Integrated simulation and assessment of water quantity and quality for a river under changing environmental conditions

The water cycle and water resources within river basins under changing environmental conditions undergo profound changes, which have significant effects on the water environment of the river. Owing to the water resources demanded for economic and social development, water quantity and quality are becoming the core constraints of water resources development and utilization. In this paper, the dual attributes of water resources, progress into research regarding water quantity and quality joint assessment and simulation and the shortcomings associated with these techniques are summarized and described with respect to water quantity and quality. The results indicated that under the current environmental conditions, the method used for traditional water quality assessment of single water bodies cannot meet the requirements for water resources management. Moreover, a coupled hydrodynamic and water quality numerical model for river networks and lakes that applies to the river water environment system was developed for the river network flow and pollutant migration and transformation process and validated. This validation revealed that the error between the simulated values calculated by the model and the monitored values was small, meeting the application requirements and realizing the integrated and dynamic simulation of water quantity and quality of the river water environmental system. On this basis, the integrated simulation model was applied to the Luanhe River Basin.