Palaeoflood floor series reconstruction method based on river mountain pass alluvial-proluvial fan rock stratum structure

Abstract

The invention relates to the palaeoflood hydrology research field and provides a palaeoflood floor series reconstruction method based on a river mountain pass alluvial-proluvial fan rock stratum structure. Several longitudinal sections are arranged in the water flow direction on a river mountain pass alluvial-proluvial fan where the palaeoflood floor series is about to reconstructed, geological prospecting drilled holes are arranged at certain intervals for geological prospecting, and according to obtained geological prospecting data, the rock stratum structure sectional drawings of all the sections are drawn; according to the rock stratum structure sectional drawings, a point location including all the rock stratums is selected on the forefront edge of each section; drilled holes are arranged in the selected point locations for geological prospecting, the lithology is obtained, and the maximum rock particle of each rock stratum is analyzed; a hydrodynamic model is established, and themaximum flows needed when the maximum rock particles are flushed to the positions from the alluvial-proluvial fan apex are simulated; according to the simulated maximum flows, the maximum flow of theriver mountain pass of the time corresponding to each rock stratum is reckoned; by the adoption of the isotopic dating technology, the formation time of the corresponding rock stratum at each position location is measured; according to the reckoned floor peak discharges and the times, the palaeoflood series is constructed.

Description

technical field [0001] The invention relates to the field of paleo-flood hydrology research, in particular to a method for reconstructing paleo-flood sequences. Background technique [0002] In the construction of high-risk projects such as large-scale water conservancy and hydropower projects, it is necessary to calculate floods such as century-old, thousand-year or even ten-thousand-year standards. However, the existing measured flood records are generally only a few decades old, and even adding historical survey floods is far from meeting this requirement. kind of request. When the measured flood records and historical flood records cannot meet the requirements, it will cause great uncertainty in the flood frequency analysis and design flood calculation, which will directly affect the reliability of the calculation results. Through the reconstruction of paleo-floods, river flood records can be extended to a century, millennium, or even ten-thousand-year scale, and the ti...

AI Technical Summary

Problems solved by technology

At present, advective sediments are mainly used in paleo-flood reconstruction, but advective sediments and their pinch-out points as flood indicators are not easy to find in the wild. On the other hand, it is difficult to establish paleo-flood sequences with this method

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