Predict Dry Period Using Standardized Precipitation Index For Period (2000-2025) And Forecast Drought Under Climate Change Conditions For Future In Najaf City, Iraq

Abstract

Drought is a climatic condition resulting from a severe and prolonged lack of precipitation, accompanied by high temperatures. This paper examines the time series of average precipitations for the period (2000-2024) from NASA Power data website, and this period represented on an average precipitation distribution map using Geographic Information System (GIS) and computes the Standardized Precipitation Index (SPI) for Najaf Governorate. For future period (2025-2044), the climate model from the NSF National Centre for Atmospheric Research website (NCAR) data are used and computes SPI by using DrinC software. The results showed that the period (2000-2017) recorded lower average precipitation amounts than the period (2018- 2025), and it was concentrated towards the north and decreases towards the south, and the SPI values ranged between moderately wet to mildly wet. The period from 2025 to 2044 experienced lower amount of average precipitation. SPI results varied from extremely wet to extremely dry, with the (2035–2044) period, in particular, being characterized by dry conditions.