Rui Hugman

Second PEST Conference

The second PEST conference will be held in San Diego, California. Subtitled “The Path from Data to Decisions”, it will run from March 6th to March 9th, 2023. The conference will address how tasks performed by PEST and PEST++ (which include calibration, sensitivity analysis, uncertainty analysis, optimisation and optimisation under uncertainty) can support model-based environmental …

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The Maths Behind PEST and PEST++

GMDSI presented three webinars delivered by John Doherty (author of PEST). Webinar 1: Wednesday 28th September – Video Recording and PowerPoint PresentationWebinar 2: Wednesday 12th October – Video Recording and PowerPoint PresentationWebinar 3: Wednesday 26th October – Video Recording and PowerPoint Presentation These webinars will give you a good understanding of the mathematical concepts that underpin model …

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GMDSI Tech-Talk: Scripted Workflows vs. GUIs

There has been a lot of discussion recently on groundwater modelling workflows – that is, how to build and history-match a model, and then use it to support important decisions. GMDSI’s next webinar explores this topic by hosting presenters from both ends of the workflow spectrum.  Both of our presenters are groundwater modelling heavyweights. They …

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The Regulatory Framework: Consultations and Discussions

The last in a series of meetings that GMDSI hosted on the groundwater regulatory framework was held on August 18th, 2022. This meeting (attended by 73 people, most of whom were not regulators) discussed the use of groundwater modelling in the regulatory framework. After a brief introduction by Peter Baker (Office of Water Science), and …

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Introduction to Regression

  Introduction to Regression¶ This tutorial proves an overview of linear regression. It illustrates fitting a polynomial to noisy data, including the role of SSE (reponse curve), degrees of freedom, the gradient of that surface (Jacobian) and overfitting. We use a very simple model (a polynomial function) to illustrate these core concepts and the maths …

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Scientifically-Based, Decision-Support Groundwater Modelling

GMDSI is preparing a two-part book. A draft of the first part of this book is now available. Authored by John Doherty, it provides a comprehensive conceptual framework for decision-support groundwater modelling. Based firmly on scientific principles, it suggests ways in which modelling can better serve the imperatives of environmental management than it does now. …

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Worked Example: Contaminant Source Identification

Locating sources of groundwater contamination is an inverse problem on steroids. It is, in fact, two inverse problems. Source locations must be back-calculated from field measurements. The hydraulic properties of aquifer material through which groundwater flows, and contaminants are transported, must also be inferred from these same measurements. Another spice in the inverse problem soup …

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Groundwater Modelling and the Scientific Method: Part 2

This is the second of a two-part series recorded by John Doherty. The first video is philosophical. The second video provides real-world examples of the philosophy at work. Two examples are discussed. Both of these are the subject of GMDSI worked example reports. The first example illustrates how, through simultaneous history-matching of six aquifer tests, …

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