Quantitative Analysis of Qanat Water Changes and Its Impact on the Agricultural Cultivated Area in Lenjan from 1991 to 2012

Qanat is one of the most complicated human invention techniques to extract underground water in arid and semi-arid areas which has been constructed for irrigating. In spite of the Zayandehrood River’s water, Qanat in Lenjan is still an important source of water for irrigating agricultural areas.
The “descriptive-analytic” method has been used in this research, and all data have been collected from related libraries and institutes. In this research, the relation between the qanat water quantity and the agricultural area under cultivation has been studied in Lenjan. For doing so, the statistical data has been analyzed using SPSS and Excel by standardized score analysis method. Next, the linear regression of time series, hydrograph charts, and correlation methods have been applied for further data interpretation and analysis. It has been found that the rate of qanat discharge has been decreased in Lenjan compared to the previous time periods especially in drought years. This has caused to complete dryness of some of the qanat sources during 19991-2012. In addition, a direct relation has been found between the amount of qanat water drainage and the cultivated areas which have been shown by significant factor 0.001 and the correlation coefficient 0.69.