Measuring and Mapping Flood Processes

Floods are no doubt a major hazard and the risks they pose are increasing due to shifts in meteorological forcings, population pressures, as well as anthropogenic change to riverine landscapes. Flood waves and related processes are observed globally, through either river gauging networks or remote sensing acquisitions. River gauging stations are declining globally and although historical and current gauges are providing useful and frequent data in the developed world, the number of gauges in developing and emerging economies is very small and measurement stations are often very far apart and in remote locations thus making inference of processes and data collection difficult. Remote sensing, space-borne, and airborne can alleviate some of these limitations but has its own shortcomings. Hydrodynamic models can complement observations but the accuracy and complexity of the flood flow models used vary with both spatial scale at which they are applied and complexity of the topographic landscape. Furthermore, models are only as good as the data used to drive and calibrate them. In recent years, substantial efforts are being made to improve this complex situation of observing, mapping, and modeling flood processes, both in terms of flood model development and remote sensing, particularly satellite platforms. This chapter provides a detailed account of this complex interplay between models and data to observe, simulate, and understand flood processes on various scales and in different landscape settings.