supplied canal water evapotranspires, the groundwater level rises.     

宁夏银北灌区井渠结合灌溉三维数值模拟与分析

为实现银北灌区水资源联合调度 ,减少引黄水量 ,充分利用地下水的目标 ,对选定典型区的地表水、地下水联合调度进行模拟 ,对井渠结合灌溉模式和运作方式进行了计算。通过三维的数值模拟计算发现 ,在规划渠系利用条件下 ,可以根据当地实际情况 ,在来水保证率低的春灌或冬灌期实施井灌 ,以控制地下水位 ,减少土壤返盐 ,也可以对部分农田采用集中井灌的方式 ,以提高用水效率。     

河套灌区井渠结合地下水数值模拟及均衡分析

建立了河套灌区三维地下水数值模型,用2006-2013年灌区实测地下水埋深资料对模型进行率定和验证,并在规划的井渠结合区内,设置3种不同井灌区灌溉定额和3种秋浇频率,组合共9种井渠结合节水情景,分别分析了9种节水情景下的地下水动态变化.结果表明:井渠结合后全灌区地下水埋深范围为1.863~2.029 m,较现状条件增加0.084~0.250 m;不同灌域结合区井渠结合后地下水埋深差别很大,解放闸结合区地下水埋深最大,为2.308~2.803 m,永济结合区地下水埋深最小,为2.079~2.455 m;井渠结合后,入渗补给量减少2.01×10⁸ ~3.63×10⁸ m³/a,潜水蒸发量减少1.69×10⁸ ~3.03×10⁸ m³/a.