4051

3829

كارشناسي ارشد

آبياري و زهكشي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1386

چهارده، 142، [II] ص.: مصور، جدول، نمودار

ص.ع. به: فارسي و انگليسي

فرهاد موسوي، مجيد سرتاج

سعيد اسلاميان، نادر فتحيان پور

18/04/87

مجيد افيوني، كيوان اصغري

مهندسي كشاورزي

ID3829

به فارسي و انگليسي: قابل رؤيت در نسخه ديجتال

Abstract Agriculture is the main non point source of pollution of groundwater in irrigated areas as fertilizers and other agrochemicals are the main contaminants in the water that drains out of the root zone to recharge the aquifers Nitrate released from fertilizers and dissolved in percolation water is lost from irrigated fields The concentration of nitrate in the percolated water depends on the variation of soil mloisture in the field and nitrogen balance over the area Its concentration in the groundwater depends on the total recharge pollution loading groundwater flow and solute transport within the aquifer In this research non point source pollution of groundwater and its variation in Arak plain located in Markazi province ws investigated by applying AVSWAT X Visual Modflow 4 and its solute transport model MT3DMS simultaneously From fall 2006 until summer 2007 seasonal pH DO NO3 Fe Zn Pb EC TDS BOD COD and Total Coliforms were measured in 40 selected wells In addition 42 geoelectric soundings were performed to recognize bedrock and aquifer type Nitrate leaching was estimated by using AVSWAT X model and its inputs including DEM soil map land use climate information fertilizers application and cultivated crops Then the aquifer was simulated by gathering input data such as climate data hydrogeologic parameters hydrology data water level in pizometric wells and water withdrawal from the aquifer and using Visual Modflow 4 and MT3DMS subroutine The model was calibrated with PEST code Correlation coefficient and RMSE were 0 998 and 2 27 for groundwater flow and 0 88 and 15 for nitrate transport in groundwater in calibration stage In general application of these models resulted in good estimation of nitrate concentration in groundwater Some of the wells had only nitrate and EC content higher than drinking standards Mean nitrate concentration for the whole period was 22 92 mg lit and it range was 5 21 53 88 mg lit in different wells Seasonal averages of nitrate concentration from fall 2006 till summer 2007 were 21 32 20 49 24 29 and 25 58 mg lit respectively Generally EC of 83 of the wells was higher than standards 0 7 dS m for drinking Modeling results showed that nitrate concentration has been increasing in some regions such as suburb of Arak and west and south of the plain Simulation results shwed that in the next 15 years nitrate concentration has almost doubled in the west region from 10 to 20 mg lit and from 20 to 35 mg lit in the suburb of Arak However it does not change in the north but the plume has enlarged and moved to the east and south pdfMachine A pdf writer that produces quality PDF files with ease Produce quality PDF files in seconds and preserve the integrity of your original documents Compatible across nearly all Windows platforms if you can print from a windows application you can use pdfMachine Get yours now

فرهاد موسوي، مجيد سرتاج

سعيد اسلاميان، نادر فتحيان پور

مجيد افيوني، كيوان اصغري