Classification of drought zoning by PNPI, SIAP and TOPSIS indices (Case Study Yazd Province)

Drought hazard is one of the environmental phenomena that mainly is due to climate change. In fact, this is one of the main periodic features of different geographical regions. This phenomenon has a great impact on all aspects of human activities in urban and rural areas.
The method of this study is developmental - applied and with the aim to determine frequency and severity of droughts in Yazd province, examines this issue. It should be noted that required information has been collected for zoning drought in Yazd province in cooperation with related organizations such as Meteorological site and Statistical Center of Iran and by using spatial approach, information reviewed and data analyzed.
Findings: It should be mentioned that about 50 percent of this paper consists of research findings. In this regard, with the help of TOPSIS model and use of rainfall normal indices and annual index, Coefficients and weights of drought index calculated and rainfall intensity determined. The results according to TOPSIS model indicated that in terms of humidity and temperature factors, station of Nir city is the driest station. Also, normal and annual rainfall indices demonstrated that Meibod and Khatam Stations respectively are in normal and very high drought conditions.
In conclusion of the present research, based on the rainfall average index, only Meibod is in normal condition and Katam, Yazd, Mehriz, Taft, Saduq, Abarkouh and Ardakan stations respectively are in severe drought conditions. Also, according to annual moderate index, Saduq, Abarkouh, Ardakan, Bafg and Tabas stations are in a state of moderate drought and Meibod and Bahabad stations respectively are in mild and normal drought conditions. In conclusion, considering regional drought and variations in rainfall is very essential for planning and environmental studies.