جستجوی مقالات مرتبط با کلیدواژه "ساری" در نشریات گروه "زمین شناسی"

Globally, rivers are under tremendous anthropogenic stress caused by stream fragmentation, land use changes, and regulation and water quality has been widely declined. In a review of studies, the integrity of flowing water systems largely depends on their natural dynamic characteristics, which sustain habitat. In this study, the physical and chemical factors of the Tajan River water, which is the habitat of various fishes and where the release of some economic fishes of the Caspian Sea takes place, are investigated in 7 stations during the year 2022. The results of the physical and chemical parameters such as water temperature, pH, electrical conductivity, total suspended solids, turbidity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, ammonium, nitrite, nitrate, phosphate, water quality index and comprehensive pollution index were recorded as 14.50-32.00 °C, 6.48-12.24, 562-10020 µs/cm, 2.35-185.71 mg/l, 1.8-328 NTU, 1.01-14.11, 0.58-16.05, 2.39-50.21, 0.020-1.028, 0.005-0.771, 0.49-58.56, 0.010-1.610 mg/l, 17.0-75.0 and 1.20-7.33, respectively. Based on the principal component analysis, the biochemical oxygen demand, nitrite, nitrate, and phosphate variables are in the first component, which is more important in the Tajan River. Also, based on the step-by-step regression analysis of the water quality index, the most effective variable was recorded biochemical oxygen demand, turbidity, and phosphate, and according to the comprehensive pollution index, the water quality of this river was dependent on the variables of phosphorus, phosphate, and nitrate. Finally, based on the physical and chemical parameters and various water use indicators, the Tajan River is unsuitable for fish life. Based on various indicators, station one (placed in a separate group in the cluster test) compared to other stations has more suitable conditions for releasing fish juveniles.

Soil temperature is the most important factor in sustainable development and agriculture. These factors are not controllable, but by examining the facts and figures it can be predictable and under control. The aim of this study was to evaluate soil temperature at synoptic stations in Sari, Mazandaran province. The study period is from 2003 to 2014. The database consisted of soil temperature at depths of 5, 10, 20, 30, 50 and 100 cm, dry air temperature, soil moisture and air in the above-mentioned period which is collected by the equipment used in meteorological stations. Neural network method is used to estimate the model. Results showed that soil temperature is directly related to air temperature But deep down near the surface of this dependency has been.and Soil temperature with air humidity has fluctuates. So that up to 50 cm rise but decreased with increasing depth. Soil moisture also examined and The results have shown that this agent is effective in high depths.

In this study active faults in the region of Shahid Rajai dam of sari with 100 km radius was categorized on based fractal dimension of faulting and Earthquake and also evaluating of slip rate and investigate those activity rate. Using the fractal dimension of faulting and earthquake with squares method (Box-counting) and finally by classification this fractals dimension، the faults of North Alborz، Damghan and Garmsar more activity faults in the region of study area during 100 years late which based on activity degree of faulting and Earthquake with method of fractal analysis which based on assessment of activity degree of faulting and earthquake with method of fractal analysis also set in BD grade and this activity was confirmation. For assessment of slip rate beginning the seismicity parameters (a&b) of study area was determination، then these parameters were normalized for each fault. Based on existing relationships and having a&b for each fault، the seismic moment those fault was calculated. According to The relationships for calculating the rate of seismic moment، slip rate of each fault has been estimate and based on faults in study area was classification. The Faults with very low slip rate and high return period of earthquake could cause occurrence large earhquakes which earthquake of 856 A. D Qumes and causing smith therefore Damghan Fault could this fault know. Thereupon Therefore expectance larger slip in the future on faults such as Astaneh، Rameh، Cheshme-Ali and etc Will have. High slip rate along the New faults introduced (Khorram-Abad، Majid، etc.) in this area is noteworthy that according to occurrence the earthquakes in the privacy of their fault، the high slip rate is reasonable.