Flood Hydrograph Simulation and Analysis of its Components with Landscape Metrics in Amoughin Watershed, Ardabil Province

The landscape metrics are used to quantify the spatial properties of landuse patches and classes as a useful tool in assessing effect of human activities on flooding processes. This study aims to evaluate the efficiency of HEC-HMS model in flood simulaion of Amoughin watershed and exploring the relationships of landscape metrics and the flood components. The HEC-HMS model was runned with SCS-CN (loss module), SCS-Unit hydrograph (rainfall-runoff transformation) and Muskingum (routing). The model parameters were optimized using 6 events considering Nash-Sutcliffe objective function and three excluded events used during validation. The components of simulated hydrographs were defined by 25-year design rainfall. The landscape metrics were quantified using Fragstat and appropriate landscape metrics slected by PCA. The correlation and regression analysis were performed in R programming. The value of Nash-Sutcliffe criterion was 0.63 in validation which proves the accuracy of model in flood simulation. The results showed a positive relationship between Qp, runoff volume and base time with total area (TA) and MESH metrics. Relationship of Qp with TA, patch density (PD) and slope were evaluated as positive (p-value