Hydrogeologist & Water Resources Specialist
Welcome to hydrogeologist.net. This site is the home of J. Malcolm Ashworth a Consultant Hydrogeologist and Water Resources Specialist with +30 years of experience. I offer independent and international expertise in solving groundwater problems.
What I can offer you:
The following are some of the skills and services that I can offer you:
River Basin Assessment and Management:
Legislative and economic considerations aside, water resource management plans start with a comprehensive assessment of the components of a river basin’s water balance, available resources and the appreciation of how changes to one or more components of this balance affect other components and the environment in terms of quantity, quality and location.
Information collated into databases and presented on maps, using ArcGIS, are key to a regional perspective for the management of water resource components. In general, four general categories of data are required.
Expert services can be provided to collate and process water resources information from stakeholders, field inventories, pilot projects and the internet, onto ArcGIS maps, for assessment, management, reporting and presentation purposes.
Key sets of data required for groundwater resource assessments are often missing or inadequate. Drilling exploration boreholes, conducting aquifer tests, and initiating appropriate monitoring programs are then needed. Associated services that can be provided include facilitating remote sensing investigations (airborne, satellite and geophysical investigations), borehole designs, preparation of tender documents and specifications, supervision of drilling and borehole construction, aquifer and borehole testing, and analyses of data.
Effective groundwater management may require a range of different development options. The three most common requirements are:
Consulting services can be provided for the design, tendering, supervision (testing and construction) and management of these groundwater development options, or other schemes as required.
Technical advice can be provided to determine the effectiveness of groundwater assessment, management and development programs.
Technical advice can be provided to help resolve water conflicts
Groundwater models are useful tools for solving and predicting groundwater flow and transport problems in aquifers. Typically these problems might involve: calculating the radius of influence of a well or wellfield; modelling the movement of leachate, leachate production, transportation and attenuation; and, calculating the impact of large scale groundwater abstractions on other users and on available resources. Analytical or numerical models can be deployed for solving these issues. The selection of the most appropriate model depends on the complexity of the problem at hand.
Analytic models such as LANDSIM, GFLOW or BLUEBIRD, allow steady-state 2-D groundwater flow systems to be simulated using analytic functions. In these programs, a library of specialized “analytic elements” are superimposed to model a variety of features such as head of leachate, flow rates, engineered barriers, advective transport, contaminant concentration, drains, slurry walls, wells and reservoirs. The functions associated with these elements meet Darcy’s law and Mass Continuity equations everywhere in the domain. Some of these models such as LANDSIM are specially designed to produce estimates of possible contaminant concentrations using probabilistic assessment techniques.
Numerical models such as the U.S. Geological Survey’s (USGS) developed Modular
Finite-Difference Flow Model (MODFLOW) provide the code for solving groundwater
flow and contaminant transport in 3-D. Since its development in 1983, numerous
codes or packages have been developed for MODFLOW. Packages can be stand-alone
codes or can be integrated with MODFLOW. These packages include advective
transport model (PMPATH), the solute transport model (MT3D), parameter
estimation programs (PEST), solute transport model (MOC3D), inverse models (MODFLOWP)
and seawater intrusion (SEAWAT).
ENVIRONMENTAL ASSESSMENT & REMEDIATION
Expert services can be provided to assist with Environmental Assessments and Remediation, including:
Identify sources of contamination. Sampling to delineate and characterise the extent of soil and groundwater contamination. Monitoring and testing to determine aquifer properties, hydraulic heads, groundwater velocities and flow patterns.
Assessments to determine volume of soil and groundwater impacted, assess routes of contaminant migration and to identify potential environmental and human receptors.
Assessment of groundwater vulnerability using analytical or numerical groundwater models, or ArcGIS overlay and index methods.
Countries of work-experience.