Investigation of runoff and sediment yield using N-SPECT model in Pelasjan (Eskandari), Isfahan, Iran

Paper Details

Research Paper 01/04/2015
Views (175) Download (11)

Investigation of runoff and sediment yield using N-SPECT model in Pelasjan (Eskandari), Isfahan, Iran

Sahar Khalili, Ali Akbar Jamali, Mohammad Hasanzadeh, Abolfazl Morovvati
J. Bio. Env. Sci.6( 4), 80-88, April 2015.
Certificate: JBES 2015 [Generate Certificate]


Identifying and quantifying the runoff and Sediment yield are the necessary measures in the issues of soil erosion in a watershed. Pelasjan watershed located in West of Isfahan and it is one of the sub basins of Zayanderud which is taken as the study area. In this study the amount of runoff and Sediment yield has been evaluated using the Nonpoint-Source Pollution and Erosion Comparison Tools (N-SPECT) model which is an extension to ArcGIS software. The input layer maps in the GIS environment, including land use, the rain erosion, vegetation, soil erodibility, contour map and watershed boundary map were prepared. By entering the input data and running N-SPECT model, runoff and Sediment yield raster maps of the study area were obtained. To evaluate the model and data comparing, the values obtained from the model and the actual data values of runoff and Sediment yield were converted to the eigenvalues. Special amount of runoff from the model equals 1483 m3/ha/year and the actual runoff is equivalent to 1253 m3/ha/year for 21 water years ,from 1991 to 2012. From the values obtained by the model and the actual data it can be concluded that the model is sufficiently accurate for estimating runoff since the actual runoff value and the value obtained from the model are close to each other and statistically, there is no significant difference between them during this 21 water year. In relation to a Sediment yield, the amount obtained from the model was 7.8 ton/ha/year and the average amount of Sediment yield for 21 water years is 2.1 ton/ha/year, which by comparing with the values obtained for Sediment yield it can be concluded that the model overestimates about three times from the actual amount and there is a significant difference between the real data and data obtained by model so the model has not been very successful in Sediment yield estimating. One of the advantages of this model for estimating runoff and Sediment yield is point to point estimation of runoff and Sediment yield in output maps of the region. This model is particularly recommended for harsh and difficult access regions of the watershed.


Baaybordi M. 2009. Soil Physics, Tehran University Press, ninth edition, 671 p.

Betrie GD, Mohamed YA, van Griensven A, Srinivasan R. 2011. Sediment management modeling in the Blue Nile Basin using SWAT model. Hydrol. Earth Syst. Sci. 15, 807–818.

Esmaeely A, Abdullahi Kh. 2010. Soil Conservation and Watershed Management, Mohaghegh Ardebili University, first edition, 574 p.

Ghorbani Kh. 2012. Geographically Weighted Regression: Tools for drawing isorain maps in Gilan province, soil and water Journal (Agricultural Science and Technology), 26, Number 3, pp. 752-743.

Hassani pak A. 1998. Geostatistics, Tehran University Press, 314 p.

Hongya W, Xu L, Sun Xu, Lu M, Du Xi, YuyingHuo lan S. 2011. Comparing mineral magnetic properties of sediments in two reservoirs in “strongly” and “mildly” eroded regions on the Guizhou Plateau, southwest China, A tool for inferring differences in sediment sources and soil erosion, Sweden University, 3, 255-271

Hossein Zadeh R, Jahadi Tarafi M. 2013. Assess the accuracy of digital elevation models (DEMS) obtained from topographic maps and comparative case study with satellite DEM and ASTER DEM of Aabghe region in Khorasan Razavi, natural Geographical Journal (Geographical Research) 45(1), 71-86.

Jabbari I, Arefi M. 2003. Estimation of soil erosion and sediment yield by measuring a shower, Geographical Research Quarterly, No. 84, pp. 53-74.

Javadi M, zehtabian Gh, Ahmadi H, Ayoobi Sh, Jafari M. 2011. Comparison between estimations of the suspended sediment potential in various units using a rainfall simulator in Namehrood, the Natural Resources Science and Technology, 2, 14 -21.

Mahdavi M. 2007. Applied Hydrology, Volume II, Second Edition, Tehran University Press, 435 p.

Mahmoodabadi M, Charkhabi A, Refahi H, Gorgi M. 2005. Zoning of erosion Hazard in the Golabad watershed, Isfahan using MPSIAC model and GIS, Journal of Agricultural Science of Iran, 36( 2), 520-511.

Mahmoodabadi, M., Ghadiri, H., Rose, C., Yu, B., Rafahi, H., Rouhipour, H., 2014. Evaluation of GUEST and WEPP with a new approach for the determination of sediment transport capacity, Journal of Hydrology, 513, 413-421.

Nojavan M, Mohammadi A, Gholami V. 2012. Determining erosion rates using the BLM and Fargas models, case study Bandareh watershed, Journal of Geography and Development, 29, 130-119.

Pandy A, Chowdary VM, Mal BC, Billib M. 2008. Runoff and sediment yield modeling from a small agricultural watershed in India using the WEPP model, Journal of Hydrology, 348 (3), 305-319.

Setegn Shimelis G, Dargahi B, Srinivasan R, Melesse Assefa M. 2010. Modeling of sediment yield from Anjeni gauged watershed, Ethiopia using SWAT model. JAWRA 46 (3), 514–526.

Shen AY, Gong, YW, Li YH, Hong Q, Xu L, Liu RM. 2009. A comparison of WEPP and SWAT for modeling, soil erosion of the Zhangjiachong Watershed in the Three Gorges Reservoir Area, Agricultural Water Management 96 (10), 1435-1442.

Soorinezhad A. 2002. Estimation of runoff volume in Kashkan watershed using GIS, Geographical research Journal 43, 80-85.

Sun H, Cornish PS. 2005. Estimating Shallow groundwater recharge in the Headwaters of the Liverpool Plains using a SWAT Hydrol process 19 (3), 795-807.

Tolson BA, Shoemaker CA. 2007. Cannonsville reservoir watershed SWAT 2000 model development, calibration, and validation. J. Hydrol. 337, 68–86.

Yesuf HM, Assen M, Alamirew T, Melesse AM. 2015. Modeling of sediment yield in Maybar gauged watershed using SWAT, northeast Ethiopia. Catena 127, 191-205

Zahabioun B, Goodarzi M, Masah Bavani A. 2010. Application of SWAT model to estimate watershed runoff in future periods affected by the climate, Climatology Research Journal 1(3), 58-44.