La quantification de la répartition de l'eau dans le sol et des flux hydriques est essentielle pour comprendre les relations sol eau plante. Pour les plantations d'Eucalyptus de la région de Pointe-Noire (Congo) installées sur des sols sableux très filtrants, une bonne connaissance du comportement de l'eau dans les couches supérieures de sols apparaît comme capitale pour une gestion durable des plantations d'Eucalyptus, mais aussi pour mesurer l'impact de ces plantations sur les ressources en eau de la région. L'objectif de cette étude est de paramétrer un modèle de transfert hydrique dans le sol sous trois plantations d'eucalyptus à l'aide d'un logiciel spécifique HYDRUS 1D et à des expériences de drainage interne in situ afin (i) de comparer ces trois parcelles quant à leur fonctionnement hydrique, et (ii) d'établir le bilan hydrique de peuplements d'Eucalyptus à différents stades de développement. Les résultats montrent des caractéristiques hydriques différentes pour les parcelles imputables à la géométrie et à la morphologie de l'espace poral et au passé cultural des sols. Les bilans hydriques pour les quatre stades de développement des plantations sont présentés et l'implication de ces résultats est discutée. (Résumé d'auteur)

"Water Supply and Pollution Control, Seventh Edition has been revised and modernized to meet the contemporary needs of civil and environmental engineering students who will be engaged in the design and management of water and wastewater systems, practicing engineers, and those planning to take the examination for licensing as a professional engineer. Warren Viessman, Jr. and Mark J. Hammer emphasize the application of scientific methods to problems associated with the development, movement, and treatment of water and wastewater. Treatment processes are presented in the context of what they can do rather than compartmentalizing them along clean water or wastewater lines. The concept of total water management, recognizing that all waters are potential sources of supply, is a dominant theme."--Jacket.

National audience

The retention and movement of water and atrazine (2-chloro-4-ethylamino-6- isopropylamino-s-triazine) was investigated in a calcareous soil (Krome) amended with three types of compost: (1) Clean organic waste (COW)- municipal solid waste cleaned of plastic materials and metal containers, (2) Biosolids (BSD)- sludge from municipal waste and (3) Bedminster (BDM)-a mixture containing 75% COW and 25% BSD. The research was conducted in two phases; a column-leaching study (dynamic) and a batch-equilibrium method (static). The column study demonstrated that while applying simulated rain, atrazine, leached out at a slower rate by 41, 24, and 18% from soil amended with BDM, BSD, and COW composts, respectively, during the first simulated storm event. BDM application resulted in lowest water movement and atrazine-leaching rate compared to the other composts tested. This study suggests that adding 134 t ha-1 of compost to the calcareous soil increased soil water holding capacity, reduced water movement and increased atrazine detention and reduced leaching potential of atrazine thereby reducing the potential for groundwater pollution. This study further demonstrates that soil amendment (particularly BDM) is effective in reducing the leaching potential of atrazine at the low rainfall amounts (corresponding to 0.5 pore volume). However, such amendment may not be effective in preventing leaching under more intense rain conditions or multiple rainfall events (corresponding to 3 or more pore volumes).