Progress in Research on Hydrological Hysteresis in Lake Flood Plain
Lake flood plain boasts of complicated hydrologic process. Hysteresis shown in the rise and regression of water level is one of the characteristics of hydrological nonlinearity. Zhang Qi and his colleagues, making Poyang Lake as the target and using the physical mechanism-based distributed hydrological model, launched a research on hydrological hysteresis shown in lake flood plain. They have found that the relation between lake surface area, lake storage and lake level shows a distinct characteristic of clockwise hysteresis(except for some parts in extreme south of the lake where shows a counterclockwise hysteresis); the degree of nonlinearity is mainly dependant on the river runoff process, and secondarily the water level of Yangtze River; characteristics of the floodplain wetland plans exerts a distinguishing influence on the degree of nonlinearity, such that increase of the plants’ density will enhance the nonlinearity of hysteresis. The research finding of this paper is significant to make a deep knowledge of the basic hydrological law of lake flood-plain system, and it is a first research ever to quantitatively differentiate the degrees of hysteresis nonlinearity in flood plain and permanent water. The research finding has been carried on Journal of Hydrology.(http://dx.doi.org/10.1016/j.jhydrol.2015.04.068)。