Author(s): Elena Matta, Florian Selge, Günter Gunkel, Reinhard Hinkelmann
Linked Author(s): Elena Matta
Keywords: TELEMAC-3D, numerical simulation, tracer transport, wind, Itaparica reservoir
Abstract: Many water bodies throughout the world are currently facing more frequent extreme events driven by climate change (e. g. droughts or floods), water quality problems (e. g. periodically nutrients overload) and conflicts over water uses. This is likewise the case of Ic�-Mandantes bay, located in Itaparica reservoir, S�o Francisco River, Northeast Brazil. Multiple uses of water (e. g. fishery, irrigation agriculture), long drought periods and intense rain events, as well as high water level variations (up to 5 m/y) and a new water infrastructure project (i. e. water diversion to nearby watersheds) are some of the existing challenges. Furthermore, the bay is quite isolated by the reservoir's main stream and characterized by low flow velocities (order of mm/s). The wind has an important role in the bay, being one of the main drivers of water movement and exchange, as shown in previous research using two-dimensional (2D) models. In the current paper, the effects of mean and extreme wind on water flow and on passive transport of nutrients (i. e. emissions from fish farming) were investigated with TELEMAC-3D, observing results over the water column and over time. The aim was to explore the capabilities of the 3D modeling, in order to understand whether 2D is satisfactory enough for water management. The outcomes of this work showed that the answer is complex and cannot be given a priori, since it is highly dependent on the objective and the conditions of the study, e. g. extreme wind yields not non-negligible 3D effects in shallower areas of the bay. Further studies are needed and currently focusing on 3D density-induced flow and heat exchange with atmosphere
Year: 2017