Wheat Drought Monitoring by Using Generalized Scalogram Model for Mashhad and Shiraz Synoptic Stations

Drought is a multivariate phenomena that caused by variation in some meteors. In this study، a new multivariable model purposed to monitor wheat drought in Mashhad and Shiraz synoptic stations during 50 years period. Purposed model was designed based on multivariable Scalogram model، with some meteorological variables as inputs such as annual evapotranspiration، number of rainy days and amounts of precipitation in autumn، winter and spring. In proposed model، imperfection of former Scalogram model including threshold levels and weights of meteorological variable were modified. In the new model drought condition will not be determined only based on precipitations amounts، but the other important meteors such as number of rainy days، evapotranspiration and especially time distribution of precipitation is considered. Results showed the modified Scalogram model، is enable to monitor agricultural drought of wheat by considering distribution of precipitation in time and the amount of evapotranspiration.