Design of an Index System for Deep Groundwater Management Efficiency Evaluation: A Case Study in Tianjin City, China

An effective evaluation system can provide specific and practical suggestions to the deep groundwater management. But such kind of evaluation system has not been proposed in China. In this study, an evaluation index system is specifically developed to evaluate deep groundwater management efficiency. It is composed of three first-level indicators(law enforcement capability, management ability, and management effectiveness) and eleven second-level indicators. The second-level indicators include seven mandatory indicators and four optional indicators. Piecewise linear function is used to normalize the quantitative indicators, and expert scoring method and questionnaire survey method are used to normalize the qualitative indicators. Then a comprehensive indicator weighting evaluation method is used to evaluate the first-level indicators and the target topic. A case study is carried out to evaluate deep groundwater management efficiency in Tianjin City. According to the evaluation score in each period, the management efficiency of every district in Tianjin City gradually improved. The overall evaluation score in the early deep groundwater extraction period is 0.12. After a series of deep groundwater protection efforts, this score reached to 0.61 in 2007, and met the regulation criteria. The evaluation results also showed that the further groundwater management efforts in Tianjin City should be focused on building a dynamic database to collect comprehensive deep well-log data; and on a reasonable design and distribution of the groundwater monitoring network. It demonstrated that the index system is suitable to locate the deficiencies of current groundwater management systems and to guide further improvements. It can then be used to protect deep groundwater.

Groundwater Management under the Kabu-ido System in Noubi Plain, Japan, 1810s-1860s

The purpose of this paper is to clarify how the Kabu-ido system can be employed to successfully regulate groundwater pumping. This was accomplished by analyzing surviving historical documents, including budgetary notes and a diary. The Kabu-ido system was a customary institution for groundwater management in a ring levee area of the Noubi Plain in Japan that consisted of three programs： restriction of groundwater pumping through a permit system, groundwater pricing and economic compensation. The system was created in the 1810s and survived for 100 years. This paper covers the Kabu-ido system from the 1810s to the 1860s, the first half of the 100-year history. Excessive groundwater pumping is not a new environmental problem. Although many case studies have investigated remedial actions, few have investigated how local residents addressed the problem before the 20th century because of a lack of documents. The Kabu-ido system is an exception in which of the procedure was documented in writing. The historical data indicate that it was a pioneering institution for groundwater management.

Groundwater Management at West El-Minia Desert Area, Egypt Using Numerical Modeling

Water shortage is the main problem facing any development in Egypt especially in the desert lands. River Nile is considered the main source of water in Egypt but its water covers only the area of flood plain where its tributaries do not reach to the desert. The desert fringes, west of El-Minia governorate, Egypt, are areas of natural expansion for agricultural, industrial, and civil activities. This implies an increasing demand for groundwater. A numerical groundwater model is one of the main tools used for assessment of the resource potential and prediction of future impact under different circumstances and stresses. In this paper, a transient groundwater flow model in the desert district west of El-Minia, Egypt, was developed. The conceptual model was built by analyzing the hydrogeological data and previous work. Steady state model of year 1990 was used to investigate and calibrate the parameters such as hydraulic conductivities, recharge and conductance of the surface water streams. The storage coefficients are calibrated by the transient model based on the available data observed from 1990 to 2013, which provides insights to understand the behavior of groundwater system in Quaternary Aquifer and to predict spatial-temporal distributions of groundwater levels and groundwater flow in responding to extraction of water. The calibrated transient model will be used to predict the impacts of desert development schemes and water resources management schemes on groundwater in the study area.

Developing three-dimensional groundwater flow modeling for the Erbil Basin using Groundwater Modeling System (GMS)

