Γ型地貌瞬时单位线探讨

A STUDY OF GAMMA TYPE GEOMORPHOIOGIC INSTANTANEOUS UNIT HYDROGRAPH

在地貌瞬时单位线中作者假定沿任一“路径”的等待时间密度函数成Γ型分布。本文讨论了Γ型地貌瞬时单位线的推导、参数确定和特点。并取蛇家口、三川口流域的突测资料验证,计算洪峰值和涨洪历时与实测值十分接近。

Horton's empirical laws of network composition is studied and applied to six catchments in North Shaanxi Province of China, The relationships between Horton parameters are discussed.Based upon the Horson's laws, a geomorphologic instantaneous unit hy-drograph (GUH) model is proposed, in which, the waiting time distribution in each path is supposed to be a Gamma distribution. General expressions for the inital state probability anb the transition probability in GUH are derived. All the parameters but one in the GUH are calculated from Horton parameters and stream flow velocity of each flood event. The unknown parameter is decided by optimization.The proposed model is applied to ten rainfall-runoff events in two catchments, the results are encouraging.