The water carrying capacity and the water carrying state are two similar
concepts, and there are no clear boundaries between them, so there exists
confusion during the evaluation process. Additionally, current evaluation
methods cannot meet the dynamic change requirements under different control
measures. This study emphasizes the difference between the two concepts and
points out that the core of the water carrying capacity is the determination
of thresholds. In contrast, that of the water carrying state is a state
evaluation. A coupled iterative model is proposed based on the extended
Fourier amplitude sensitivity test algorithm and a modified state-space
method. In order to evaluate and regulate the water carrying state
dynamically, the iterative calculation is introduced into the evaluation of
the water carrying state. During the iterative process, the water resources
in the non-overloaded area are allocated to the surrounding adjacent
overloaded areas until the water resource carrying state of the original
over-loaded area reaches an acceptable level, and the total amount of water
resources allocation during multiple iterations is given. In this study, we
take Jilin Province as the research object. We hope that the iterative
coupling model of the water carrying state proposed in this paper can be
widely applied in the future.