Proposal of Canal Detour Degree Index for Mountainside Irrigation Canals

Abstract

This study proposed a new index, the canal detour degree index, to provide information for the functional evaluation of irrigation canals that support agricultural areas of hilly and mountainous areas. First, the proposed index was tested on a virtual geometric irrigation canal, which confirmed that the index varies with the detour degree and the number of detours. Next, the index was applied to 189 real-life irrigation canals in Japan and its relationship with the topography such as valleys and ridges was examined. The results confirmed that this index appropriately quantifies the influence of topography such as valleys and ridges in irrigation canals length. However, the relationship among the index, the canal length, and the intake elevation was unclear.