Investigation of flow field around/through simplified emergent isolated tree-like vegetation

Rivers are perfect balanced formations which have been being evolved for hundred thousands of years with the natural effects such as morphological and/or biological effects. This perfect balance of rivers and waterfront areas are excessively fragile against human activities. Nowadays, river ecosystems are faced with human-induced impacts in a while that, is significantly short compared to long-drown-out evolution period. In recent years, exchanging human based artificial impacts with natural arrangments by understanding the river ecosystem dynamics is becoming hot topic in the river management community. In this new field, aquatic and riparian vegetation impacts are incontrovertible. To apply an ecological, multi-functional and sustainable river restoration comprehending deeply the both aquatic and riparian vegetation's role is crucial. Aquatic and riparian vegetation have great impacts on river ecosystems as, those plants increase the bank stability, provide habitat for animals and invertebrates, improve the water quality, build pioneer landforms by trapping and stabilizing sediment, promote biodiversity, regulate water temperature. The main motivation of this thesi is to contribute to ecological river restoration knowledge. In the present study the flow field alteration of tree-like vegetation that are widespread located in riparian zones, which represents the interface between land and river. The plant canopy was simplified by placing different configurations of cylindrical elements onto a wooden rod and testing them individually, on the porpose of idealizing the complex architecture of the canopy in natural vegetation. The tested configurations are a rigid cylinder and two hexagonal arrays of circular cylinders with equal overall diameter. The tested hexagonal array configurations identified as dense array and sparse array according to their solid volume fractions, ∅=0.335 and ∅=0.132, respectively. Experiments done firstly with uniform forms of the solid cylinder and the hexagonal arrays, then same experiments conducted with tree-like elements, which the same obstacles served as canopies, and real vegetation (Cupressus macrocarpa). If the uniform and tree-like cases are considered as two different experiment groups. Comparisons made for all experiment groups in itself and in between.