Mozafar Ansari; Sadat Feiznia; Hassan Ahmadi; MohammadAli Fattahi Ardekani
Abstract
Soil is one of the most vital natural resources in any country. Nowadays, lands are rarely found worldwide without having severe erosion problem. Landslide is one of the soil erosion processes in which a huge volume of soil is washed away. SHETRAN Model was used in this study to assess the landslides ...
Read More
Soil is one of the most vital natural resources in any country. Nowadays, lands are rarely found worldwide without having severe erosion problem. Landslide is one of the soil erosion processes in which a huge volume of soil is washed away. SHETRAN Model was used in this study to assess the landslides being occurred in Zidasht catchment, Taleghan. At the first stage, sediment-water mixed samples were gathered at the outlet of the Catchment for calibration purpose in 2011. To run the model, regions undergoing landslide were identified using GISLIP sub-model. Secondly, after hydrological and sediment production simulations in a sub-model of SHETRAN for the region, calibration was made for spring season. After the calibration process, the model was run again, this time for the regions having landslide (for 418 spots), and in regions where landslide sediments do not pour into water courses, these regions were omitted, the final amount of sediment was calculated using SHETRAN sub-model and the results were compared with the previous studies. The results show that 19.75% of the total sediment belongs to landslides. With regard to the current sediment quantity of about 111248 kg, total sediment in landslides was estimated to be around 120668kg.
S.M Soleimanpour; majid Soufi; hassan Ahmadi
Volume 63, Issue 1 , June 2010, , Pages 41-52
Abstract
Gully erosion has an important role in Fars province due to sediment production and enormous damages to land, roads and infrastructures. In this research, 15 gullies were selected to measure their morphometric characteristics. The length, depth, top and bottom width and volume of gully erosion were then ...
Read More
Gully erosion has an important role in Fars province due to sediment production and enormous damages to land, roads and infrastructures. In this research, 15 gullies were selected to measure their morphometric characteristics. The length, depth, top and bottom width and volume of gully erosion were then measured. Influential factors on the sediment production and gully development were analyzed and determined by using stepwise method in SPSS software. The results indicate that sediment production due to gully development is related to three variables including drainage area, silt and the sand percent of the watershed above the gully heads. These results imply that surface runoff is acting as dominant hydrologic process on gully development. Investigation on the topographic threshold reveals that drainage area exponent (b) is negative and these results are in the same line with the results of some recent relevant studies. The results also indicate the watershed characteristics and geological formation impact on the gully sediment production. Gully development could be reduced by decreasing the area of bare land as the main source of surface runoff by vegetation planting and terracing. Constructing of small earth dams at the end of gullies collect surface runoff and provides better situations for vegetation establishment around gullies.
