Nghiên cứu tác động của mực nước đến chất lượng nước trong các hệ thống thủy lợi vùng đồng bằng sông Hồng

Abstract

During the spring of 2022, a study was undertaken to investigate the influence of water levels on water quality in seven irrigation systems located in the Red River Delta. The study encompassed three distinct monitoring periods, each corresponding to different water levels. During phase 1 (January 15 to January 22, 2022), the average water level on the main canals exhibited its highest values, ranging from 55.81% to 94.49% of the designated water level. In phase 2 (February 21 to February 28, 2022), the average water level on the channels experienced a decrease compared to phase 1, reaching values between 42.63% and 86.6% of the designated water level. The water level on the main channels exhibited its lowest values during the three monitoring periods encompassing Phase 3 (April 11 to April 18, 2022), with a range spanning from 27.69% to 85.0%. The results of the correlation analysis reveal a positive correlation between the average water level and the Water Quality Index (WQI), with a correlation coefficient (r) ranging from 0.7 to 0.99. This indicates that as the water level increases, there is a corresponding increase in the WQI value, suggesting an improvement in water quality. The water quality index (WQI) is evidently impacted by variations in water level. During the monitoring periods, it was observed that Period 1 exhibited the highest mean average and Water Quality Index (WQI) among the three phases. Conversely, Phase 2 demonstrated a lower average water level and WQI compared to Phase 1. Finally, Phase 3 displayed the lowest average water level and WQI when compared to the other two monitoring periods. Consequently, a significant factor contributing to the escalation of water pollution is the decline in water levels. In conjunction with waste management strategies, it is imperative to implement measures aimed at augmenting water supply to bolster the self-purification capacity and mitigate water pollution within the Red River Delta.