دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 54 4 2023 01 21 Paleo Temperature Reconstruction using Juniperus Species Dendroclimatology in the North of Kerman Province بازسازی دیرینه دمای سالیانه شمال استان کرمان با استفاده از اقلیم‌شناسی درختی گونه ارس 445 465 86933 10.22059/jphgr.2022.332532.1007651 FA محمدمهدی آبادی جو راوری گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران ایران قاسم عزیزی گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران ایران مصطفی کریمی گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران ایران Journal Article 2022 09 02 A B S T R A C T 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 Extended Abstract Introduction In addition to responding to human scientific curiosity, research on the past climate is essential to understand the trends, quiddity, factors, and impact of these environmental changes. One of the most widely used methods of reconstructing climate data for decades and centuries is tree rings. Trees are living climatic evidence that records the changes and fluctuations of climate change that occur annually through their growth. By studying their annual rings, we can better understand paleoclimate conditions. Juniperus Polycopos trees are a valuable species in Dendroclimatology studies due to their longevity and suitable wooden trunk widely distributed in Kerman province. The Juniperus habitat we studied is located in the northern highlands of Kerman province. Using tree rings, data related to the temperature of the past few centuries of the region has been reconstructed, and by studying them, climate change trends have been studied. Methodology The Juniperus habitat of this study is located at a mountainous massif in the north of Kerman province, between the three cities of Ravar, Zarand, and Kuhbanan, 31° 25’ north and 56°50’ east. Juniper trees in these heights are found in several habitats with higher density and single trees scattered in the mountains, frequently on the southern, southwestern, and western slopes of the habitat at an altitude of 2700 to 3200 meters. 200 samples of 96 trees in the habitat were taken with an increment borer. Rings were counted, and their width was measured by LINTAB desktop and TSAPWin software from bark to the trunk with an accuracy of 0.01 mm. The cross-dating between the growth curves of the trees, done with TSAP software, and the results of GLK, CDI, GSL, CC, and Tv statistics showed the desired quality for the obtained cross-dating growth curves for most of the trees. Based on the obtained growth curves, the chronology of Juniperus trees in the region was made in ARSTAN software by the BiweightRobust averaging method. Then De-trending and standardized by a negative exponential curve. Finally, the Standard chronology was selected for use in studies. The chronology length is 517 years (1500-2017 AD), with a reconstruction confidence period of 252 years. The quality of chronology was measured by the mean correlation statistics of all habitat trees (Rbt), Expressed population signal (EPS), signal-to-error or anomaly ratio (SNR), mean sensitivity (MS), and Autocorrelation (AC1). Then, the relationship between climate and width of the rings was measured using station data of Kerman province and CRU TS4.01 climatic data for Iran-116 last year by Pearson correlation coefficient, and temperature reconstruction was performed using a linear regression model. Results and discussion As The results indicated, the temperature of the months before the growing season and March at the beginning of the growing season positively affected the width of the rings. The temperature of April, May, and June had a negative effect. In the middle of March, when the growing season in the study area begins, we have the most positive relationship between air temperature and the width of the rings. April and May show weak negative relations with temperature. There is no significant correlation during the growing season, i.e., from April to September. According to the described months, the annual and winter temperatures have a weak positive correlation, the spring and summer temperatures have a non-correlation, and the temperatures of the multi-month periods related to the cold months of the year have a weak positive correlation. The chronology and temperature trends have shown the divergence between temperature and growth rings in the last 25 years. This is the difference between the recorded and reconstructed temperatures of the width of the rings. The past temperature reconstruction in divergent chronologies leads to overestimating the reconstructed temperature. In this paper, the divergence problem is solved by using the long period of CRU data and obtaining the temperature-width correlation of the rings from 1996 onwards. The habitat reconstructed temperature increased about 1.5 degrees over the last two decades compared to the long-term average (517 years). Other periods obtained include a relatively colder period, close to the average in the eight decades of the twentieth century, with a short-term increase in the 1950s and an increase in temperature of about 0.5 degrees compared to the average in 1840, 1850, and 1870. A period of 0.5-degree decrease in 1760-1820 AD, a period of 0.5 to 1-degree increase from 1720 to 1760 AD, and a long period of temperature drops from about 1700 to 1500 AD with different rates of decrease from 0.5 to 1 degree, noted. In general, the reconstructed temperature, except for a warm period from 1700 to 1760, generally showed a decrease of 0.5 to 1.5 degrees in the period 1500-1830 AD, coinciding with the event of the Little Ice Age in Europe for the study area. Conclusion Results show that the temperature before the growing season and especially in March at the beginning of the growing season directly affects the width of the rings. The positive correlation between March temperature and ring width is due to the beginning of cambium activity during the early growing season. Higher temperatures in March can cause the growing season to start earlier, resulting in a wider ring in the target year. In the warmer months of the year, the width of the rings shows a weak negative relationship with temperature, which can be due to the occurrence of water stress for trees with rising temperatures and increased evapotranspiration. Although the start of cambium activities at the beginning of the growing season depends on the increase in average air temperature, moisture is a much more important factor in arid regions such as northern Kerman province and affects the annual growth of the tree. Therefore, increasing the average temperature increases the evapotranspiration of the tree, decreases soil moisture, and shows its negative impact on annual growth. In general, air temperature in the study area in the months before the growing season has a positive effect, and in the months of the growing season harms the width of growth rings. The results of temperature reconstruction in the habitat show two more important periods. Initially, there was a steady drop in temperature between 0.5 and 1.5 degrees Celsius between 1830 and 1500 AD, coinciding with the Little Ice Age and studies in other parts of the world, including continental Europe. This indicates that the study area is also affected by differences in the temperature decrease during the Little Ice Age. Another period is the sharp rise in temperature in the last two decades compared to the long-term average indicates that the study area is affected by global warming. Funding There is no funding support. Authors’ Contribution All of the authors approved thecontent of the manuscript and agreed on all aspects of the work. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper در پژوهش حاضر با استفاده از حلقه‌های رشد سالیانه درختان ارس (Juniperus polycopos) در رویشگاه تنگل راور در شمال استان کرمان، پارامتر دما بازسازی‌شده است. ازاین‌رو نمونه‌هایی از 95 درخت به‌وسیله مته رویش سنج برداشت شد. شمارش تعداد، اندازه‌گیری پهنای حلقه‌ها و تطابق زمانی بین منحنی‌های رویشی درختان به‌وسیله میز کار LINTAB و نرم‌افزار TSAPWin با دقت 01/0 میلی‌متر صورت پذیرفت. گاه شناسی منطقه در نرم‌افزار ARSTAN به طول 517 سال (1500-2017 م) ساخته، روند زدایی و استانداردسازی شد و کیفیت آن با آماره سیگنال تجمعی (EPS) بررسی و درنهایت گاه شناسی Residunal برای بازسازی انتخاب شد. ارتباط آب‌وهوا و پهنای حلقه‌ها با استفاده از داده‌های ایستگاه‌های کرمان و زرند و داده‌های CRU TS4.01 برای 116 سال گذشته ایران، سنجیده شد. نتایج نشان داد که دمای ماه‌های پیش از فصل رویش و ماه مارس در ابتدای فصل رویش بر روی پهنای حلقه‌ها اثر مثبت و دمای ماه‌های آپریل، می و ژوئن دارای اثر منفی هستند. همچنین بررسی‌ها، وقوع مسئله واگرایی بین دما و حلقه‌های رشد در 25 سال اخیر و متأثر شدن منطقه از گرمایش جهانی در دو دهه اخیر را نشان داد. دمای بازسازی‌شده به‌صورت کلی کاهش 5/0 تا 5/1 درجه‌ای در دو دوره 1750-1800 و 1700-1500 میلادی هم‌زمان با رویداد عصر یخبندان کوچک در اروپا را برای منطقه موردمطالعه نشان داد.

