Reliability of Design Storms used to Size Urban Stormwater System Elements
Notice bibliographique
Résumé
The objective of this study was to generate hydrographs using design storms and real rain data recorded over a 30 y time period.In the first step rainfall characteristics were investigated using Intensity-Duration-Frequency (IDF) relationships.IDF curves were developed, called UM IDF curves, and when compared to the official Hamilton IDF curves showed a striking similarity for events with low return periods, and some variation for 50 and 100 y return periods.From the UM IDF curves three new design storms (SCS type 2, AES Canadian and Chicago Storm), referred to as UM Design Storms, were developed for comparison with the Hamilton design storms.The differences in intensity-duration of the less frequent storms (observed in the IDF comparison) were also reflected in the design storm volume and peak discharge.All the different design distributions, for a wide range of return periods, were entered into the rainfall-runoff model, PCSWMM, for event simulation of design storms.PCSWMM was also run for continuous simulation of the coarse observed data.Keeping the geomorphic conditions and loss parameters constant, differences were quantified in terms of computed flow and storage capacities for two design applications.The designs derived from the coarse observed data were considered to be optimal and used to decide suitability or otherwise of the designs based on other synthetic distribution patterns, and it was found that almost all the Reliability of Design Storms to Size Stormwater System Elements application designs obtained from design storm hyetographs were overdesigned.In other words, for every return period, the flow capacity and detention storage required to accommodate the design storm hydrographs was greater than what would be required if the same applications were designed for historic storms in continuous simulation.Given the coarse continuous data these results are to be expected, and should be reexamined when continuous at a fine time step become available.Evidently design storms generate a hydrograph with greater volume and a higher peak, requiring more detention storage, greater flow capacity and larger pipe sizes, than using coarse continuous simulation.It is still not yet clear whether structures based on design storms are over-sized and costlier than necessary.The study showed that SCS type 2 and the AES Canadian design storms yield flow and storage capacities relatively closer to the coarse continuous data while the Chicago design storms produce over-sized flow and storage capacities.The latter may be deemed to not provide representative rainfall distributions for Southern Ontario.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,005 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».