Determination of soil volume loss due to gully erosion and estimation of its economic cost (Case study: Ghazeian watershed, Fars province)

Gully erosion is known as one of the most important and destructive forms of land degradation, and the loss of soil throughout the world. As estimation of soil volume loss and understanding the economic costs of soil erosion are of great importance; this study has been carried out to calculate the amount of soil volume loss due to gully erosion and estimate its economic cost in Ghazeian watershed located in north of Fars province. To do so, the volume of gullies was calculated and thereafter, the mass of soil loss was determined using soil bulk density. Then, total amount of soil loss mass was determined by summation of the mass of soil loss from gullies. The results showed that an average of 201.10 m3 (263.43 ton) soil eroded and loss each year due to gullies erosion in this region, and it damaged the soil resources by an average of 7376.25 dollars (295050000 Rials) per annum. These results indicate the destructive effect of gully erosion on soil loss, and therefore, more attention is required to control this type of erosion by establishing native and consistent vegetation, increasing the roughness coefficient, diverting runoff path, and performing precise research in different regions of the country.