DEVELOPING TOOLS FOR COMPUTATION OF BASIN TOPOGRAPHIC PARAMETERS IN GIS
Keywords: Shape Factor, Bifurcation Ratio, Drainage Frequency, Drainage Density, Harmonic Slope, Average Slope, Time of Concentration, Hypsometric Curve
Abstract. Although water use has been increasing day by day depending on fast population increase, urbanization and industrialization in the world, potential of usable water resources remains stable. On the other side, expansion of agricultural activities, industrialization, urbanization, global warming and climate change create a big pressure on current water resources. Therefore, management of water resources is one of the most significant problems of today that is required to be solved and ‘’Integrated Basin Management’’ has gained importance in the world in terms of decreasing environmental problems by more efficiently using current water resources. In order to achieve integrated basin management, it is needed to determine basin boundaries with sufficient accuracy and precision and encode them systematically. In various analyses to be done on the basis of basin, topographic parameters are also needed such as shape factor, bifurcation ratio, drainage frequency, drainage density, length of the main flow path, harmonic slope, average slope, time of concentration, hypsometric curve and maximum elevation difference. Nowadays, basin boundaries are obtained with digital elevation models in geographical information systems. However, tools developed for topographic parameters are not available. In this study, programs were written in Python programming language for afore-mentioned topographic parameters and each turned into a geographical information system tool. Therefore, a significant contribution has been made to the subject by completing the deficiency in the geographical information system devoted to the topographic parameters that are needed in almost every analyses concerning to the hydrology.