چکیده:
This research studies the potential impact of climate change on future trend and changes of two well known
drought indicators namely RDI and SPI in Yazd meteorological station, in central part of Iran. For this purpose, data
of HadCM3 model that were resulted from GCM-runs based on the IPCC-SRES scenarios of A2 and B2 were
acquired and analyzed for projection of daily Tmin, Tmax and precipitation for the projected period of 2010 to 2039.
RDI and SPI drought indicators then were calculated and validated based on corresponding observations of historical
period (1961-1990). Comparison of the results indicate that SPI and RDI of A2 scenario would have a negative trend
along with the projected years, while these indicators tend to have positive trend when resulted from B2 scenario. The
latter result demonstrates an increase of vulnerabilities based on up coming droughts.
خلاصه ماشینی:
H. Rahimiand a Associate Professor, Faculty of Natural Resources, Yazd University, Yazd, Iran b Assistant Professor, Faculty of Agriculture, Abureyhan College, University of Tehran, Tehran, Iran c MSc Graduatet, Yazd University, Yazd, Iran d Research expert, National Salinity Research Center, Yazd, Iran Received: 27 March 2010; Received in revised form: 11 November 2011; Accepted: 28 December 2011 Abstract This research studies the potential impact of climate change on future trend and changes of two well known drought indicators namely RDI and SPI in Yazd meteorological station, in central part of Iran.
Methodology In this study three main sources of data were used which are as fallows: 1- Historical daily temperature and precipitation data of Yazd meteorological station from 1961 to 1990 (Tmin, Tmax and P) 2- Projected monthly data of HadCM3 for projected period of 2010 to 2039 (Tmin, Tmax and P), that were resulted from GCM-runs for the Third Assessment Report (TAR) based on the IPCC-SRES scenario of A2.
RDI and SPI drought indicators In the current study, drought assessment was achieved using the Standardized Precipitation Index (SPI) and the Reconnaissance DroughtWhere, TGCM (19611990),i and TGCM ( 2010 2039 ),i are Index (RDI) for the Yazd meteorologicalmean monthly temperatures (Tmin or Tmax) that were resulted from different scenarios (A2 and B2) for baseline (1961-1990) and projected (2010-2039) periods in month i.
Monthly distributions of observed and projected evapotranspiration (ET) and precipitation (P) at Yazd meteorological station under B2 scenario As the main purpose of this study, potential impacts of climate change on drought indicators were investigated.