Abstract
Water level fluctuation (WLF) in shallow lakes in the middle and lower reaches of the Yangtze River has been a concern of many researchers. This work aims to investigate the effects of climate change and regulation of floodgates and the Three Gorges Dam (TGD) on WLF and lake volume in Huayang Lakes during the past 52 years. The results revealed that precipitation is the dominant factor that leads to seasonal variation of lake levels, whereas regulation of floodgates and TGD are the key drivers of hydrology regime change in the past 20 years. Natural lake regime has higher water level when there is more precipitation and less lake volume. Floodgates and TGD regulations have changed this pattern since 2003, causing less difference in water level in spite of more precipitation and lake recession. Under the combined impacts of floodgates and TGD regulations, Huayang Lakes have experienced a prolonged outflow time since 2003 and the contribution rate caused by the floodgates and TGD regulations has increased by 19.90%. Additionally, the water level of Huayang Lakes decreased by approximately 0.3~0.5 m from September to November, but it showed no alteration from January to March in the past two decades. This indicated that floodgate regulations used for agricultural irrigation and fishery culture dominate the hydrology regime in winter and early spring. This study is beneficial for aquatic ecosystem protection in floodgate-controlled lakes under the circumstance of climate change and vigorous anthropology activities.
Highlights
Lakes are essential to ecosystems at regional scales related to water resources, utilization of water resources, and communities of plants and animals in the wetland [1]
Despite many efforts to analyze the causes of water level variation in natural lakes interrelated and interacted with the Yangtze River, most studies focused on the influence of Three Gorges Dam (TGD) regulation, reclamation and climate change on Poyang Lake and Dongting Lake, while few of them paid close attention to floodgate-controlled shallow lakes, which take up 60% of the total lake area in the middle and lower reaches of Yangtze River area in China [3]
Water level fluctuation (WLF) in lakes is very sensitive to floodgate operation
Summary
Lakes are essential to ecosystems at regional scales related to water resources, utilization of water resources, and communities of plants and animals in the wetland [1]. Some researchers pointed out that TGD regulation is the core factor leading to water level decline in September and October every year in natural lakes since 2003 [4,5,6]. Some research revealed that TGD impoundment weakened the river forcing on the natural lake and reduced the water level of Poyang Lake in autumn under similar precipitation conditions [8]. Despite many efforts to analyze the causes of water level variation in natural lakes interrelated and interacted with the Yangtze River, most studies focused on the influence of TGD regulation, reclamation and climate change on Poyang Lake and Dongting Lake, while few of them paid close attention to floodgate-controlled shallow lakes, which take up 60% of the total lake area in the middle and lower reaches of Yangtze River area in China [3].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
