ارزيابي تخمين رواناب و رسوب با استفاده از مدل SWAT2000 در زير حوزه ونك از حوزه آبخيز كارون شمالي

چكيده انگليسي :

Abstract Formatted Font 10 pt Bold Soil erosion is one of the most important problems in the world and one of the main Complex Script Font 10 pt Boldfactors effecting ecosystems Soil erosion in Iran is high According to the availableinformation 59 percent of the 17 basins that have been studied in Iran have been severelydegraded Erosion prediction technology is a powerful tool used for more than half acentury in policy development erosion inventories conservation planning andengineering design Spatially distributed hydrological models are useful tools to supportthe design and evaluation of water management plans The objective of this study was touse SWAT2000 Soil Water Assessment Toll to evaluate runoff and sediment estimationin Vanak Vanak sub basin 3198 km2 located in southeast of north Karun watershed SWAT is a conceptual physically based long term continuous watershed scalesimulation model that operates on a daily time step This model was developed to predictthe impact of land management practices on water sediment and agricultural chemicalyields in large complex watersheds with varying soils land use and managementconditions over long periods of time Model calibration and uncertainty analysis wereperformed with SUFI 2 which was interfaced with SWAT using the generic SWAT SAIprogram SUFI 2 is a semi automated inverse modeling procedure for a combinedcalibration uncertainty analysis In this study runoff and sediment data of fourhydrometery stations Aghblagh Kasgan Soolgan and Vanak were used for calibrationand validation model Five factors were used to model evaluation include percentdifferences factor R2 coefficient Nash Sutcliffe coefficient d factor and p factor First the model considers basin dam and springs was run but because inaccuracy anddiscontinuity data in runoff simulation they were omitted Data from period of 1989 2004 were used Model calibration and validation were performed with and data respectively After calibration model was used to simulate monthly runoff in Kasgan Soolgan and Vanak stations satisfactory R2 coefficient Nash Sutcliffe coefficient d factor and p factor were 0 68 0 41 1 14 and 0 78 for Aghblagh 0 6 0 58 1 16 and 0 71for Kasgan 0 7 0 64 0 97 and 0 79 for Soolgan and 0 85 0 76 0 77 and 0 8 and forVanak respectively These factors after monthly runoff validation were 0 72 0 7 0 95and 0 81 for Aghblagh 0 7 0 1 2 04 and 0 79 for Kasgan 0 84 0 75 1 12 and 0 77 forSoolgan and 0 87 0 78 0 86 and 0 89 for Vanak respectively These values forAghblagh Soolgan and Vanak have acceptable accuracy Monthly runoff simulationresults in Vanak basin showed that model can not estimated runoff peak because thesnowfall snowmelt process was not estimated correctly Daily sediment simulation wasnot satisfactory Limited and inaccuracy of the data and inconvenient simulation fordaily runoff may be the reasons Also in this study effect of three plow instruments onrunoff that include Moldboard Plow Chisel Plow and Duckfoot Cultivator wasconsidered Moldboard Plow is the equipment that is the mostly used in this basin Runoff simulation results with this instruments showed application of Moldboard Plowincreased peak flow and decreased base flow but Chisel Plow and Duckfoot Cultivatorapplication decreased peak flow and increased base flow reason of this maybe thatMoldboard Plow with barring plant residual and transporting deep soil to surface causingdeep soil moisture loss Chisel Plow and Duckfoot Cultivator with remaining plantresiduals on surface limit erosion and surface evaporation cause better infiltration andstore moisture

ژاله ، اعظمه

ارزيابي تخمين رواناب و رسوب با استفاده از مدل SWAT2000 در زير حوزه ونك از حوزه آبخيز كارون شمالي

مدل هاي رگوسيوني , چرخه هيدرولوژي , روزيابي ماسكينگام , ضريب نش _ ساتكليف