https://jphgr.ut.ac.ir/article_86933_9f002d13dbc9b0463374b990ac02aaa8.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 54 4 2023 01 21 Presenting a regional model of shell mobility in Khanmirza basin ارائه مدل منطقه‌ای تحرک پوسته ای در حوضه خانمیرزا 467 479 90996 10.22059/jphgr.2023.342251.1007696 FA خدیجه مرادی گروه جغرافیای طبیعی، دانشکده جغرافیای طبیعی، دانشگاه اصفهان، اصفهان، ایران محمد حسین رامشت گروه جغرافیای طبیعی، دانشکده جغرافیای طبیعی، دانشگاه اصفهان، اصفهان، ایران قاسم خسروی گروه سیستم‌های اطلاعات مکانی و سنجش از دور، واحد لنجان، دانشگاه آزاد اسلامی، اصفهان، ایران کورش شیرانی کورش شیرانی، پژوهشکده حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران Journal Article 2022 09 02 A B S T R A C T 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. Extended Abstract Introduction In recent decades, the sudden movement towards developing quantitative geomorphology has led to progress in statistical methods and mathematical models to describe geomorphological processes. The wide scope of the work has led to the foundation of quantitative geomorphological methods useful in the interpretation and interpretation of transformational-morphological processes and in the study of active tectonic areas. The earth is a dynamic system that changes, and transformation is one of its characteristics. Almost no area on its surface has not been affected by new earth-building activities during the last few thousand years. Active land construction is changing the shape of the earth's surface. Much research has been done in Iran on tectonic evaluation with geomorphic indicators. Among the works that can be mentioned: Ramsht et al. (2013) evaluated the accuracy and correctness of geomorphological indicators using geodynamic data in the Jajroud watershed northeast of Tehran. The geomorphological indices and geodynamic data results indicate that the basin studied in this research is active in new land construction. However, the level of activity of new land construction movements is different everywhere, and the upstream areas of the basin are more active in this respect. The purpose of this research is to use geological and seismological information in a GIS environment and satellite images to obtain a view of the tectonic activity of the present era in Khanmirza plain. Also, the research focuses on simplifying the displacement calculation, evaluating the amount of land surface displacement and parameters affecting this displacement. Moreover, finally, it seeks to provide a suitable model in the SPSS environment for this plain. The innovation of this research is to evaluate the amount of displacement with non-morphological indicators and measure their relationship with crustal movements. Methodology In this article, geological and topographical data, Envisat satellite images, and various software such as SPSS, ARC MAP, and Envi 3.5 have been used to present a regional model for the Khanmirza basin. Results and discussion This article was designed in five basic steps, the first of which is the preparation of GIS layers required by the region. Considering that the physiographic conditions of the basin, such as slope, slope direction, profile curvature, surface curvature, distance from the road, distance from the fault, the density of the fault, and earthquake intensity are less considered in the topic of crustal mobility, in the article we tried to use from these parameters, new relations should be defined. Their correlation level with displacement value can be obtained. For this purpose, first, all these maps were drawn in the ARC MAP environment; in the next step, with the help of 22 radar interferometry images in the Envi environment and with the help of the Sarscape plugin, the amount of displacement was calculated for 8 years. The final map of the amount of displacement was obtained in GIS Came. In the present study, radar images from 2003 to 2010 were exerted to investigate displacement rates. What can be seen from this 8-year-old map is the 33-centimeter drop of this plain in the east and south, which is marked in red, and the 59-centimeter rise of the mountains on the west side of the map, which is marked in blue. In the next step, the correlation between the displacement rate and the parameters was calculated in the SPSS environment using the Pearson method. The results show the highest correlation of the displacement rate with the fault density, slope, earthquake intensity, direction of slope and surface curvature, distance from the road, distance from the fault, profile curvature, and DEM, respectively. In the fourth step, the best displacement model of the region was presented in the SPSS environment with the help of the stepwise model. The dependent variable of the eight-year displacement rate and the independent variables include DEM elevation layers, slope, slope direction, surface curvature, profile curvature, distance from the road, distance from the fault, fault density, and earthquake intensity in the form of 9 independent variables. Model 13, with the highest correlation coefficient, coefficient of determination, adjusted coefficient of determination, and standard error, was recognized as the best model. Moreover, in the last step, with the help of the formula obtained from the fourth step and the final displacement map in the ARC MAP environment, an estimated regional model map was prepared based on the indicators. Conclusion Due to the location of Iran in an active tectonic region, which is in the direct collision of two Eurasian-Arabian plates in the north-northeast direction and also in the southeast region in the indirect collision of the Indian Arabian plates, it causes movement and displacement in different proportions in the shells, and Various parts are continental and oceanic. The location of Khanmirza plain in terms of geo structure in the folded Zagros zone and the south of Dena fault and the presence of piezometers protruding from the soil and springs and other signs of crustal movement have created a destructive effect on the level of underground water and agriculture in this plain. In this research, in order to evaluate the displacement of the earth's surface and the parameters affecting this displacement, as well as to provide a suitable model by calculating the 8-year displacement rate of the earth's surface (2003-2010) using D-InSAR radar images and radar interferometry. The amount of elevation was 59 cm, subsidence was 33 cm, and the average displacement was 13 cm. Therefore, to better understand the causes of this event, effective parameters such as DEM elevation layer, slope, slope direction, profile curvature, surface curvature, distance from the road, distance from the fault, the density of the fault, earthquake intensity were calculated on this displacement in the GIS environment. Moreover, to measure the relationship between these factors and this event in the SPSS environment, through Pearson's correlation, the value of the relationship between each parameter and displacement rate was calculated, and the highest correlation between