Understanding Of Groundwater System Research Articles

Groundwater Modelling of Jamwa Ramgarh using Visual MODFlow Flex

A steady state finite difference model, MODFLOW, is developed to quantify groundwater in Jamwa Ramgarh, Jaipur (Dt) Rajasthan, using Groundwater data from 06 observation wells. ArcGIS was used to generate various shapefiles required as input files in Visual MODFlow Flex. The findings indicate that the calculated contours of groundwater levels closely correspond to the observed contours. The sustainable utilization and management of groundwater resources pose significant challenges for many countries worldwide. In recent years, groundwater modelling has emerged as an effective approach to tackle these challenges. Various modelling software tools are available to simulate groundwater flow, with MODFLOW being widely used to investigate the interactions between surface water and groundwater and to develop models for specific study areas. MODFLOW, a renowned groundwater modelling software, enables researchers and water resource professionals to understand and analyze the complex dynamics of groundwater systems. By utilizing MODFLOW, it becomes possible to assess the interactions between surface water and groundwater, evaluate the impacts of pumping or recharge activities, and make informed decisions regarding the sustainable management of groundwater resources. The utilization of MODFLOW and similar modelling software plays a crucial role in advancing our understanding of groundwater systems and supporting effective groundwater resource management practices.

A Hydrostratigraphic Framework for the Paleozoic Bedrock of Southern Ontario

Groundwater systems in the intermediate to deep subsurface of southern Ontario are poorly understood, despite their value for a number of societal uses. A regional hydrostratigraphic framework is a necessary precursor for improving our understanding of groundwater systems and enabling development of a 3-D hydrostratigraphic model to visualize these groundwater systems. This study is a compilation and integration of published and unpublished geological, hydrogeological, hydrochemical and isotopic data collected over the past 10 years to develop that framework.Bedrock is covered by a thin veneer of surficial sediments that comprise an aquifer/aquitard system of considerable local variability and complexity. Aquifers in the bedrock are thin and regionally extensive, separated by thick aquitards, within a well-defined lithostratigraphic framework and a well-developed hydrochemical depth zonation comprising a shallow fresh water regime, an intermediate brackish to saline sulphur water regime, and a deep brine regime of ancient, evaporated seawater. Occurrence and movement of groundwater in shallow bedrock is principally controlled by modern (Quaternary) karstic dissolution of subcropping carbonate and evaporite rocks, and in the intermediate to deep subsurface by paleokarst horizons developed during the Paleozoic. Flow directions in the surficial sediments of the shallow groundwater regime are down-gradient from topographic highs and down the regional dip of bedrock formations in the intermediate regime. Shallow karst is the entry point for groundwater penetration into the intermediate regime, with paleo-recharge by glacial meltwater and limited recent recharge by meteoric water at subcrop edges, and down-dip hydraulic gradients in confined aquifers. Hydraulic gradient is up-dip in the deep brine regime, at least for the Guelph Aquifer and the Cambrian Aquifer, with no isotopic or hydrochemical evidence of infiltration of meteoric water and no discharge to the surface.Fourteen bedrock hydrostratigraphic units are proposed, and one unit comprising all the surficial sediments. Assignment of lithostratigraphic units as hydrostratigraphic units is based principally on hydrogeological characteristics of Paleozoic bedrock formations in the intermediate to deep groundwater regimes, below the influence of modern meteoric water. Carbonate and evaporite rocks which form aquitards in the subsurface may form aquifers at or near the surface, due to karstic dissolution by acidic meteoric water, necessitating compromises in assignment of hydrostratigraphic units.

The 3D Water Atlas: a tool to facilitate and communicate new understanding of groundwater systems

Effective management of groundwater resources requires an understanding of the complexity of groundwater systems by the experts, and a certain level of understanding and trust in management by the community. Groundwater data sharing and visualisation systems are being used across the world to provide an insight into groundwater systems. The 3D Water Atlas of the Surat Basin, Queensland, Australia, provides a way of visualising and analysing hydrogeochemical information in a way that is accessible to a wide audience. It combines data on the location, construction, water chemistry and water levels of groundwater bores within the framework of a geological model and other spatial datasets. It is freely available on a single Web-based interactive three-dimensional (3D) platform. Visualisation tools such as line graphs of groundwater bore water levels, pie charts and animations of major ions, can be used to advance understanding of groundwater resources. For example, a general regional decline, but with local variability in Hutton Sandstone groundwater levels in the Surat Basin can be seen by using the 3D Water Atlas. The combination of groundwater data with filtering, analysis and visualisation tools in the 3D Water Atlas helps to communicate complex hydrogeological concepts. It can also assist with the management of groundwater resources by improving confidence in decision-making, as necessary information can be viewed together, in context. Although the 3D Water Atlas was produced for the Surat Basin, its design means that 3D Water Atlases for different regions can be produced easily.

Methods for using argon-39 to age-date groundwater using ultra-low-background proportional counting

Argon-39 can be used as a tracer for age-dating glaciers, oceans, and more recently, groundwater. With a half-life of 269 years, 39Ar fills an intermediate age range gap (50–1,000 years) not currently covered by other common groundwater tracers. Therefore, adding this tracer to the data suite for groundwater studies provides an important tool for improving our understanding of groundwater systems. We present the methods employed for arriving at an age-date for a given sample of argon degassed from groundwater.

Field studies in groundwater hydrology—A new era

Recent field studies aimed at obtaining a three‐dimensional understanding of groundwater systems are described. Studies of plumes of contaminated groundwater as well as studies focusing on aquifer recharge, the interaction of groundwater with surface waters, and the siting of a geologic repository for high‐level radioactive waste are included in the discussion.