Climatology
Fatemeh Taghavi nia; Batool Zeinali; Abbasali Dadashi Roudbari
Abstract
Climate change is a key factor in most weather-related disasters worldwide. Regarding its distinctive geographical location and diverse climate, Iran has the most variable climate in the world. The present study aims to investigate the effectiveness of the MPI-ESM-LR model from the CMIP5 model series ...
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Climate change is a key factor in most weather-related disasters worldwide. Regarding its distinctive geographical location and diverse climate, Iran has the most variable climate in the world. The present study aims to investigate the effectiveness of the MPI-ESM-LR model from the CMIP5 model series in predicting the monthly temperature of Iran under representative concentration pathway scenarios (RCPs) with the CORDEX-WAS project. In this research, for the historical period of 1980-2005, the daily air temperature data of 49 synoptic stations of the country and the MPI-ESM-LR model under the CORDEX project were used. Likewise, for the future period, from the predicted temperature data of RCP 8.5, RCP 4.5, and RCP 2.6 scenarios of the mentioned model in three periods of the near-future (2021-2050), mid-future (2051-2075) and far-future (2076-2100) was used. Validation of the model was done with three statistical indices: r, RMSE, and MBE. The results revealed that the model has a good performance. The slope of the temperature trend in station data and model data has been increasing in the historical period and the future period in RCP8.5 and RCP4.5 in all months, the temperature trend slope has been observed in every decade. In all months, the maximum anomaly of temperature under the scenarios studied in all three future periods can be seen in the northwest and western highlands. The eastern and southeastern regions of Iran have indicated minimum temperature anomalies, except in RCP 2.6 and RCP 8.5, respectively, the southern coasts and the northeastern heights of the country also show minimum temperature anomalies. In the cold half of the year, the minimum area of temperature anomaly has been extended to the north-western heights and low-altitude interior regions of the country.
Climatology
Shirin Mahdavian; Batool Zeynali; Bromand Salahi
Abstract
Climate diversity and land use / land cover change have a significant impact on hydrological regimes, especially in arid and semi-arid regions with critical water shortage problems. Therefore, estimating and evaluating climate change and land use and its consequences in each catchment is essential. This ...
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Climate diversity and land use / land cover change have a significant impact on hydrological regimes, especially in arid and semi-arid regions with critical water shortage problems. Therefore, estimating and evaluating climate change and land use and its consequences in each catchment is essential. This study examined the climate change of Kiwi Tea Basin using the data of four models of the Fifth Climate Change Assessment Report (CMIP5) under both optimistic and pessimistic scenarios (RCP8.5 and RCP4.5) using the LARS-WG6 microcirculation model. Changes in precipitation and temperature during three different periods (2040-2021, 2060-2041 and 2080-2061) compared to the base period (2019-1987) have been studied and for calibration and validation of LARS-WG6 model, observational data and output data of models with The use of F and T tests as well as RMSE, MSE, MAE and R2 indices were compared and evaluated. Based on the results of most of the models and the average of the studied models, in general, it is expected that the amount of precipitation and the minimum and maximum temperature in all the studied models will increase compared to the base period. Also, the results of evaluating land use changes with object-oriented classification showed that rangeland use with an area of 1224.18 and 1046.59 square kilometers, respectively, covered the largest area in both periods, while in 1987, residential use with an area of 3.66 square kilometers and in In 2019, water use with an area of 3.77 square kilometers had the lowest area. Also, the most modified use of rangeland use was dryland agriculture (181 square kilometers), which indicates thedestruction of rangelands
Geomorphology
Imanali Belvasi; sayyad asghari; Fariba Esfandiari Dorabad; Batool Zeynali
Abstract
Introduction
Morphological Assessment will be necessary to understand the current situation and the potential for possible river changes in the future. Natural factors such as floods, soil erosion, landslides and human factors such as land use change and sand removal from the riverbed affect the morphology. ...
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Introduction
Morphological Assessment will be necessary to understand the current situation and the potential for possible river changes in the future. Natural factors such as floods, soil erosion, landslides and human factors such as land use change and sand removal from the riverbed affect the morphology. River systems have always been of interest to humans as one of the most vital elements of the Earth's surface. Humans also change the face of the earth by changing their use, destroying natural resources, plowing the land in the direction of the slope, planting trees in the riverbeds. Any Manipulation into the riverbed will change the process of erosion and sedimentation along the river. Understanding the characteristics of flow and sediment is the basis for evaluating the behavior of rivers and deciding on engineering activities. Therefore, it is necessary to obtain the necessary information on how they work before starting engineering projects for rivers.
