Acta Geographica Sinica ›› 2015, Vol. 70 ›› Issue (7): 1165-1176.doi: 10.11821/dlxb201507012

• Hydrology • Previous Articles     Next Articles

Hydrological reconstruction of Holocene palaeofloods and historical floods in the Longmen Gorge of the Yihe River

Guiming HU(), Chunchang HUANG(), Yali ZHOU, Jiangli PANG, Xiaochun ZHA, Yongqiang GUO, Yuzhu ZHANG, Xueru ZHAO   

  1. College of Tourism and Environmental Sciences, Shaanxi Normal University, Xi'an 710062, China
  • Received:2015-04-08 Revised:2015-05-18 Online:2015-07-20 Published:2015-08-11
  • Supported by:
    National Natural Science Foundation of China, No.41471071

Abstract:

In this study, palaeoflood hydrological and sedimentary investigations were carried out in the Yiluohe River basin. Typical loess-soil stratigraphy of the Holocene period was identified at the Longmenxia (LMX) site in the Yihe River basin. Based on the analysis of sedimentary characteristics, magnetic susceptibility and particle-size distribution, the five flood slackwater deposits were identified and interbedded into the loess-soil stratigraphy. By the stratigraphic correlation and the optically stimulated luminescence method (OSL), the four episodes of flooding events occurred at 3100-3000 a BP, 1800-1700 a BP, 770-610 a BP and 420-340 a BP, respectively, namely at the end of the mid-Holocene Climatic Optimum and the beginning of the late Holocene, the dynasties of Eastern Han to Western Jin, Song-Yuan and the Ming-Qing, respectively. These flooding events might include the AD223 and 1761 flooding events and they well corresponded to the phase of the Holocene monsoonal shift, climatic abrupt change and climatic decline. The flooding peak stages were estimated with the elevations and the depositional depths of the SWD. According to the flood peak stages and hydraulic parameters, the peak discharges were reconstructed at 14100-15800 m3/s with the slope-area method. The reconstructed peak discharges of the flooding events are much more than those of the gauged modern floods at the Longmenxia gauge station in the middle reach of the Yihe River.

Key words: palaeoflood, slackwater deposits, Yiluohe River, Holocene