This study presents the development of a comprehensive three-dimensional groundwater flow model for the Erbil Basin utilizing the Groundwater Modeling System(GMS).The Erbil Basin,situated in the Kurdistan Region of Iraq,is a vital water resource area facing increasing water demands and environ-mental challenges.The three-dimensional nature of the groundwater flow system is crucial for accurately understanding and managing water resources in the basin.The modeling process involved data collection,geological and hydrogeological characterization,conceptual model development,and numerical simulation using GMS software MODFLOW 2000 package.Various parameters such as hydraulic conductivity,recharge rates,and boundary conditions were integrated into the model to represent the complex hydrogeo-logical conditions of the basin.Model calibration was performed by comparing simulated groundwater levels with observed data from monitoring wells across the basin,using the automatic calibration method of automated Parameter Estimation(PEST).Pilot points were applied to adjust the hydraulic conductivity in the model area spatially.Sensitivity analysis was conducted to assess the influence of key parameters on model predictions and to identify areas of uncertainty.The developed three-dimensional groundwater flow model provides valuable insights into the dynamics of groundwater flow,recharge-discharge mechanisms,and potential impacts of future scenarios such as climate change and water resource management strategies.It serves as a useful tool for decision-makers,water resource managers,and researchers to evaluate differ-ent management scenarios and formulate sustainable groundwater management policies for the Erbil Basin.In conclusion,this study demonstrates the effectiveness of using GMS for developing three-dimensional groundwater flow models in complex hydrogeological settings like the Erbil Basin,contributing to improved understanding and management of groundwater resources in the region.

Approach to the Relation of Mutual-Feed Joint-Variation in Groundwater Management Model

In groundwater management,the exchanges between groundwater and other water such as surface water and spring water need to be considered.Some exchange is dependent on the ground-water level,which is called covariate.The pumping rate,groundwater level,and covariate interact and the relation of mutual-feed joint-variation is used to describe their interaction.This article presents a new approach of dealing with the relation in groundwater management model.The mathematical for-mulation of the relation,as an additional equality constraint in the optimization model,is developed using response matrix method.Thereby the groundwater management model with covariate is set up.The code for the simulation and management of groundwater system with covariate is programmed with Fortran 90,and the optimal pumping rate,groundwater level,and covariate are obtained.The approach is verified with a hypothetical case.Finally,the approach is applied to the groundwater management of Qianguo（前郭） area in western Jilin（吉林） Province.The results indicate that the ap-proach is feasible.It provides a universal solution for various covariates and reduces the computational complexity compared to iteration method.The approach is proven to be very efficient to solve ground-water management problem with covariate.

Climate change and groundwater resources in Mekong Delta, Vietnam

Groundwater resources have considerable influences on the human population and socioeconomic development of Vietnam and the Mekong River Delta(MRD). This paper presents an overview of the relationship between climate change and groundwater in the MRD, including the challenges, strategies and technical measures. Our results showed that groundwater levels are related to other climate and hydrological variables(i.e., rainfall, river levels, etc.); therefore, the impacts of climate change on the groundwater resources of the Mekong delta are significant, especially on groundwater recharge. Based on the results of this study, it is recommended that groundwater development in the future should focus on reducing groundwater harvesting, enhancing groundwater quantity by establishing artificial works and exploiting surface water. This study suggests that the Artificial Neural Network(ANN) model is an effective tool for forecasting groundwater levels in periods of 1 month and 3 months for aquifers in the natural and tidal regime areas of the delta.

Tools to Estimate Groundwater Levels in the Presence of Changes of Precipitation and Pumping

Central Wisconsin has the greatest density of high capacity wells in the state, most of which are used for agricultural irrigation. Irrigated agriculture has been growing steadily in the region since the 1950’s, when irrigation systems and high capacity wells became inexpensive and easy to install. Recent low lake and river levels have increased concerns that unregulated groundwater pumping for irrigation will undermine the availability of groundwater to support surface waters and domestic uses. Some research has quantified the magnitude of groundwater level declines due to irrigation pumping, but no studies have identified its relation to climatic precipitation changes. Changes in precipitation can appear to exacerbate or mask the effect of groundwater pumping. In this study, four groundwater monitoring wells and five climate stations were examined for shifts in groundwater levels and precipitation changes. Through statistical analysis, significant precipitation increases were identified in the southern part of the study area which averaged 2.7 mm per year, but no significant change was determined for the northern portion. Bivariate analysis identified water level declines within the region in the years 1974, 1992 and 1999 for irrigated land covers. Multiple regression analysis explained, predicted and quantified the interaction between precipitation and pumping. Wells located in areas with many high capacity wells showed a decline in water levels of up to 1.28 meters. In the southern portion of the study area where increases in precipitation occurred, this decline was thought to be masked. Results for one region (Plover) agreed with a previously published calibrated groundwater model, which demonstrates that this statistical method may be used to separate the impact of groundwater pumping from changing precipitation, even where observation well data are not widely available.

