ASSESSMENT OF THE ENVIRONMENTAL CARRYING CAPACITY OF HON CAU MARINE PROTECTED AREA

Abstract

This study focuses on assessing the water load carrying capacity of the Hon Cau Marine Protected Area (MPA) and forecasting for 2030 the operating capacity and wastewater treatment efficiency of the thermal power plant Vinh Tan electricity before being discharged into the environment and growing socio-economic activities such as aquaculture, seafood processing, animal husbandry, sightseeing activities, festivals, and daily activities from residential areas. The authors have applied the hydrodynamic model (MIKE21/3 HD) to determine the flow field and water column depth field and incorporated the ecological module (MIKE Ecolab) to calculate water quality for coastal estuarine areas under human and environmental impacts. Hon Cau MPA area currently has an alarming water load capacity and is identified as decreasing by 2030, according to the pollutant transmission simulation. The results predicted the BOD concentration at Vinh Tan bay in the rainy season fluctuates between 2 - 135 mg/L and 2 - 150 mg/L in the dry season; DO concentration in the rainy season is below 5.6 mg/L, in the dry season: 6.5 mg/L; NH4 concentration in the rainy season is 12 mg/L, in the dry season: 15 mg/L, especially around the Hon Cau area, it fluctuates between 2 and 5 mg/L in two seasons, 20 times higher than the allowable limit with the water environment in aquaculture and aquatic conservation areas according to QCVN10-MT:2015/BTNMT; NO3 concentration fluctuates from 2 - 3 mg/L in two seasons; PO4 concentration ranges from 1.5 - 15 mg/L, up to 15 mg/L in the Ca Na beach area, in the dry season at 1.5 -1 6.5 mg/L. The assessment of Hon Cau MPA's water load carrying capacity will contribute to environmental protection and control of pollution sources, ensuring the quality of water sources for socio-economic development goals.