26. Role of Geospatial Technology in Hydrological and Hydrodynamic Modeling-With Focus on Floods Studies

Assessment of surface water with higher accuracy is very critical in the present changing environment. Such assessment requires understanding of each and every hydrological process involved in hydrological cycle. The land characteristics along with climate variables make it a daunting task. With the advent of geospatial technology, both land surface and climate parameters may be studied with higher accuracy. Some of the hydrological parameters such as precipitation, soil moisture, evapotranspiration, and water level can now directly be retrieved using remote sensing data. However, other hydrological components such as rainfall-runoff, snowmelt-runoff, peak discharge, or flood hydrograph need modeling approach. Most of the surface and climate inputs required for hydrological and hydrodynamic (H&H) modeling nowadays can be quantified using the geospatial datasets. It makes modeling more realistic, and hydrological response of large basins can be studied. The H&H models are utilized for studying the hydrological extremes such as flood and droughts. Floods are one of the most naturally re-occurring hazards, which significantly impact the long-term sustainable use of land and water resources of a geographical region. The chapter focuses the use of geospatial technology for H&H modeling with relevant case studies on flood modeling. Further, the improvements in modeling outputs may be done by assimilating the geospatial inputs in near-real time. Moreover, these geospatial inputs are being updated and improved in spatial–temporal domain with the advancement in geospatial technology.