fault density and displacement rate was obtained. Following correlation measurement with the help of multiple linear regression, a stepwise model was presented in SPSS software, and the output of this model was 13 proposed methods. The 13th method, with the best correlation coefficient of 0.826, a determination coefficient of 0.682, an adjusted determination coefficient of 0.675, a standard error of 0.0099, and a significance level of 99% among these 13 methods, is the best regional model for calculating shell mobility. It is on the level of this plain. This map's estimated regional model of the uplift value coefficient is about 40 cm, and the subsidence value is 21 cm. Also, the average change of 10 cm elevation in this plain was calculated with this method. The results of this research can be used in different planning related to the watershed, including identifying and introducing the areas involved in the risk of earthquake and subsidence, investigating and studying underground water sources, etc. Maintaining the water balance is the most important solution to prevent land subsidence in this area, which can be achieved by controlling unlicensed wells and preventing excessive water extraction Funding There is no funding support. Authors’ Contribution All of the authors approved thecontent of the manuscript and agreed on all aspects of the work. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper قرارگیری دشت خانمیرزا ازنظر زمین‌ساختاری در زون زاگرس چین‌خورده در جنوب گسل دنا و وجود پیزومترهای بیرون‌زده از خاک و همین‌طور وجود چشمه و ... از نشانه‌های تحرک پوسته‌ای در سطح این دشت است. هدف از این پژوهش به‌کارگیری اطلاعات زمین‌شناسی، لرزه شناختی و تصاویر ماهواره‌ای به‌منظور به دست آوردن نگرشی از فعالیت تکتونیکی عصر حاضر در دشت خانمیرزا و همین‌طور ساده‌سازی محاسبه جابجایی، ارزیابی مقدار جابه‌جایی سطح زمین و پارامترهای موثر بر این جابه‌جایی و ارائه مدل مناسب برای این دشت است. در این مطالعه نرخ جابه‌جایی 8 ساله سطح زمین (2010-2003) با استفاده از تصاویر راداری D-InSAR و تداخل سنجی راداری محاسبه شد و پارامترهای موثر لایه ارتفاعی DEM، شیب، جهت شیب، انحنای نیمرخ، انحنای سطح، فاصله از جاده، فاصله از گسل، تراکم گسل، شدت زلزله بر این جابه‌جایی در محیط GIS به دست آمد و از طریق رگرسیون چند متغیره در محیط SPSS به ارائه بهترین مدل برای این دشت پرداخته شد در این محیط نرخ جابه‌جایی 8 ساله به‌عنوان متغیر وابسته و بقیه پارامترها به‌عنوان متغیر مستقل در نظر گرفته شدند و نتایج در مدل STEPWISE به چالش کشیده شدند. نتایج نشان داد که از بین 13 روش، روش 13 با ارائه بهترین ضریب همبستگی 826/0، ضریب تعیین 682/0 و ضریب تعیین تعدیل‌شده 675/0 و خطای استاندارد 99 درصد بهترین مدل منطقه‌ای برای محاسبه تحرک پوسته‌ای در سطح این دشت است و میانگین تحرکات در این حوضه 10 سانتیمتر بالاآمدگی برای 8 سال می‌باشد.

https://jphgr.ut.ac.ir/article_90996_2dfc9be5ac2888868b6dcc978d60ecdd.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 54 4 2023 01 21 Evaluation of geomorphic stability of Lashkarak-Dizin road with emphasis on geotechnical data with the aim of safety and development ارزیابی پایداری ژئومورفیکی جاده لشکرک به دیزین با تاکید بر داده های ژئو مکانیکی با هدف ایمنی و توسعه 482 496 91256 10.22059/jphgr.2023.346394.1007718 FA عطااله کاظمی ایمن آبادی گروه جغرافیای طبیعی، پردیس کیش، دانشگاه تهران، تهران ایران منصور جعغربگلو گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران ایران ابراهیم مقیمی گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران ایران Journal Article 2022 09 02 A B S T R A C T 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 Extended Abstract Introduction Lashkark road starts from Lashkark in the northeast of Tehran city and extends towards Shamshak and Dizin. This route runs along the length of the Alborz mountain range, after Lashkarak, passing through the Quchak Stem at the entrance of Lavasan city, with a northwesterly direction from the residential areas of Zardband, Roodak, Hajiabad, Fashm, Meigun, Jiroud, Durood, Darbandsar and Shemshak at the end of the range. It crosses Tehran province and then extends towards Dizin in Alborz province and finally connects to Kandovan road in Shahrestanak region. The need to increase traffic safety in this route due to the increase in traffic and at the same time the possibility of connecting the east of the city and Tehran province to Tehran-North Freeway is the focus of this study. In addition, by establishing this communication, especially during peak traffic times, which usually occur during official holidays, or when there is a traffic problem in a part of the Tehran-North Freeway, It can help to traffic on Tehran - North Freeway. Methodology In this research, using geological maps, topography and satellite images, the initial identification of the active points of the field and the existing conditions of the route was done. Then, by determining the factors affecting the instability of the track domain, the information layers related to them were prepared in the GIS environment. Since the physical properties of sediments and rocks are considered to be the most important foundations of engineering calculations, along with field surveys and route zoning, sampling of soil and rock domains in order to know more precisely the effective Sedimentological and lithological characteristics. It was done on the slopes overlooking the road. In this regard, the important physical characteristics including internal friction angle and adhesion, grain measurement and determination of Atterberg limits in soil domains, compressive strength in rocky slopes, texture , sorting of sediments and slope rocks were investigated and compared. Results and Discussion According to the results of the tests, Physical properties including angle of internal friction, cohesion and texture are similar in a large number of harvested samples. This is consistent with the stratigraphy of the studied area. The results of the internal friction angle are in the range of 32 to 40 degrees and the soil cohesion is in the range of 0 to 0.02 kg/cm2, which indicates that the grain is separated and with low cohesion of the slopes and indicates the high ability of slope sediments to fall and slide. The grains sorting the sediments are also generally in a very poor range. But in the end ranges of the studied route, especially in the Shemshak area, they have a medium rating. The results of Atterberg tests also confirm the non-cohesion of the range sediments, and according to the results of the same test, it can be said that the possibility of range movements in the form of creep or solifluction is very limited. The results of the compressive strength of the rock slopes show that the uniaxial compressive strength of the rock slopes of the path, except for one case with a resistance of 23 kg/cm2, is generally in the range of 80 to 110 kg/cm2, which indicates the uniform characteristics of the rocks. The texture of these rocks varies depending on the type, but they are mainly includ limestones from Karaj, Shemshak, Route and Doroud, as well as pyroclastic rocks. Considering the texture, low compressive strength and layered nature of the rocks in the majority of the path, it can be