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Record W1543093973 · doi:10.20381/ruor-19845

Propagation of uncertainty in a watershed model

2007· dissertation· en· W1543093973 on OpenAlexaboutno aff
Igor Iskra

Bibliographic record

VenueuO Research (University of Ottawa) · 2007
Typedissertation
Languageen
FieldEnvironmental Science
TopicGroundwater flow and contamination studies
Canadian institutionsnot available
Fundersnot available
KeywordsWatershedEnvironmental scienceComputer scienceGeographyMachine learning

Abstract

fetched live from OpenAlex

The Hydrological Simulation Program FORTRAN (HSPF) model was calibrated for the South Nation watershed located in Eastern Ontario. Three nonlinear automatic optimization techniques were applied and compared: Gauss-Marquardt-Levenberg (GML) method, Random Multiple Search Method (RSM), and Shuffled Complex Evolution method developed at the University of Arizona (SCE-UA). The best GML, RSM, and SCE-UA variable values beyond which objective function improvement is insignificant were suggested. It was found that more than one parameter set is able to maintain the model in a calibrated state which reflects correlation among model parameters and equations. The lowest value of the objective function (OF) does not necessarily correspond to the optimum solution. Comparison of scatter plots, graphs of residuals, and plots of cumulative differences are required to determine the best model parameter set. Combination of Nash and Sutcliffe (NS) model fit, coefficient of efficiency, and index of agreement proved to be the best statistics for model comparison. Proper definition of the OF is crucial to successful model calibration. Over 60 single and compound OFs were compared. The OF expressed as a log of observed and simulated flows was found to be the most appropriate single OF. A compound OF expressed as a sum of squared residuals of equally weighed log-transformed maximum (top 1% of flows), minimum (bottom 20% of flows), and middle flows was found to be best for most general model applications. Uncertainty of HSPF parameters was explored by the method of moments (MM), Monte Carlo (MC) with Latin hypercube and induced correlation, and response surface (RS) methods. Typically, the MM results in the most conservative uncertainty. The 95% confidence intervals of parameter uncertainty correspond to up to 10% variations in spring maximum flows. The predictive confidence interval and predictive noise for spring maximum and autumn minimum flows using single and compound OFs were computed. The predictive intervals were computed from the 95% confidence limits of the OF. It was found that HSPF can be an efficient tool to predict flows in ungaged watersheds with parameter transfer from calibrated neighbouring watersheds. The impact of DEM resolution on HSPF topographical parameters was studied.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.005
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: Simulation or modeling
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.081
Threshold uncertainty score0.161

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.005
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0010.001
Scholarly communication0.0010.001
Open science0.0010.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0010.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.038
GPT teacher head0.305
Teacher spread0.267 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designSimulation or modeling
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2007
Admission routes1
Has abstractyes

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