Water Resources Scientists and Engineers are always in the hunt to synthesize stream flow from ungauged catchments. The most popular approach is use of empirical relationships for determining parameters of conceptual models. However, such relationships do not remain accurate, as variations in global atmosphere may bring about changes in the rainfall patterns and geomorphology as well. Commonly used modelling approach is application of linear theories. Main problem with application of linear theories is determination of instantaneous unit hydrographs (IUH) for a basin. IUH, which is unit impulse response function of a basin, describes the link between geomorphologic laws and hydrologic response of the basin. Linking of geomorphology with hydrology of a basin is likely to provide a better picture of the hydrologic behaviour of a catchment, particularly the ungauged ones. This book deals with development of Geomorphological IUH. The book provides a comprehensive approach to development of GIUH for a Himalayan Catchment in India; involving use of toposheets on two different scales. The book will be useful to research scholars, academicians, hydrologists and water resources engineers.