[S-RD24] Cutting-edge sensing technology applied to geology and resource exploration

[SRD24-P02] River Styles in the Agno River Basin in Luzon, Philippines

*Francis Ian Pabillar Gonzalvo¹, Decibel Villarisco Faustino-Eslava¹, Jenielyn Tuando Padrones¹, Juan Miguel Guotana¹, Loucel Cui¹, Eduardo Calzeta¹, Cristino Tiburan, Jr.¹, Tomas Reyes, Jr.¹, Kennethjer Alejo¹, Ylam Shalev Matba¹, Kim Bryan Cabrera¹, Laura Quick², Richard Williams² (1.University of the Philippines Los Banos, 2.University of Glasgow, United Kingdom)

Keywords:River management, Fluvial geomorphology, Philippine tropical catchment, River Styles Framework, Remote sensing

A considerable portion of the rivers in the Philippines remain understudied despite recent advances in remote sensing technology. Whilst information on water quality and flow discharge is given a high priority, fluvial geomorphology is often overlooked. However, interpreting fluvial landscapes can provide insight into past and present sediment dynamics and morphological change, which can be key to informing natural hazards, fluvial biodiversity, and sediment flux management strategies. Project PAMANA or the “Philippine Mining at the National to Catchment Scale: From Legacy Impacts to Sustainable Futures” is a joint project between the Philippines and the United Kingdom that focuses on novel watershed monitoring and management of river systems in mineralized areas in the Philippines. One of the project’s objectives is to baseline survey the features of the Agno Watershed in Luzon, Philippines. This study area is one of the critical watershed areas in the Philippines with little research having been previously conducted about its character and behavior. By using the River Styles Framework, we identified six distinct River Styles in the Agno Watershed, showing considerable geomorphic variations within a relatively small watershed area. Two River Styles are in a confined valley setting, three in a partly confined valley setting, and one in a laterally unconfined valley setting. Identified river styles were validated through ground truthing. Reaches that were inaccessible on the ground were validated by acquiring high-resolution topographic images using a drone and aerial photographs. The recognition of geomorphic river diversity through the analysis of river characterization and behavior has been shown to support more effective watershed monitoring. Furthermore, the continued application of the River Styles Framework will help to better understand how rivers in the Philippines are impacted by mining activities to inform a more sustainable management of mineralized watersheds.