Studying the Draughts in Kerman Using four Indices, Namely TOPSIS, SPI, PNPI and Z

Iran territory which is located on the world’s dry belt has constantly been exposed to fluctuations and irregularities of precipitation regime in spite of shortage of water. Meanwhile, the condition of southeast parts of Iran is more complicated because in spite of less precipitation as compared to national average, adjacency to one of the harshest dessert hotspots in the world, strong winds have doubled the environmental problems and complications of this area. In this research therefore, the draught at Kerman station during a 51-year period (1955-2005) was studied using four indices, namely TOPSIS, SPI, PNPI and Z and also by using DIC software in order to execute the said four indices. The results revealed that in TOPSIS method, Kerman station faced 1 wet year, 13 normal years, 4 weak, 17 average and 16 serious draught years. The most durable draught periods referred to 1964-1971 and 1998-2005. In SPI index, Kerman station faced 1 very serious wet year, one mild wet year, 36 years close to normal, 7 mild draught, 3 serious draught and 2 very serious draught years. The longest period close to normal referred to 1974-1984. In PNPI index, 34 years were at normal threshold, 6 weak, 7 mild, one serious and 2 very serious draught years occurred. The longest draught period referred to 2002-2005. In z index, there were 2 serious draught years, 12 mild draught years, 10 mild wet years, 24 approximately normal years, and 3 seriously wet years and the longest period referred to 1976-1984