References of "Petit, François"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailBehavioural tactics and spawning activity of rheophilic cyprinids radio-tracked in the transition zone between natural flow and minimum flow conditions
Ovidio, Michaël ULg; Guillaume, Nicolas; Hallot, Eric ULg et al

Conference (2007, June)

Using water resources for hydro-electricity production influences and limits the quality and quantity of habitat available for use by resident fishes. Changes in the fish community structure after setting ... [more ▼]

Using water resources for hydro-electricity production influences and limits the quality and quantity of habitat available for use by resident fishes. Changes in the fish community structure after setting minimum flow conditions have been more frequently studied than the behavioural adaptations of fish living in the vicinity of the disturbed river section. In the River Amblève (River Meuse basin, Belgium), a hydraulic power plant bypasses the river over a length of 10 km. Adult nase Chondrostoma nasus (n=10) and barbel Barbus barbus (n=8) were captured in the restitution zone of the turbinated flow several weeks before their reproduction periods. They were equipped with implant radio transmitters and manually and intensively tracked over several months to more than 1 year. The environmental conditions (water temperature and flow) as well as the geomorphology of the river were compared in both natural and flow-regulated sections. Nase and barbel demonstrated the capacity to map their contrasted environment and adapted their space and habitat utilisation as well as the choice of their spawning sites in relation with their specific biological characteristics and the environmental variations. The results are discussed in the context of the management of fish movements in flow-regulated rivers. [less ▲]

Detailed reference viewed: 47 (7 ULg)
Full Text
Peer Reviewed
See detailMobility and home-range use of Atlantic salmon parr over short time scales
Ovidio, Michaël ULg; Enders, Eva C.; Hallot, Eric ULg et al

in Aquatic Living Resources (2007), 20(1, JAN-MAR), 95-101

This study performed in the Patapedia River (Quebec, Gaspesie) was designed to examine the space utilization and mobility patterns of individual Atlantic salmon parr over short time scales with frequent ... [more ▼]

This study performed in the Patapedia River (Quebec, Gaspesie) was designed to examine the space utilization and mobility patterns of individual Atlantic salmon parr over short time scales with frequent detections of position. In August 2004, n = 7 radio-tagged Atlantic salmon parr were located every 20 min during 10 tracking periods chosen to take into account the dawn, day, dusk and night periods. Parr showed important inter individual variability in space utilization and mobility patterns, occupying large home ranges (123 to 5602 m(2)) and sometimes migrating 2 km upstream in the river. No differences were observed in the mean distance travelled among the four daily periods by individual fish, but the estimated home ranges utilized during the four daily periods overlapped only partially, demonstrating that parr partly occupy different areas of the river during different parts of the daily cycle. The results suggest that an intense survey on a small number of fish may contribute to a complementary comprehension of space utilization and mobility patterns of Atlantic salmon parr when viewed in association with results from studies surveying larger number of fish at lower frequency. [less ▲]

Detailed reference viewed: 106 (55 ULg)
See detailEtudes sédimentologiques dans les cours d’eau à moules perlières en Ardenne
Mols, J.; Defechereux, O.; Petit, François ULg et al

in Rencontres nationales techniques, gestion des ruisseaux de têtes de bassin set zones humides associées (2007)

Detailed reference viewed: 21 (4 ULg)
Full Text
Peer Reviewed
See detailComparison of impacts of dams on the annual maximum flow characteristics in three regulated hydrological regimes in Quebec (Canada).
Assani, A. A.; Stichelbout, E.; Roy, A. G. et al

in Hydrological Processes (2006)

Detailed reference viewed: 14 (6 ULg)
Full Text
Peer Reviewed
See detailFréquence et importance du charriage dans les rivières du massif ardennais
Houbrechts, Geoffrey ULg; Hallot, Eric ULg; Gob, F. et al

in Géographie physique et Quaternaire (2006)

Detailed reference viewed: 85 (47 ULg)
Full Text
Peer Reviewed
See detailApproche méthodologique pour la délimitation des espaces de liberté des rivières du massif ardennais
Snijders, Jean-Philippe; Hallot, Eric ULg; Houbrechts, Geoffrey ULg et al

in Bulletin de la Société Géographique de Liège (2006), 48

Dans les schémas départementaux d’aménagement et de gestion des cours d’eau (France), le concept d’espace de liberté des cours d’eau, introduit en 1991, attribue à la rivière un espace de mobilité propre ... [more ▼]

Dans les schémas départementaux d’aménagement et de gestion des cours d’eau (France), le concept d’espace de liberté des cours d’eau, introduit en 1991, attribue à la rivière un espace de mobilité propre, de manière à restaurer la dynamique naturelle d’érosion des berges. Une partie de la méthodologie proposée repose sur l’utilisation de documents cartographiques anciens en vue de déterminer les espaces de divagation historique des cours d’eau. Cette démarche a été appliquée à différentes rivières du massif ardennais (Ourthe, Amblève, Semois, Rulles). Les espaces de mobilité obtenus pour ces rivières étant assez réduits, il a été nécessaire de prendre en considération les erreurs liées à la correction géométrique et au géoréférencement des différents documents utilisés. L’utilisation des microscories, rejets de l’ancienne industrie du fer, en tant que marqueur stratigraphique, nous a permis de tester, sur plusieurs rivières, les vitesses d’érosion latérale obtenues par la méthode cartographique. En conclusion, la méthode cartographique entraîne une nette surestimation des vitesses d’érosion latérale et des espaces de mobilité des cours d’eau dans leur plaine alluviale. [less ▲]

