关键词: 大气降水;土壤水;地下水;水分运移;氢氧稳定同位素;淮北平原;

Abstract: The water level-flow relationship of Luoshan Station is a significant basis for the allocation of excess flood volume and the formulation of flood control scheme in the middle and lower reaches of Changjiang River. However, due to its unique geographical location, the water level-flow relationship is affected by many factors. Thus, when studying the flood discharge capacity of Luoshan Station, it is often necessary to distinguish and eliminate the influence of special hydraulic elements, and correct the measured flow results of different hydraulic conditions to the same hydraulic condition. In this paper, we analyzed the characteristic of the relationship between water level and flow of Luoshan Station in 2020 based on measured data in massive flood years from 1954 to 2020, exploring its main influence factors and variation laws. The results showed that the relationship between water level and flow of Luoshan Station in 2020 was affected by the flood backwater of downstream, leading to higher water level at the same discharge, similar to that in 1998 and 2016. The overall range of fluctuation of Luoshan Station in 2020 was within the scope of the massive flood years such as 1998 and 2016. In recent years, the water level-flow relationship of Luoshan Station has changed within a certain range mainly due to different intra-annual and inter-annual hydrological regimes, but there was no trend change, reflecting that there was no significant change in the flood discaharge capacity of Chenglingji reach.

Key words: water level-flow relationship; influence factor; Luoshan Station; Chenglingji reach; middle and lower reaches of Changjiang River