Detection of climate change with extreme precipitation indices in great Khorasan

Climate changes with change in climate models and disrupt the order of ecosystems, imports Serious consequences on the environment. Changes in weather patterns can led to the Severe flooding, Extreme heat and cold, More frequent droughts, Sea Level Rise, global warming and Permanent ice melting. Even each of these phenomena can put one of the region's food supply at risk. In this reaearch, for detecting the climate change in great Khorasan, were use 25 year synoptic meteorological stations(14 station) statistics from1/1/1987 to 31/12/2011. Results show that few stations such as Ghochan (10 indices), Bojnourd (7 indices), Golmakan (5 indices), Sabzevar (3 indices) show an increase in the number of extreme precipitation indices. Ferdows, Torbat heidarieh, Ghaen and Nehbandan stations 100% and Birjand. Tabas, Gonabad, Mashhad and Kashmar stations over than 90% suffer from Rainfall changes. Among the indices, Consecutive wet days index(CWD) with 92.9% , Total annual precipitation wet days index (PRCPTOT) with 85.7%, Show the largest percentage decline. So in the north-west of Iran, except of Ghochan and to some extent Bojnourd , other station have experienced drastic changes in precipitation In the last 25 years