Evolution of lake water volume in global closed basins since the Last Glacial Maximum and its implication for future projection

摘要

Mostly concurring with arid and semi-arid regions, closed basins are faced with water scarcity, prominent imbalance between water resource supply and demand, and ecological degradation. Spatial-temporal patterns of water resource change in closed basins have received increasing attention in recent years, but it is still unclear whether there is a connection between the present patterns and those under the millennial-scale natural state. According to lake records, lake models and paleoclimate simulations, we provided a preliminary impression of water volume changes in the long history of different closed basins, which clarified the linkages and differences between the past and present water volume changes. We also evaluated possible water volume changes in the near future. We found that there has been a declining trend of water volume in closed basins of mid-latitude since the Last Glacial Maximum in general, whereas there has been a rising trend of water volume in closed basins of low-latitude over the same period. Over the last few decades, the declining trend of water storage in Western North America, Sahara and Arabia and Central Eurasia possibly has inherited the decreased water volume conditions across the millennial-scale under the natural state, while the increasing water storage in Great Rift Valley and Southern Africa and the decreasing water storage in Dry Andes and Patagonia may be temporary. The assessment of near future water volume changes from a paleoclimatological perspective indicates that the water volume in parts of Western North America, northern Dry Andes, northern Sahara, and southwestern Central Eurasia will continue to decline, while in parts of southern Sahara, southern Great Rift Valley, southeastern Central Eurasia, and eastern Australia it will continue to rise.