A New Algorithm for Association of Rain Gauging Stations in Flash Flood Prevention and Control Areas

Rain gauging station is an important defense for flash flood disaster. It provides primary data support for flash flood disaster early warning. To improve the insufficient consideration of the upstream to downstream topology in the watershed and insufficient representativeness of the rain gauging stations, an association algorithm between the automatic rain gauging stations and the flash flood prevention and control area based on the watershed's topological relationship is proposed, with the weight of the associated rain gauging stations determined by the Thiessen polygon method. Moreover, the simple rain gauging stations is proposed to act as the backup stations to improve the resilience of the early warning system under extreme rainstorm conditions. The Tonghua village in Linchuan County is investigated. The related rain gauging stations are searched in and around its upstream area according to the principle of effective coverage. The rain gauging stations are then in logical correspondence with the prevention and control area, and the weights of the rain gauging stations are determined. These conform to the spatial variation of rainfall in the basin, so the rainfall quantity for early warning could be more representative and accurate.