Study of multiple flow direction algorithm in watershed scale by LAPSUS model

In this research, LAPSUS model is introduced as a suitable model to surface runoff rutting by Multiple Flow Direction (MFD) algorithms. Flow distribution algorithms grouped into two main types including Single Flow Direction (SFD) and MFD algorithms. LAPSUS model is a landscape evolution and a multi-module dynamic landscape evolution model. Studied processes included overland erosion, land sliding, tillage erosion and tectonics. Input data in LAPSUS model was DEM, rainfall, runoff coefficient and convergence factor. This model has written in C++. This model has been used for runoff rutting in Kakhk watershed of Gonabad, Iran, for the first time. For this purpose, surface runoff resulted from 34 rainfall events was simulated for multiple flow direction analysis between 2008 and 2018. Results showed that LAPSUS model can simulate total volumes of events with a high accuracy by MFD with the amount of nRMSE of 3.9 percent.