The effect of climate change on Maharlo lake level change using satellite image processing

Study of the long term dynamic of the lake is crucial to evaluate regional water resources management and environmental changes. The main aim of this study was to evaluate and mapping the impact of climate change in the dynamic of the lake Maharlo located in the boundary of Shiraz city. Landsat satellite images during the past 18 years (1997-2016) in mid-spring were used to determine dynamic changes of the study lake (After geometric, radiometric and Atmospheric correction of satellite images, the annual lake level was extracted using a thresholding method on the band 5 and NDWI index. The results show that, a general reduction trend was observed in the lake area. Most of the changes were occurring in the eastern part. The correlation between water level changes of the lake with some of the climatic parameter changes (evaporation January to May, annual rainfall, average temperature January to May, the average maximum temperature January to May) was also investigated). According to Pearson correlation coefficient between the lake level and evaporation of the months of January to May, annual rainfall, the average temperature of January to May, maximum temperature of the months of January to May were -0.44, 0.77, -0.28, -0.52, respectively. A significant trend was observed between rainfall change (decrease and increase) and lake level. Minimum annual rainfalls were 147 and 192 mm in the years of 2007-2008 and 2008-2009, respectively, which minimum lake level was observed in the same years (14146 and 15095 hectares). The maximum rainfall was occurred in 2004-2005 (745 mm) when the maximum water surface was measured in the lake (25806 ha). According to the results, 58% of the variability of the lake could relate to rainfall change.