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

Abstract

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

A GIS-Based Spatial Analysis Model Approach for Identification of Optimal Hydrotechnical Solutions for Gully Erosion Stabilization. Case Study

“…Spatial analysis is based on the integration of spatial databases, representing the digital and alphanumeric elevation model, represented by the values that outline the unitary drainage hydrograph through HEC-RAS software v. 5.0.7, this being one of the best hydraulic analysis software. The software allows the realization of 2D computation simulation models based on the 2D fully dynamic equations and the 2D diffusion wave equations [46,47].…”

Urban Flood Risk and Economic Viability Analyses of a Smart Sustainable Drainage System

“…In studying the affected area, measuring the risk level can be one measurement method for efficiency when dealing with a new solution such as SuDS [39]. Other techniques like experimental investigations can be very expensive and hard to provide enough accuracy in the SuDS topic [40].…”

“…To apply the tech-236 nique all the streets with the most vulnerability to flooding were selected to still allow 237 normal circulation of people and vehicles, as seen in Figure 6. In studying the affected area, measuring the risk level can be one measurement 243 method for efficiency when dealing with a new solution such as SuDS [39]. Other tech-244 niques like experimental investigations can be very expensive and hard to provide enough 245 accuracy in the SuDS topic [40].…”

Assessment of Storm Floods in a Small Tropical Andean Basins

“…This is a result of basin impermeabilization, which causes lower infiltration, interception, and evapotranspiration levels, and consequently, increased volume of surface runoff (Jha et al, 2012;Hirabayashi et al, 2013;Woods Ballard et al, 2015;Huang et al, 2017;Feng et al, 2021). This generates storm floods, which occur when runoff flows overcome the flow designed for the drainage network, and subsequently creates mobility problems (Gómez Valentín, 2006;Jha et al, 2012;Ertan and Çelik, 2021), infrastructure damage, and in extreme conditions, pedestrian death. This is a broadly studied problem in basins with medium to low slopes.…”