The Impact of Topography on Rainfall Distribution in Duhok Governorate Using Geographic Information Systems (GIS)

Abstract

Duhok Governorate is one of the border provinces located in the northern and northwestern part of Iraq. It possesses a complex topography, with elevations ranging between (350-2500m) above sea level. This study emphases on the application of Geographic Information Systems (GIS) as an effective tool for analyzing and understanding the topographical variations of the region and their impact on the distribution of rainfall across the area.

The key objective of this research is to utilize a statistical method to determine the relationship between topography and rainfall rates. The study methodically examines how elevation, slope, and the orientation of mountain ranges influence the volume and distribution of precipitation within Duhok Governorate. To realize this, a Digital Elevation Model (DEM) and isohyetal maps (rainfall contour maps) were developed based on meteorological data from (11) main stations across the governorate, covering the historical from (2004-2024) Furthermore, Minitab software was employed to determine the relationship ratio between these two variables (topography and rainfall) and to assess the level of impact each has on the other.

The most important results of the study specify that elevation is a main topographical factor influencing rainfall decorations. This impression is more pronounced in the North-Northwest direction compared to the East and West of the governorate. The correlation between topography and rainfall is highly significant; according to the Regression analysis, it reaches 90%. Additionally, elevation alone controls 80% of the rainfall circulation in the governorate, while the remaining 20% is attributed to other factors such as wind direction, slope orientation, temperature, and atmospheric pressure systems.