continuous rainfall-runoff simulation

Knowledge of the watershed natural ability to produce runoff is an essential requirement toward optimal planning for runoff utilization. The aim of this paper is to evaluate HEC-HMS model using Soil Moisture Accounting (SMA) with continuous rainfall-runoff simulation in watershed and estimate the base flow contribution from direct runoff in Abolabbas watershed. It is possible to manage and plan water resources utilization by separating baseflow contribution and direct runoff from total runoff. SMA model use a series of storage layers including interception, canopy storage, soil storage profiles (upper layer storage and tension storage), and groundwater storage consider water loss in the watershed. Model calibration was performed using daily precipitation, evapotranspiration, temperature and river flow from 2001 to 2009 data and model verification was performed using 2010 to 2015 data. Results showed that HEC-HMS model with SMA have well consistently in simulation of daily runoff in wet and dry periods in Abolabbas watershed. Results showed that base flow contribution effect on total watershed runoff is more than direct runoff, in which the average percentage of total direct runoff and base flow runoff are 9.05 and 90.95 percent respectively. The results showed that on average, the percentage of runoff coefficient during the statistical period in Abolabbas watershed was 6.6 percent.