The Assessment of Urbanization Effect and Sustainable Drainage Solutions on Flood Hazard by GIS

Rapid and uncontrolled changes in land use patterns due to urbanization negatively affect urban rainfall-runoff processes flood hazard. In this study, a method that included different sustainable drainage solutions, such as green infrastructure (GI) usage for hazard mitigation with various scenarios on geographic information system (GIS) platform within 1653 ha catchment of the Kağıthane Stream İstanbul, Turkey is presented. Developed are follows: scenario one (SN1) current situation; two (SN2) used roof application buildings permeable surface roads; three (SN3) only buildings; four (SN4) rainwater barrel collecting water, swale canal road added additional structures open areas observe urbanization; five (SN5) considered multiple GI implementations; six (SN6) full urbanization. The results indicate greener implementation provides benefits reducing both runoff coefficient peak flowrate, inundation area number affected by risk were decreased. integrated evaluation system, which consisted assessment 1D HEC-RAS hydrologic model, was applied evaluate mitigation.