Changes in Water Level Regimes in China’s Two Largest Freshwater Lakes: Characterization and Implication

Abstract

The complex water regimes and fragile ecological systems in Dongting Lake and Poyang Lake, located in the middle reach of the Yangtze River, have been significantly affected by regional climate change and anthropogenic activities. The hydrological data from the outlets of Dongting Lake (Chenglingji station) during 1955–2016 and Poyang Lake (Hukou station) during 1953–2014 were divided into two periods: the pre-impact period and the post-impact period. Four statistical tests were used to identify the change years: 1979 at Chenglingji and 2003 at Hukou. The indicators of hydrologic alteration and range of variability approach were used to assess alterations in water level regimes. Results show that the severely altered indicators were January water level at both lake outlets, and 1-, 3-, 7- and 30-day minimum water level at Chenglingji, with the degree of hydrological alteration being larger than 85%. The overall degrees of hydrological alteration at Chenglingji and Hukou were 52.6% and 38.2%, respectively, indicating that water level regimes experienced moderate alteration and low alteration or that ecosystems were at moderate risk and low risk, respectively. Changes in water level regimes were jointly affected by climate change and anthropogenic activities. Water level regimes at Dongting Lake outlet were mainly affected by increased rainfall and dam regulation. Decreased rainfall, dam regulation, and sediment erosion and deposition were the main impact factors of water level regimes at Poyang Lake outlet. These changes in water level regimes have greatly influenced both aquatic and terrestrial ecosystems, especially for fish and vegetation communities. This study is beneficial for water resource management and ecosystems protection under regional changes.

Water Level Fluctuation under the Impact of Lake Regulation and Ecological Implication in Huayang Lakes, China

“…There has been a long-time and heated controversy over the influencing factors of water level variation and its complication in lakes. For example, water level in natural lakes (e.g., Poyang Lake and Dongting Lake) declined in the autumn over the past 20 years [3][4][5][6][7]. 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].…”

Quantitative assessment of hydrological alteration over multiple periods caused by human activities at the Jingjiang Three Outlets, China

“…Additionally, the hydrological indicators of IHA and their features are listed in Table 1. Their impacts on the ecosystem are very common and can be found in Ma et al (2014), Cheng et al (2019).…”

“…The RVA uses 33 hydrological indicators to assess the hydrological alteration, which are divided into five groups addressing the magnitude, timing, frequency, duration, and rate of change (Yang et al 2008). The RVA method has been widely used in assessing changes in the hydrological regimes of global rivers and lakes (Galat & Lipkin 2000;Magilligan & Nislow 2004;Cheng et al 2019). To be specific, Papadaki et al (2015) highlighted that climate change would reduce the summer flow in mountain rivers in the southwestern Balkans with the RVA method and have potential impacts on typical biota habitats.…”

Spatiotemporal Variation of Siberian Crane Habitats and the Response to Water Level in Poyang Lake Wetland, China

“…Meanwhile, a variety of quantitative techniques have evaluated migratory bird habitats, such as the vulnerability index [43], habitat efficiency index [44], Geographic Information System (GIS) and remote sensing (RS) technologies [45,46], and fuzzy comprehensive evaluation [47]. More recent studies have focused on the impact assessment of human activities on migratory bird habitats, such as fisheries [48][49][50], dredging [51], and water conservation projects [52][53][54].…”