با استفاده از داده هاي صحرايي HEC-6 تحليل حساسيت مدل رياضي

Sensitivity Analysis of HEC-6 Model Using Field Data M. Ghomeshi

Today a number of numerical softwares are used to analyse long-term scour and deposition in rivers and reservoirs. HEC-6 model is one of the HEC series models designed for analysis of scour and deposition in rivers and reservoirs. The input data of the model can be arranged in geometric, sediment and hydrologic data. To run the model it is needed to determine and measure many parameters including geometry of reservoir or river, movable bed limits, roughness, bed material gradation, inflow sediment load, flow rate and selected sediment transport functions. It is essential for the user to comperehend the behavior of each parameter and analyse sensitivity of the model. For this purpose it is needed to apply the sensitivity analysis technique to understand the effect of variations in the input data. In this paper at first the sensitivity of the model is generally Abbaspour Reservoir located on Karoun River), and small changes in each parameter, the effects on water elevation profile, bed elevation, trap efficiency and accumulative sediment deposition are presented and discussed. The result obtained indicated that the model sensitivity to simulated bed profile changes is very high to variations in the movable bed limits. Also the variations in the bed material gradation, sediment load, and method of particles fall velocity has shown high sensitivity of the model. The variation in the inflow discharge follows medium sensitivity. The results obtained also indicated that the model sensitivity to simulated trap efficiency and sediment deposition is low to variations in the sediment transport equation and is high to variation in the method of particles fall velocity.