predicted that the erosion potential as well as the power of falling of these slopes is high and its effects can be seen in different parts of the path. In the rocky slopes of the path to Fasham, the type of rock formations includes pyroclastic and limestone layers, and depending on the direction of the layering and the slope of the slope, the erosion performance varies from lahar erosion to the fall of stone fragments. The most prominent example of this function can be seen in the Haji Abad area after the Galukan bridge, where weathered sediments in the form of Lahars are seen on the slopes of the road, and later, By changing the direction of the rock layers in relation to the road, rockfalls prevail. By passing Meigun, changing the geological formations and the type of rocks, their compressive strength and texture also changed, subsequently the type of activity of the rocky slopes was also different. Rockfalls of the slopes were less seen and the stability of the slopes increased significantly. Conclusion The results obtained from the analysis of geomorphic factors, including weathering conditions, elevation, slope and hydrological data, show similar results with the results obtained from geomechanical tests on the samples of sediments and rocks on the slopes of the road in terms of the stability of the slopes. In general, the length of the road that has traversed the Alborzmountain range is mostly consistent with the stratigraphic structures of the route. The slope direction of the slopes in relation to the road trenches is one of the most important factors of slope instability in this route, in such a way that the direction of the slope of the rock layers or soil cover with the road trenches causes rock falls or slope slides in the route has been lengthened and at the same time it has affected the possibility of transverse expansion of the road. This research, which has been done by combining the information obtained from the analysis of geomorphological processes and the results obtained from geomechanical data, has the ability to be used in the evaluation of other transportation routes in the country and can be used to help manage the safety of the route as well as the road development plan by the Ministry of Roads and Urbanization is used. Funding There is no funding support. Authors’ Contribution All of the authors approved thecontent of the manuscript and agreed on all aspects of the work. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. جاده مورد مطالعه از لشکرک در شمال شرق تهران شروع و در ورودی لواسان با تغییر جهت به سمت شمال غربی با عبور از مناطق زردبند، رودک، حاجی آباد، فشم، میگون، جیرود، دورود، سه راهی دربندسر و شمشک به سمت دیزین در استان البرز امتداد می‌یابد. این جاده در شرایط فعلی با وجود داشتن بار ترافیکی نسبتاً زیاد از ایمنی مطلوبی برخوردار نیست بنابراین افزایش ایمنی مسیر جهت تسهیل ارتباط شرق شهر و استان تهران به آزاد راه تهران-شمال با توسعه این جاده، از اهداف اصلی مطالعه حاضر میباشد. در این تحقیق، با استفاده از نقشههای زمینشناسی، توپوگرافی و تصاویر ماهوارهای نسبت به شناسائی وضعیت دامنههای اطراف جاده و تهیه لایه‌های اطلاعاتی و منطقهبندی مسیر در محیط GIS اقدام شد و با نمونهبرداری از سنگها و دامنه‌های خاکی جاده، آزمایشهای ژئومکانیکی انجام گرفت و نتایج ارزیابی‌های ژئومکانیکی با پهنههای به دست آمده از داده‌های ژئومورفولوژیکی مورد مقایسه قرار گرفت و طول مسیر از نظر پایداری ژئومورفیکی و ایمنی جاده به شش طبقه تقسیمبندی شد. نتایج حاصله نشان داد که هم راستا بودن جهت شیب دامنه‌ها با جهت لایههای سنگی و پوشش خاکی دامنههای حاشیه جاده، از مهمترین عوامل ناپایداری دامنه‌ای و تعیین کننده نوع فعالیت فرایندها در این مسیر است. این پژوهش که با روش تلفیق اطلاعات حاصل از نتایج ژئومورفولوژیکی و ژئومکانیکی انجام شده است، قابلیت کاربرد در ارزیابی سایر مسیر‌های مواصلاتی کشور را داشته و می‌تواند جهت مدیریت ایمنی و توسعه جاده‌ها مورد استفاده قرار گیرد.

https://jphgr.ut.ac.ir/article_91256_e4d1f631ce3ffba64e45c9e59d9409b3.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 54 4 2023 01 21 Monitoring of Debris-glacial floods by radar interferometry (case study: Debris-glacial flood of 2022 in Oshtorankuh East Lorestan) پایش سیلاب‌های واریزه‌ای-یخچالی با استفاده از اینترفرومتری راداری مطالعه موردی: سیلاب مرداد 1401 اشترانکوه، تکنیک ردیابی و پایش جابجاشدگی ها 497 511 91377 10.22059/jphgr.2023.355408.1007750 FA ابوالقاسم گورابی گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران سید موسی حسینی گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران پویا کامرانی گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران Journal Article 2022 09 02 A B S T R A C T 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 Extended Abstract Introduction Natural hazards can affect living beings and especially humans in various scales. Also, geomorphological hazards are considered one of its most important sub-sections. Also, it is necessary to record information such as: magnitude, frequency, extent of the area, speed of onset, spatial distribution and time interval for each of the geomorphic hazards. Every year debris floods cause great damages to humans and significant geomorphic changes in the mountaneous basins. Debris floods carry a lot of sediments along with the remains of plants, trees and large boulders for a long distance and in a short time, they have the ability to cause significant human and financial losses in the downstream areas. In general, a flash flood phenomenon has three parts: 1- source area, 2- transfer area, and 3- accumulation area. Monitoring and environmental changes caused by debris floods play an important role in planning and managing land use. ongoing land use and climate changes increases the frequency of debris floods. Due to complexity of flood debris occurance mechanism, it attract many researchers attentions.Since, the debris floods in mountainous areas, contain glacial sediments, it also called debris-glacial floods. The researchers identify the heavy rains that happened in a short period of time and the melting of snowdrifts and the sudden increase in air temperature in the mountainous areas as the main driving factors for the occurrence of devastating debris floods. Tracing the origin of glacial sediment production in flood in different parts of a mountain can help us in the implementation of protection plans to identify sediment production areas and prevent their transfer in subsequent floods to the downstream areas. One of the technologies for tracking and monitoring debris-glacial floods is the use of interferometric radar. One of the techniques used in interferometric radar is the use of offset tracking, that its efficienvy is proven in the studies related to monitoring glaciers, landslides, and moving dunes. Monsoon rains in the summer of 1401 occurred in large areas of Iran, which caused avalanche-glacial floods in Oshtorankuh. In this study, the interferometric method was used to trace the origin of the debris flood event occur at july 2022 in Oshtorankuh area located in eastern Lorestan. Materials and methods The type of this sudy is applied-developmental research and its method is analytical-field. The input data used for this research is