鄱阳湖口石钟山岩崖壁上记载的水位变化初探

通过对鄱阳湖口石钟山岩壁的观察,识别出了高于目前水位的6次较为明显的洪水印痕及凹槽,进一步与鄱阳湖全新世沉积剖面以及其它气候信息进行了对比。初步认为,它们分别指示了不同时期鄱阳湖水位的变化以及持续的时间,较低的3次洪水印痕可现性较高,持续时间较短;而较高的3次洪水凹槽则可现性较低,持续时间较长,可能指示全新世中期以来暖期气候背景下鄱阳湖水位。从鄱阳湖东侧全新世沉积剖面特点及相应时期内气候背景2个角度对比,推测各不同高度洪水印痕及凹槽可能形成的时间,并从石钟山崖壁历史洪水痕迹初步揭示了全新世中晚期鄱阳湖水位变化的历史洪水信息,同时为鄱阳湖水位与气候背景的密切相关性提供了佐证。

Preliminary Study on the Change of Water Level Recorded on the Cliff of Shizhongshan Rock in Poyang Lake

Six notable flood marks and corrosion grooves on the Shizhongshan cliff of Poyang Lake higher than the current water level were identified through observations, and were further compared with the Holocene sedimentary profile of Poyang Lake and other climate information. The flood marks and grooves indicate the change and the duration of water level of Poyang Lake in different periods. Three lower flood marks are highly reproducible and last for short time, while the higher three flood grooves are less reproducible and last longer, which may indicate the water level of Poyang Lake in the context of warm period since mid-Holocene. By comparing the flood marks and grooves with the Holocene sedimentary profile on the east side of Poyang Lake and the climatic background in the corresponding period, we can infer the possible formation times of flood imprints and grooves at different heights, and preliminary reveal the historical flood information of water level change of Poyang Lake in the middle and late Holocene. The present research proves that the water level of Poyang Lake is indeed closely related to the climate background.