Topographic Position-based Stream definition (TPS): A simple method to address spatial variability of drainage density in stream networks. Issue 6 (26th April 2022)

• Record Type: Journal Article
• Authors: Barbedo, Rafael; Siqueira, Vinícius; Collischonn, Walter
• Is Part Of: Hydrological sciences journal. Volume 67:Issue 6(2022)
• Page Start: 858
• Page End: 869
• Publication Date: 2022-04-26
• Subjects: river network definition -- topographic position index -- variable drainage density -- heterogeneous landscapes; Hydrology -- Periodicals; 551.4805
• DOI: 10.1080/02626667.2022.2047190
• Languages: English
• ISSNs: 0262-6667

Abstract

ABSTRACT: Defining river networks from a digital elevation model (DEM) is a critical step in many hydrological studies. Most methods rely on analyses of flow accumulation based on a single drainage area threshold value. Landscape heterogeneity hinders the definition of drainage pixels by exceeding a threshold. In this study, we propose a method that automatically accounts for variable drainage density in the definition of river networks from relatively coarse DEMs by using the topographic position index (TPI) as an auxiliary variable, therefore calling it the Topographic Position-based Stream definition (TPS). We tested the TPS method with the 90 m resolution MERIT-DEM (Multi-Error-Removed Improved-Terrain DEM) in Brazil, applying it to three river basins with contrasting landforms and climates. The method improved drainage representation in all analysed regions. It successfully represented stream networks with intra-basin variable drainage density by using a single DEM and three parameters, showing potential for hydrological applications at multiple spatial scales.