Flood Modeling, Prediction, and Mitigation

Abstract

Floods are among the natural extreme events that occur after intensive storm rainfall events as excessive water volumes over the earth surface more than the capacity of surface natural or artificial conveyance systems (stream and river basins, creeks, estuaries, wadis, valleys, canals, channels, culverts, dams, cities). Apart from the rainfall causative floods, there are others as consequences of snowmelt, sea surge and tides, tsunamis, ground water level rise, urban sewer capacity overflow, dam breaks in addition to confined aquifer overflows. Since the start of human history, societies have been exposed to the danger of natural events such as earthquakes, droughts, and floods that could not be avoided completely even with the modern-day scientific and technological facilities, preparedness, mitigation, and early warning systems. The most hazardous extreme natural event is the flood occurrence not only due to the intensive rainfall effects, but more significantly due to human settlement along flood dangerous areas such as floodplains, adjacent to riverbanks, and valleys. The floods are extremely beneficial events in arid regions, because they are the main source of groundwater recharge along drainage basins (wadis), where there are no human settlements or urban area exposed to flood danger. For this purpose, there are even runoff harvesting works in many arid regions of the world. However, flood beneficial aspects are outside the scope of this book, which is concentrated on floods and flash floods. In order to achieve successful works to reduce flood danger and hazard, it is necessary to know scientific fundamental aspects of flood definition and generation processes, which pave way for methodological procedures to predict their future behaviors and to take precautions by means of hardware through the engineering water structures and software by means of early warning systems and also public awareness through educative training. The main purpose of this book is to bring together all the layman, technicians’, engineers’, and scientists’ methodological procedures that have been developed for flood peak discharge prediction during the last 150 years. Early approaches are rather logical and empirical, but later on, more systematic and analytical approaches are developed on the basis of rational, probabilistic, statistical, and stochast