Dramatic variations in emergent wetland area in China's largest freshwater lake, Poyang Lake. (October 2016)

• Record Type: Journal Article
• Authors: Mei, Xuefei; Dai, Zhijun; Fagherazzi, Sergio; Chen, Jiyu
• Is Part Of: Advances in water resources. Volume 96(2016)
• Page Start: 1
• Page End: 10
• Publication Date: 2016-10
• Subjects: Variations in lake water level -- Emergent wetland area -- Poyang Lake -- Three Gorges Dam (TGD); Hydrology -- Periodicals; Hydrodynamics -- Periodicals; Hydraulic engineering -- Periodicals; 551.48
• DOI: 10.1016/j.advwatres.2016.06.003
• Languages: English
• ISSNs: 0309-1708

Abstract

Highlights: Strong periodicities and a significant increase in time are detected in EWA. Wetlands dry one month earlier in winter, possibly leading to ecosystem degradation. TGD is responsible for the dramatic variation in Poyang Lake's EWA. Abstract: Freshwater wetlands are important ecosystems experiencing rapid degradation around the world. As much as 64% of world's wetland area has been lost since 1900; the situation is even more serious in Asia, where land reclamation and anthropogenic modifications of rivers are increasing the rate of wetland disappearance. In this study, we provide a first complete estimation of daily Emergent Wetland Area (EWA) in Poyang Lake, China's largest freshwater lake, from 1955 to 2012. A wavelet analysis indicates a strong periodicity in the monthly EWA time series with two oscillations having a period of 12 and 60–72 months, respectively. A dramatic increase in mean annual EWA is detected since 2003, when the Three Gorges Dam (TGD) was completed, mainly due to the seasonal drying of 1078 km 2 of wetlands in October. It is found that the timing of wetland emergence during the dry season has been anticipated of one month, from November to October, since the establishment of TGD. It is argued that a significant increase in wetland exposure and an observable shift in the seasonal timing of flooding and drying will seriously degrade the wetland system and threaten the endangered migratory birds that inhabit it unless effective countermeasures are implemented. Graphical abstract: