Stochastic modeling of surface stream flow at different time scales: Sangsoorakh karst basin, Iran

Karstic watersheds are one of the most important areas for water supply.Because the role of groundwater contribution to surface water flow in karst watersheds is not well understood, the commonly used hydrologic models in most regular basins do not provide satisfactory estimates of runoff in karstic regions.This paper uses time-series analysis to model karstic flow in the Sangsoorakh karst drainage basin in the Karkheh subbasin of southwest Iran.The comparison of model forecasting performance was conducted based upon graphical and numerical criteria.The results indicate that autoregressive integrated moving average (ARIMA) models perform better than deseasonalized autoregressive moving average (DARMA) models for weekly, monthly and bimonthly flow forecasting applications in the study area.