This book presents select proceedings of the International Virtual Conference on Trends in Hydrological and Environmental Systems (ITHES 2021). Various topics covered in this book include urban hydrology, hydrological extremes, statistical analysis of hydro-meteorological data, impacts of climate change, hydrological modelling, groundwater studies, water resource management and applications of RS & GIS in hydrology. The book also discusses various topics on applications of CFD in water resources and environmental engineering, water and wastewater treatment, solid waste management and air quality. The book will be a valuable reference for beginners, researchers, and professionals interested in environmental civil engineering, especially hydrological and environmental systems.

This book documents the various impacts of urbanization on hydrological systems and water resources. The first half of the book is focused on urbanization and surface waters, starting with the status of hydrological systems in the urban areas, i.e. the catchment characteristics and changes in rainfall dynamics. The most pronounced hydrological problems in cities are changes in runoff due to precipitation. Recently, rain events have been less frequent but more intense, sometimes leading to flash floods. Though the substantial increase in runoff causes floods in the urbanized area, it may be attributed to the reduction of infiltration due to construction of roads. This, in turn, results in groundwater decline and depletion. The second half of the book covers the impact of urbanization on groundwater, which starts with hindered or significantly reduced recharge taking place due to altered urban surfaces. The limited groundwater resources are over-exploited by the urban population, leading to water scarcity and depletion. Groundwater gets polluted due to solid waste dumping sites or by wastewaters discharged by industries. The book will be useful for researchers, educators, municipal/city authorities, government officials, and NGOs.