Abstract:

Analyzes made with morphometric indices provide fast, comparable data with the developing Geographical Information Systems (GIS) and geological, geomorphological and hydrographic characteristics of the basins can be explained with this information. In this study, the drainage network development and fluvial processes of the İnegöl basin, which has various structural elements, geomorphic units, tectonic features, were examined through morphometric index analysis and maps. In the research, topography sheets and Digital Elevation Model (DEM) were created, calculations of areal, linear and superficial 26 morphometric indices were made over the basin-wide and three main sub-basins, and maps were produced with GIS. Among the analyzes, especially drainage density, stream density, asymmetric factor, topographic symmetry factor, valley width-valley height ratio, stream-length gradient index, dissection index and erosion-fragmentation index data show that the structure, tectonic events and strikes are the main factors in the drainage development of the basin. It has been determined. According to the results of the morphometric index, while lithological units in the İnegöl plain located in the north of the basin enabled the rivers to drain through a single channel, the granite topography in the Domaniç Mountains caused the density of the stream. Valley width-valley height ratio, stream-length gradient index, dissectin index and topographic roughness index data reveal the presence of a concentrate stream, the drift of the rivers in certain areas of the basin, creating strait valleys by overcoming the steepness of the fault. It was observed that the general drainage in the basin was of the centripetal type, and dandritic, latticed and parallel drainage networks developed in the sub-basins and local areas. With the applied indices, it has been determined by numerical evidence that the effect of tectonic movements is the dominant factor in the development of the drainage network and fluvial processes.

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