Computing a design flood in the absence of historical records

Summary A design flood for a Venezuelan river is computed in the absence of rainfall and stream-flow data of more than a few years. From synoptic studies of an area embracing northern South America and the Caribbean, the type of disturbance producing the abundant rains of the area is determined. A disturbance of this type is maximized on the basis of the ratio of energy dissipated through friction to released latent energy represented by rainfall — in other words, theefficiency of the system is given its highest reasonable value. The synthetic disturbance is moved over the river basin in a manner most favorable for heavy rain. Certain data available from other rivers are used as a cross-check on the resultant flood values.