The Effects of Changing Level of Maharlou lake on Humidity and Temperature Level of Shiraz City

Maharlou Lake، due to its proximity to metropolis of Shiraz، plays an important role in moderating the temperature and humidity of this metropolis city. Droughts in recent decades and the subsequent decline in the water level of the lake and its surrounding areas have negatively impacted on temperature and humidity conditions in the city which have led to undesirable effects accordingly. This study is aimed at examining Maharlou Lake shoreline changes and their impacts on climatic elements، especially humidity and temperature of the surface of the lake adjacent areas. To assess the changes in the coastline، ETM + & TM sensor LANDSAT satellite data on 22 May 1987 and 17 May 2000 and 20 March 1999 and 18 in 2009 were used. Also، supervised classification algorithm with maximum likelihood was employed to process the satellite images and calculate the water level fluctuations at different time periods. The results indicated a 29-square-kilometer reduction in Lake Level in May of 1987 and 2000 and 107-square-kilometer reduction in March of 1999 and 2009. Average percent vegetation index buffer in surroundings of 10 kilometers in 1987 and 2000 decreased 15 percent in the same month whereas in 1999 and 2009، only 3 percent drop was seen in March. Nevertheless، minimum temperature، average and maximum land surface had an increasing trend in the space around the lake on the same low water period.