10.1016/s0967-0653(97)81423-8
Notice bibliographique
Résumé
This study of the U.S. Army Corps of Engineers' (USACE) shore protection program was undertaken as a result of a request from the Office of Management and Budget (OMB). The investigation disclosed that the USACE shoreline protection program covers 8 percent of the nation's 2,700 miles of critically eroding shoreline and consists of 82 specifically authorized projects. Total expenditures, including periodic nourishment, for these 82 projects from 1950 to 1995 have been $731 million. When updated to 1995 dollars this expenditure becomes $1,662 million. Over the period of time covered by this study (l950-current) the program has shifted from primarily hard structures (groins, seawalls, breakwaters, etc.) to primarily soft beach restoration and nourishment through placement of sand. Beach restoration and nourishment is also the most environmentally compatible shore protection measure. The projects receive intense preconstruction coordination with environmental agencies to assure no long term adverse environmental impacts result from the projects. Over this same time period, as a result of Administration policy and law, the program has shifted from primarily recreation oriented to one of protection for storm damage reduction. From the standpoint of program cost and volumes of sand emplacements the evaluation of the long-term performance of the program shows that it is a well-managed and cost-effective program. Overall, costs were slightly less than estimated, and overall quantities of sand were slightly higher than estimated. Whether or not the projects are performing as expected from a benefit standpoint, however, is very difficult to determine. Because of the high variable and largely unpredictable nature of coastal storms, the actual storm damage reduction benefits of shore protection projects can differ greatly from those forecasted during planning and design. The key to the benefit-cost analysis is that the benefits are based on a probabalistic assumption that, over the period of analysis (generally 50 years), a comparable sequence of events will occur as in the past, causing a comparable level of property damages. Hence, the longer the period of record, the more likely that the estimated benefits will converge on the actual or measured benefits (and costs). One item of specific concern to OMB was that of induced development, i.e., do shore protection projects' lead to more growth and development in protected areas, and hence, ultimately to increases in storm damages rather than a reduction in damages. Three specific economic analyses were applied during the course of the study to determine whether USACE shore protection projects induce development in the areas they protect. These three complementary studies were: (1) a survey of beachfront community residents; (2) an econometric model of beachfront development;and (3) an econometric analysis of beachfront housing prices. None of these approaches could verify that there is a measurable induced development link. The analyses demonstrated that the primary determinant of development of beachfront communities is growth in beachfront demand based on rising income and employment in noncoastal areas, rather than the presence or absence of a shore protection project. In fact, there is limited public awareness of the Federal shore protection program, where Federal projects currently exist, and of the involvement of the USACE in reducing risks through project construction.
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 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,003 | 0,001 |
| Méta-épidémiologie (sens large) | 0,002 | 0,002 |
| Bibliométrie | 0,003 | 0,002 |
| Études des sciences et des technologies | 0,002 | 0,002 |
| Communication savante | 0,005 | 0,006 |
| Science ouverte | 0,004 | 0,004 |
| Intégrité de la recherche | 0,007 | 0,003 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,992 | 0,993 |
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; l’étiquette directe de Gemma et le classifieur distillé Codex s’accordent sur ce qui est montré ici.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».