Sentinel 1A_IW-GRDH data in two ascending and descending orbits for use in offset tracking and McVitie techniques and Sentinel-2A data for use in the NDSI index. The offset tracking technique was used to determine the places in the Oshtorankuh with the most sediment mass displacement. This method is based on the calculation of the displacement in the pixel unit using the optimization of the mutual correlation between the pair of images resulting from the phase intensity of the SAR data. Also, the Normalized-Difference Snow Index (NDSI) was used to monitor the condition of the snow reserves of Oshtorankuh before and after the monsoon rains. This index is based on low reflectance in the mid-infrared and high reflectance in the visible region, which can distinguish snow-covered areas from non-snowy and cloudy areas. McVittie technique was used to determine the situation and prepare a flood map downstream of the Kamandan basin. Result and discussion By using the offset tracking technique, the soil masses displacemant after the northeast monsoon rains of Oshtorankuh (Kamandan) in two descending orbits and ascending orbits were identified and analyzed. The results show that the highest recorded values are due to displacement tracking belonging to the cirques, snowdrifts, and glacial deposits of Oshtorankuh. Also, the highest displacement and speed of movement related to the sediments of Kol-e Geno Cirque and Aznadar glacial deposits are located in and at the lower levels of the sediments in Kol Jeno and Aznader glacial valleys. From this event, the V shape (interglacial period) was in the U-shaped bed (glacial period), it has given its place again to the U shape (caused by the sediments carried by the debris flow). Also, the changes in snow cover before and after the monsoon rains were poreover, the results revealed melting of all the snowfields located around the cirques and glacier valleys of Kol-e Geno and Eznader ranges in the period. Also, the morphological responses of the waterways to the debris-glacial flood event were not the identical, and some responded by digging or filling. Another point is that the degree of sphericity and poor compaction of the sediments transported by the debris flood shows that there are few channel erosions in them and most of them are from the glacial sedimentary deposits of this mountain such as the end parts of the cirques and moraines. This dangerous event also caused a lot of damage to the water conceyancy structures and canals from this region to Aliguderz and Azna. The condition of the downstream basin and the recently drained Kamdan Dam showed the retention effect of this structure on preventing the flooding of the downstream parts. Conclusion Nowadays, the use of interferometric radar in monitoring environmental changes has become a popular and practical tool. In this research, it was found that it is possible to evaluate and identify the displacement and origin of sediment deposits, as well, quantify their speed and movement patterns using interferometric radar and the Offset tracking technique. The monsoon event occurred at July 2022 leads to sudden melting of the snowfields in Oshtorankuh played and a flash floods along with glacial deposits. But field evidence showed that waterway responses to this event is not identical. Considering that this region plays an important role in supplying water to its neighboring cities and some regions of central Iran, the results of this research can be used in the management and supply of water resources and the management of torrential floods to reduce possible damages to water transmission channels. The evaluation of the floodplains in the lower basin shows that the dams can be at risk of being filled with deposited sediments. Therefore, it is requested that the potential of a deposited flood be taken into account in the location stage. Although Kamandan reservoir stored a significant part of the flood and prevented damage to the residential and agricultural areas downstream of the dam. Funding There is no funding support. Authors’ Contribution All of the authors approved thecontent of the manuscript and agreed on all aspects of the work. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. پایش عملکرد و تغییرات محیطی ناشی از سیلاب‌های واریزه‌ای در برنامه‌ریزی و مدیریت آمایش سرزمین نقش مهمی دارد. بارش‌های مونسونی تابستان 1401 در مناطق وسیعی از ایران به وقوع پیوست که در اشترانکوه سبب ایجاد سیلابی واریزه‌ای-یخچالی شد. همچنین تغییرات مورفولوژیکی قابل‌توجهی بر مهم‌ترین رودخانه این منطقه (کمندان) داشت و به تأسیسات انتقال آب شهرهای ازنا و الیگودرز آسیب وارد شد. امروزه روش‌های راداری در مطالعه ابعاد کیفی و کمی جریان‌های واریزه‌ای، با دقتی بالا و هزینه‌ای کم مؤثر هستند، این پژوهش نیز جهت ردیابی منشأ رسوبات واریزه‌ای - یخچالی از روش‌های راداری و داده‌های Sentinel-1 و شاخص (NDSI) برای ارزیابی تأثیر ذوب ناگهانی برف در برف‌چال‌های منطقه استفاده کرده است. نتایج بیانگر ذوب ناگهانی برف‌چال‌های منطقه به دلیل بارش مونسونی بود که در ایجاد سیلاب واریزه‌ای-یخچالی نقش مهمی را ایفا کرده بود. این جریان با گذر از دره‌های یخچالی این منطقه، رسوبات و بقایای گیاهی این ناحیه را بر روی تأسیسات انتقال آب منتقل و خسارت‌های زیادی به آن‌ها وارد کرده بودند. تحلیل راداری پهنه‌های آبی نیز نشان دادند که سد کمندان قبل از مرحله آبگیری، با جذب سیلاب در خود، مانع از ورود آسیب‌های جدی‌تر به مناطق پایین‌دست شده است.

https://jphgr.ut.ac.ir/article_91377_9630a07aff622b90a14f52c27cf73eda.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 54 4 2023 01 21 Analysis of the temporal and spatial trend of atmospheric circulation patterns and its effects on Iran's rainfall in the last two decades تحلیل روندِ زمانی و مکانی الگوهای گردشی جو و اثرات آن بر بارش‌های ایران در دو دهۀ اخیر 513 532 91153 10.22059/jphgr.2023.353619.1007739 FA زهرا ماه آورپور گروه جغرافیای طبیعی، دانشکده علوم جغرافیایی و برنامه‌ریزی محیطی، دانشگاه اصفهان، اصفهان، ایران 0000-0002-1842-6339 جواد خوشحال دستجردی گروه جغرافیای طبیعی، دانشکده علوم جغرافیایی و برنامه‌ریزی محیطی، دانشگاه اصفهان، اصفهان، ایران سیدابوالفضل مسعودیان گروه جغرافیای طبیعی، دانشکده علوم جغرافیایی و برنامه‌ریزی محیطی، دانشگاه اصفهان، اصفهان، ایران 0000-0001-6227-6713 محمدعلی نصراصفهانی گروه مهندسی منابع آب، دانشکده کشاورزی، دانشگاه شهرکرد، شهرکرد، ایران Journal Article 2022 09 03 A B S T R A C T 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. Extended Abstract Introduction Atmospheric circulation patterns play an essential role in the emergence of environmental phenomena, which is why the classification of weather systems is one of the main goals of synoptic climatology. With the advent of computers and advanced mathematical algorithms, such as principal component analysis (PCA) and cluster analysis (CA) methods, as well as the availability of digital data, quantitative methods replaced manual methods. Most methods used and discussed for classifying circulation patterns are based on using multivariate statistics, principal component analysis, and clustering techniques. This research uses the same method to classify atmospheric circulation patterns. Due to a large amount of data, MATLAB software