A water ecosystem model based on complex dynamics and its application

This paper presents a complex dynamical model to give the evaluation and prediction to water scarcity, which contains four subsystems: population subsystem, agricultural subsystem, industrial subsystem and environment subsystem, that are coupled each other and affected by the inner parameters. Then, the supply water coming from environment subsystem, and the demand water depending on the other three subsystems are evaluated and predicted by Vensim. Correspondingly, we choose the water deficit calculated from the difference between the quantities of supply and demand water to measure the ability of a region to provide clean water. Focusing on the region of the South Africa, where the water is moderately overloaded, we employ the dynamical water ecosystem model to evaluate and predict the water scarcity. It is obtained that there are three main factors that influence water deficit: rainfall, recycle sewage and water demand per capita by parametric sensitivity analysis. Simulation results demonstrate that the year, at which the quantity of supply water can't meet the demand, is delayed by changing the three factors in a positive direction. We expect our work to provide insight into the challenging problem of harnessing the global water scarcity problem.