بررسی روند خشکسالی تحت شرایط تغییر اقلیم در حوضه کشف رود Drought has significantly affected the environmental and socio-economic conditions in Iran. Three drought indices were used for monitoring drought intensity and duration in Kashafrood basin (northeast of Iran). The standardized precipitation Index (SPI), Precipitation Index Percent of Normal (PNPI) and Agricultural Rainfall Index (ARI) were calculated for the base period (1961-1990). All these indices were used to assess future drought in Kashafrood basin under climate change attributed to low and high greenhouse gas emission scenarios (SRES B2 and A2, respectively) for 3 periods (2010-2039, 2040-2069 and 2070-2100). Projected changes in precipitation, temperature and potential evaporation were simulated by statistical downscaling of HadCM3 outputs. Main results showed: (i) slight increase in precipitation means, around 2.2% to 5.4% under A2 scenario and 6.8% and 8.6% under B2 scenario. (ii) Slight increase in maximum temperature, around 4.6 oC to 5.6 oC for A2 scenario and 4.25 oC and 4.6 oC under B2 scenario. (iii) Slight increase in minimum temperature, around 1.6oC to 1.9 oC under A2 scenario and 1oC and 2.23oC under B2 scenario. (iv) Higher drought frequency associated with global warming was demonstrated by all indices for both scenarios. Such an increase in drought frequency would have major implications for natural resources management, water security planning, water demand management strategies, and drought relief payments.

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