COMPLETE CLOSURE OF THE NANAKITA RIVER MOUTH IN 1994

Abstract

Very severe draught occurred in Japan during the dry season in 1994. Due to considerably reduced river discharge, complete closure was induced five times at the Nanakita River mouth in Japan during this period. Detailed field observations were carried out immediately before and after the closures. By analyzing hydraulic characteristics measured at the mouth, date of the closure occurrence can be estimated. An analytical solution is derived for predicting time-variation of river mouth width under the combined influence of incoming waves and effluent river discharge.