Detailed reference viewed: 90 (20 ULg)
Full Text
See detailLa Cartographie des Zones Inondées : Approche géomorphologique et Enquêtes de Terrain
Peeters, Alexandre ULg; Van Campenhout, Jean ULg; Donnay, F. et al

in Les risques majeurs en Région wallonne : prévenir en aménageant (2006)

Detailed reference viewed: 94 (33 ULg)
Full Text
Peer Reviewed
See detailUtilisation des microscories métallurgiques comme traceur de la sédimentation dans les plaines alluviales ardennaises
Houbrechts, Geoffrey ULg; Petit, François ULg

in l'érosion entre société, climat et paléoenvironnement (2006)

Detailed reference viewed: 55 (15 ULg)
Full Text
Peer Reviewed
See detailLa dynamique fluviale d’un cours d’eau de marge passive : le Chassezac (Cévennes, France)
Jacob, N.; Gob, F.; Bravard, J. P. et al

in Géomorphologie : Relief, Processus, Environnement (2006)

Detailed reference viewed: 21 (5 ULg)
Full Text
Peer Reviewed
See detailCritical specific stream power in gravel-bed rivers
Petit, François ULg; Gob, Frédéric ULg; Houbrechts, Geoffrey ULg et al

in Geomorphology (2005), 69(1-4), 92-101

Experiments with marked pebbles were carried out on different sized rivers of the Belgian Ardenne (catchment areas varying from less than I km(2) to 2700 km(2)). Specific stream power required to cause ... [more ▼]

Experiments with marked pebbles were carried out on different sized rivers of the Belgian Ardenne (catchment areas varying from less than I km(2) to 2700 km(2)). Specific stream power required to cause bedload movement was evaluated and critical values were obtained. Three types of relationship between critical specific stream power (omega(0)) and grain size (D) were established. The values for coo in the largest river (the Ourthe) were the lowest and were close to the values obtained for mountainous rivers carrying large boulders. In medium sized rivers (catchment area between 40 and 500 km(2)), the critical unit stream power was higher. It is likely that it is due to the bedform's greater resistance. This resistance would use up some of the energy that can cause movement and transport of bedload. The amount of resistance of the bedform can be expressed as bedform shear stress (tau ''), determined by the relationship between grain shear stress (tau'-that determines movement and transport of the bedload) and the total shear stress (tau). This ratio varies between 0.4 and 0.5 in the medium sized rivers, compared to 0.7 in the Ourthe. In headwater streams (less than 20 km(2)), there is greater loss of energy due to bedform resistance (tau'/tau < 0.3). Critical specific stream power is higher in this third type of river than in the other two. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 166 (24 ULg)
Peer Reviewed
See detailHabitat use of juvenile Atlantic salmon (Salmo salar): the relation between physical variables and individual mobility.
Roy, Mathieu; Ovidio, Michaël ULg; Enders, Eva et al

Conference (2005, May)

Detailed reference viewed: 11 (3 ULg)
Full Text
Peer Reviewed
See detailRiver dredging, channel dynamics and bedload transport in an incised meandering river (the River Semois, Belgium).
Gob, F.; Houbrechts, Geoffrey ULg; Hiver, J. M. et al

in River Research & Applications (2005)

Detailed reference viewed: 38 (17 ULg)
Full Text
Peer Reviewed
See detailAnalyse des inondations en aval du barrage de Nangbeto sur le fleuve Mono (Togo et au Bénin).
Ago, Expédit Evariste ULg; Petit, François ULg; Ozer, Pierre ULg

in Geo-Eco-Trop (2005), 29

The analysis of risk of flood downstream from the hydroelectric dam of Nangbeto in the Mono River was about the survey of interannual variability of rainfall and rivers flows from 1955 to 1999, the ... [more ▼]

The analysis of risk of flood downstream from the hydroelectric dam of Nangbeto in the Mono River was about the survey of interannual variability of rainfall and rivers flows from 1955 to 1999, the population vulnerability, the hydrological modification and the impacts downstream in Togo and Benin from the dam constructed in 1987. The analysis of the mean annuel discharge has revealed no tendency, showing thus that the change of land use, the increase of waterproof areas and even the functioning of the hydroelectric dam have not modified in a significant manner the river's rate of flow. Apart from the return to the improvement in rainfull as far back as the end of years 80, the anthropic pressure and the demographic explosion have best explained the magnitude and frequency of flooding downstream from the hydroelectric dam of Nangbeto. The soil degradation, the deforestation of the floodplain, the increase in the number of human settlements in the river boundary increases the vulnerability of population faced with flooding. [less ▲]

Detailed reference viewed: 299 (25 ULg)
Full Text
See detailDetermining the competence of mountainous Mediterranean streams using lichenometric techniques
Gob, F.; Jacob, N.; Bravard, J. P. et al

in International Association of Hydrological Sciences : “River Catchment Dynamics : Natural Processes and Human Impacts (2005)

Detailed reference viewed: 14 (6 ULg)
Full Text
Peer Reviewed
See detailEvaluation des puissances spécifiques de rivières de moyenne et de haute Belgique
Petit, François ULg; Hallot, Eric ULg; Mols, J. et al

in Bulletin de la Société Géographique de Liège (2005)

Detailed reference viewed: 81 (41 ULg)
Full Text
Peer Reviewed
See detailParamètres hydrologiques et physico-chimiques de sources du Crétacé du Pays de Herve et de la Hesbaye sèche
Mols, J.; Petit, François ULg

in Bulletin de la Société Géographique de Liège (2005)

Detailed reference viewed: 26 (6 ULg)
See detailTurbulence et patron d’utilisation de l’habitat du saumon atlantique juvénile
Roy, M. L.; Ovidio, Michaël ULg; Hallot, Eric ULg et al

Scientific conference (2004)

Detailed reference viewed: 1 (0 ULg)