关键词: 外源流水, 地表演化, 流域袭夺, 数值模拟

Abstract: Since the late Neogene and early Quaternary, many endorheic basins have been transformed into exorheic basins. The transformation of the endorheic lake brings a large amount of water to its downstream drainage. The inflow of exogenous water reshapes the drainage landscape and influences the evolution of rivers within the basin. Based on the finite volume method, we present a numerical experimental analysis of the coupling effect between the exogenous inflow and the uplifting landscape evolution. The result indicates that the exogenous inflow will deeply incise the main downstream channel. The tributary incision is enhanced with the erosion basis's elevation decreasing, and so the elevation of the overall drainage gradually decreases. When the exogenous inflow discharge is large enough, the downstream drainage captures its adjacent drainage. The incision coefficient controls the time that the drainage capture begins. Two factors affect the drainage capture velocity: the incision coefficient and the exogenous inflow discharge. The average elevation of the drainage depends on the uplift rate, the incision coefficient, and the exogenous inflow discharge. The numerical results provide useful insights into the evolution of the Jinshan Yellow River and Fen River drainage.

Key words: exogenous inflow, landscape evolution, drainage capture, numerical simulation