A new rapid watershed delineation algorithm for 2D flow direction grids. (November 2018)

• Record Type: Journal Article
• Authors: Haag, Scott; Shakibajahromi, Bahareh; Shokoufandeh, Ali
• Is Part Of: Environmental modelling & software. Volume 109(2018)
• Page Start: 420
• Page End: 428
• Publication Date: 2018-11
• Subjects: Watershed marching algorithm (WMA) algorithm -- Graph theory -- Modified nested set algorithm -- Watershed boundaries; Environmental monitoring -- Computer programs -- Periodicals; Ecology -- Computer simulation -- Periodicals; Digital computer simulation -- Periodicals; Computer software -- Periodicals; Environmental Monitoring -- Periodicals; Computer Simulation -- Periodicals; Environnement -- Surveillance -- Logiciels -- Périodiques; Écologie -- Simulation, Méthodes de -- Périodiques; Simulation par ordinateur -- Périodiques; Logiciels -- Périodiques; Computer software; Digital computer simulation; Ecology -- Computer simulation; Environmental monitoring -- Computer programs; Periodicals; Electronic journals; 363.70015118
• DOI: 10.1016/j.envsoft.2018.08.017
• Languages: English
• ISSNs: 1364-8152

Abstract

Abstract: In this paper we propose an algorithm for retrieving an arbitrary watershed boundary from a 2D Flow Direction Grid. The proposed algorithm and associated data model provides geometric speed increases in watershed boundary retrieval while keeping storage constraints linear in comparison to existing techniques. The algorithm called Watershed Marching Algorithm (WMA) relies on an existing data structure, the modified nested set model, originally described by Celko and applied to hydrodynamic models by Haag and Shokoufandeh in 2017. In contrast to existing algorithms that scale proportionally to the area of the underlying region, the complexity of the WMA algorithm is proportional to the boundary length. Results for a group of tested watersheds ( n = 14, 718) in the ≈ 36, 000 km 2 Delaware River Watershed show a reduction of between 0 and 99% in computational complexity using a 30 m DEM vs. existing techniques.