Projections of salt intrusion in a mega-delta under climatic and anthropogenic stressors

• Published in: Communications earth & environment 2021-12, Vol.2 (1), p.1-11, Article 142
• Main Authors: Eslami, Sepehr, Hoekstra, Piet, Minderhoud, Philip S. J., Trung, Nam Nguyen, Hoch, Jannis M., Sutanudjaja, Edwin H., Dung, Do Duc, Tho, Tran Quang, Voepel, Hal E., Woillez, Marie-Noëlle, van der Vegt, Maarten
• Format: Article
• Language: English
• Subjects: Anthropogenic factors; Climate change; Deltas; Drought; Environmental changes; Environmental stress; Fluvial sediments; Groundwater; Human influences; Intrusion; Mathematical models; Natural resources; Numerical models; River beds; Saline water; Saline water intrusion; Salts; Sea level; Sea level rise; Subsidence; Urbanization
• ISSN: 2662-4435; 2662-4435
• DOI: 10.1038/s43247-021-00208-5

Rising temperatures, rapid urbanization and soaring demand for natural resources threaten deltas worldwide and make them vulnerable to rising seas, subsidence, droughts, floods, and salt intrusion. However, climate change projections in deltas often address climate-driven stressors in isolation and disregard parallel anthropogenic processes, leading to insufficient socio-political drive. Here, using a combination of process-based numerical models that integrate both climatic and anthropogenic environmental stressors, we project salt intrusion within the Mekong mega-Delta, in the next three decades. We assess the relative effects of various drivers and show that anthropogenic forces such as groundwater extraction-induced subsidence and riverbed level incisions due to sediment starvation can increase the salinity-affected areas by 10–27% compared to the present-day situation, while future sea level rise adds another 6–19% increase. These projections provide crucial input for adaptation policy development in the Mekong Delta and the methodology inspires future systemic studies of environmental changes in other deltas.