作者: Li, Yunliang; Zhang, Qi; Tan, Zhiqiang; 等

The present study uses a 2D floodplain hydrodynamic model in combination with hypothetical scenarios to investigate the coupled effects (or maximum contribution) of floodplain vegetation on the hydrodynamic behaviors of Poyang Lake (China), a flood-pulse-influenced river-lake system. Model simulations reveal that the influences of the floodplain vegetation on lake water levels, flow velocities and outflow discharges were stronger during the rising and receding water phases than during the flooding phase, indicating the interactions between vegetation and hydrology that vary with the floodplain seasonally. The addition of floodplain vegetation affects conveyance efficiency of the system, decreasing flow velocities by 0.2 m/s, increasing water levels by 0.3 m and associated storage volume of the lake by up to similar to 5%. The distributed effect of floodplain vegetation on the flow velocities shows more complex and sensitive responses than the water levels across the lake-floodplains, demonstrating a strong linkage between the vegetation structure of the floodplain and the velocity distribution. Sensitivity analysis indicates that the transition between different vegetation cover types cannot produce significant influences on the hydrodynamic behaviors, relative to the coupled effects of floodplain vegetation. This study provides important knowledge regarding the role of floodplain vegetation changes to decision-makers for both Poyang Lake and other similar flood pulse systems, given proposals to cope with the flood risk and the accelerating pace of human interventions.

JOURNAL OF HYDROLOGY   卷:  585     文献号: 124852   出版年:  2020