Application of the index flood method to flow-duration-frequency approach
Bibliographic record
Abstract
The aim of this work is to adapt the index flood method to the flow-duration-frequency (QdF) approach.. Like rainfall intensity-duration-frequency curves, QdF curves represent discharge distributions relating to one duration d (d = 1, 3, ..., N days). The developed model describes Q(d,T) quantiles as a function of two variables: the return period T and the duration d. This local QdF model has been applied to about 150 basins from Ontario and Quebec provinces. On this area, different regional models had been tested, such as the index flood method. A regional QdF model is defined for each homogeneous region. It is then possible to obtain Q(d,T) quantiles, even for ungauged basins. Firstly, it appears that the local QdF model yields very satisfactory results. Furthermore, model parameters make it possible to characterise the local flood regime. Secondly, the regional QdF model shows a good regional validity. Nevertheless, for ungauged basins, the estimation of local flood indexes is still tricky. This is due to the fact that it is difficult to find relevant explanatory variables other than, obviously, catchment area. / Le but de ce travail est d'adapter la méthode de l'indice de crue à l'approche débit-durée-fréquence (QdF). De façon analogue aux courbes intensité-durée-fréquence pour les précipitations, les courbes QdF constituent une collection de distributions, chacune étant relative à un débit de crue de durée d (d = 1, 3, ..., N jours). Le modèle fournit une relation analytique du quantile de crue Q(d,T) en fonction de la période de retour T et de la durée d. Le modèle local QdF a été appliqué sur 150 bassins des provinces de l'Ontario et du Québec. Plusieurs méthodes de régionalisation ont ensuite été testées, dont la méthode de l'indice de crue. Un modèle régional QdF a été défini pour chaque région homogène. Il est alors possible de reconstituer les quantiles de crue Q(d,T) sur un site non jaugé. Les résultats montrent un bon comportement du modèle local QdF, dont les paramètres caractérisent le régime local des crues. Le modèle régional QdF montre une bonne validité spatiale. Il reste toutefois difficile d'estimer l'indice de crue, sur un site non jaugé. Ceci est dû au fait que peu de variables explicatives restent pertinentes, après la superficie du bassin versant.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot 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.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".