Documents disponibles écrits par cet auteur

Evaluation of bendway weir bank stabilization techniques for stream restoration / Kumud Acharya in JRBM : International journal of river basin management, Vol. 10 N° 2 (Avril 2012) 

Public ISBD [article]  in JRBM : International journal of river basin management > Vol. 10 N° 2 (Avril 2012) . - pp. 171-176 Titre : Evaluation of bendway weir bank stabilization techniques for stream restoration Type de document : texte imprimé Auteurs : Kumud Acharya, Auteur ; Mahesh Gautam, Auteur Année de publication : 2012 Article en page(s) : pp. 171-176 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Streambank  stabilization  Restoration  Spur  dikes  Las  Vegas  wash Résumé : In this study, velocity distribution patterns in a stream in the presence of bendway weirs were assessed for their effectiveness in bank stabilization in a demonstration site in the Las Vegas Wash, Nevada, USA. Streambanks of the target stream had been stabilized previously by longitudinal stone toe protection (LSTP) and stone spur dikes. Stone toes are meant to protect the toe of streambanks. Similarly, stone spur dikes consist of a series of dikes (of a crest relatively higher than that of the bendway weirs) protruding at right angles from the convex side of the streambanks. Velocity measurements were taken to evaluate the velocity field in the channel in the following three different cases: Case 1, channel with LSTP and the pre-existing spur dikes; Case 2, channel with LSTP with no deflecting structures (spur dikes removed); and Case 3, channel with LSTP and bendway weirs. The results suggested that bendway weirs caused a reduction in the uncontrolled high-velocity flow near the outer bank (right bank), allowing only controlled flow. Thus, bendway weirs were found to be more effective than spur dikes in reducing the velocity of flow at the vulnerable weir zones near the outer banks, thus providing a means to stabilize the streambanks. ISSN : 1571-5124 En ligne : http://www.tandfonline.com/doi/full/10.1080/15715124.2012.679737 [article] Evaluation of bendway weir bank stabilization techniques for stream restoration [texte imprimé] / Kumud Acharya, Auteur ; Mahesh Gautam, Auteur . - 2012 . - pp. 171-176. Hydraulique Langues : Anglais (eng) in JRBM : International journal of river basin management > Vol. 10 N° 2 (Avril 2012) . - pp. 171-176 Mots-clés : Streambank  stabilization  Restoration  Spur  dikes  Las  Vegas  wash Résumé : In this study, velocity distribution patterns in a stream in the presence of bendway weirs were assessed for their effectiveness in bank stabilization in a demonstration site in the Las Vegas Wash, Nevada, USA. Streambanks of the target stream had been stabilized previously by longitudinal stone toe protection (LSTP) and stone spur dikes. Stone toes are meant to protect the toe of streambanks. Similarly, stone spur dikes consist of a series of dikes (of a crest relatively higher than that of the bendway weirs) protruding at right angles from the convex side of the streambanks. Velocity measurements were taken to evaluate the velocity field in the channel in the following three different cases: Case 1, channel with LSTP and the pre-existing spur dikes; Case 2, channel with LSTP with no deflecting structures (spur dikes removed); and Case 3, channel with LSTP and bendway weirs. The results suggested that bendway weirs caused a reduction in the uncontrolled high-velocity flow near the outer bank (right bank), allowing only controlled flow. Thus, bendway weirs were found to be more effective than spur dikes in reducing the velocity of flow at the vulnerable weir zones near the outer banks, thus providing a means to stabilize the streambanks. ISSN : 1571-5124 En ligne : http://www.tandfonline.com/doi/full/10.1080/15715124.2012.679737

Mechanical analysis for emergent vegetation in flowing fluids / Chen, Li in Journal of hydraulic research, Vol. 49 N° 6 (Novembre/Décembre 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 6 (Novembre/Décembre 2011) . - pp. 766-774 Titre : Mechanical analysis for emergent vegetation in flowing fluids Type de document : texte imprimé Auteurs : Chen, Li, Auteur ; Stone, Mark C., Auteur ; Kumud Acharya, Auteur Année de publication : 2012 Article en page(s) : pp. 766-774 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Drag  force  Ecohydraulics  Hydraulic  roughness  Stress  Vegetation  bending Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : Vegetation plays an important role in stream processes and management efforts. However, the description of mechanical behaviours of vegetation–fluid interaction requires an improved understanding of the underlying physics and of the methods used for investigating this interaction. The objective of this research was to develop a method for describing vegetation mechanics in flowing fluids. This was accomplished by outlining methods for describing vegetation responses to flow under rigid and bending conditions for simple vegetation elements. The results of the theoretical analyses provide insight into influences of vegetation biomechanical properties to force distributions, bending behaviour, and potential vegetation rupture locations and conditions. The approach can be used to estimate hydraulic conditions for vegetation failure and flow resistance caused by vegetation, especially for flexible species. Although the techniques developed here are based on simplifying assumptions, the present analysis provides a foundation for future development for submerged vegetation and complex vegetation clusters. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.621359 [article] Mechanical analysis for emergent vegetation in flowing fluids [texte imprimé] / Chen, Li, Auteur ; Stone, Mark C., Auteur ; Kumud Acharya, Auteur . - 2012 . - pp. 766-774. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 6 (Novembre/Décembre 2011) . - pp. 766-774 Mots-clés : Drag  force  Ecohydraulics  Hydraulic  roughness  Stress  Vegetation  bending Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : Vegetation plays an important role in stream processes and management efforts. However, the description of mechanical behaviours of vegetation–fluid interaction requires an improved understanding of the underlying physics and of the methods used for investigating this interaction. The objective of this research was to develop a method for describing vegetation mechanics in flowing fluids. This was accomplished by outlining methods for describing vegetation responses to flow under rigid and bending conditions for simple vegetation elements. The results of the theoretical analyses provide insight into influences of vegetation biomechanical properties to force distributions, bending behaviour, and potential vegetation rupture locations and conditions. The approach can be used to estimate hydraulic conditions for vegetation failure and flow resistance caused by vegetation, especially for flexible species. Although the techniques developed here are based on simplifying assumptions, the present analysis provides a foundation for future development for submerged vegetation and complex vegetation clusters. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.621359