National-scale geodatabase of catchment characteristics in the Philippines for river management applications

• Published in: PloS one Vol. 18; no. 3; p. e0281933
• Main Authors: Boothroyd, Richard J, Williams, Richard D, Hoey, Trevor B, MacDonell, Craig, Tolentino, Pamela L M, Quick, Laura, Guardian, Esmael L, Reyes, Juan C M O, Sabillo, Cathrine J, Perez, John E G, David, Carlos P C
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 08-03-2023; Public Library of Science (PLoS)
• Subjects: Accuracy; Artificial satellites in remote sensing; Automation; Availability; Basins; Catchment areas; Catchments; Climate change; Computer and Information Sciences; Creeks & streams; Datasets; Digital Elevation Models; Drainage; Drainage density; Earth Sciences; Ecology and Environmental Sciences; Emergency preparedness; Environmental aspects; Floods; Gene mapping; Geological hazards; Geomorphology; Hydrology; Interferometric synthetic aperture radar; Management; Methods; People and Places; Philippines; Protection and preservation; Research and Analysis Methods; River catchments; River management; River systems; Rivers; Sediments; Slopes; Synthetic aperture radar; Topography; Watersheds; Workflow; Philippines
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0281933

Quantitative descriptions of stream network and river catchment characteristics provide valuable context for enabling geomorphologically-informed sustainable river management. For countries where high-quality topographic data are available, there are opportunities to enable open access availability of baseline products from systematic assessment of morphometric and topographic characteristics. In this study, we present a national-scale assessment of fundamental topographic characteristics of Philippine river systems. We applied a consistent workflow using TopoToolbox V2 to delineate stream networks and river catchments using a nationwide digital elevation model (DEM) acquired in 2013 and generated through airborne Interferometric Synthetic Aperture Radar (IfSAR). We assessed morphometric and topographic characteristics for 128 medium- to large-sized catchments (catchment area > 250 km2) and organised the results in a national-scale geodatabase. The dataset realises the potential of topographic data as part of river management applications, by enabling variations in hydromorphology to be characterised and contextualised. The dataset is used to reveal the diversity of stream networks and river catchments in the Philippines. Catchments have a continuum of shapes (Gravelius compactness coefficient ranges from 1.05 to 3.29) with drainage densities that range from 0.65 to 1.23 km/km2. Average catchment slope ranges from 3.1 to 28.1° and average stream slope varies by more than an order of magnitude from 0.004 to 0.107 m/m. Inter-catchment analyses show the distinctive topographic signatures of adjacent river catchments; examples from NW Luzon highlight topographic similarity between catchments whereas examples from Panay Island shown marked topographic differences. These contrasts underline the importance of using place-based analyses for sustainable river management applications. By designing an interactive ArcGIS web-application to display the national-scale geodatabase, we improve data accessibility and enable users to freely access, explore and download the data (https://glasgow-uni.maps.arcgis.com/apps/webappviewer/index.html?id=a88b9ca0919f4400881eab4a26370cee). The national-scale geodatabase provides a baseline understanding of fundamental topographic characteristics in support of varied geomorphological, hydrological and geohazard susceptibility applications.