Tomorrow's İstanbul: Adaptive urban flood mitigation planning for climate change-induced hydro- meteorological hazards

Abstract

The urban flooding hazard occurrences increasing around cities worldwide, which directly affects infrastructure, economies, and inhabitants. The large number of people exposed to flood risks, 1.81 billion directly facing the threat of 1-in-100-year flood events (Jafino et al., 2023). This reality highlights the urgency of proactive intervention, demanding both mitigation strategies and adaptive approaches to weather the urban flooding. Climate change stands as a main contributor in this growing crisis. Its influence alters precipitation patterns, intensifies extreme weather events like hurricanes and cyclones, and pushes sea levels ever higher (IPCC, 2022). The hydro-meteorological hazards resulting from climate change have concrete consequences on several aspects in our lives and can have negative impacts on inhabited locations. The study materials have assessed research on urban flooding at worldwide, regional, and national levels. An aspect of the study focused on the varying dispositions of countries in different geographical regions towards urban flooding. In this analysis, the criteria of the nations were evaluated based on legal, administrative, and planning principles. This study's findings will provide insight into urban flood risk mitigation strategies that focus on building-level through adaptive urban planning. Adaptive urban flood mitigation planning (ad-UFMP) is the method of using adaptive spatial planning as a tool for lessening the impacts of extreme climatic conditions creates major floods in urban areas more frequently. Two stages of analyses evaluated for detecting most vulnerable urban flooding areas for ad-UFMP. In first stage, the urban vulnerability levels find outs then spatial environmental indicator uses for superposing to designate the case area. After detecting the surface situation in terms of permeability ad-UFMP suggest nature-based solutions in spatial level. The thesis examines the escalating risk of urban flooding in Istanbul and emphasizes the necessity of adopting a comprehensive strategy to mitigate the impacts of enhanced rainfall, rising sea levels, and inadequate drainage capacity. The proposed approach emphasizes a multifaceted response, encompassing vulnerability assessments, flood risk management strategies, adaptive spatial planning, and community engagement. This dissertation aims to address the complex issues of climate change, hydro-meteorological hazards, and adaptive urban planning in order to develop strategies for making implementation area more robust and flexible in terms of adaptability. The goal is to ensure that the city is well-prepared to withstand any future challenges. This framework, with its potential for wider application, will be used in Istanbul. As the tide of urban flooding rises due to human-induced climate change altered hydro-meteorological hazards, this research urges us to build not just seawalls, but resilient communities, capable of not just mitigating the floods, but adapting to thrive in the face of a changing climate externalities. The thesis study focuses on hydro-meteorological investigations of Istanbul to choose a suitable sample region. By systematically analyzing various datasets, certain regions were identified inside the provincial boundary. These findings, when applied to the planning areas of Istanbul, will aid in mitigating urban risk by implementing ad-UFMP method with adaptive spatial planning across many scales, ranging from the macro level to the micro level.