2.1 Study site
The studied area is the Eskandari watershed (Figure \ref{652980}), situated at an elevation of 2620 meters above sea level and covers an area of approximately 1649 square kilometers. The case study covers a geographical location that extends from 50 degrees 2 minutes to 50 degrees 40 minutes east longitude and 32 degrees 41 minutes to 33 degrees and 11 minutes north latitude. This watershed is located within the Zayandeh-Rud basin, home to the largest river in the Iranian plateau in the center of Iran. The Plasjan River, the second most significant river in the Zayandeh-Rud basin, originates from the heights of Fereydon Shahr and flows into the Eskandari watershed. Eventually, it joins the Zayandeh-Rud River at the western end of the Zayandeh-Rud Dam, the primary water source for agriculture, drinking, and industry in Isfahan province. As the water demand increased in the region, the Cheshmeh-Langan tunnel, an inter-basin water transfer project, was implemented in 2005. This tunnel, depicted by the green line in Figure \ref{652980}, transfers water from the Sardab River, Sibak River, and Cheshmelangan Spring into the Palasjan River within the Zayandeh-Rud River basin. It is located 176 kilometers west of Isfahan, specifically in Fereydon Shahr City. The tunnel’s geographic coordinates range from 50° 5 min to 50° 15 min east longitude and 32 degrees and 45 min to 33 degrees north latitude.