Time series analysis of saraw springs - SE of Sulaimaniya, Iraqi Kurdistan region

Abstract

Saraw Springs are located 45 km southeast of Sulaimaniya city of the Iraqi Kurdistan Region. This group of three vauclusian springs is recharged by infiltration through Cretaceous and Jurassic limestone outcrops. During three years of drought (1999-2001), one of the springs located at a few meters higher elevation than the others dried up. It became again active after the heavy rains at the end of December 2001. Based on the daily discharges measurements from October 2004 until the end of June 2006, a high correlation between discharge rates of the springs has been observed which indicates the prevailing role of long term reserves. The gentle declining of the auto-correlogram with no inter-subsistence of any peaks during that period indicates a type of homogeneity in the fissured systems, with no significant double porosity. The cross-correlogram shows that the stochastic connection between precipitation and discharge rate is weakly synchronized. This confirms dominant discharge through small fissures of the aquifer. The late reactions of the bigger channels can be forecasted according to the highly significant correlation of the first two days. In accordance with the obtained recession coefficients the average total dynamic reserves for the three springs equals 22 × 106 m3 per 277 days.