Abstract

Although the water flow is a part of the natural functions of the valleys in the water basins, the manifestations of the surface runoff are transformed into stages that exceed the capabilities of the valleys’ streams. They are called flash floods and they occur at indefinite periods, so they are considered hydrologically dangerous because of the human and material losses they cause to various economic activities. The valleys within the water basin and the drainage basins vary among themselves in the occurrence and severity of floods, and they are related to a number of natural and human environmental factors and variables (geology, geomorphological, hydrological, climatic, land use, and others). A multivariate method based on geographic information systems (GIS-MEC) was adopted to model the flood risks of one of the water basins in the Simil region (Kardim Basin) with an area of ​​(100.0) km2 and its estuaries end in the Tigris River north of Mosul Dam lake on the eastern side. The modeling included ( 7) Variables which are (Row depth RD)-(flow volume-(SRV(CN flow curve)-(Geological formations)-(Slope)-(Aspect)-)-(NDVI vegetation).
The outputs of the model showed that (59.22%) of the basin area, the movement of torrents is classified as moderately dangerous and (31.45)%, which are concentrated in the upper parts of the basin within the heights of Aqrah, the degree of torrential risk is high and very high, and (9.33)% the degree of torrential risk is few and very few.