The study discussed the change in rainfall amounts in two governorates of Iraq, one in the north and the other in the south, differing in topographic elevation, The descriptive analytical approach, drawing inferential maps, and adopting a digital elevation model were used to prove the results. The study aimed to clarify the effect of the erosion factor on the increase and decrease in rainfall The decrease in sea level in the two study areas emerges the importance of using the DEM model as an analysis tool in building three-dimensional models of terrain phenomena to give a comprehensive survey of the Earth’s surface, and this in turn enhances the accuracy of the extracted results. The most important results are that the areas most abundant in rain have rains of more than 360 mm corresponds to the highest terrain, which reaches a height of 1800 meters above sea level, represented in the areas of the Aqrah Sinjar Makhmur Mountains within Nineveh Governorate. We find in the second study area, Basra Governorate, that the highest areas are located within the desert range of the Western Plateau and Wadi Hafar Al-Batin, approximately 290 meters, which is sandy land, so that the originality of the scientific fact is revealed in the study, which is the decrease in rain values in areas where the total amount of rain does not exceed 182 mm, as the abnormality of the precipitation system became clear in it, as we find low-lying areas exposed to more rain than areas that are penetrated by a high contour line due to the rock formation. And its limestone, which is located within the desert tongue of the Iraqi Western Plateau region, adjacent to the states of Kuwait and Saudi Arabia, and the scientific value comes from the results obtained in showing the importance of the difference in the factor of erosion in (two governorates) of Mosul, which has a mountainous nature, and the high erosion and surface features in the Basra Governorate, which has low land, and the role of modern technologies, To highlight the effect on the difference in rainfall rates in both