فصلنامه پژوهش های جغرافیای طبیعی
پیاپی 122 (زمستان 1401)

In the present study, the temperature parameter has been reconstructed by using the annual growth rings of juniper trees (Juniperus polycopos) in Tengel Raver habitat in the north of Kerman province. Therefore, samples of 95 trees were taken using a growth gauge drill. Counting the number, measuring the width of the rings and matching the time between the growth curves of the trees was done by LINTAB desktop and TSAP Win software with an accuracy of 0.01 mm. The chronology of the region was constructed, detrended and standardized in ARSTAN software for 517 years (1500-2017) and its quality was checked with Cumulative Signal Statistics (EPS) and finally Residual chronology was selected for reconstruction. The relationship between climate and the width of the rings was measured using data from Kerman and Zarand stations and CRU TS4.01 data for the last 116 years of Iran. The results showed that the temperature of the months before the growing season and the month of March at the beginning of the growing season have a positive effect on the width of the rings, and the temperature of the months of April, May and June have a negative effect. Also, the investigations showed the occurrence of the issue of divergence between temperature and growth rings in the last 25 years and the region being affected by global warming in the last two decades. The reconstructed temperature showed a general decrease of 0.5 to 1.5 degrees in the two periods of 1750-1800 and 1700-1500 AD simultaneously with the Little Ice Age event in Europe for the studied area.

From the point of view of geo structure, the location of Khanmirza plain in the folded Zagros zone in the south of the Dena fault and the presence of piezometers protruding from the soil, the presence of springs etc. are signs of crustal movement on the surface. The purpose of this research is to use geological information, seismological information, and satellite images in order to obtain a view of the tectonic activity of the present era in the Khanmirza plain, as well as to simplify the displacement calculation, to evaluate the displacement of the earth's surface and the parameters affecting this displacement, and providing a suitable model for this plain. In this study, the displacement rate of the earth's surface for 8 years (2003-2010) was calculated using D-InSAR radar images and radar interferometry. The effective parameters of the DEM elevation layer, slope, slope direction, profile curvature, surface curvature, distance from The road, the distance from the fault, the density of the fault, and the earthquake's intensity were obtained from the GIS environment. Furthermore, multivariate regression in the SPSS environment presented the best model for this plain. In this environment, the 8-year displacement rate was considered dependent, and the rest of the parameters were considered independent variables. The results were challenged in the STEPWISE model. The results showed that among the 13 methods, the 13th method is the best regional model for calculating crustal mobility in this plain by providing the best correlation coefficient of 0.826, a determination coefficient of 0.682, an adjusted determination coefficient of 0.675, and a standard error of 99%. Moreover, the average movement in this basin is a 10 cm rise for 8 years.

The studied road starts from Lashkarak in the northeast of Tehran and at the entrance of Lavasan, changing its direction to the northwest, passing through the areas of Zardband, Rudak, Haji Abad, Fasham, Migun, Jiroud, Durud, Darbandsar and Shamshak to Dizin in the province. Alborz extends. This road does not have a good level of safety in the current conditions despite having a relatively high traffic load, so increasing the safety of the road to facilitate the connection of the east of the city and the province of Tehran to the Tehran-North Freeway by developing this road is one of the main goals of the present study. . In this research, geological maps, topography and satellite images were used to identify the condition of the slopes around the road and prepare information layers and route zoning in the GIS environment. and the results of geomechanical evaluations were compared with the areas obtained from geomorphological data and the length of the route was divided into six categories in terms of geomorphic stability and road safety. The results showed that the alignment of the slope of the slopes with the direction of the stone layers and the soil cover of the roadside slopes is one of the most important factors of slope instability and determines the type of activity of the processes in this direction. This research, which was conducted by combining the information obtained from geomorphological and geomechanical results, has the ability to be used in the evaluation of other transportation routes in the country and can be used for road safety management and development.

