Linking watershed and eutrophication modelling for the Shihmen Reservoir, Taiwan

Area of Science:

• Environmental science
• Hydrology
• Water quality modeling

Background:

• The Shihmen Reservoir in northern Taiwan faces significant pollution challenges.
• Anthropogenic activities in the watershed contribute to the degradation of water quality.

Purpose of the Study:

• To simulate and analyze nutrient loads from the Shihmen Reservoir watershed.
• To predict water quality within the reservoir using a coupled modeling approach.

Main Methods:

• Employed the BASINS (Better Assessment Science Integrating point and Nonpoint Sources) model to simulate watershed hydrology and nutrient loads.
• Utilized the CE-QUAL-W2 model, driven by BASINS outputs, for water quality predictions.
• Calibrated and verified models using field data including water surface elevation, temperature, dissolved oxygen, nutrients, and chlorophyll a.

Main Results:

• Watershed modeling identified substantial nutrient loads generated during storm events.
• The eutrophication model successfully simulated and predicted key water quality parameters within the reservoir.

Conclusions:

• The study demonstrates the effectiveness of integrated watershed and water quality models for assessing reservoir pollution.
• Findings highlight the impact of watershed management on reservoir water quality, particularly during storm events.