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HUN GW Uncertainty Analysis v01

Abstract

The dataset was derived by the Bioregional Assessment Programme from multiple source datasets. The source datasets are identified in the Lineage field in this metadata statement. The processes undertaken to produce this derived dataset are described in the History field in this metadata statement.

This dataset contains all the scripts used to carry out the uncertainty analysis for the maximum drawdown and time to maximum drawdown at the groundwater receptors in the Hunter bioregion and all the resulting posterior predictions. This is described in product 2.6.2 Groundwater numerical modelling (Herron et al. 2016). See History for a detailed explanation of the dataset contents.

References:

Herron N, Crosbie R, Peeters L, Marvanek S, Ramage A and Wilkins A (2016) Groundwater numerical modelling for the Hunter subregion. Product 2.6.2 for the Hunter subregion from the Northern Sydney Basin Bioregional Assessment. Department of the Environment, Bureau of Meteorology, CSIRO and Geoscience Australia, Australia.

Dataset History

This dataset uses the results of the design of experiment runs of the groundwater model of the Hunter subregion to train emulators to (a) constrain the prior parameter ensembles into the posterior parameter ensembles and to (b) generate the predictive posterior ensembles of maximum drawdown and time to maximum drawdown. This is described in product 2.6.2 Groundwater numerical modelling (Herron et al. 2016).

A flow chart of the way the various files and scripts interact is provided in HUN_GW_UA_Flowchart.png (editable version in HUN_GW_UA_Flowchart.gliffy).

R-script HUN_DoE_Parameters.R creates the set of parameters for the design of experiment in HUN_DoE_Parameters.csv. Each of these parameter combinations is evaluated with the groundwater model (dataset HUN GW Model v01). Associated with this spreadsheet is file HUN_GW_Parameters.csv. This file contains, for each parameter, if it is included in the sensitivity analysis, tied to another parameters, the initial value and range, the transformation, the type of prior distribution with its mean and covariance structure.

The results of the design of experiment model runs are summarised in files HUN_GW_dmax_DoE_Predictions.csv, HUN_GW_tmax_DoE_Predictions.csv, HUN_GW_DoE_Observations.csv, HUN_GW_DoE_mean_BL_BF_hist.csv which have the maximum additional drawdown, the time to maximum additional drawdown for each receptor and the simulated equivalents to observed groundwater levels and SW-GW fluxes respectively. These are generated with post-processing scripts in dataset HUN GW Model v01 from the output (as exemplified in dataset HUN GW Model simulate ua999 pawsey v01).

Spreadsheets HUN_GW_dmax_Predictions.csv and HUN_GW_tmax_Predictions.csv capture additional information on each prediction; the name of the prediction, transformation, min, max and median of design of experiment, a boolean to indicate the prediction is to be included in the uncertainty analysis, the layer it is assigned to and which objective function to use to constrain the prediction.

Spreadsheet HUN_GW_Observations.csv has additional information on each observation; the name of the observation, a boolean to indicate to use the observation, the min and max of the design of experiment, a metadata statement describing the observation, the spatial coordinates, the observed value and the number of observations at this location (from dataset HUN bores v01). Further it has the distance of each bore to the nearest blue line network and the distance to each prediction (both in km). Spreadsheet HUN_GW_mean_BL_BF_hist.csv has similar information, but on the SW-GW flux. The observed values are from dataset HUN Groundwater Flowrate Time Series v01

These files are used in script HUN_GW_SI.py to generate sensitivity indices (based on the Plischke et al. (2013) method) for each group of observations and predictions. These indices are saved in spreadsheets HUN_GW_dmax_SI.csv, HUN_GW_tmax_SI.csv, HUN_GW_hobs_SI.py, HUN_GW_mean_BF_hist_SI.csv

Script HUN_GW_dmax_ObjFun.py calculates the objective function values for the design of experiment runs. Each prediction has a tailored objective function which is a weighted sum of the residuals between observations and predictions with weights based on the distance between observation and prediction. In addition to that there is an objective function for the baseflow rates. The results are stored in HUN_GW_DoE_ObjFun.csv and HUN_GW_ObjFun.csv.

