Gullie's allometric models in Dareshahr region, Ilam province, Iran

Gully erosion is one of the most important erosion types in southern Iran that destroys lands and threats the life of the residents. This study was conducted in Darehshahr city located in Ilam province، Iran، owing to the importance of gully erosion in the study area to assess allometric relationships and to find out affective accessible variables for designation of other gully morphometric characteristics as well. To achieve the study purposes، the area induced by gully erosion was designated and 18 axial، digitated and frontal gullies were recognized and then categorized into five classes through applying cluster analysis. The different gully morphometric characteristics viz. length، head distance، depth، head height، top and bottom width، cross section area and perimeter، length، hydraulic radius، mean depth، maximum depth، longitudal slope، side slope and form factor were surveyed. The relationship between morphometric factors were then assessed with the help of regression analysis. The results of the allometric studies oft-approved linear and significant relationship among different gully morphometric characteristic. It was also verified that the easily accessible variables of gully length، head distance، height difference، head height and bank slope with the significant determination coefficient of 0. 6 to 0. 97 and different and mainly acceptable estimation and validation errors