Environmental Suitability of Agricultural Lands under the Influence of Gully Erosion in Hawarteh Valley Basin

Abstract

The Hawarteh Valley basin is located in northern Iraq, in Erbil Governorate, in the Kurdistan Region of Iraq, within the boundaries of the (Bradost) district, between latitudes (36°42'59.0") and (36°51'15.0") north, and longitudes (44°35'41.0") and (44°51'57.0") east, with an area of (220.56 km2). The natural characteristics were studied for use as inputs to the process of calculating the environmental suitability of agricultural lands and creating a distribution map. After that, the researcher studied the characteristics of gully erosion in the basin according to the (Bergsma, 1983) law, then intersecting the gully erosion map with the environmental suitability map to create a map of environmental suitability under the influence of gully erosion for agricultural lands in the Hawarteh Valley basin.

The research aims to demonstrate the importance of the gully erosion layer in calculating the environmental suitability of agricultural lands as a fifth layer with the four layers required to find the environmental suitability, because the slope layer is not sufficient to represent the process of gully erosion due to its reliance on calculating the total river tables in one area unit, which was proven to the researcher when reducing the area of the (suitable after modification) category from (51.07 km2) without calculating gully erosion to (15.95 km2) after calculating the erosion, as well as the (suitable for forests and grazing only) category, which decreased in area from (163.37 km2) to (78.12 km2).