The world\u2019s earliest Aral-Sea type disaster: the decline of the Loulan Kingdom in the Tarim Basin

Steffen Mischke,Pengcheng Jiao,Hua Zhang,Chenglin Liu,Chengjun Zhang,Jiafu Zhang,Birgit Plessen

doi:10.1038/srep43102

Abstract

Remnants of cities and farmlands in China’s hyperarid Tarim Basin indicate that environmental conditions were significantly wetter two millennia ago in a region which is barren desert today. Historical documents and age data of organic remains show that the Loulan Kingdom flourished during the Han Dynasty (206 BCE–220 CE) but was abandoned between its end and 645 CE. Previous archaeological, geomorphological and geological studies suggest that deteriorating climate conditions led to the abandonment of the ancient desert cities. Based on analyses of lake sediments from Lop Nur in the eastern Tarim Basin and a review of published records, we show that the Loulan Kingdom decline resulted from a man-made environmental disaster comparable to the recent Aral Sea crisis rather than from changing climate. Lop Nur and other lakes within the Han Dynasty realm experienced rapidly declining water levels or even desiccation whilst lakes in adjacent regions recorded rising levels and relatively wet conditions during the time of the Loulan Kingdom decline. Water withdrawal for irrigation farming in the middle reaches of rivers likely caused water shortage downstream and eventually the widespread deterioration of desert oases a long time before man initiated the Aral Sea disaster in the 1960s.

Highlights

The Tarim Basin (Xinjiang Province) in northwestern China hosts the Taklamakan Sand Sea, the second largest sand desert of the world
The extensive transformation of alluvial fans and plains to irrigated fields in the Tarim Basin and Hexi Corridor supported the migration of people from the previous mainland of the Chinese Empire during the Han Dynasty but led to intensive trade along the Silk Road two millennia ago[1,2,5,6,7,12]
We investigated the sediments of Lop Nur and compared the results with palaeoclimate records from other lakes in the region to examine whether climate change triggered the deterioration of the flourishing desert oases suggested as result of previous studies[1,2,5,6,7,9]

Summary

Introduction

The Tarim Basin (Xinjiang Province) in northwestern China hosts the Taklamakan Sand Sea, the second largest sand desert of the world. Earlier in the stable isotope record, the lowest δ18O values 8500 years ago indicate the wettest conditions in the Lop Nur region.

Results

Conclusion