Mô phỏng diễn biến mặn trong hệ thống thủy lợi Bắc Hưng Hải cho kịch bản lấy nước ngược từ sông Thái Bình

Abstract

This paper presents simulation results of salinity in the Bac Hung Hai irrigation system in response to the scenario of taking water from the Thai Binh river. The time series of water level and salinity measured at Cau Xe and An Tho from 18-12-2020 to 15-01-2021 have been used to evaluate the correlation between salinity and water level using wavelet analysis. Salinity at An Tho has a strong correlation with water level in the duration of 1 hour for low tide and 0,5 hour for high tide, while the above value is about 2 hours at Cau Xe. The advection-dispersion module of the MIKE 11 model has been applied to simulate the salinity in the system for the scenario of taking water from the Thai Binh River through Cau Xe and An Tho with salinity in the above period. The simulation results show that saline in the system can intrude for a distance of up to 24,92 km in the Cuu An River, while the salinity intrusion length is about 18,90 km in the Dinh River. At the confluence between Cau Xe and An Tho and between Dinh Dao and Cuu An, the calculated salinity values ​​are 0,5 and 0,35 PSU, respectively. The influence of the diffusion coefficient on the salt variation in the system was also investigated and discussed