天明絵図に見られる黒部川氾濫原の離散的堤防群が今後の治水対策に与える示唆について

抄録

During the Edo period, discontinuous levee systems were commonly used to control river flooding. In this study, the construction process and hydraulic function of the levee system developed in Kurobe Alluvial Fan was investigated based on old map analysis and numerical flow simulation. Using a pictorial map drawn in 1785 and a levee survey map in 1894, the layouts of the discontinuous levees in the late 18th century and the 19th century was determined. The numerical flow simulation showed that fragmentary levees to suppress the divergence of river flows constructed in the18th century were integrated to a largescale levee system completed in the 19th century which contained a series of levee openings for intentional restricted flood divergence to old river channels and flood convergence after the flood peak.