Meteorological drought monitoring in order to sustainability in RCP scenarios Case study: Doiraj watershed

The aim of this study is to preserve the sustainability of the Doiraj watershed in RCP scenarios. The observation and future period in this study is (1987-2015) and (2044-2016). For this purpose, the combined weight of 5 models of Fifth Report (AR5), rcp8.5 scenario, used to assess changes in temperature and precipitation in the coming period. MOTP weighting method to reduce uncertainty of GCM models were used Meteorological drought monitoring in monthly, Seasonal and yearly intervals using Markov chain, frequency analysis and drought indexes SIAP, SPI, Z score and BMDI was calculated. The results showed that long-term average monthly rainfall and temperature at a rate of 14 percent and 2.1 degrees Celsius as compared to the baseline. Markov chain probability of uncertainty precipitation showed, two months without precipitation in winter, spring and autumn, respectively 56, 63 and 52 percent and the chance of precipitation after a month of dry seasons, respectively 44, 35 and 47 percent. Based on the analysis of the indices during the years 2017-2018 than in 2016-2017 wetter and future years in the period 2024-2025 and 2025-2026 wettest years on the basis of this research.