The latter files are used in scripts HUN_GW_dmax_CreatePosteriorParameters.R to carry out the Monte Carlo sampling of the prior parameter distributions with the Approximate Bayesian Computation methodology as described in Herron et al (2016) by generating and applying emulators for each objective function. The scripts use the scripts in dataset R-scripts for uncertainty analysis v01. These files are run on the high performance computation cluster machines with batch file HUN_GW_dmax_CreatePosterior.slurm. These scripts result in posterior parameter combinations for each objective function, stored in directory PosteriorParameters, with filename convention HUN_GW_dmax_Posterior_Parameters_OO_$OFName$.csv where $OFName$ is the name of the objective function. Python script HUN_GW_PosteriorParameters_Percentiles.py summarizes these posterior parameter combinations and stores the results in HUN_GW_PosteriorParameters_Percentiles.csv.

The same set of spreadsheets is used to test convergence of the emulator performance with script HUN_GW_emulator_convergence.R and batch file HUN_GW_emulator_convergence.slurm to produce spreadsheet HUN_GW_convergence_objfun_BF.csv.

The posterior parameter distributions are sampled with scripts HUN_GW_dmax_tmax_MCsampler.R and associated .slurm batch file. The script create and apply an emulator for each prediction. The emulator and results are stored in directory Emulators. This directory is not part of the this dataset but can be regenerated by running the scripts on the high performance computation clusters. A single emulator and associated output is included for illustrative purposes.

Script HUN_GW_collate_predictions.csv collates all posterior predictive distributions in spreadsheets HUN_GW_dmax_PosteriorPredictions.csv and HUN_GW_tmax_PosteriorPredictions.csv. These files are further summarised in spreadsheet HUN_GW_dmax_tmax_excprob.csv with script HUN_GW_exc_prob. This spreadsheet contains for all predictions the coordinates, layer, number of samples in the posterior parameter distribution and the 5th, 50th and 95th percentile of dmax and tmax, the probability of exceeding 1 cm and 20 cm drawdown, the maximum dmax value from the design of experiment and the threshold of the objective function and the acceptance rate.

The script HUN_GW_dmax_tmax_MCsampler.R is also used to evaluate parameter distributions HUN_GW_dmax_Posterior_Parameters_HUN_OF_probe439.csv and HUN_GW_dmax_Posterior_Parameters_Mackie_OF_probe439.csv. These are, for one predictions, different parameter distributions, in which the latter represents local information. The corresponding dmax values are stored in HUN_GW_dmax_probe439_HUN.csv and HUN_GW_dmax_probe439_Mackie.csv

Dataset Citation

Bioregional Assessment Programme (XXXX) HUN GW Uncertainty Analysis v01. Bioregional Assessment Derived Dataset. Viewed 13 March 2019, http://data.bioregionalassessments.gov.au/dataset/c25db039-5082-4dd6-bb9d-de7c37f6949a.

Dataset Ancestors

Data and Resources

Additional Info

Field Value
Title HUN GW Uncertainty Analysis v01
Type Dataset
Language eng
Licence Creative Commons Attribution 2.5 Australia
Data Status active
Update Frequency daily
Landing Page https://data.gov.au/data/dataset/3b9239f2-561b-47f4-b5f5-eb3bea4bdd47
Date Published 2018-06-18
Date Updated 2022-06-28
Contact Point
Bioregional Assessment Program
bioregionalassessments@environment.gov.au
Temporal Coverage 2018-06-18 00:00:00
Geospatial Coverage POLYGON ((0 0, 0 0, 0 0, 0 0))
Jurisdiction NONE
Data Portal data.gov.au
Publisher/Agency Bioregional Assessment Program