Development of geographical information system based conceptual monthly rainfall-runoff model

Monthly rainfall-runoff models are frequently used in water resources planning and management. These models transform monthly rainfall values into monthly runoff series. Lumped models, which use mean basin characteristics, are commonly preferred in practice for simplicity. However, evaluation of water resources requires considering spatial and temporal variation of basin parameters such as land use, land cover, soil texture and geology. Thus, many lumped models in the literature integrates traditional hydrologic models and Geographical Information Systems. This thesis presents a 5-parameter lumped monthly rainfall-runoff model integrated to the Geographical Information Systems -- GIS Based Conceptual Hydrologic Model. The model considers spatial variabilities of land use, soil texture and geological formations. In the model, cell based runoff estimations are simulated by a conceptual hydrologic model once input variables and model parameters are organized in raster data sets. Simulations are implemented a matrix-based computer program developed. The result of the test study for Gördes basin an important fresh water source of Izmir shows that GIS based 5-parameter monthly rainfall-runoff model produces significant cell based runoff estimates. These estimates are especially valuable for the basins with spatial distrubuted rainfall data as well as known basin charecteristics. The model can be also beneficially used for the identification of pollution distribution throughout basins.