Modelo de intrusão salina no estuário do incomati baseado na influẽncia geométrica e topográfica do estuário

Abstract

The present work focuses on the determination of the saline intrusion in the Incomati Estuary, and also on the determination of the flow that minimizes it, considering its progression upstream of the estuary driven by the reduction of the river flow, mainly in the dry season. if the saline intrusion model that was applied by Cossa (2001) and Macuiane (2003), with the particularity of, in this study, the model considers the influence of the estuary boundaries. The model underlying this determination, the classic salt diffusion and advection equation proposed by Bowden (1983) and Turrei et al. (1996) is presented here considering the topography and geometry of the estuary as important factors in the modeling of the saline intrusion process. The dynamic equilibrium stage of the tide at the mouth of the estuary is considered. This study covers the summer and winter periods, covering twelve months from 2002 to 2004. The results point to a great vulnerability of the estuary to saline intrusion, especially when the flow is low. In most months the saline intrusion exceeds 20 km upstream of the river, which means that this process compromises agricultural activities and the ecological system in general. To mitigate this problem it is necessary to establish a flow that ensures that the cultivated land located 20 km upstream is not affected. The flow determined in this work has the value of 24 m3s_1. ( TRADUÇÃO NOSSA)