Landscape planning recommendations in terms of sustainable stormwater management: The case of Bornova stream catchment

In this study the amount of runoff volume in the Bornova Stream Catchment, which has a surface area of 48.13 km2 in the city of Izmir, was calculated and the effect of land use decisions on the surface runoff was revealed. The Modified NRCS CN Method, which is based on the NRCS Curve Number Method, was used to determine the runoff volume. In determining the effect of land use decisions on surface runoff; land use change scenarios have been designed for the Bornova Stream Catchment within the framework of land use decisions of the 1/25.000 scaled Izmir Metropolitan Area Master Plan. As a result of the study, it was calculated that the runoff volume of the Bornova Stream Catchment is 2.717.841.34 m3. It is concluded that the runoff volume will increase by 8,3% if the pessimistic land use change scenario is implemented and if the optimistic land use change scenario is implemented, this rate will decrease by 0,4%. Landscape planning proposals were supported by providing legal, administrative, economic, socio-cultural and technological suggestions to ensure the sustainable stormwater management in the catchment.