Drought deciles index for spatial and temporal assessment of satellite-based precipitation datasets

Abstract

Obtaining precise and long-term precipitation datasets is vital for addressing hydrological and climatic concerns. Limitation of drought recurrent characterizing and its impact in Iraq have been hampered primarily by unavailability of reliable climate data sets. This work assesses the performance of four gridded precipitation products (GPDs), APHRODITE for the period (1983–2007), CHIRPS for the period (1983–2017), PERSIANN for the period (1983–2017) to evaluate their potential for drought monitoring. This was accomplished by analyzing their ability to estimate the Drought Deciles Index (DDI) at multiple time scales (1-month, 3-month, 6-month, 12-month, and 24-month) across 22 ground stations (GS) in semi-arid Iraq during the period 1970–2018. The study area was divided into three zones based on Köppen's climate classifications. The results confirmed the potential of GPDs for monitoring drought in Iraq. Their performance was stronger for shorter time scales with time scales of 1, 3, and 6 and becomes weaker for time scales of 12 and 24. Furthermore, better performance of GPD found at locations with higher annual precipitation rates and altitudes. Overall, APHRODITE and TRMM showed the greatest potential for accurately representing GS. In addition, it is revealed that the DDI's was capable for effectively analyzing and monitoring drought periods in Iraq.