Study on Holocene Paleoflood in Malian River Basin

Through investigations in the middle and lower reaches of Malian River,Holocene palaeoflood slack-water deposition profile were identified in Heshui County.Samples of the palaeoflood slackwater deposits were collected,and the grain-size distribution and the quartz grain surface texture were examined.All of these index-es showed that the slackwater deposits were typical in the study area.Stratigraphic correlations showed that the slackwater deposits recorded the largest floods occurred between 4200-4000 a B.P.on the river.The flood peak discharges were estimated to be 16780-17200 m3/s by using the slope-area method.Reconstruction of the peak discharge of the 2003 and 2005 floods with the same method and indicators showed that the palaeoflood recon-struction was reliable.These results are important for hydraulic engineering and flood control along the Malian River.