Integrating Real-Time monitoring and 3D hydrodynamic Modelling to Assess Tidal Impacts on Water Quality in a Mangrove-Influenced Aquaculture Zone in Central Sulawesi, Indonesia

Abstract

Understanding the effect of tidal fluctuations on water quality in estuarine and mangrove-influenced aquaculture zones is essential for healthy and productive pond management. This study investigated how water quality parameters respond to tidal changes in Tanah Mea estuary, Central Sulawesi, Indonesia. A PC-based real-time Water Quality Monitoring System (WQMS) and IoT sensors were deployed in situ to record data, while OpenFlows Flood software was used to simulate spatial distribution patterns of key parameters during the tidal phase. Statistical correlation analysis was employed to quantify the relationship between water level and each measured parameter. The results showed strong inverse correlations between tidal height and both pH and dissolved oxygen, with weaker associations for nitrite, temperature, and salinity, while electric conductivity exhibited minimal correlation with tides. Spatial simulations show gradients of dissolved oxygen and salinity from upstream to open waters, with dilution and oxygenation improving further from the estuary. In conclusion, tidal influence plays a critical role in shaping water quality, and recommends timing pond water intake during or shortly after low tide to optimize dissolved oxygen levels and avoid the buildup of nitrite. This integrated approach provides a replicable model for sustainable aquaculture water management in mangrove estuarine ecosystems.