Lake Changes during the Past Five Decades in Central East Asia: Links with Climate Change and Climate Future Forecasting

Abstract

As one of the most important reservoirs of water in arid regions, lakes experience a series of complicated changes. However, the natural driving mechanisms behind such changes remain unclear. In this study, we collected data from 1333 lakes in the arid region of Central East Asia (CEA) to investigate the underlying natural causes of lake changes over the past five decades. The lakes were located within three different geomorphological zones: (I) Tibetan Plateau zone; (II) high mountain—basin zone; and (III) low mountain zone. Our results show that lakes as a whole in CEA exhibit a unique change trend, with an overall lake area increase of 7099 km2 (41%) and with heterogeneous spatial variations over the past five decades. The lake area increase was 6236 km2 (47%), 935 km2 (31%) and decrease was 72 km2 (~1%) in zones I, II, and III, respectively. The different geomorphological zones have influencing factors. In zones I and II, increased precipitation (including cloud water) and temperature rise (causing glacier, frozen soil, and snow melt) contributed to approximately 66% of the change in lake area; in zone III, changes in precipitation contributed to approximately 87% of the lake changes. Increased atmospheric circulation of water vapor caused by warming of the ocean surface appears to be the main driving factor of these changes; this is supported by future projection scenarios. From 2006 to 2098, temperature and precipitation will increase by 4.0–7.8 °C and 1.07 to 1.29 mm per day, respectively, under both the RCP4.5 and RCP8.5 scenarios. Notably, although the climate appears to have become more optimum for lakes in CEA at the interdecadal timescale, short timescale climatic events such as lake expansion will bring more extreme climate events, such as extreme high-temperature heat waves, which should be considered as a potential threat to lake ecology in the future.

Spatiotemporal Changes of Ecosystem Service Values in Response to Land Cover Dynamics in China from 1992 to 2020

“…The grassland area exhibited a large-scale decrease in the southeastern half of China due to the significant increase of either croplands or forelands, while the grassland area in the arid/semi-arid regions in northwestern China (such as Gansu, central Inner Mongolia, southwestern Tibet, northern Qinghai) increased significantly due to joint effects of the Grain to Green Program and the climate wetting and warming in those areas [49]. While the overall change in the area of water was not significant, there was a significant change in some local areas, such as the Qinghai-Tibet Plateau due to the increase in glacial meltwater and precipitation caused by global warming [50], while the area of water in the southeast has decreased significantly, mainly due to human activities, such as the large amount of irrigation diversions and the construction of upstream reservoirs, which have led to a decrease in the downstream water supply. There was a large and highly significant increase in the area of built-up land in the southeastern half of China (from Heilongjiang to Yunnan) where the economy developed very fast and the population density is very high, whereas the northwestern half experienced little increase in built-up lands except for scattered locations.…”

Exploring the Relationship between Hydroclimate and Lake Area in Source Area of the Yellow River: Implications for the Paleoclimate Studies

“…The warmer temperatures have caused melting glaciers and thawing permafrost, which have in turn increased the flow of water into the lake. This increase in water volume has caused the lake area to expand [12,13]. A major consequence of human activity is global warming, which is caused by overusing fossil fuels.…”

“…By using the remote sensing Landsat images, the area of lakes in the arid region of central east Asia has increased by 41% over the past five decades. Increased precipitation and temperature rise are the main driving factors of lake changes in central east Asia [13]. In addition to the changes in lake level, water volume, and water quantity, changes in lake water quality are also a major concern.…”