Development,hotspots and trend directions of groundwater numerical simulation:A bibliometric and visualization analysis

Groundwater is a vital component of the hydrological cycle and essential for the sustainable development of ecosystems.Numerical simulation methods are key tools for addressing scientific challenges in groundwater research.This study uses bibliometric visualization analysis to examine the progress and trends in groundwater numerical simulation methods.By analyzing literature indexed in the Web of Science database from January 1990 to February 2023,and employing tools such as Citespace and VOSviewer,we assessed publication volume,research institutions and their collaborations,prolific scholars,keyword clustering,and emerging trends.The findings indicate an overall upward trend in both the number of publications and citations concerning groundwater numerical simulations.Since 2010,the number of publications has tripled compared to the total before 2010,underscoring the increasing significance and potential of numerical simulation methods in groundwater science.China,in particular,has shown remarkable growth in this field over the past decade,surpassing the United States,Canada,and Germany.This progress is closely linked to strong national support and active participation from research institutions,especially the contributions from teams at Hohai University,China University of Geosciences,and the University of Science and Technology of China.Collaboration between research teams is primarily seen between China and the United States,with less noticeable cooperation among other countries,resulting in a diverse and dispersed development pattern.Keyword analysis highlights that international research hotspots include groundwater recharge,karst water,geothermal water migration,seawater intrusion,variable density flow,contaminant and solute transport,pollution remediation,and land subsidence.Looking ahead,groundwater numerical simulations are expected to play a more prominent role in areas such as climate change,surface water-groundwater interactions,the impact of groundwater nitrates on the environment and health,submarine groundwater discharge,ecological water use,groundwater management,and risk prevention.

Role of Multiple High-Capacity Irrigation Wells on a Surficial Sand and Gravel Aquifer

Within McHenry County, IL, the fastest growing county in Illinois, groundwater is used for 100% of the water needs. Concerns over water resources have prompted the investigation of the surficial sand and gravel aquifers of the county. While the eastern portion of the county is urbanizing, the western portion remains devoted to agriculture. High-capacity irrigation wells screened within the surficial sand and gravel aquifer are used for crop production. To assess the impacts of the irrigation wells on the aquifer, a groundwater flow model was developed to examine five different scenarios reflecting drought conditions and increased pumping. Results show that the surficial sand and gravel aquifer is capable of meeting current water demands even if recharge is decreased 20% and pumping is increased 20%. The additional loss of discharge and increases in pumping result in head differences throughout the aquifer.

A Heuristic Approach to Estimating Spatial Variability of Vertical Leakage in the Recharge Zone of the Gambier Basin Tertiary Confined Sand Aquifer, South Australia

The vertical leakage to confined aquifers is rarely quantified in complex settings, where the recharge zone is characterized by both diffuse and preferential flows. In such setting, conventional hydraulic or tracer based estimation of recharge or vertical leakage is problematic, unless the effects of duality of flow regimes are considered. A water balance approach by the use of calibrated groundwater models can be used, as the mass balance is independent of the particular mode of recharge and vertical leakage processes. Here, we adopt a water balance approach to provide a first order assessment of recharge to the unconfined Tertiary limestone aquifer (TLA) and vertical leakage to the Tertiary confined sand aquifer (TCSA) within the Glencoe-Nangwarry-Nagwarry (GNN) recharge zone of the Gambier Basin in South Australia. Despite many studies expressing concern about the impact of land use on recharge to the TLA and vertical leakage to the TCSA, no estimates have been made to quantify the vertical leakage within the GNN recharge zone. In the GNN recharge zone, relatively high recharge to the unconfined aquifer and vertical leakage to the confined aquifer occurs as a result of both diffuse and preferential flow processes. This is due to presence of structural faults and thin or absent aquitard. Within the Hundred of Nangwarry, where 83% of the area is covered with plantation forest, the model calculated recharge to the TLA of 80 mm·year-1, about 44% reduction compared to adjacent non-forested area (144 mm·year-1). Vertical leakage to the TCSA within the Hundred of Nangwarry area is higher (84.5 mm·year-1) than recharge to the TLA. Higher vertical leakage combined with the reduced recharge to TLA resulted in depletion of the TLA storage, as evidenced by drying of the TLA at one locality. In contrast, in plantation forest areas where diffuse recharge is the dominant process (Hundred of Penola), recharge to the TLA is about 19 mm·year-1, a 78% reduction compared to the non-forested areas, a mix of irrigation and dryland pasture. In these areas, vertical leakage to the TCSA is much smaller: 8 mm·year-1 through a thick aquitard. Simulation of a management scenario in which plantation forest is replaced by dryland pasture in the Hundred of Nangwarry results in 135 mm·year-1 recharge to TLA and a 98 mm·year-1 vertical leakage to the TCSA.

