VNU Journal of Science Earth and Environmental Sciences, Vol 37, No 4 (2021) 61 69 61 Original Article Evaluation of Processes Affecting the Variation of Groundwater Quality in Quang Nam, Da Nang, Vietnam Phan Nam Long*, Nguyen Thi Ngoc Anh, Bui The Vinh, Can Thu Van, Nguyen Thu Thao, Huynh Thi Thu Thuy Ho Chi Minh City University of Natural Resources and Environment, 236B Le Van Sy, Ho Chi Minh City, Vietnam Received 16 September 2020 Revised 25 Janurary 2021; Accepted 29 Janurary 2021 Abstract[.]