Investigating the role of meteorological variables and excessive groundwater withdrawal on reduction of the Lake Maharloo water level

Over the last few decades, the water level appears to have declined for most of the Lakes as a consequence of global warming. Besides, in addition to climatic factors, human activities have had profound impact on lowering lakes water level and ecosystem changes. The aim of this study was trend analysis of climatic factors (rainfall and evapotranspiration) and water balance (flow and underground water withdrawal) in Maharloo Lake region during last five decades using Man Kendall and Petit Tests. The results showed a %82 decrease of Lake water level. Rainfall did not show a significant trend at %1 significance level , but there exist a significant trend for evapotranspiration which might be a major cause for  observed reduction of water level. Human activities and increased consumption and withdrawal in Maharloo basin may be considered as the other major affecting factors. Such that the discharge of Khoshkrood river which flows into the lake has significantly decreased since 2006.