从地质背景看汉魏隋唐时期洛阳盆地的河道变迁

River Course Transformation in the Luoyang Basin During the Han, Wei, Sui, and Tang Dynasties

洛阳盆地伊、洛、瀍、涧四水流向与其地质背景密切关联。四水走向均受控于盆地基底的地层断裂线。伊、洛二水的走向主要取决于东西向及北东向的断裂线,洛水的流路主要受麻屯—偃师断裂影响,伊水的流路主要受宜阳—偃师断裂影响。瀍、涧二水的走向与北西向的断裂线一致,主要受新安—半坡等断裂影响。洛水在汉魏隋唐时期表现出持续北迁的态势,伊水则持续东延南移。伊、洛二水历史时期以来渐趋南北分离,伊洛交汇点逐步东移。盆地内的南北不等量沉降、沉积中心的向北倾斜导致洛河北迁,中央凸起、“两堑夹一垒”型的复式断陷致使伊河东延南移。

In the Luoyang Basin during the Han,Wei,Sui,and Tang dynasties,the flow patterns of the Yi,Luo,Chan,and Jian rivers were closely related to their geological setting.The orientations of these rivers are predominantly determined by the underlying geological fault lines of the basin.The orientations of the Yi and Luo rivers are mainly determined by east-west and northeast-oriented fault lines,with the flow path of the Luo River primarily influenced by the Matun-Yanshi fault and the Yi River influenced by the Yiyang-Yanshi fault.Jian and Chan Rivers share simultaneous spatial similarities and transient transformation similarities,both following city site migrations,turning from being sectioned eastward during Han and Wei dynasties to falling back to the natural southward flow during Sui and Tang dynasties.Luo River exhibited a trend of continual northward transformation during Han,Wei,Sui,and Tang dynasties,while Yi River constantly extends eastward and southward.Over historical periods,the Yi and Luo rivers gradually separated north and south,with their confluence point shifting eastward.Unequal north-south subsidence and a northward tilt of the sedimentary center caused Luo River to migrate northward,while a central bulge and‘two cut first base’complex fault depression caused Yi River to extend eastward and southward.