A STUDY OF THE IMPACT OF WETLANDS ON REGIONAL WATER CYCLE: THE QINGDIANWA WETLAND EXAMPLE

摘要

Wetlands are an important component of the global eco-environment and play a significant role in runoff regulation and flood control within the global water cycle. In this paper, the impact of two types of wetland (riverine and rapirian-zone wetlands) on the hydrological cycle was discussed and a new method of assessing the impact proposed. The distributed hydrological model (SWAT) is modified, and applied to simulate the Qingdianwa depression wetland over a 25-year period. A scenario analysis of different restoration areas, ranging from 30 to 150 km~2, was performed. Results showed that natural unregulated wetlands are not effective in mitigating floods, especially during wet years. When comparing the effectiveness of riverine and rapirian-zone wetlands in the runoff regulation, riverine wetlands were clearly much more effective and able to reduce the annual average flow to 7.4 million m~3, i.e. a reduction of 30%. However, it must be noted that both kinds of wetland are important in flood control, river flow regulation, groundwater recharge, and flood reclamation.