Daily changes In Seasonal Rainfall indicators in Southern Iraq

Abstract

A number of indicators revealing aspects of climate change in the study area were addressed based on the number of rainy days on a seasonal level in southern Iraq. These indicators are: the number of rainy days with precipitation less than (>1) mm/day, which expresses drought; the heavy rainfall indicator (R10mm); and the very heavy rainfall indicator (R20mm) for the studied stations (Al-Hussein, Al-Nasiriyah, Al-Amarah).

An increase appeared in the general seasonal average of the rainfall indicator less than (1 mm) in the study area throughout the study period. The seasonal rate of change in these stations reached (13.3), (9.1), (-5.6) days, representing percentages of (47.6), (52.4), and (50)% higher than the general average, respectively. This indicates a high level of maximum daily durations in their drought levels.

As for the seasonal change within the heavy rainfall indicator (R10mm), there was a negative trend in Al-Hussein station and a slight increase in Al-Nasiriyah and Al-Amarah stations. The seasonal rate of change in these three stations reached (-1.3), (0.2), (0.4) days throughout the study period, representing percentages of (64.3), (64.3), and (54.8)% lower than the general average, respectively.

Regarding the very heavy rainfall indicator (R20mm), it was found that the study area experiences a clear spatial seasonal variation in the directions and magnitudes of rainfall change (generally) with weak rates, particularly in Al-Hussein and Al-Nasiriyah stations, indicating a slight increase in Al-Amarah station. The seasonal rate of change for these stations reached (0.3), (2.2), (1.7) days, with percentages of (71.4), (71.4), and (61.9)% lower than the general average, respectively.