Opposing industrial era moisture patterns between basins and mountains in southern arid Central Asia

Abstract

Investigations of the evolution of naturally and anthropogenically driven hydrology in arid regions are of great significance for hydrological forecasts. Here, we built the past ∼500-year history of lake area and discharge of Lake Tuosu in the northeastern Qaidam Basin. We found that the lake area and inflow variations were sensitive to westerly-forced winter-spring precipitation and showed long-term decreasing trends after 1850. Enhanced local human activities (e.g., agricultural irrigation) led to further rapid shrinkage of Lake Tuosu during 1990–2000, and the lake size reached its minimum in the past 500 years in approximately 2000. Our integrated moisture indices for mountains and basins in southern arid Central Asia showed opposing trends, and the humidity gradient from mountains to basins successively increased after 1850, which may be linked to the migration of the boreal westerlies, global warming, and human activities. After 1950, the humidity increased further, reaching its maximum value in approximately 2000, which likely resulted from the excessive utilization of water resources from anthropogenic activities. Therefore, the mountain-river-basin hydrological system in arid Central Asia has changed significantly, beyond the natural variation pattern, after CE 1950. Therefore, integrated management and rational utilization of water resources are important for ecological protection and sustainable development in the future.