برنامه ريزي استفاده از اراضي زير حوزه شاخه اصلي زاينده رود به كمك مدل SWAT و ارزيابي اراضي

چكيده انگليسي :

Incorporating Land Capability Evaluation and SWAT Model for Land use Planning in Zayandehrud Watershed Mohammad Hossein Hemmat Joo m hemmatjoo@ag iut ac ir Date of Submission 2010 1 16 Department of Soil Science College of Agriculture Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor S Ayoubi ayoubi@cc iut ac ir Abstract Soil erosion is one of the most important economic social and environmental problem in the world Soil erosion is the main index in ecosystem health assessment According to available information the Asia suffers more than other continents in soil erosion In our country due to lack of sufficient number of measuring stations and lack of long term data bases for estimating soil erosion in watershed hydrological modeling is a main concern for evaluating soil erosion in watershed scale Modeling as a powerful procedure has been used sucessfuly for more than half century for predicting soil erosion In the present study the SWAT2005model and land capability evaluation were used to land use planning in Zayanderoud watershed to achieve reduction of soil loss The SWAT model is a continuous conceptual and long term field scale model that was being designed based on daily and sub daily periods Calibration validation and uncertainty analysis have done using SUFI 2 program After collecting input data including digital elevation model DEM strearm network land use soil map database files climate and soil temperature and rainfall data bases for minimum and maximum meteorological station study area model was ran for period of 1987 2005 75 percent of data were used for calibration and 25 percent for validation In order to evaluate efficency of model the validation indices such as p factor d factor coefficient of determination R2 and t Nash Satclife coefficien NS were applied Results of monthly runoff simulation was very satisfactory so that R2 and N S were 0 79 and 0 69 for calibration and 075 and 0 61 for validation respectively For daily runoff and daily sediment simulation R2 and N S calculated 0 75 and 0 67 for calibration daily runoff and 0 57 and 0 51for calibration daily sediment respectively and 0 72 and 0 59 for validation daily runoff 0 52 and 0 45 for validation daily sediments respectively P factor in all calculation steps caculated larger than 50 and d factor calculated less than 1 was also conifremed the satisfaction in runoff and sediment yield simulation Then the land capability evaluation of the selected watershed was persormed using Mahler approach and the best relevant of major land use was determined for each of land units Afterwards the calibrated and validated SWAT model was ran for the proposed land uses as a new scenario Finaly the resultes obtained from the two scenarios current and proposed land uses were compared using t test computation in 99 probability level The resultes of comparision of two mentioned scenarios revealed that land use based upon their fitness and capabilites decreased significantly p 0 01 maximum sediment and runoff Morover base flow of the Zayanderud river showed more qunantity in proposed land use scenario than current land use because of deep perculation of water and increasing probably spring flow and decresing direct runoff Overall results of the study showed if the land of the given watershed are being used to on their capabilities the run off and sediment yields are decresed significantly Keywords SWAT2005 model land evaluation calibration validation and Nash satclife coefficient

همت جو، محمد حسين

برنامه ريزي استفاده از اراضي زير حوزه شاخه اصلي زاينده رود به كمك مدل SWAT و ارزيابي اراضي

واسنجي , اعتبار سنجي و ضريب ناش , سا تكليف