Preface

In this timely and comprehensive edited volume, the reader embarks on a journey through the complex and multifaceted aspects of floods and their intricate relationship with climate change.

Floods have long been recognised as one of the most significant natural hazards, posing substantial threats to communities and ecosystems worldwide. However, in the context of a changing climate, these risks are further amplified, necessitating a deeper understanding of both existing and emerging risk drivers. With that in mind, this volume focuses on the dynamic nature of floods and their intricate relationship with climate change.

Through a journey across chapters, each focusing on a specific aspect of floods and their risk drivers, this volume sheds light on the multiple factors influencing flood occurrence, intensity, and impacts in our rapidly changing world. From exploring the role of constructed wetlands in stormwater management to assessing flood risk in historic urban areas, analysing non-stationarity of extreme rainfall to advancing torrential rainfall forecasts, and examining flood damage on agricultural land to understanding post-fire debris flow susceptibility, every facet is meticulously investigated here to obtain knowledge and actionable insights.

Chapter 1 focuses on the role of constructed wetlands as a nature-based solution for stormwater management. Integrating nature into urban landscapes, constructed wetlands offer a sustainable approach to managing stormwater and reducing flood risks. This sets the stage for the exploration of effective flood management strategies.

Chapter 2 takes the reader to the historic city centre of Aveiro in Portugal. Through a large-scale flood risk assessment, a multidisciplinary, international research team applies a methodology to identify buildings and areas of Aveiro at risk. Based on this assessment, the authors provide essential insights into the flood risk scenario and possible strategic rehabilitation interventions for protecting this area while preserving the heritage value of its buildings.

In Chapter 3, the focus of the reader shifts to the middle and lower reaches of the Yangtze River basin in China. By analysing the non-stationary characteristics of extreme rainfall events, the authors explore the correlations of extreme rainfall with large-scale atmospheric circulations such as El Niño–Southern Oscillation and Western Pacific Subtropical High. The discussion and results offered in this chapter demonstrate how accounting for climate change-induced shifts in flood magnitudes and frequencies can lead to better-informed decision-making and, consequently, to more resilient infrastructure.

Advancements in torrential rainfall forecasts and their role in improving early warning systems take centre stage in Chapter 4. In this chapter, the author explores the use of innovative approaches and technologies, such as high-resolution weather models and ensemble forecasting, to enhance the accuracy and lead time of torrential rainfall predictions. As shown in this chapter, such tools and applications can play a critical role in empowering communities to take timely and appropriate actions in response to potential flood events.

**Chapter 1**

**Abstract**

*and Tristan Gilbert*

MUSIC modeling, TN, TP, TSS

**1. Introduction**

Understanding the Role of

Constructed Wetlands in

Stormwater Management

*Shirley Gato-Trinidad, Jamie Carroll, Ezreena Aladin* 

literature to address these concerns relating to constructed wetlands.

**Keywords:** constructed wetlands, pollutants reduction, flood mitigation,

effectiveness monitored and maintained once these are established.

Whilst constructed wetlands have been utilized for some time in the treatment of wastewater, they only gained popularity for the treatment of stormwater runoff and flood protection in the last couple of decades [1, 2]. Constructed wetlands are employed to remove sediment and nutrients, primarily phosphorus and nitrogen, from contaminated water [1]. However, with increased urbanization and enhanced climate change, these constructed wetlands need to be managed and their treatment

Constructed wetlands remove sediments using large ponds which allow for dissipation of water velocities, making sediment particles drop out of the water column, settling at

Constructed wetlands have been utilized for some time in the treatment of wastewater and have been recognized for the treatment of stormwater runoff and flood protection in the last couple of decades. Constructed wetlands are built to remove sediment and nutrients, primarily phosphorus and nitrogen, from contaminated water. However, with increased urbanization and enhanced climate change, these constructed wetlands need to be managed and their treatment effectiveness monitored and maintained especially at the post-construction phase. In addition, a greater understanding of the role of these systems in the urbanized environment and how they treat wastewater are needed to optimize their performance. As more advanced computer modeling is developed there is a need to ascertain what parameters and how these changes overtime and what skills are required to enable the adoption of constructed wetlands for future planning and management. There has been limited research into constructed wetlands for flood mitigation and with some receiving inflows larger than their design intent, it is necessary to determine if these systems would still be able to treat pollutants. This chapter involves a review of the

Chapter 5 explores the impact of catastrophic floods on agricultural land in cold regions with glaciers. By examining examples of the impacts of floods of different sizes in these areas, the authors investigate the effects of floods on yields and possible measures aimed at reconstructing soils with the ultimate goal of regaining productivity. With this discussion, the author provides insights into mitigating the long-term effects of floods on agricultural systems and highlights the importance of safeguarding food production and rural livelihoods.

Finally, Chapter 6 focuses on the increasingly relevant topic of post-fire debris flow events. In this study, the authors apply the cellular automaton RuiCells to assess flash flood susceptibility in sedimentary areas affected by extreme fires. The findings of this study highlight the relationships between morphological patterns, surface water flows, and debris flow susceptibility and showcase the importance of understanding the relationship between wildfires and flood risks for the definition and implementation of effective proactive measures aimed at enhancing resilience and protecting communities in fire-affected regions.

Together, these six chapters offer valuable insights and innovative approaches. By embracing a multidisciplinary perspective and unravelling the complex interactions between climate change, natural systems, and human activities, this volume equips researchers, practitioners, and policymakers with the knowledge and tools necessary to prepare for and mitigate the impacts of floods in a more effective way, with the goal of contributing to a more resilient and sustainable future where communities worldwide are better prepared to face the challenges posed by floods in a climate-changing context.

> **Dr. Tiago Miguel Ferreira** School of Engineering, Department of Geography and Environmental Management, University of the West of England (UWE Bristol), Bristol, United Kingdom

> > **Dr. Haiyun Shi** School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
