10. Using the WQI index to assess water quality in Quy Nhon city from 2015 to 2020
Abstract
Based on surface water monitoring data in Quy Nhon city, the study uses the WQI method to calculate pH, DO, BOD5, COD, N-NH4, N-NO3, P-PO4 and total Coliform at 14 sampling locations. The results showed that the WQI composite index was widely fluctuated (25 - 99) from 2015 to 2020. The WQI value varies according to the Ha Thanh river basin, gradually decreasing towards the estuary and then increasing gradually towards the Thi Nai lagoon; in which, at some point, the WQI level was "poor", corresponding to the orange water quality level. In the lakes, the majority of sampling sites had an increased WQI, indicating improved water quality over time. The findings also showed that the surface water quality in Quy Nhon city can be used for a variety of purposes. Upstream water quality is suitable for domestic use but requires appropriate treatment measures. Water quality in the other areas is suitable for cultivation and aquaculture activities.
