River section search method, recording medium recording a river section search program and river section search program

摘要

PROBLEM TO BE SOLVED: To provide a river section retrieving method for automatically retrieving a river section.;SOLUTION: River section ID (for example, numbers) having regularity for regularly discriminating a river name, a river basin, an upstream region, a downstream region and a merging direction is assigned to river section line data within a nationwide river basin by using geometrical information as a base, and the river section ID is preliminarily stored in a storage part. This processing part performs the automatic retrieval of the river section (the extraction of the river section of all the upstream region flowing in the arbitrary river section and the extraction of the flowing-down path of the river from the arbitrary river section to the sea) by using the regularity of the river section ID stored in the storage part. For example, this processing sets reference river section ID being a reference for retrieval (for example, ID represented by white numbers in Figure), and classifies the respective river section IDs into categories of the "upstream region", the "downstream region" or "neither the upstream region nor the downstream region" from the reference river section ID on the basis of the respective river section ID and the reference river section ID stored in the storage part, and stores each river section ID in each predetermined file.;COPYRIGHT: (C)2006,JPO&NCIPI