was used in this research. Methodology The statistical population of this research includes the rainfall station data of the National Meteorological Organization from 1979 to 2018, which have been converted into grid data (2491 cells) with a resolution of 0.25 degrees using the kriging interpolation technique. For typification of daily data of geopotential height level of 500 hectopascals (hPa) for the frame (coordinates) zero to seventy degrees east longitude and ten to sixty degrees north latitude from ECMWF European Center for Medium-term Atmospheric Forecasting, ERA-INTERIM project from 1/1/1979 to 12/31/2018 has been used for 14610 days. The data were divided into two 20-year periods for a two-decade comparison. This framework was considered significant enough to represent the circulation patterns affecting Iran's climate properly. Finally, the data matrix was prepared with two matrices with dimensions of 3621 x 7305. Then principal component analysis was performed on these two matrices. The purpose of this analysis is, on the one hand, to reduce the amount of data and, on the other hand, to classify and identify the most important patterns and changes in geopotential height of 500 hectopascals (hPa) in the last two decades. Twelve components of the S matrix with a level of 500 hectopascals (hPa) were used as the required input for the following classification step to identify the types of air and classify them. Then, nine patterns or weather types were identified by cluster analysis. With the help of the Mann-Kendall test and Sen’s slope estimator, pattern changes were done on time and places (pixels). Results and discussion The correlation coefficient parameter was used to identify similar patterns in two periods. In this way, three winter patterns, three temperate season patterns, and two summer patterns were determined. Pattern 3 from the first period is a winter pattern, and pattern seven from the second period is a pattern with the features of the warm season, and no suitable pair was identified. These two patterns had the lowest correlation coefficient with each other. It is seen that the CTA3 pattern, a winter pattern with heavy rainfall, was removed in the second period, and the CTB7 pattern, a spring-summer pattern with little precipitation, was born instead. The Mann-Kendall trend test on the patterns did not show a negative trend in the time series for any pattern. Two pairs of winter patterns have a significant positive trend, and pattern number 3 was removed. Two pairs of the temperate season pattern and two pairs of the summer pattern showed a significant positive trend, and the seven summer patterns appeared in the second period. The trend test on the pixels of the region for the pattern of one winter showed all of Southwest Asia with significant positive trends, which indicates the weakening of this pattern with warmer winters. The second winter pattern in the country's eastern half shows the weakening of the second cold season with wide positive trends. Another noteworthy point is the significant negative trends for the pair of moderate CTA5B4 patterns significantly and widely over our country, which can lead to rain if other conditions are available. The two pairs of the summer pattern have covered almost the same range in terms of the significance of the trend and its values. Significant positive trends (increase in geopotential height) for summer patterns provide conditions for increasing stability, reducing rotation, and reducing precipitation. The conducted analyses show that under the influence of climate change, the rule of a hotter and drier climate in our country in the last two decades is quite evident. The expansion of low rainfall areas can be clearly seen for all patterns. The comparison of the rainfall maps of the country related to the pair of winter patterns PA1, PB1, and PA2, PB2, and PA9, PB3 shows that in addition to the decrease in the rainfall of these patterns, their spatial distribution has also undergone significant changes. The core of the maximum rainfall from the country's west to the southwest side has been moved. Conclusion A side-by-side comparison of the models showed significant changes in the models. The patterns associated with high-altitude and ridge settlements on all or a large part of Iran are more frequent, consistent with Masoudian's research (2006). The significant positive trend in the Sudan and Mediterranean circulation systems, which play an essential role in the rains of our country's winter and autumn seasons, revealed the weakening of these systems in the last two decades. These results are in harmony with the research of Alizadeh (2013) and Darand (2014). Another result of this research is that the patterns of Iran's rainy seasons (winter and autumn) have weakened significantly in the past two decades. Significant positive high-altitude trends for summer patterns showed increasing stability and strengthening of these patterns. Significant positive high-altitude trends for summer patterns showed increasing stability and strengthening of these patterns. Also, the CTA4B5 transition pattern pair showed significant negative trends over a wide part of the country; the nature of this pattern determined that with the establishment of the CTB5 pattern (the second-period pair) if moisture is available, it can provide the possibility of widespread rains in the country. Correlation coefficients identified two inconsistent patterns. The CTA3 pattern is a winter pattern with heavy rainfall that has not occurred in the last two decades and can be said to have disappeared, and instead, the CTB7 pattern is a summer pattern that has appeared with a frequency of 10.7% in the last two decades. Funding There is no funding support. Authors’ Contribution All of the authors approved thecontent of the manuscript and agreed on all aspects of the work. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. در این پژوهش از داده‌های روزانه ارتفاع ژئوپتانسیل تراز 500 هکتوپاسکال با تفکیک مکانی 1 درجه از پایگاه داده ECMWF برای جنوب غرب آسیا و داده‌های ایستگاهی بارش از سازمان هواشناسی کشور (1979 تا 2018) بهره‌جویی شده است. تکنیک بکار رفته تحلیل مؤلفه اصلی و تحلیل خوشه‌ای است. با این تحلیل‌ها 9 الگوی گردشی شناسایی شدند. تغییرات الگوها در سطح 95 درصد معناداری، بوسیلة آزمون ناپارامتری من‌کندال آزموده و برای برآورد میزان تغییرات از تخمین‌گر شیب سن بهره گرفته شد. آزمون معناداری روند برای الگوهای زمستانی در فصل بارش‌های ایران، روند معنادار افزایش ارتفاع ژئوپتانسیل؛ که منجر به کاهش شیو فشار و کاهش ناپایداری و نهایتاً تضعیف الگوهای بارشی زمستانی گردیده است را آشکار ساخت. روندهای معنادار مثبتِ ارتفاع ژئوپتانسیل، تداوم این شرایط را برای الگوهای تابستانی (افزایش پایداری، کاهش چرخندگی و کاهش بارش) نشان دادند. از 9 الگوی شناخته‌شده تنها برای یک الگوی فصل گذار روند معنادار منفی بر روی کشور مشاهده شد. این الگو با اندکی افزایش بارندگی بیانگر شکل‌گیری شرایط ناپایدار است که در صورت مهیا بودن رطوبت می‌تواند منجر به بارش‌های فصل معتدل گردد. یافته‌ها نشان دادند که یک الگوی زمستانی بارش‌زا در دو دهه اخیر حذف‌شده و بجای آن یک الگوی تابستانی ظاهر گردیده است.