Data and Method
In this study, geological maps at a scale of 1: 100000 of the Geological Organization, topographic maps at a scale of 1: 50,000 digits of the Geographical Organization of the Armed Forces, Landsat satellite images, 2020 April, November 1995, Climatic data Temperature and precipitation (1399-1374) of Lorestan Meteorological Organization and Digital elevation model of 30 meters has been used. Arc GIS software was used for spatial analysis and ENVI software was used for processing satellite images. The normalized water difference index is the first index of water extraction in images and remote sensing data. In this indicator, two green and infrared bands are used. Positive values of this index indicate water and negative values indicate phenomena other than water. Researchers have proposed different methods for studying changes in river channels. The transect method is used to evaluate changes and displacements in river channels. In this method, lines with specific distances on both sides of the river route are drawn as baselines. These lines are constant for the time periods studied. River channel displacements relative to these lines are quantified. To further evaluate the Kahman River canal, the canal migration rate method was used. The Kahman river Canal was divided into two areas, mountainous areas and plain and agricultural areas, based on topography and land use.
Results and Discussion
To calculate the area to the right and left of the transects, the Kahman river channel was cut separately with a transect layer in 1995 and 2020. Calculation of changes in the area of transects shows that about 185.85 hectares of land adjacent to the Kahman river (1995-1999) have been eroded. On average, about 7.43 hectares of these lands have been destroyed annually. The maximum value of this index in transect 30 is calculated at 8.27 hectares. In order to better understand the changes and dynamics of the Kahman river Canal, the migration rate index (Rm) was also used. First, two fixed lines were drawn around the Kahman river channel. The area between the two was calculated using Arc GIS software functions. The average migration rate of Kahman river (1399-1374) was 2.51 meters per year. The lowest level of this index occurred in Trasket 49 at 0.18 meters per year. The mountain factor and stabilization operations along the river have been the most important reasons for its control and stabilization. The highest rate of migration occurred in transects 4, 32 and 30 at 4.80, 5.5 and 6.12, respectively. Shortcuts and land use changes have been the main reasons for the high rate of duct migration in these transects. The largest amount of lateral changes in the Kahman river route occurred in parts of the plain and agricultural areas, including transects 30 to 35. The most important factor was the high lateral changes of the Kahman river route in the plain area due to the high erosion of the coastal and floodplain materials. Most of the constituents of the bed and banks of the Kahman river in these periods are from fine to coarse sands.
Conclusion
Duct migration rate index showed that the average displacement of Kahman river canal (1374-1399) was 2.51 meters per year. The lowest value of this index was 0.18 meters per year and the maximum value was 6.12 meters per year. Calculation of changes in the area of transects showed that about 185.85 hectares of land adjacent to the Kahman River (1374-1399) has been destroyed. On average, about 7.43 hectares of these lands are lost every year. In the mountainous area, the effects of the mountains were the most important factor in determining the morphological changes of the Kahman River channel. The presence of erodible materials along the Kahman River in the plains and agricultural areas has increased the lateral migration of meanders and the width of the valley and floodplains adjacent to the river has increased significantly. Therefore, it can be said that the Kahman River has had more geometric changes in the plains and agricultural lands.
Climatology
Batool Zeinali; Sayyad Asghari
Volume 22, Issue 65 , November 2018, , Pages 205-222
Abstract
Purposes of this research are introduction acceptable index for detection of dust storms and also identifying sources and pathways affected by this phenomenon in the East of Iran by studying a the dust storm using MODIS satellite images. For this purpose were used dust storm hourly data, satellite images ...
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Purposes of this research are introduction acceptable index for detection of dust storms and also identifying sources and pathways affected by this phenomenon in the East of Iran by studying a the dust storm using MODIS satellite images. For this purpose were used dust storm hourly data, satellite images of Modis and also digital and visual indexes including NDDI, BTDI, BTD, LRDI and false color composing for identifying dust storms. Finally, the studied dust storms were monitored using satellite images. Results indicated that LRDI index and false color composing have the higher resolution than the other indexes for detection of dust storms. Results monitoring dust storm event in the eastern Iran in summer indicated that storms sources of east area are dry beds of Hamoon lakes, Rigistan, Margo and Khas deserts at the convergence of the borders of Iran, Afghanistan and Pakistan and central Iran. The results of this research can be used in identifying of dust sources and pathways affected from this phenomenon by organizations and institutions to national and international planning.
