ABSTRACT
Hydrogeological models are an approximation of real systems. The structure of these models, includes several equations which are known as the system transfer functions that define the relationship between inputs and outputs. The transfer functions and the impulse response functions (i.e., Kernel function) of the karst springs, Pireghar and Dimeh, are identified by means of the ARX model. Daily rainfall data of the Chelgard and Farsan rain gauge stations and daily spring discharge of the Dimeh and Pireghar Springs during the period of 1999-2011 are selected as input and output, respectively in the modelling processes. The results show different contribution of the flow components, slow flow and quick flow, in the springs. The slow flow component in the Dimeh and Pireghar springs is 90% and 64% of the total spring discharge, respectively. Moreover, in order to evaluate spring discharge variations in response to a hypothetical drought conditions (assuming a decreasing trend in precipitation during the next twelve years), the spring discharge is predicted based on the calibrated model. The results reveal that, the Pireghar Spring will be more affected by drought events compared to the Dimeh Spring.