https://jphgr.ut.ac.ir/article_91153_1aec33693279993c6538cc3608d6c9e5.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 54 4 2023 01 21 Statistical analysis of zonal wind component in the occurrence of sudden stratospheric warming تحلیل آماری مؤلفه‌ی مداری باد در رخ داد گرمایش ناگهانی پوشن سپهری 533 548 90598 10.22059/jphgr.2023.349716.1007726 FA ثریا دریکوند گروه جغرافیا، دانشکده ادبیات و علوم انسانی، دانشگاه لرستان، خرم‌آباد، ایران بهروز نصیری گروه جغرافیا، دانشکده ادبیات و علوم انسانی، دانشگاه لرستان، خرم‌آباد، ایران هوشنگ قائمی گروه هواشناسی، پژوهشگاه هواشناسی و علوم جو، تهران، ایران مصطفی کرمپور گروه جغرافیا، دانشکده ادبیات و علوم انسانی، دانشگاه لرستان، خرم‌آباد، ایران محمد مرادی گروه هواشناسی، پژوهشگاه هواشناسی و علوم جو، تهران، ایران Journal Article 2022 09 03 A B S T R A C T 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 Extended abstract Introduction In this research, sudden stratospheric warming has been investigated. The stratosphere and the troposphere play an active role in determining the climate of the Earth's surface. Sudden stratospheric warming refers to a large-scale winter disturbance that significantly affects the temperature and circulation in the middle atmosphere. One of the goals of this research is to investigate and discover the relationship between the changes in the speed of the zonal component of the wind and the occurrence of the two sudden winter significant warming and the final warming. Methodology In order to further understand the phenomenon of sudden stratospheric warming, the average zonal wind component at the pressure level of 10 hPa on the longitude of 60° N was investigated for 73 years (1948-2020). NCEP/NCAR reanalysis data have been used to reveal this phenomenon. Moreover, from the zonal component of the wind at the level of 10 hPa on the 60° N, from zero to 360 degrees, which has 144 points with a spatial resolution of 2.5 degrees, a zonal average was taken; then in each month of the year for the number of years, the average zonal component of the wind has been averaged (measured) again. This study has been limited to the occurrence of this phenomenon only in the cold period of the year because it occurs only in cold seasons. The calculations were done by using Excel and MATLAB software. The criterion for detecting sudden stratospheric warming is the negative value of the average zonal component of the wind, and its intensity is considered based on the amount of this component going below zero and the number of consecutive days when this quantity has negative values. For the sudden warming of the stratosphere to occur, the speed of the zonal component of the wind must decrease, and as a result, the temperature must increase. Moreover, in the warming of March, the researcher did her best to allocate a time gap of at least 20 days with the final warming. Pearson's correlation test has been used to correlate the changes in the wind component with the final warming event. Results and Discussion Investigating and understanding the changes in the zonal wind speed will shed light on many factors. The speed of the zonal component of the wind is not the same throughout the year, but this component also changes due to the changes in the angle of the sun's rays. The highest speeds of this component are in January, with 44.05 m/s, and in December, with 39.94 m/s. The average speed of the zonal component of the wind is 21.29 m/s in October, 33.91 m/s in November, 36.31 m/s in February, and 23.34 m/s in March. In April, the speed of the currents is greatly reduced, and in some years, in the second half of the month, the wind currents blow eastward. The overall average wind speed in this month is 5.27. From May onwards, wind currents blow to the east; in other words, they become negative. Furthermore, this means the warm season and final warming have begun. The duration of the effect of wind speed changes on the amount of temperature changes was obtained by running Pearson correlation calculations between these two components. In addition to simultaneous correlation, the delayed correlation was also used. The degree of simultaneous correlation was measured to be -0.73 and has been the most related to the applied delays. These calculations show that reducing the speed and changing the direction of the wind simultaneously have the most significant effect on increasing the temperature. After examining and extracting the warming that occurred, the intensity of this phenomenon was also investigated by drawing a two-line graph for the two components of wind and temperature for all the years under investigation. Identification of 36 sudden stratospheric warmings of the major type and determination of their intensity was carried out. The intensity of this phenomenon is different in each occurrence. The maximum drop in wind speed and the number of days below zero are the criteria for measuring the intensity of sudden stratospheric warming. In the year between 2017 and 2018, the most severe warming occurred with the negative direction of the zonal wind at the rate of -48.8 and remaining in a negative state for 20 days. The most likely occurrence of a sudden warming of the major type is related to February. The intensity of warming that occurred in each month shows a direct relationship with the amount of zonal wind speed. January ranks first in terms of warming intensity, with a rate of -20.5 m/s. Seemingly, March has had the slightest warming with a rate of -7.1 m/s. The annual fluctuation in the zonal component of the wind at the beginning of the final warming is a significant value. This relationship was explored by calculating the correlational strength between the zonal wind speed's standard deviation and the major warming's starting day. The degree of this correlation in all years under study (in years both with and without warming) is -0.6, which shows a moderately strong inverse relationship. Moreover, it means that the higher the standard deviation of the wind speed, the earlier ending of cold season and the occurrence of final warming. The commencement of the final warming, or in other words, the end of the cold season in years with sudden warming, was calculated as follows: The correlation between the intensity of sudden stratospheric warming and the interval time of the major warming and the final warming was measured; with a rate of -0.8, this correlation indicates a rather strong but inverse one between the two figures – it also states that the higher the intensity of the sudden warming, the sooner the final warming will occur, and the shorter the time interval of the two warmings will be. Conclusion Changes in the zonal wind speed at the level of 10 hPa on the longitude 60° have a relatively strong relationship with factors such as sudden stratospheric warming, the intensity of sudden warming, the percentage of sudden warming, and the time of final warming. The zonal wind speed in each month depends on the angle of the sun's rays. This has caused the possibility of sudden stratospheric warming to be different each month and also affects the intensity of the warming. With a zonal wind speed of 44.05 m/s, January has the most intense warming in terms of polar vortex destruction, which changes the direction of the wind orbit by 20.5 m/s. The degree of correlation between zonal wind changes and the occurrence of final warming indicates a strong but inverse relationship between the two. The higher the standard deviation of the zonal wind speed, the sooner the final warming will arrive. Finally, the relationship between the two major winter warmings and the final warming can be expressed as follows: In years when sudden stratospheric warming occurs, the greater the warming intensity is, the earlier the final warming occurs. Funding There is no funding support. Authors’ Contribution All of the authors approved thecontent of the manuscript and agreed on all aspects of the work. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. در این پژوهش، گرمایش ناگهانی پوشن‌سپهر، با استفاده از داده‌های باز تحلیل NCEP/NCAR، در دوره آماری 2020-1948 موردبررسی قرار گرفت. نتایج تحلیل نشان داد که فراوانی رخداد گرمایش ناگهانی پوشن‌سپهر، در ماه فوریه با 17 درصد، بیش از سایر ماه‌ها می‌باشد. پس از محاسبه شدت گرمایش‌های آشکار شده، مشخص شد که در گرمایش 2018-2017، میانگین مؤلفه مداری باد به 48- متر بر ثانیه رسید و مقادیر منفی این کمیت 20 روز ادامه داشته است؛ این گرمایش به‌عنوان شدیدترین گرمایش ناگهانی پوشن‌سپهر در دوره آماری موردمطالعه شناسایی‌شده است. میزان همبستگی بین تغییرات مؤلفه مداری باد با زمان شروع گرمایش پایانی در تمام سال‌های تحت بررسی 6/0- می‌باشد و بدین معناست که هرچه انحراف معیار داده‌های مؤلفه مداری باد بیشتر باشد، پایان فصل سرد و گرمایش پایانی زودتر فرامی‌رسد. میزان همبستگی فاصله دو گرمایش زمستانه و گرمایش پایانی با شدت گرمایش اصلی 8/0- می‌باشد و نشان‌دهنده ارتباط قوی و معکوس بین این دو پارامتر می‌باشد و نشان می‌دهد هر چه گرمایش پوشن‌سپهر زمستانه (اصلی) شدیدتر باشد، گرمایش پایانی زودتر رخ می‌دهد و فاصله دو گرمایش اصلی و پایانی کمتر می‌شود.