Geomorphology
Batoul Zeinali; Mahdei Aalijahan; fatemeh dashtbani; Rahim Fazeli
Abstract
Floods are one of the most destructive atmospheric hazards which push different communities all over the world to suffer from life and financial damages. The present research has the aim of detection of synoptic and hydrometeorology features of flood in Herochay. For this goal, the data from daily rainfall ...
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Floods are one of the most destructive atmospheric hazards which push different communities all over the world to suffer from life and financial damages. The present research has the aim of detection of synoptic and hydrometeorology features of flood in Herochay. For this goal, the data from daily rainfall of stations in Khalkhal, Khanghah, Arpachayi and Lamber and the data from Hydrometer station in River Kivichay was used to detect the rainfall and flood happened and for synoptic inspection of this phenomenon, the data from Sea level pressure, upper layers of atmosphere like Geopotential high, Omega, Orbital wind, Meridional wind and Relative humidity in levels of 500 to 1000 HPA was used. The obtained results show that presence of low-pressure system on the surface of ground, occurrence of blocking and located of the study area on the east of the trough on the upper levels, negativity of atmospheric eddies and omega on different levels with humid supply of Black Sea and Mediterranean sea on the levels of 500 to 700 HPA, Red sea and Persian Gulf and Oman Sea on the levels of 850 and Caspian Sea on the levels of 925 and 1000 HPA have prepared the conditions needed for generation of instability over the atmosphere of the studied area. The mentioned conditions have caused intense thunderstorm and increase of Herochay discharge and generation of flood in that region.
Geomorphology
Aliakbar Taghiloo; Sayad Asghari Saraskanroud; Batol Zeinali; Saleh Asghari Saraskanroud
Volume 20, Issue 56 , August 2016, , Pages 39-53
Abstract
Geo-tourism has been existed from combine of geo (earth) and (tourism) words. Geo-tourism is tourism that has attractions of geology, geomorphology, cultural heritage and aesthetic of the geography location. The aim of this research is evaluating of geotourist capacity of Kandovan village located in ...
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Geo-tourism has been existed from combine of geo (earth) and (tourism) words. Geo-tourism is tourism that has attractions of geology, geomorphology, cultural heritage and aesthetic of the geography location. The aim of this research is evaluating of geotourist capacity of Kandovan village located in Osco city. For this was used descripted -analyzed method. In descripted method, work tool of researchers is field and documented studies. In next stage, capability of village geo-tourism was evaluated by view of experts and tourists. Finally, analysis of data was performed by dynamical model. The results showed that scientific value index of village Geo-tourism, residual values index and region's vulnerability coefficient are 22.88, 29.08 and 2.47 respectively. Finally geo-tourist capacity of Kandovan was evaluated well based on qualitative (54.45) and quantitative criteria of model.
Saeed Jahanbakhsh Asl; Batool Zeynali; Tahereh Jalali
Volume 16, Issue 39 , May 2012, , Pages 25-49
Abstract
In this research amount of seasonal effect of the Mediterranean Sea surface temperature (MedSST) has been investigated on seasonal precipitation of East Mountainsides of Zagros and Iran Central basins. For this purpose, warm, cold and base periods were determined for dates of MEDSST[1] in statistics ...
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In this research amount of seasonal effect of the Mediterranean Sea surface temperature (MedSST) has been investigated on seasonal precipitation of East Mountainsides of Zagros and Iran Central basins. For this purpose, warm, cold and base periods were determined for dates of MEDSST[1] in statistics period of (197-2005) for every season. Then statistic Medians of precipitation were determined so as (Rw, RC and Rb)[2] in each period and for all stations. Theses medians in every season and period were compared to specify amounts of these effects. The results indicated when MedSST is colder than base in winter season, precipitation of winter increases in the studied regions, but the temperatures of warmer than base in autumn increase autumn precipitation. Also MEDSST of colder than base of autumn is the cause of precipitation increase in winter and MEDSST of warmer than base of summer is cause of precipitation increase in autumn. The results of correlation analysis indicated that between oscillations of MEDSST and precipitation in winter there is negative correlation, in autumn it is positive correlation and between oscillations of MEDSST in autumn season and precipitation in winter season there is negative correlation. Between anomalies of MEDSST in summer and precipitation of autumn there does not exist any relevant correlation but between increases of autumn precipitation of the study region and warmer than normal MedSST of summer season the trends exist.
[1]- Mediterranean Sea Surface Temperature (MEDSST).
[2]- Rain Median of Warm period, Rain Median of Cold period and Rain Median of Base period of Mediterranean SST.