Numerical modeling of regional groundwater flow in the Heihe River Basin,China:Advances and new insights

Numerical groundwater modeling is an effective tool to guide water resources management and explore complex groundwater-dependent ecosystems in arid regions.In the Heihe River Basin(HRB),China’s second largest inland river basin located in arid northwest China,a series of groundwater flow models have been developed for those purposes over the past 20 years.These models have elucidated the characteristics of groundwater flow systems and provided the scientific basis for a more sustainable management of groundwater resources and ecosystem services.The first part of this paper presents an overview of previous groundwater modeling studies and key lessons learned based on seven different groundwater models in the middle and lower HRB at sub-basin scales.The second part reviews the rationale for development of a regional basin-scale groundwater flow model that unifies previous sub-basin models.In addition,this paper discusses the opportunities and challenges in developing a regional groundwater flow model in an arid river basin such as the HRB.

Applicability of Artificial Recharge of Groundwater in the Yongding River Alluvial Fan in Beijing through Numerical Simulation

A groundwater transient flow model was developed to evaluate the applicability and effectiveness of artificial recharge scenarios in the middle-upper part of the Yongding River alluvial fan in Beijing. These scenarios were designed by taking into account different types of recharge facilities and their infiltration rate with the Middle Route Project for South-to-North Water Transfer（MRP） as the recharge water source. The simulation results suggest that：（1） the maximum amount of artificial recharge water, for scenario I, would be 127.42×106 m3 with surface infiltration facilities; and would be243.48×106 m3 for scenario II with surface infiltration and recharge wells under the constraint of the upper limit of groundwater;（2） with preferred pattern of recharge facilities, groundwater levels in both optimized recharge scenarios would not exceed the upper limit within the given recharge period; and（3implementation of the recharge scenarios would efficiently increase the aquifer replenishment and the groundwater budget will change from-54.11×106 to 70.89×104 and 183.36×104 m3, respectively. In addition, under these two scenarios groundwater level would rise up to 30 and 34 m, respectively, without increasing the amount of evaporation. The simulation results indicate that the proposed recharge scenarios are practically feasible, and artificial recharge can also contribute to an efficient recovery of groundwater storage in Beijing.

In-situ observation and transport modelling of arsenic in Gangetic plain,India

The focus of this study is to investigate the arsenic movement and impacts on the residual concentrations on groundwater pollution load.The Gangetic plain area in the Ballia,Uttar Pradesh is selected as study area,which is also reported to extreme arsenic pollution in soil-water system.A modelling approach is developed to assess the arsenic flux in partially saturated zone using data of soil texture,soil hydraulic properties and stratigraphy.Soil type,slope,and land-use cover is considered for estimating the transient flux at the top boundary from daily precipitation and evapotranspiration data of the study area.Solute transport in the subsurface is predicted by the mass transfer equation,which is derived by integrating Darcy's law with the equation of mass balance.The arsenic profiles of varying hydrogeological conditions associated with different locations in the study area are presented as breakthrough curves.The results shows that the arsenic transport is dominated by the advective flux and strongly depends on the soilmoisture flow conditions.Which may increases the arsenic load to underlaying groundwater resources.The simulated results suggest that mobility plays a vital role arsenic transport as well as on adsorbed arsenic concentration in subsurface.Likewise,the adsorption isotherms show that the high peak curve for Bairai and low at Sikarderpur.A higher pollution risk is observed in the Belthara Road,whereas a lower vulnerability is computed in the north and northeast regions.This study can help in strategising sustainable groundwater management and protection planning of identified regions of India.

Models of Numerical Simulating of Multiaquifer in Zhengzhou City, China

In this paper, quasi\|three\|dimensional numerical simulating and optimum management model was established for evaluating and managing groundwater resources in Zhengzhou city. Based on coupling simulating model with planning model, optimum management model of groundwater resources was established. Through controlling the groundwater seepage field, environment problems caused by unreasonable extracting groundwater resources in the studied area were decreased to the minimum level, which supply scientific foundation for groundwater resource management in Zhengzhou city.