| Based on the detailed investigation in the Gaoling part of the Weihe River and the grain size analysis of 110 samples and the chronology material recorded by the historical book,the flood depth,the flood scale,the relations between flood and the climate change for nearly 120 years have been studied.According to the analysis some conclusions have been summarized as follows: The thickness of high mausoleum alluvial flat deposit of the Weihe River is approximately 4.0m in the past 120 years.The size ingredients mainly include the thick silt and the silver sand and the thin sand.The average content of the thick silt,the silver sand and the thin sand is 31.79%,23.55% and 19.63% respectively.The contents of colloid granularity,the clay granularity,the thin silt,the middle sand and the coarse sand are all small,but each content has obvious difference.There is an obvious variety rhythm of granularity along with the depth.The profile include 16 obvious deposit formations and it represents 16 deposition stages and instructs 16 obvious big flood processes,in which the 6th、9th、12th、15th、16th、1st are the catastrophic flood,the 5th、14th、7th、11th、3rd、13th、8th、10th、4th、2nd are the big flood stages,these flood stages have reflected the climate and precipitation change during the deposition time. |