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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Rangeland Science
- نوع مقاله: Journal Article
- کلمات کلیدی: Support vector machine,Desertification,NDVI,Landsat,MSAVI
- چکیده:
- چکیده انگلیسی: More than one-third of the earth is characterized by arid and semi-arid climate and desertification phenomenon in these areas has been intensified in recent decades. This study aims to investigate the trend of desertification using vegetation indices and Iranian Model of Desertification Potential Assessment (IMDPA) in Abarkooh Plain, Yazd province, Iran. The satellite images (Landsat images in May 1987, 2000 and 2013) were used to map the land uses in the region. After the image preprocessing with a supervised classification method (support vector machine) that had the highest accuracy in all years, the map of land use changes was prepared in five kinds of land uses such as residential and industrial lands, agriculture and horticulture lands, arid and desert lands, playa and saline soils, and mountainsT .hen, the desertification map of Abarkooh Plain was prepared by calculating the Normalized Difference Vegetation Index (NDVI( and Modified Soil Adjusted Vegetation Index )MSAVI( according to IMDPA model. Three criteria, urban and residual lands to agricultural land ratio (Ur/Ag), plant canopy density and vegetation renewal indicators were used in IMDPA model. On the basis of the Ur/Ag ratio, 5.74%, 6.74% and 87.52% of the region were characterized by severe, moderate and low desertification, respectively due to land-use change factors. In the viewpoint of aboveground canopy density indicator, desertification in the area was classified into four classes including very severe, severe, moderate, and low desertification. In this regard, 99.06%, 0.76%, 0.13% and 0.05% of the areas are put in very severe, severe, moderate and low desertification classes, respectively. According to vegetation renewal indicator, 92.51%, 3.21% and 4.28% of the area were characterized as unchanged, low and very severe desertification, respectively.
- انتشار مقاله: 29-04-1395
- نویسندگان: Mohammad Ali Hakimzadeh Ardakani,Fatemeh Cheshmberah,Mohammad Hossein Mokhtari
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Nanofiltration,Florfenicol,Total ammonia nitrogen,Trout fish farm,Wastewater
- چکیده:
- چکیده انگلیسی: An aquaculture system can be a potentially significant source of antibacterial compounds and ammonia in an aquatic environment. In this study, the removal of total ammonia nitrogen and florfenicol antibiotic from synthetic aqueous wastewater was assessed by applying a commercial TFC (thin film composite) polyamide nanofilter. The effects of pH (6.5-8.5), pressure (4-10 bar), concentration of total ammonia nitrogen (1-9 mg/L), and florfenicol (0.2-5 mg/L) on the removal efficiency of the nanofilter were studied at a constant 70% recovery rate. It was found that by increasing the pH within the range of 6.5 to 8.5, it enhanced the removal efficiency by up to 98% and 100% for total ammonia nitrogen and florfenicol, respectively. With an increase in pressure from 4 to 7 bar, the removal percentage increased and then, it decreased from 7 to 10 bar. The interactions factors did not have significant effects on the both pollutants removal efficiencies. To obtain optimal removal efficiencies, an experimental design and statistical analysis via the response surface method were adopted.
- انتشار مقاله: 16-04-1395
- نویسندگان: Ali Reza Solaimany Nazar,Fatemeh Cheshmberah,Mehrdad Farhadian
- مشاهده