https://jphgr.ut.ac.ir/article_90598_f7263651e4979c20f306390146646bc3.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 54 4 2023 01 21 Evaluation and Calibration of Thornthwaite equation for Estimating Reference Evapotranspiration in windy areas (case study of Sistan region) ارزیابی و واسنجی معادله ترونت‌وایت برای تخمین تبخیر تعرق در اقلیم باد خیز مطالعه موردی منطقه سیستان 549 564 90529 10.22059/jphgr.2023.350271.1007728 FA هما دارابی گروه مهندسی آب، دانشکده آب و خاک، دانشگاه زابل، زابل، ایران محمد مهدی چاری گروه مهندسی آب، دانشکده آب و خاک، دانشگاه زابل، زابل، ایران پیمان افراسیاب گروه مهندسی آب، دانشکده آب و خاک، دانشگاه زابل، زابل، ایران حلیمه پیری گروه مهندسی آب، دانشکده آب و خاک، دانشگاه زابل، زابل، ایران Journal Article 2022 09 03 A B S T R A C T 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 Extended Abstract Introduction Evapotranspiration is one of the most important components of the hydrologic cycle in the nature and its exact determination is essential for water balance studies, irrigation and water resources management. One of the most accurate methods of estimating ETo is in different climates of FAO Penman-Monteith equation (PMF-56) the accuracy of this method for calculating evapotranspiration in all over the world has been proven successfully. PMF-56 method as a standard method requires a large meteorological data such as air temperature, relative humidity, wind speed at a height of 2 meters and solar radiation. Provide exact data on all areas is not and also if it is possible it is not very reliable. Some of the evapotranspiration methods require only air temperature for ETo estimation. One of these methods is Thornthwaite. The Sistan region in the southeast of Iran is one of the regions that is unique in Iran due to the 120-day winds and high day-night temperature changes. The purpose of this research is to evaluate the different existing methods of the Thornthwaite equation (6 methods) and adjustment the Thornthwaite equation for the Sistan region. Methodology Six Thornthwaite approaches were used in this study are described below: 1) The Thornthwaite method (Thornthwaite 1948) is a temperature-based method for the estimation of ET0 as a function of the average monthly temperature. 2) Camargo et al. (1999) improved the performance of the Thornthwaite method using an effective temperature ( ) instead of the mean temperature ( ) and of the daily temperature amplitude: (1) where k = calibration coefficient. Camargo et al. (1999) found that k = 0.72 is the best value for estimating monthly ET0. 3) Pereira and Pruitt (2004) recommended k = 0.69 for estimating daily ET0. 4) Trajkovic (2005a) expressed the equation reference evapotranspiration where Thornthwaite equation depend on maximum possible duration of sunshine and mean air temperature in the i-th month. 5) The data from Serbian stations Palic, Belgrade, and Nis were used to calibrate the Thornthwaite equation (Trajkovic 2005b): (2) 6) Bautista et al. (2009) calibrated the Thornthwaite equation by changing the value of the corresponding constant p = 16. In this research, in addition to evaluating different methods and determining the best method, the value of coefficient k for Sistan region is recalibrated and its best value is stated. Results and Discussion The results based on FAO-56 PM equation show that amount of daily evapotranspiration varied from about 21 mm per day in July to 0.7 mm day-1 in the beginning of December.The annual average value of evapotranspiration according to the FAO-56 PM equation is 8.21 mm day-1. Six Thornthwaite approaches were used in this study were compared to full FAO-56 PM equation. The statistical summary including RMSE (mm day-1), MBE (mm day-1) and r ( ) for Sistan location is presented in Table 1. The value of RMSE in original Thornthwaite equation was equal to 4.15 mm day-1, the value of MBE was equal to -3.92 mm day-1, and the value of r was equal to 0.52, which indicates Thornthwaite equation was very poor in estimating ET0 and greatly underestimated PM values. The method of Camargo et al. (1999) with RMSE value of 3.14 mm day-1 and MBE value of -2.49 mm day-1 and r value of 0.7 had the best results among all methods. Generally, the accuracy of this method is low compared to the PMF-56 method. Among the studied approaches, only the method of Bautista et al (2009) overestimates the amount of evapotranspiration. The average amount of annual evaporation in this approache is equal to 11.84, which has been overestimated by about 44%. The best monthly values of k (optimal value) was obtained using the trial and error method and minimizing the value. The results show that the value of coefficient k varies from 0.755 in March to 1.04 in October and its average value is 0.825. By using the solver option and based on the lowest value of the root mean square error between Thornthwaite evapotranspiration and the FAO-56 PM method, the value of k coefficient was also obtained, which was equal to 0.802. In the following, by using three k coefficient values, including optimal variable coefficient ( ), average variable coefficient ( ) and obtained from the solver option ( ), the evapotranspiration value were calculated and evaluated. Table (2) shows the statistical indices of the evapotranspiration value calculated with the adjustment Thornthwaite equation based on the coefficient k. The results showed that the use of variable coefficient with RMSE equal to 0.14 mm day-1, MBE -0.04 mm day-1 and r equal to 0.99 had the best results. It can be concluded that usingof and we will reach satisfactory results in calculating evapotranspiration in Sistan region. Conclusion The results of this study showed that the 60% of the amount of evapotranspiration in the Sistan region occurs in the four months of June to September when the winds blow for 120 days. The total evapotranspiration in the three months of December, January and February is equal to 8% of the annual evapotranspiration value. The results showed that the six existing methods of estimating evapotranspiration with Thornthwaite method have low accuracy, so its value should be recalibrated. Hence, based on this study, reference evapotranspiration can be easily calculated for the windy region of Sistan with the available metorological data and the calibrated Thornthwaite equation. In developing countries where good quality data are relatively scarce, using such simple methods may be beneficial for the farmers and local water organizations. Funding There is no funding support. Authors’ Contribution All of the authors approved thecontent of the manuscript and agreed on all aspects of the work. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. روش‌های زیادی برای محاسبه تبخیر-تعرق وجود دارد که به داده‌های زیادی نیاز دارد، اما تعدادی از روش‌های فقط به دمای هوا نیاز دارند. یکی ازاین‌روش‌ها ترونت‌ویت است. منطقه سیستان در جنوب شرقی ایران یکی از مناطقی است که با توجه به بادهای 120 روز در ایران منحصربه‌فرد است. هدف از این تحقیق: 1) ارزیابی 6 روش مختلف ترونت‌ویت موجود در منابع در مقایسه با روش فائو پن‌من مانتیث و 2) اصلاح معادله برای منطقه بادخیز سیستان است. نتایج نشان داد معادله اصلی ترونت‌وایت مقدار تبخیر-تعرق را کم برآورد محاسبه می‌کند. در بین روش‌های موجود استفاده از ضریب دارای بهترین نتایج بود. برای واسنجی معادله ترونت‌وایت ضریب دمای موثر معادله ( ) باید اصلاح گردد. نتایج نشان داد مقدار بهینه k بین 755/0 تا 04/1 متغیر هست. میانگین سالانه مقدار جذر میانگین مربعات خطا (RMSE)، با توجه به مقادیر k متغیر برابر با 14/0 میلی‌متر در روز به دست آمد. همچنین با استفاده از حداقل کردن مربعات خطا مقدار k را به‌طور ثابت 802/0 در نظر گرفتیم که مقدار RMSE برابر با 19/1 میلی‌متر در روز به دست آمد. می‌توان نتیجه‌گیری کرد که پس از اصلاح معادله ترونت‌وایت می‌توان آن را در منطقه سیستان استفاده کرد.

https://jphgr.ut.ac.ir/article_90529_b3135887fedde9b287c0216a6d626521.pdf