Ata ghafari gilandeh; vahid safarian zengir
Abstract
In the current research, based on the data of the satellite images of the MODIS sensor, located on the Terra and Aqua satellites and the GRACE gravimetric satellite, with the innovative approach of algorithm and coding in the web system of Google Earth Engine in the cities of the provinces (Golestan, ...
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In the current research, based on the data of the satellite images of the MODIS sensor, located on the Terra and Aqua satellites and the GRACE gravimetric satellite, with the innovative approach of algorithm and coding in the web system of Google Earth Engine in the cities of the provinces (Golestan, Mazandaran and Gilan) and within the interval of years 2001 to 2022; Estimation and analysis of changes trend in snow surface area, snow depth, snow equivalent water and underground water aquifer changes in the studied area were done. According to the obtained results, the highest surface area of snowfall with a value of 9496.01 Km2 occurred in 2005 and the lowest with a value of 2906.21 Km2 in 2010, while the maximum amount of snow depth with a value of 0.07 meters in 2008 and the highest water equivalent of snow was obtained with a value of 10 kg/m2 in 2008, and this shows the high correlation between snow depth and water equivalent of snow. The results of the investigation of the groundwater aquifer based on the three CSR, GFZ and JPL models in the studied years showed that the maximum volume of the groundwater aquifer with a value of 12.5 cm was in 2005 and the lowest with a value of -27.5 cm is in 2017. The findings of the research show the decrease in the groundwater aquifer in relation to the decrease in snowfall in the study area.
Behroz Sobhani; Leyla Jafarzade Aliabad; Vahid Safarian Zengir
Abstract
The aim of the current research is to study and predict hazardous extreme temperatures in some cities of central Iran, for this purpose the minimum and maximum temperature data of 15 meteorological stations (cities: Esfahan, Shahreza, Natanz, Nain, Ardestan, Semnan, Shahroud, Garmsar, Damghan, Yazd, ...
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The aim of the current research is to study and predict hazardous extreme temperatures in some cities of central Iran, for this purpose the minimum and maximum temperature data of 15 meteorological stations (cities: Esfahan, Shahreza, Natanz, Nain, Ardestan, Semnan, Shahroud, Garmsar, Damghan, Yazd, Bafaq, Gariz, Meibod, Qom and Salafchagan) were collected for the time period (1999 - 2019) and analyzed using the innovative method of hybrid artificial neural network and ANFIS adaptive neural network model. Finally, Topsis and Saw multi-variable decision-making models were used to prioritize more exposed areas of temperature increase. The results of this study showed that according to ANFIS modelling for predicting station temperatures, the lowest mean educational error and the average error of validation for the minimum temperature, with a value of 0.010 was for the station Yazd and 1.66% for Damghan station. The lowest mean educational error and the mean error of validation for the maximum temperature curve were obtained at 0.016 for Garmsar station and 9.39% for Shahroud station, respectively. The maximum temperature fringe based on the Topsis model of two stations of Garmsar and Bafgh with a percentage of 1 and 0.96, will be in higher priority with increasing temperature. Based on the Saw model, Garmsar and Salafchegan stations with the highest percentages i.e., 1 and 0.98, respectively, were exposed to higher temperatures.
Climatology
vahid safarian zengir; Broumand Salahi; Roghayeh Maleki Meresht; MohammadKia Kianian
Abstract
The aim of this study was to analyze rainfall drought indices to predict and reduce their negative effects in Ardebil province, which involved a descriptive-analytical study in terms of research type. Data were collected using documentary method. Accordingly, the information of mean rainfall and mean ...
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The aim of this study was to analyze rainfall drought indices to predict and reduce their negative effects in Ardebil province, which involved a descriptive-analytical study in terms of research type. Data were collected using documentary method. Accordingly, the information of mean rainfall and mean temperature on a monthly basis in synoptic stations of Ardebil, Germi, Parsabad, Meshkinshahr and Khalkhal were received from the Meteorological Organization in Ardebil province for the period (1996-1996). Dip and Dic software were used to analyze the SPI and CZI indices data in each of the 5 synoptic stations of the province. Drought zoning was then performed in two scales of 6 and 12 months, from IDW interpolation, in ArcGIS software. The innovation of the present study was the use of if-then rules in MATLAB software in combining drought indicators in the field of climatology. The results showed that very severe droughts at the 12-month scale were less than at the 6-month scale, and in all 5 stations studied, the number of moderate droughts was more than severe and very severe ones. Also, the highest frequency of drought was observed in Ardebil city and the lowest in Germi station. Similarly, a comparison of the two indicators displayed that their performance did not differ much; but it turned out that the SPI index, could reveal the number of droughts better than the CZI index.
environment
vahid safarian zengir; BATOL Zenali; Leyla Jafarzadeh Aliabad
Abstract
y in Ardabil province analyzed the precipitation data of 30 years from 1987 to 2016. Most of the precipitation occurred on 09/12/1991.Synoptic atmospheric maps of this date at a level of 500 Millibars were prepared by sea level elevation maps, geopotential heights, wind speed and direction, humidity, ...
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y in Ardabil province analyzed the precipitation data of 30 years from 1987 to 2016. Most of the precipitation occurred on 09/12/1991.Synoptic atmospheric maps of this date at a level of 500 Millibars were prepared by sea level elevation maps, geopotential heights, wind speed and direction, humidity, temperature, perceptible water on ground level and blocking (omega), using satellite images from NCEP/NCAR databases which Affiliating to the National Oceanographic Organization of the United States. The research method is a circular environmental approach. The results showed that in addition to the ground and climate conditions that have been effective in causing heavy rainfall during this history, the internal situation with the external pattern, such as the seas around and adjacent to Iran like the Black Sea and the Mediterranean has been affected. The monthly precipitation of Khalkhal station as a region that is more prevalent in the south of Ardebil province and southwest of the Caspian Sea in the three months of the spring season is more than February (1321/8 mm), March (1716.7 mm) and April (1448 mm). The most natural atmospheric hazards affected by heavy rainfall and flood damage in Khalkhal, inland, village, river and agricultural damages occurred during these months.
environment
Behroz Sobhani; vahid safarian zengir; Rabab dyhm
Abstract
Thunderstorms rainfalls are a kind of unstable storms that are caused by an extremely strong abnormal state of atmospheric displacement and are one of the most important climatic phenomena in the northwest of the country.The aim of this study was to determine the spatial distribution of thunderstorms ...
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Thunderstorms rainfalls are a kind of unstable storms that are caused by an extremely strong abnormal state of atmospheric displacement and are one of the most important climatic phenomena in the northwest of the country.The aim of this study was to determine the spatial distribution of thunderstorms rainfalls in Ardabil province by using satellite images and Estimation of perceptible water. In this study, synoptic stations data, satellite imagery and MODIS bands 17 and 18 for Estimation of perceptible water were used. Images of thunderstorms rainfalls on 05.10.2010 and 18.06.2012 in ENVI4.4 software was processed and then they were interpolated in ArcGIS. Also, the results of interpolated field data revealed that the highest thunderstorms rainfalls are at Khalkhal station and lowest occurs in Meshkinshar station. In addition, thunderstorms rainfalls in the province in the spring and early summer lightning occurs. The results of the analysis of ground data and satellite imagery indicated this fact that the thunderstorms rainfalls derived from satellite imagery is far more accurate than data that obtained from the harvest of the earth. Also, maps of thunderstorms rainfalls can be extracted quickly and accurately, as well as using in the prediction of atmospheric hazards and optimal water resources planning in Ardabil province.
