冀中平原历史地貌研究与白洋淀成因的探讨

Historic Landform in Central Hebei Plain and Causes of Formation of Baiyangdian Lake

使用1926年出版的顺直地形图做历史地貌研究,发现冀中平原、白洋淀流域存在大量的特殊地貌单元"碟形洼地"。研究这些特殊洼地的个体形态、群体分布规律,特别是使用数字高程模型(DEM)分析这些洼地,发现"碟形洼地"可能是分布在第四纪松散沉积物上撞击坑的遗迹。初步推测这种地貌可能是全新世中期以后不久一次规模巨大的陨石雨撞击的结果,白洋淀更可能是一些较大的撞击坑在地表流水的侵蚀、后经人工改造逐步形成的。陨石雨的撞击导致了重大的史前环境灾害,这可能涉及到全新世中-后期自然环境的变化等一系列重大科学问题。

On the basis of the Shunzhi Relief Map published in 1926, the historic landform in the North China Plain is studied and a large quantity of special geomorphic units--dish-shaped pits are discovered in the Baiyangdian drainage area. In studying the individual appearance and total distribution of these special pits, especially by the digital elevation model （DEM）, the authors have realized that the ＂dish-shaped pits＂ might be the remains of impact craters on the Quaternary loose deposit and inferred primarily that an impact event of a largescale meteorite shower might have occurred in this area. After long-time erosion by surface water and artificial transformation gradually, some larger craters finally formed the Baiyangdian Lake. The impact of meteorite shower resulted in a prehistoric huge astrogeological disaster, which produced significant effects on the prehistoric environment and culture development since then.