Showing 3 results for Esfandiary
Fariba Esfandiary Darabad, Masoud Rahimi, Khodadad Lotfy, Ebadi Elhameh,
Volume 20, Issue 57 (6-2020)
Abstract
So that the morphological and transverse changes of the Ghezelozan River have been evident in recent years and caused some problems. In this study, the detection of river side changes was carried out using satellite imagery of TM and OLI Landsat 5 and 8 in the period 1993 to 2013, during which an interval of 158 km from the Ghezelozan River, using the transect method evaluated. The channel duct was divided into 24 transects based on morphology and the process of change. The average migration rate of the Gezelozan River duct has been around 4.47 m / year over the past 20 years. The highest transhumance rate between 1993 and 2013, at 10.58 m / year, is related to transect 16, resulting in 52.51 hectares on the right bank of the river. Overall, the results show that during the period 1993 to 2013, close to 207.14 hectares was added to the right bank of the river and nearly 215.31 hectares from the right bank were decreased. Also, in this study, sinusoidal index was used to study the shape of the duct flat, based on which there are 15 sinusoidal transects.
Fariba Esfandiary Darabad, Morteza Gharachorlu,
Volume 23, Issue 69 (6-2023)
Abstract
This study was aimed at identification and determination the spatial variations of sediment yield in Qarasu watershed located in Ardebil province, NW Iran, considering the negative consequences of erosion and sediment yield. In this regard, the monthly time scale, as the basis of work, was used to prepare the sediment rating curves. Preparation of monthly sediment rating curves based on sample flow and corresponding sediment discharge data in 19 hydrometry stations at the watershed during 14 years (2002-2015). All of statistical analyses were done by SPSS statistical software. Also, presentation of spatial variations in sediment yield over the watershed were made possible through the capability of GIS. The results of regression relations between flow and sediment discharge showed a close and significant relationship on a monthly time scale. The regional generalization of these relations for the whole basin showed that the seasonal difference was evident and the highest and lowest coefficient of determination was allocated to May (R2 = 0.74) and August (R2 = 0.55), respectively. Also, the highest and lowest sediment transport was observed in spring and summer, respectively, indicating the type of rainfall-runoff regime dominated on Qarasu watershed. In terms of the annual sediment yield, Yamchi station with 3970 tons per year and Nanakaran station with 66 tons per year, have the highest and lowest sediment yield among 19 stations of Qarasu watershed, respectively. According to the high levels of sediment yield in the Balikhly and Khyav sub-watersheds, it was recommended that more attention be paid to protecting and strengthening the water and soil elements and reducing the driven forces of erosion and sediment production in these sub-watersheds.
Dr Raoof Mostafazadeh, Dr Fariba Esfandiary, Miss Mahnaz Hamzeei, Miss Nazila Alaei,
Volume 24, Issue 72 (3-2024)
Abstract
The purpose of this study was to evaluate the temporal variations of vegetation cover of Gharesou River riparian area in Ardabil province using landscape metrics over a period of 8 years which is important for morphology assessment and river ecosystem protection planning and management. The Google Earth imagery for the years 2011, 2016, 2019 due to their live view and high resolution were used to map the Gharesou River riparian area vegetation. Correlation analysis in R environment was used to evaluate the relationship between landscape metrics in the study time period. The results showed that there is an increase in the number of patches, which showed an increase in landscape fragmentation of the riparian area vegetation. Landscape connectivity index was 91.52% to 95.49% in this region during the study period, indicating the removing small patches of vegetation communities around the river. The number of patches in the present study showed an increasing trend, which was the highest amount at 2019 year. The results of changes in the width of the Gharesou River showed that the river width in 2019 was 27.43m and 3.97 m, respectively. Comparison of river width values over the three study periods indicates an increasing trend in river widths, which may be due to the limitation of river width by human activities or the protection of river banks to protect agricultural lands against flooding effect. Also, the correlation of river width showed that the correlation between time period 2019 and 2016 was 0.63 and significant at 0.001 levels. The lowest correlation between the period 2019 and 2011 was 0.30 at 5% significant level. In conclusion, the results of changes in riparian area communities can be linked to the extension of agricultural land adjacent to the main river course.
