The Decrease in Lake Numbers and Areas in Central Asia Investigated Using a Landsat-Derived Water Dataset

Abstract

: Although Central Asia has a strong continental climate with a constant moisture deficit and low relative humidity, it is covered by thousands of lakes that are critical to the sustainability of ecosystems and human welfare in the region. Vulnerability to climate change and anthropogenic activities have contributed to dramatic inter-annual and seasonal changes of the lakes. In this study, we explored the high spatio–temporal dynamics of the lakes of Central Asia using the terraPulse™ monthly Landsat-derived surface water extent dataset from 2000 to 2015 and the HydroLAKES dataset. The results identified 9493 lakes and significant linear decreasing trends were identified for both the number (rate: −85 lakes/year, R2:0.69) and area (rate: −1314.1 km2/year, R2: 0.84) of the lakes in Central Asia between 2000 and 2015. The decrease rate in lake area accounted for 1.41% of the total lake area. About 75% of the investigated lakes (7142 lakes), mainly located in the Kazakh steppe (especially in the north) and the Badghyz and Karabil semi-desert terrestrial ecological zones, experienced a decrease in the water area. Lakes with increasing water area were mainly distributed in the Northern Tibetan Plateau–Kunlun Mountains alpine desert and Qaidam Basin semi-desert zones in the east-south corner of Central Asia. The possible driving factors of lake decreases in Central Asia were explored for the Aral Sea and Tengiz Lake on yearly and monthly time scales. The Aral Sea showed the greatest decrease in the summer months because of increased evaporation and massive irrigation, while the largest decrease for Tengiz Lake was observed in early spring and was linked to decreasing snowmelt.

Hydrological Evolution of a Lake Recharged by Groundwater in the Badain Jaran Desert Over the Past 140 years

“…Arid zones are more sensitive than other areas to temperature changes during global climate change, especially desert areas (Chen et al, 2015;Huang et al, 2016;Liang et al, 2020). Remote sensing data show that the lake areas in the BJD and central Asia have decreased in recent decades (Zhang et al, 2013;Che et al, 2021). With ongoing global warming, our results suggest that lakes in arid areas, especially in desert areas, will become increasingly salty, and this issue should have been addressed earlier.…”

“…Furthermore, dry basins or shrinking lakes in the geological period also occurred under the high temperature and precipitation climate in the northeastern Tibetan Plateau and Hexi Corridor (Liu et al, 2013;Wang et al, 2014;Wu et al, 2020). Therefore, for other areas of the world, although there are differences in the timing of temperature increases, they all lead to droughts and extreme events (Hegerl et al, 2018;Neukom et al, 2019;Woolway et al, 2020;Che et al, 2021).…”

Phenological changes and driving forces of lake ice in Central Asia from 2002 to 2020

“…The increasing of evaporation of land surface which decreases the lake surface area in the low elevation and plain regions, while the melting of glaciers leads to the formation of new lakes in the high elevation regions [4]. In the past few decades, a widespread water loss occured in the global endorheric system [5] and total lake area in Central Asia exhibited a decreased trend [6][7][8]. Previous study have shown that nine lakes in the Central Asia lost their area about 45,352 km 2 , which accounts for approximately 49.62% of their total surface area [6] and the number of lake decreased from 7309 in 2000 to 6585 in 2015, with a decline rate of 85 lakes per year [7].…”

“…In the past few decades, a widespread water loss occured in the global endorheric system [5] and total lake area in Central Asia exhibited a decreased trend [6][7][8]. Previous study have shown that nine lakes in the Central Asia lost their area about 45,352 km 2 , which accounts for approximately 49.62% of their total surface area [6] and the number of lake decreased from 7309 in 2000 to 6585 in 2015, with a decline rate of 85 lakes per year [7]. Hence, global climate change greatly affects the evolution of lakes.…”

Comparison of Typical Alpine Lake Surface Elevation Variations and Different Driving Forces by Remote Sensing Altimetry Method

“…As an important part of the global hydrological and biogeochemical water cycle, lakes play an important role in runoff regulation, water recharge, and the ecological balance of watersheds [ 1 , 2 , 3 ]. Their formation and disappearance, expansion and contraction, and evolution of the surrounding ecosystem are the results of complex interactions of global, regional, and local tectonic and climatic events [ 4 ].…”