عنوان مقاله [English]
In water efficiency studies, the values of runoff, evapotranspiration and range production are the main variables. Rangelands of Golestan province, Iran, have a high potential of run-off due to the geographical location, climate, and destruction of these resources as well as drastic land use change from forests and rangelands to agricultural lands. Therefore, in the present study, in order to determine the best management of rangelands, we developed a rangeland improvement model using the Soil and Water Assessment Tool (SWAT) in the Gorganrud Watershed, Golestan Iran. Calibration and validation of model was performed using Sequential Uncertainty Fitting Program (SUFI-2) in the eco-hydrological model SWAT. For this purpose, the SWAT was calibrated and validated for a 31-year period of discharge and 5-year period of range production and then the model was executed for different scenarios of rangeland management. The results showed that the model performance was satisfactory for predicting discharge. The values of Nash-Sutcliffe coefficient were calculated to be 0.72, 0.71 and 0.64 in calibration period and 0.59, 0.48 and 0.53 in validation period for Basirabad, Tilabad and Haji Ghoshan stations, respectively. As well, four range improvement scenarios (mechanical, biological, biomechanical and livestock grazing management) were defined in this study. On average, by applying mechanical, biological, biomechanical, and grazing management scenarios evapotranspiration was increased to 2.3%, 12.8%, 15.5% and 2.8%, respectively, in comparison with actual evapotranspiration. According to the obtained results, the biomechanical scenario was identified as the best one in increasing evapotranspiration in poor and moderate rangelands.
- Abbaspour, K. C., 2011. User Manual for SWAT-CUP, SWAT calibration and uncertainty analysis programs. Swiss Federal Institute of Aquatic Science and Technology, Eawag, Duebendorf, Switzerland, 103p.
- Abbaspour, K. C., Yang, J., Maximov, I., Siber, R., Bogner, K., Mieleitner, J., Zobrist, J. and Srinivasan, R., 2007. Modeling hydrology and water quality in the pre-Alpine/Alpine Thur watershed using SWAT. Journal of Hydrology, 333(1): 413–430.
- Arnold, J. G., Srinivasan, R., Muttiah, R. S. and Williams, J. R., 1998. Large area hydrologic modeling and assessment—Part 1. Model development. Journal of the American Water Resources Association (JAWRA). 34:73–89.
- Azimi, M., Heshmati, G. A., Farahpour, M., Faramarzi, M. and Abbaspour, K. C., 2013. Modeling the impact of rangeland management on forage production of sagebrush species in arid and semi-arid regions of Iran. Journal of Ecological Modeling. 250(1): 1–14.
- Croke, B. F. W., Merritt, W. S. and Jakeman, A. J., 2003. A dynamic model for predicting hydrologic response to land cover changes in gauged and ungauged catchments. Journal of Hydrology 291: 115–131.
- Faramarzi, M., Yang, H., Schulin, R. and Abbaspour, K. C., 2010. Modeling wheat yield and crop water productivity in Iran: Implications of agricultural water management for wheat production. Journal of Agricultural Water Management, 97(1):1861–1875.
- Folbert, C. H., Gaiser, T., Abbaspour, K. C., Schulin, R. and Yang, H., 2012. Regionalization of a large-scale crop growth model for sub-saharan Africa: Model setup, evaluation and estimation of maize yield. Journal of Agriculture, Ecosystem and Environment, 151(2): 21-33.
- Gao, Y. and Long, D., 2008. Inter comparison of remote sensing-based models for estimation of evapotranspiration and accuracy assessment based on SWAT. Journal of Hydrological Processes, 22(25): 4850-4869.
- Hargreaves, G. H. and Samani, Z. A.,1985. Reference crop evapotranspiration from temperature. Journal of Applied Engineering Agriculture, (1): 96-99.
- Holechek, J. L., Pieper, R. D. and Herbel, C. H., 2004. Range Management: Principles and Practices. Pearson Education, Inc., New Jersey. 736p.
- Hosseini, M., Ghafouri, M., Tabatabaei, M., Nadergholi, E. and Zare Garizi, A., 2016. Estimation of hydrologic budget for Gharesou watershed, Iran. Journal of Ecopersia, 4(3): 1455-1469.
- Khatir Namani, J., 2008. Reports of range assessment in different climate area in Golestan province. Iran. Golestan Agricultural and Natural Research Center. Research Institute of Forest and Rangelands. 89pp.
- Mahzari, S., Kiani, F., Azimi. M., and Khormali, F., 2016. Using SWAT model to determine runoff, sediment yield and Nitrate loss in Gorganrood watershed, Iran. Journal of Ecopersia. 4(2): 1359-1377.
- Moriasi, D. N., Arnold, J. G., Van Liew, M. W., Bingner, R. L., Harmel, R. D. and Veith, T. L., 2007. Model evaluation guidelines for systematic quantification of accuracy in watershed simulations. American gournal of Society Agriculture Biology. Engineering, 50: 885-900.
- Nash, J. E. and Sutcliffe, J. V., 1970. River flow forecasting through conceptual models, Part 1. A discussion of principles. Journal of Hydrology, 10: 282–290.
- Neitsch, S. L., Arnold, J. G., Kiniry, J. R., Williams, J. R. and King, K. W., 2012. Soil and water assessment tool. Theoretical documentation: Version 2009. TWRI TR-406. College Station, Texas: Texas Water Resources Institute. 647pp.
- Sadodin, A. and Gholi nejad, M., 2011. Analysis of flow river in Gorganrood watershed. Golestan Regional Water Corporation.GLW-87001. 20p.
- Shahriari, A., Khormali, F. and Azarmdel, H., 2011. Clay mineralogy of Mollisols and Mollisols-like soils as affected by physiographic unit formed on loess deposits in southern Gorgan River, Golestan province. Journal of Water and Soil Conservation, 18(4): 63-79.
- Asareh, M. H. and Akhlaghi, S. J. S., 2009. Strategic framework for developing and promoting natural resources research in I.R. Iran. Iranian Research Institute of Forest and Rangelands, 379p.
- Wang, S., Kang, S., Zhang, L. and. Li. F., 2008. Modeling hydrological response to different land-use and climate change scenarios in the Zamu River basin of northwest China. Journal of Hydrological Processes, 22(1): 2502-2510.
- Zadsar, M. and Azimi, M., 2016. Using SWAT Model to Investigate the Impact of Rangeland Management Practices on Water Conservation (Case Study: Gorganroud Watershed, Golestan. Journal of Range Land Science, 6(4): 309-319.
- Ziyaee, A., Pashael, A., Khormali, F. and Roshani, M. R., 2012. Sign of pedogenesis in loess-paleosol sequences as indicator of paleoclimate, Golestan Province. Journal of Water and Soil Conservation, 20(1): 1-28.