MODELAGEM DE CANAIS INCISIVOS - REVISÃO
Resumo
O objetivo deste artigo é documentar as mais importantes pesquisas e aspectos histórico-cronológicos sobre a modelagem da incisão de canais. São apresentados os aspectos qualitativos e quantitativos envolvidos, desde a dedução das equações de Saint-Venant e de Exner, até as mais recentes pesquisas sobre o alargamento e o deslizamento das margens dos canais, considerando a coesão das mesmas. Do ponto de vista quantitativo, ainda há muitos processos importantes a serem solucionados, com destaque para os mecanismos envolvidos na desagregação e transporte de partículas de solo coesivas. Pesquisas recentes mostram que a estimativa da desagregação pelos métodos tradicionais de determinação da resistência do solo pode não ser a mais recomendada para avaliar a resistência na interface solo-água. Isto aponta para a importância dos processos físico-químicos envolvidas na estabilidade das partículas do solo e, conseqüentemente, na sua suscetibilidade à erosão, assim como a importância da sua representação matemática e inclusão na modelagem do processo de incisão de canais.
Incised channel modeling - revision
Abstract
This paper aims at documenting some of the more important research and historical-chronological aspects concerning incised channels modelling. Qualitative and quantitative aspects are presented, beginning with the deduction of the Saint-Venant and Exner equations and going through the more recent equations explaining the enlargement and stability of cohesive riverbanks. From a quantitative point of view, there are still many important processes to be solved, specially those regarding detachment mechanisms and transport of cohesive soil aggregates. Recent research has shown that soil evaluation aggregates detachment by conventional methods (soil strength determination) cannot measure the properties at the soil-water interface with the necessary resolution. These results allow visualizing the importance of the physicochemical mechanisms involved on aggregate stability at the soilwater interface; and, consequently, its degradation suscetibility. These mechanisms should be mathematically described and included in incised channel modeling.
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DOI: http://dx.doi.org/10.5380/raega.v8i0.3384
