Abstract

Research on the application of geographic information system (QGIS) to assess seasonal water quality (WQI) changes of Thi Tinh river to provide a database to contribute additional data sources to support the management of surface water resources of Binh Duong province. The results of calculating the WQI (Water Quality Index) from water quality monitoring locations of the Thi Tinh river in the rainy and dry seasons for many years, the study used Quantum Geographic Information Systems (QGIS) to interpolate the WQI results, create maps to compare and evaluate CLN over space and time. Average WQI of the area from bordering Binh Phuoc province, Cam Xe stream, Phu Binh bridge (WQI = 75-97); area from Phu Binh bridge, Cau Quan stream, bridge on Ring Road 4 from (WQI =73-88); area from bridge on Ring Road 4 to Ong Co bridge, location flowing to Saigon River (WQI = 77-92). Water quality on Thi Tinh River in the rainy season is better than water quality in the dry season. Thi Tinh river water quality in 2023 and 2024 is better than in 2022, and water quality in all seasons in 2023 and 2024 tends to be stable and less variable than the same period in 2022. Research to establish a map The surface water quality interpolation map on the Thi Tinh River contributes additional data sources to support the surface water source of Binh Duong province.