POSTER SESSION 2
10:30–12:30, Tuesday, September 15
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1258 | POSTER 150
BIOGEOCHEMICAL VARIABILITIES OF THE TONLE SAP LAKE: ASSESSING THE IMPACT OF NATURAL AND ANTHROPOGENIC FORCINGS ON THE MEKONG’S CENTRAL HYDROSYSTEM
Tonle Sap Lake, a central component of the Lower Mekong Basin, is Southeast Asia’s largest freshwater body. Its primary productivity relies on a unique flood-pulse system driven by Mekong River inflows, acting as a regulator for downstream delta hydrodynamics and sediment transport. Across this continuum, sediment dynamics are influenced by anthropogenic and natural forcings operating at multiple spatial and temporal scales.
To understand how these forcings impact the Suspended Particulate Matter (SPM) and its organic fraction (Particulate Organic Carbon, Chlorophyll-a), we investigated their 2016–2024 spatio-temporal dynamics using high-resolution Sentinel-2 and Landsat 8-9 images. Missing data were reconstructed using the DINEOF method. A processing chain combining Rotated Empirical Orthogonal Functions (REOF) and temporal decomposition was then applied to extract the major modes of variability, linking distinct regional physical responses directly to their underlying forcings.
Comparing these modes reveals a complex spatial decoupling between the basin’s hydrosystems. Within the Tonle Sap, a strong negative SPM-POC correlation indicates clear variations in particulate matter composition over the hydrological cycle. Analyzing upstream sediment contribution alongside lake dynamics shows contrasting regional behaviors, with varying Chl-a and SPM relationships between the deeper southern basin and the northern flooded plains. These spatial modes clarify the interactions among external forcings, sediment dynamics, and primary production, providing necessary data to predict the lake’s trajectory and its buffering capacity for the Mekong Delta.
Julien Masson*, Laboratoire d’Océanologie et de Géosciences (LOG), [email protected], https://orcid.org/0009-0001-0028-7318
Charles Verpoorter, Laboratoire d’Océanologie et de Géosciences (LOG), [email protected], https://orcid.org/0000-0002-5134-4124
Cédric Jamet, Laboratoire d’Océanologie et de Géosciences (LOG), [email protected], https://orcid.org/0000-0001-6988-6506
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
