**Preface to "Thermal and Optical Remote Sensing: Evaluating Urban Green Spaces and Urban Heat Islands in a Changing Climate"**

Urbanization, typified by land-use-land-cover transformation is a major cause of bio-physical, thermodynamic, surface energy and micro- and macro climate perturbations. These changes commonly result in environmental deterioration that in turn adversely affects bio-physical processes and quality of urban life. A major consequence of urbanization is the higher thermal values compared to the surrounding peri-urban and rural areas, causing the Urban Heat Island (UHI) effect. In recent decades, above-average heat during summer has become prevalent in global cities, a trend that is expected to continue. It is anticipated that the intensifying UHI effect, in concert with increasing anthropogenic activities, will exacerbate the vulnerability of urban landscapes to climate-related disasters such as floods and heatwaves. Hence, UHIs have become an invaluable theme in environmental research. A recent proliferation of optical and thermal remotely sensed datasets offers great potential for understanding the relationship between the urbanization processes and their respective bio-physical and climatic implications. This book focuses on the theoretical principles and practical adoption of remote sensing approaches and datasets in understanding the nexus between urbanization, natural landscapes, urban micro-climate, and climate change. This book provides a basis for understanding urban ecological and natural patterns, critical for the management of urban physical, ecological and social processes. Specifically, understanding past, current, and future Land Surface Temperature (LST) patterns and drivers is critical for, among others, urban environmental management, urban spatial planning, the optimal and sustainable use of urban landscapes and climate change mitigation. The book's first two chapters explore the potential of downscaling remotely sensed data and improved feature extraction to determine the effect of urban surface types on thermal characteristics. Chapter one adopts a Step-by-Step Random Forest Downscaling-Morphological (SSRFD-M) model to relate natural surfaces to LST, while chapter two proposes the absolute and relative indicators for the detailed derivation of landscape features and thermal values using Geofen 2 (GF-2) and Landsat 8 Thermal Infra-Red (TIR), respectively. Chapter three to five adopt the standardized Local Climate Zone (LCZ) typology to relate urban landscape feature types to thermal characteristics. Chapter three and four use the World Urban Database and Access Portal Tool (WUDAPT) and the LCZ framework in South Africa (Cape Town, Thohoyandou and East London) and Zimbabwe (Bulawayo), respectively, while chapter five relates seasonal LCZ to daytime LST in Riyadh, Saudi Arabia. Chapter six to nine investigate multi-city urban LULC and the contribution of the climate, urbanization and CO<sup>2</sup> to UHI in multiple cities. Chapter six proposes a Landsat imagery time series approach in Google Earth Engine platform to map built-up areas in 305 cities, while chapter seven compares Surface Urban Heat Island (SUHI) in relation to the SUHI fraction's key drivers in 305 Chinese cities. Chapter eight determines a critical competitive point of Artificial Surfaces (AS) and Urban Blue-Green Space (UBGS) on LST in 28 cities, while chapter nine relates the Global Land Surface Satellite (GLASS) Fractional Vegetation Cover (FVC) to CO2, urbanization, and climate in 32 major cities. Chapter ten to twelve investigate a range of UHI-mitigation approaches. Chapter 10 explores the value of urban green spaces in mitigating UHI in Marrakesh, Morocco, while chapter eleven investigates the role roof colours in assimilating surface temperature. Using vegetation's morphological Spatial Patter Analysis (MSPA), chapter twelve adopts ArborCamTM multispectral high-resolution imagery to determine the role of golf courses in assimilating urban LST. This book should be of interest to both specialists and generalists interested in, among others, urban planning, ecological conservation, the urban micro-climate, atmospheric science, environmental management, and climate change.

> **John O. Odindi, Elhadi Adam, Elfatih M. Abdel-Rahman, and Yuyu Zhou** *Editors*
