This book deals with important topics of current interest, such as climate change, floods, drought, and hydrological extremes. The impact of climate change on water resources is drawing worldwide attention in these days; water resources in many countries are already stressed and climate change along with burgeoning population, rising standard of living, and increasing demand are adding to the stress. Further, river basins are becoming less resilient to climatic vagaries. Fundamental to addressing these issues is hydrological modelling which is covered in these books. Further, integrated water resources management is vital to ensure water and food security. Integral to the management is groundwater and solute transport. The books encompass tools that will be useful to mitigate the adverse consequences of natural disasters. This book is useful for those working in river and coastal engineering. River Engineering is important for fluvial hydraulics, sediment transport, morphometry, desilting, trap efficiency, silting and desilting process. Coastal engineering includes storm surge forecast, optimization of harbour, wave modelling, and shoreline changes.