Drought/Flood change in the Guanzhong region between the 8th and the 13th Century

The Drought/Flood change sequence between the 8^th and the 13^th century in the Guanzhong region was reconstructed based on analyzing historical literature records and using the “Evaluation Method of Drought/Flood Grade”. The results indicated that Drought/Flood change in the Guanzhong region over this period was fluctuant, with the mid-10^th century as the turning point where there was a gradual shift from flood to drought. The climate in the Guanzhong region in the studied 600a can be divided into the following three stages: between 700-856 AD, the precipitation was rich and the area was wet; the climate during the period between 857-922 AD was relatively stable; after 922 AD, the climate continued to be dry with very little precipitation and the recorded number of drought was far more than the recorded number of flood. In addition, Drought/Flood change in the Guanzhong region was seasonal with the main occurrence of the Drought/Flood in summer and autumn.