جستجوی مقالات مرتبط با کلیدواژه « arvand river » در نشریات گروه « زیست شناسی »

Aquatic and semi-aquatic plants are vital components of aquatic ecosystems, contributing significantly to their ecological balance. This study focused on the analysis of marginal plants along the Arvandroud, conducting seasonal samplings with 1 x 1 square meters and 3 repetitions at each station across two periods: summer 2015 and winter 2016. The collected samples underwent pressing for herbarium studies. The survey identified 25 plant species spanning 11 families. Among these, 5 were monocotyledonous, encompassing Poaceae and Cyperaceae, while 18 were dicotyledonous, including Lamiaceae, Capparaceae, Fabaceae, Asteraceae, Convolvulaceae, Apocynaceae, Amaranthaceae, Tamaricaceae, and Polygonaceae. Notably, the dominant marginal plants observed during summer were Phragmites australis (Cav.) Trin. Ex. Steudel and Cyperus longus L., while in winter, it was Phragmites australis, Cyperus longus, and Senecio glaucus L. Phragmites australis emerged as the dominant species based on its density across both seasons. Principal Component Analysis (PCA) revealed the influential environmental factors affecting these plants, with sediment particles, total organic matter, salinity, and electrical conductivity identified as the most significant. Interestingly, plant density was higher in winter compared to summer, highlighting seasonal variations in plant distribution along the Arvandroud.

Providing faultless proceeding of the engineer in order to protect the rivers, requires understanding the morphological behavior of the river and studying the hydrodynamic phenomena of the area. The intersection of the Karun rivers as the largest and longest river in Iran with the Arvand border river is of considerable importance due to its strategic location. In this paper, using field measurement and numerical modeling, the hydrodynamic processes of this area have been investigated. Measurement of marine parameters related to the border area with hard access at the intersection of Karun to Arvand and it includes water level and current velocity, hydrography, sediment granulation, and hydrodynamic modeling of current and sediment. Current velocity measurements show that the prevailing flow velocity in this area is towards Arvand and Arvand tide can only reduce the flow velocities of this river locally. Hydrographic changes also indicate flood currents in Karun, which act like water jets, causing significant changes in the bed of the intersection of Karun and Arvand rivers and shifting the Talweg line to Iraq. At the intersection of rivers due to sharp changes in depth, sediments are coarser than other points and also the concentration of sediments increases with movement at depth. The results of the numerical model are consistent with field measurements and indicate that sediment flow in the Arvand River is carried out by the Karun River and the effects of sediment flow in the Arvand River on Karun are very small. Also, the intersection of these two rivers has a high potential for sedimentation and increase the thickness of the bed.

The purpose of this study was to identify and investigate the density and distribution of copepoda and cladosera and the structural analysis of their dominant species in the Arvand river by SEM (scaning electron microscope). Sampling was conducted with 50 μm mesh size plankton net at 6 stations and four times (in different seasons) with three reputation. The samples were detected by phase contrast microscopy and SEM. Totally 15 species of copepoda and 5 species of cladocera were identified in the river. The highest density of planktonic crustaceans including copepoda and cladocera with a mean density of 9481 and 3155 individuals per cubic meter was calculated in summer. These species, Acartia faoensis, Canthocalanus pauper, Subecalanus flemingeri, Labidocera acuta, which accounted for 61% of the total copepods abundance and 54% of the cladosera abundance were related to Moina macrocopa and Daphnia longisoina. The integrity of river were study using saprobic index which showed mesosaprobic-β (medium pollution) with mean 2.48 point.

In this study, the molecular characteristics of Chiromantes boulengeri in 2014 from intertidal waters of Arvand River in the vicinity of Minoo island were investigated. So, in October 2014 specimens from intertidal of two area of Minoo island were collected and preserved in 70% ethanol, carried out to the khoramshahr University of Marine Science and Technology laboratory and examined. To fulfill the purpose, To extract the DNA, phenol- chloroform method were used and mitochondrial gene 16S rRNA was sequenced and compare with other species from GenBank NCBI. The morphological and phylogeny sequencing results showed that all specimens belong to Chiromantes boulengeri in the study area. By polymorphism analysis, there are mutation within C. boulengeri from two area of Arvand River and it seems that this species for its survival has adapted with different ecological conditions in the study area.

Water resources under threat of pollution such as industrial waste, fertilizers, pesticides and urban sewage that negative effects on the environment and ecosystems. Arvand Rood is one of the most important navigable rivers in Iran, and it’s the most traffic place for floating which don’t have any system for delivery waste materials and discharging these waste materials in water making oil pollution. In this research, modeling pollution in the Arvand River using three-dimensional and hydrodynamic model to simulate how the pollution is studied, the Navier-Stokes equations in three dimensions and equations are solved transfer salinity and water temperature separation method. Boundary conditions applied, including changes in temperature, salinity and flow rate, temperature and salinity changes and apply for open border river and tidal components O1¡ S2¡ M2 and K1 open sea in the model used for the border. The results of modeling pollution in Arvand After running the model revealed that the pollution is pollution in the Arvand River according to location and time of release, In other words, in the Arvand River pollution from one point to another and from season to season is different, in fact, pollution is reciprocating mode. Diffusion of oil pollution in Arvand rood is depending to current. And in low tide because of same side of river current with low tide pollution reached to the Persion Gulf with high speed. The results shows, represent the effect of tie on diffusion pollution.