Decision support system for hydrological and flood modeling by using geographical information systems and remote sensing

Water resources planning and management is a very valuable issue for civilization development. Taking into account the climate-land use change, the limited water resources should be handled with quantitatively and qualitatively in a balance between protection and use, whose sustainability is rapidly endangered. In this context, water resources planning and management studies are of great importance. The thesis study mainly includes hydrological, hydraulic and flood modeling parts. In this study, HEC-HMS and HEC-RAS software developed by US Army Hydrologic Engineering Center are used. The scope of the study consists of performing integrated flood modeling by carrying out HEC-HMS gridded hydrological modeling-forecasting on a daily time scale and HEC-RAS 2D hydraulic modeling studies using a series of Geographical Information Systems (GIS)-Remote Sensing (RS) techniques. According to the literature research, in our country, there are a few studies that include distributed hydrological modeling, and numerical weather prediction data used in this study is not considered much in hydrological forecasting implementations, which makes the study more valuable. The study is a pioneering hydrological modeling application in terms of using a grid-based soil moisture accounting algorithm. In this sense, the outputs of the study, which includes integrated hydrological and flood modeling, can be used by water authorities and decision makers in water resources planning and management applications. The main motivation of this study is to implement deterministic modeling of daily flows and to make flow forecasting using numerical weather prediction data, which can be used as an early warning system, and to practice flood risk and loss mapping by hydraulic modeling after hydrological modeling, using GIS and RS techniques. In hydrological modeling, comparison of lumped and distributed conceptual models, verification of satellite products with ground observations, evaluation of model internal consistency with satellite products by using snow and soil moisture outputs as well as flow performance; in hydraulic modeling, performing model validation with satellite reference flood image are also the secondary aims of the study.