Spatial Variation of Rainfall Between Nineveh and Basra Governorates due to Terrain Elevation Using Digital Elevation Model–Geographic Information System

The study discussed the change in the amounts of rainfall falling on 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 identify the effect of the terrain elevation factor on increasing precipitation.Rainfall and its decrease with the decrease in sea level in the two study areas emerges the importance of using the digital elevation model (DEM) 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 as well as demonstrating the capabilities inherent in the geographic information system (GIS) program in dealing with input and analysis.And processing and outputting quantitative and descriptive data.The most important results are that the areas with the highest rainfall, with rain reaching more than 360 mm, correspond to the highest terrain, which reaches a height of 1800 meters above sea level, represented in the areas of the Aqra Mountains Al-Sheikhan Sinjar Makhmour, within Nineveh Governorate.In the second study area, Basra Governorate, we find that the highest elevation areas are located within the desert range of the Western Plateau and Hafr Al-Batin Valley approximately 290 m, and it is a land of lime, gravel, and sand.Thus, the originality of the scientific fact in this study becomes clear to us, which is the decrease in rain values in these areas that Its averages do not exceed 182 mm, as the anomaly in its precipitation system has become clear, as we find low-lying areas exposed to more rain than areas crossed by a high contour line, due to its rocky and limestone formation, which is located within the desert tongue of the Iraqi Western Plateau region, adjacent to both the states of Kuwait and Saudi Arabia.The scientific value comes from the results obtained in showing the importance of the factor of eroding, which has a clear difference in (two governorates) of Mosul, which has a mountainous nature, and the high eroding and surface features in the Basra Governorate, which has low land, and the role of modern technologies in highlighting the effect of this on the difference in rainfall rates in both.