Effective Groundwater Model Calibration

Hill, Mary C.; Tiedeman, Claire R.

doi:10.1002/0470041080

Cited by 361 publications

(194 citation statements)

References 0 publications

Supporting

Mentioning

177

Contrasting

Unclassified

Order By: Relevance

“…There are numerous methods for characterizing a model's sensitivity and uncertainty based on variations of calibrated parameter values [43,[50][51][52][53]. These methods are generally classified into two groups.…”

Section: Sensitivity and Uncertainty Analysesmentioning

confidence: 99%

Reconstructing Historical Voc Concentrations in Drinking Water for Epidemiological Studies at a U.S. Military Base: Summary of Results

Maslia¹,

Aral²,

Ruckart³

et al. 2016

Preprint

View full text Add to dashboard Cite

A U.S. government health agency conducted epidemiological studies to evaluate whether exposures to drinking water contaminated with volatile organic compounds (VOC) at U.S. Marine Corps Base Camp Lejeune, North Carolina, were associated with increased health risks to children and adults. These health studies required knowledge of contaminant concentrations in drinking water-at monthly intervals-delivered to family housing, barracks, and other facilities within the study area. Because concentration data were limited or unavailable during much of the period of contamination (1950s-1985), the historical reconstruction process was used to quantify estimates of monthly mean contaminant-specific concentrations. This paper integrates many efforts, reports, and papers into a synthesis of the overall approach to, and results from, a drinking-water historical reconstruction study. Results show that at the Tarawa Terrace water treatment plant (WTP) reconstructed ( Author Contributions: All authors contributed to the research discussed in this article. Morris L. Maslia oversaw and directed the water-modeling analyses and Mustafa M. Aral contributed to the development of the water-supply well operation reconstructions, numerical modeling, and probabilistic analysis. Perri Z. Ruckart and Frank J. Bove developed the epidemiological studies protocols for application of water-modeling analyses and conducted the epidemiological studies.

show abstract

Section: Sensitivity and Uncertainty Analysesmentioning

confidence: 99%

Reconstructing Historical Voc Concentrations in Drinking Water for Epidemiological Studies at a U.S. Military Base: Summary of Results

Maslia¹,

Aral²,

Ruckart³

et al. 2016

Preprint

View full text Add to dashboard Cite

show abstract

“…Thus, for 10 model parameters, sensitivity analysis commonly requires about 20 model runs; in contrast, estimating parameters commonly requires up to a few hundreds of model runs. Local model analysis methods are discussed by Hill and Tiedeman (2007). Inverse methods using singular value decomposition (SVD) parameter transformation described by Aster and others (2012) and available in PEST also can require hundreds of model runs to estimate parameter values.…”

Section: Modpath-obs and Model Analysismentioning

confidence: 99%

“…An example of this problem is presented in the Common Calibration Problems section of this report. Severe situations can diminish the utility of sensitivity analyses and optimization methods such as those described by, for example, Hill and Tiedeman (2007).…”

Section: Relating Simulated Advective Transport To Field Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Advective transport observations with MODPATH-OBS--documentation of the MODPATH observation process

Hanson¹,

Kauffman²,

Hill³

et al. 2013

Techniques and Methods

View full text Add to dashboard Cite

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS.For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.Suggested citation: Hanson, R.T., Kauffman, L.K., Hill, M.C., Dickinson, J.E., and Mehl, S.W., 2013, Advective transport observations with MODPATH-OBS-Documentation of the MODPATH observation process: U.S. Geological Survey Techniques and Methods book 6-chap. A42, 96 p., http: pubs.usgs.gov/tm/06/a42. iii PrefaceThe MODPATH-OBS computer program described in this report is designed to calculate simulated equivalents for observations (or predictions) related to groundwater transport that can be represented in a meaningful way using particle tracking. Generally this means that the observations relate to the movement of the center of a discrete plume, movement of position along a plume front selected to correct for the effects of dispersion and reactions not simulated by particle tracking, geochemical data that identify likely recharge areas, and other hydrologic features.MODPATH-OBS uses the particle tracking capabilities of MODPATH by acting as a postprocessor. MODPATH is a postprocessor for MODFLOW, so that the sequence of model runs generally required is MODFLOW, MODPATH, and MODPATH-OBS.The versions of MODFLOW and MODPATH that support MODPATH-OBS as documented in this report are MODFLOW-2000/2005 and MODFLOW-LGR (Mehl and Hill, 2005 and MODPATH (Pollock, 1994(Pollock, , 2012 or MODPATH-LGR (Dickinson and others, 2011). MODFLOW-LGR is derived from MODFLOW-2005(Harbaugh, 2005 and supports local grid refinement. MODFLOW-LGR simulations may include local grid refinement or may use a single grid. When a single grid is used, MODFLOW-LGR performs identically to the version of MODFLOW-2005 cited on the MODFLOW-LGR web page. MODPATH-LGR and MODPATH-OBS can use nearly all of the capabilities of MODFLOW-LGR. For example, simulations can be steady-state, transient, or a combination; model layers may be confined or convertible from confined to unconfined; all of the head-dependent boundary packages are supported and features simulated using the Streamflow-Routing (SFR) Package can be routed across grid boundaries. Limitations are discussed in this report. (Pollock, 1989(Pollock, , 1994(Pollock, , 2012 and supports the tracking of particles through locally refined grids. For a single grid and no observations, MODPATH-LGR performs similarly to the version of MODPATH cited on the MO...

show abstract

“…For example, new environmental tracers have been suggested (Busenberg and Plummer 2008) and a new analytical technique has had a successful start (Sturchio et al 2004) in recent years. Inverse methods for calibrating groundwater models are being used more routinely (Hill and Tiedeman 2007) and there is an increasing awareness from the mathematics of model calibration that head-independent data are vital for constraining models. Environmental tracers are an ideal source of such data.…”

Section: Future Directionsmentioning

confidence: 99%