نوع مقاله : مقاله پژوهشی
نویسندگان
1 عضو هیئت علمی، موسسه تحقیقات آب
2 گروه عمران، دانشکده فنی و مهندسی، دانشگاه بین الملل امام خمینی (ره)
3 گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه بین المللی امام خمینی (ره)
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Phosphorus is one of the vital nutrients for plants and algae growth. The low solubility of phosphorus compared to other nutrients has caused phosphorus to play a key role in algae growth and its often limiting nutrient in most freshwater. So that excessive phosphorus level in water can produce more algae that cannot be consumed by water body creatures and can cause eutrophication, water quality reduction and harmful condition for the aquatic ecosystem. Therefore, it is important to identify the main sources of entering into rivers, recognizing the mechanism of transport and its distribution as well as the conditions created in rivers due to the advection and diffusion of phosphorus. For this purpose, in this research, after identifying the main sources of phosphorus entry into the river, it investigates and simulates the advection and dispersion of phosphorus in the Qezel-Ozan, Shahrood and Sefidrood Rivers based on field measuring data and using HEC-RAS software. Five scenarios were designed based on statistics and engineering studies to predict the phosphorus concentration of rivers due to rising temperatures, changes in river discharge due to drought and wet season, human population growth and development of irrigation networks in the region for the future. Then, by numerical simulating using HEC-RAS software, the impacts of phosphorus dispersion have been investigated in the region research area. The result presented that controlling human activities that entering phosphorus to Qezel-Ozan and Shahrood rivers can reduce total phosphorus concentration of Sefidrood river, but the mass of algae has been increased only by increasing air temperature and discharge of rivers and decreasing by reduced river discharge. Besides, the results showed that the maximum total phosphorus concentration of Sefidrood River (downstream river) predicted by the numerical simulation related to the developed scenarios was higher than the maximum desired total phosphorus concentration for warm and cold-water fish. For this reason, paying more attention to limit entering phosphorus sources have to be considered for development program in the upstream rivers (Shahroood and Qezel-Ozan) in the region.
کلیدواژهها [English]