Monitoring the performance and environmental changes caused by deposited floods play an important role in land planning and management. Monson's rains in summer 1401 occurred in large areas of Iran, which in the Astran Mountain created a flood of deposits. It also had significant morphological changes to the most important river in the area  and damaged the water transfer facilities of the cities of Azna and Aligudarz . Nowadays, radar methods are effective in studying qualitative and quantitative dimensions of deposited flows, with high accuracy and low cost, and this study is also for tracking the origin of deposits-ally from radar and Sentinel-1 and index data (NDSI) to evaluate the impact of sudden snow melting. Used in snowmelts in the area. The results indicated the sudden melting of snowmelts in the area due to Monson's rainfall, which played an important role in the creation of a deposited-water flood. The flow through the glacier valleys of the area, the plant's sediments and remnants of the area were transferred to water transfer facilities and caused a lot of damage to them. Radar analysis of water zones also showed that the Kamandan Dam before the flooding phase has prevented more serious damage to the downstream.

In this research, the daily data of geopotential height of 500 hectopascals (hPa) with a spatial resolution of 1 degree from the ECMWF database for Southwest Asia and rainfall station data from the National Meteorological Organization (1979 to 2018) have been exerted. The technique used the principal component analysis and cluster analysis. With these analyses, nine circulation patterns were identified. The changes in the patterns were tested at the 95% significance level by the non-parametric Mann-Kendall test, and Sen's slope estimator was exerted to estimate the number of changes. The significance test of the trend for the winter patterns in Iran's rainy season revealed the significant trend of increasing the height of the geopotential, which has led to a decrease in the pressure gradient and a decrease in instability, and finally, a weakening of the winter precipitation patterns. Significant positive trends of geopotential height showed the continuation of these conditions for summer patterns (increasing stability, decreasing rotation, and decreasing precipitation). Of the nine known patterns, only one seasonal pattern showed a significant negative trend in the country. This pattern, with a slight increase in rainfall, indicates the formation of unstable conditions, which can lead to moderate-season rains if moisture is available. The findings showed that a rainy winter pattern had been eliminated in the last two decades, and a summer pattern had appeared instead.

In this study, the sudden heating of the Sunsphar, using NCEP/NCAR analysis data, was investigated in the statistical period of 1948-2020. The results of the analysis showed that the abundance of sudden heating events in February is 17 % more than other months. After calculating the intensity of the heating, it was found that in 2018-2017 heating, the average orbital component of the wind reached -48 m / s and the negative values of this quantity continued; This heating has been identified as the most severe sudden heating in the statistical period. The correlation between the changes of the orbital component of the wind is the time of the end of the final heating in all the years under the study of -0.6, which means that the higher the standard deviation of the wind orbital component data, the sooner the end of the cold season and the final warming. The correlation rate of the two winter heating and the final heating with the main heating intensity is -0.8 and indicates a strong and reverse relationship between the two parameters and indicates that the more intense (main) winter warming is more severe, the final heating occurs earlier and the distance The two main heating and the end are less

There are many methods for calculating evapotranspiration that require a lot of data, but a few require only air temperature. One of these methods is Trontwait. The Sistan region in the southeast of Iran is one of the regions that is unique in Iran due to the 120 days of winds. The purpose of this research is: 1) to evaluate 6 different Trontwait methods available in the sources compared to the Fau-Penman-Monteith method and 2) to modify the equation for the windy region of Sistan. The results showed that the original Trontwhite equation underestimates the amount of evaporation-transpiration. Among the existing methods, the use of coefficient k=0.72 had the best results. In order to recalibrate the Trunthwaite equation, the effective temperature coefficient of the equation (k) must be modified. The results showed that the optimal value of k varies between 0.755 and 1.04. The annual average value of the root mean square error (RMSE), according to the variable k values, was equal to 0.14 mm per day. Also, by minimizing the square of the error, we considered the k value to be 0.802 as a constant, and the RMSE value was equal to 1.19 mm per day. It can be concluded that after correcting the Trontwhite equation, it can be used in the Sistan region.