Journal of Geographical Sciences ›› 2009, Vol. 19 ›› Issue (6): 750-764.doi: 10.1007/s11442-009-0750-4

• Climate and Environmental Change • Previous Articles    

Wet-dry changes in the borderland of Shaanxi, Gansu and Ningxia from 1208 to 1369 based on historical records

DAI Junhu1, GE Quansheng1, XIAO Shufang1,2, WANG Mengmai1,2, WU Wenxiang1, CUI Haiting3   

  1. 1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China|
    2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China|
    3. College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
  • Received:2009-05-08 Revised:2009-07-22 Online:2009-12-25 Published:2009-12-25
  • Supported by:

    National Natural Science Foundation of China, No.40471047; No.40871033; The Knowledge Innovation Program of Chinese Academy of Sciences, No.KZCX2-YW-315

Abstract:

More than 240 items of historical records containing climatic information were retrieved from official historical books, local chronicles, annals and regional meteorological disaster yearbooks. By using moisture index and flood/drought (F/D) index obtained from the above information, the historical climate change, namely wet-dry conditions in borderland of Shaanxi Province, Gansu Province and Ningxia Hui Autonomous Region (BSGN, mainly included Ningxialu, Hezhoulu, Gongchanglu, Fengyuanlu and Yan’anlu in the Yuan Dynasty) was studied. The results showed that the climate of the region was generally dry and the ratio between drought and flood disasters was 85/38 during the period of 1208–1369. According to the frequencies of drought-flood disasters, the whole period could be divided into three phases. (1) 1208–1240: drought dominated the phase with occasional flood disasters. (2) 1240–1320: long-time drought disasters and extreme drought events happened frequently. (3) 1320–1369: drought disasters were less severe when flood and drought disasters happened alternately. Besides, the reconstructed wet-dry change curve revealed obvious transition and periodicity in the Mongol–Yuan Period. The transitions occurred in 1230 and 1325. The wet-dry change revealed 10- and 23-year quasi-periods which were consistent with solar cycles, indicating that solar activity had affected the wet-dry conditions of the study region in the Mongol–Yuan Period. The reconstructed results were consistent with two other study results reconstructed from natural evidences, and were similar to another study results from historical documents. All the above results showed that the climate in BSGN was characterized by long-time dry condition with frequent severe drought disasters during 1258 to 1308. Thus, these aspects of climatic changes might have profound impacts on local vegetation and socio-economic system.

Key words: wet-dry change, borderland of Shaanxi Province, Gansu Province and Ningxia Hui Autonomous Region (BSGN), historical climate, Yuan Dynasty