Assessing and selecting interventions for river water quality improvement within the context of population growth and urbanization: a case study of the Cau River basin in Vietnam

• Published in: Environment, development and sustainability development and sustainability, 2017-10, Vol.19 (5), p.1701-1729
• Main Authors: Ha, Pham Thi Thu, Kokutse, Nomessi, Duchesne, Sophie, Villeneuve, Jean-Pierre, Bélanger, Alain, Hien, Ha Ngoc, Toumbou, Babacar, Bach, Duong Ngoc
• Format: Article
• Language: English
• Subjects: Computer simulation; Cost benefit analysis; Decision makers; Domestic wastewater; Earth and Environmental Science; Ecology; Economic development; Economic Geology; Economic Growth; Environment; Environmental Economics; Environmental Management; Experts; Intervention; Local government; Methodology; Multiple criterion; Population growth; Quality control; Quality improvement; Quality management; Research methodology; River basin management; River basins; Rivers; Simulation; Socioeconomic development; Socioeconomic factors; Surface water; Sustainable Development; Urbanization; Wastewater; Wastewater treatment; Wastewater treatment plants; Water management; Water quality; Water treatment
• ISSN: 1387-585X; 1573-2975
• DOI: 10.1007/s10668-016-9822-7

In this study, a multi-criteria methodology is proposed to identify and prioritize interventions for water quality improvement with the aid of computer simulation models. The methodology can be used to elaborate and compare future socio-economic development scenarios to select the best interventions based on three criteria: (1) ideas of experts and stakeholders about the importance of scenarios, (2) impacts of each scenario on surface water quality in watershed, and (3) benefit–cost analysis for each scenario. A score is computed for each scenario based on a weighted sum technique which enables to take into consideration different level of importance for the three criteria. The methodology is applied to Cau River basin in Vietnam, with the aid of a computer tool, to assess interventions for river water quality improvement within the context of population growth and urbanization. The results show that fast future population growth in upstream has significant impacts. In 2020, an increase of 116 % of the population in Bac Kan town can lead to an increase of 120 and 135 % in BOD 5 and NH 4 + median concentrations, respectively, with the implementation of a treatment plant for 10,000 people in Bac Kan town. Therefore, the increase of the domestic wastewater treatment plant’s capacity in Bac Kan town, at least twice as the projection of local government, is necessary. These results will help decision makers to select the best interventions for Cau River basin management.