evaluation of vegetation and thermal indices efficiency and feasibility of landsat images to agricultural drought analysis (case study: city malayer)

raisins are one of the most important parts of agriculture products to export and malayer gardens are one of the most valuables lands to produce vitis vinifera for raisin industry in recent years. the region has some problems to mange water resources due to climate change effects and drought. understanding of hydrology balance and drought period is one of most tools to manage the water crisis in the middle east. todays, satellite indices are effective for monitoring of agriculture drought especially on the lands where they have not climatology stations and big watershed. within satellite indices, ones that relate to vegetation are important because vegetation have strong relationship with soil temperature and humidity thus study of it is suitable and ecologic method for monitoring of anomalies of soil temperature and humidity. in this research were computed drought indices on landsat images over the malayer gardens in april of 2007, 2009 and 2013(the driest of years in the country). vci, vdi, wsvi and ndvi indices are calculated on images and are monitored and compared agriculture droughts. the results show that ndvi and wsvi can detect drought better than the other indices in the region.