انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Comparative Assessment of Morphological Quality in Rivers on the Northern and Southern Slopes of the Alborz Mountains: A Case Study of the Vaz River and Hajimahrud (Chamestan-Noor), Hablehrud River (Garmsar), and Shahrud River (Rajaei Dasht-e Alamut) ارزیابی مقایسه ایی کیفیت مورفولوژیکی رودخانه های دامنه شمالی و جنوبی البرز ، مطالعه موردی رودخانه واز و حاجی ماهرود (چمستان نور)، حبله رود (گرمسار) و شاهرود ( رجایی دشت الموت) 1 23 222669 10.22034/gmpj.2025.518899.1558 FA دکتر محمد مهدی حسین زاده گروه جغرافیای طبیعی، دانشکده علوم زمین، دانشگاه شهید بهشتی، تهران مریم رشیدی گروه جغرافیای طبیعی، دانشکده علوم زمین، دانشگاه شهید بهشتی، تهران رضا اسماعیلی گروه جغرافیا، دانشکده علوم انسانی و اجتماعی، دانشگاه مازندران، بابلسر، ایران Journal Article 2025 04 24 Introduction Rivers have garnered increasing attention due to their role in delivering diverse ecosystem services. In recent decades, river morphology has undergone frequent alterations as a result of climate change and anthropogenic factors. In Iran, rivers have been subjected to significant pressures due to extensive human interventions, including sand and gravel mining, dam construction, channel diversion, bank stabilization, and water resource exploitation. A key tool in this field is the Revised Morphological Quality Index (rMQI), developed to enable a more precise analysis of riverine physical processes. This index provides a comprehensive assessment of a river's physical condition by evaluating three critical aspects: the intensity of anthropogenic pressures, the degree of morphological alterations, and the ecological and geomorphological functionality of the river. The objective of this study is to understand the dynamic processes shaping the channel and the morphological changes of the Vaz, and Hajimahrud Hablehrud, and Shahrud rivers over time. Using the Revised Morphological Quality Index (rMQI) method—based on the Human Pressure Index, Channel Form Adjustment Index, and Meandering Functionality Index—the morphological quality of the studied rivers was assessed. The findings of this research can inform decision-making processes aimed at mitigating environmental risks and optimizing river management practices. Methodology T he rivers studied in this research include the Vaz River and Hajimahrud (Chamestan, Nour), the Hablehrud River (Garmsar), and the Shahrud River (Rajaei Dasht-e Alamut). To collect high-resolution morphometric data, field surveys and unmanned aerial vehicles (UAVs), or drones (using stereoscopic imaging or short-range photogrammetry), were employed for image acquisition. Based on field surveys and the use of a digital elevation model (DEM), morphometric parameters of the channel, channel characteristics, and human interventions were recorded and derived. The revised Morphological Quality Index (rMQI) method was used to assess the morphological quality of the studied rivers. This method evaluates the qualitative status of rivers by applying and measuring a set of indicators, including Pressure Indicators (PI) and Channel Adjustment and Functioning Indicators (AI). The rMQI method examines the morphological quality status based on 12 human pressure indicators and 21 channel alteration indicators, consisting of 10 channel form adjustment indicators and 11 functional indicators. Results Through field surveys and processing of drone-captured images at different time intervals, the relevant indicators for each river segment were identified. Subsequently, measurements, calculations, and data scoring were performed using the rMQI method. Hajimahrud River: The values obtained from the pressure index parameters in the first and second segments were 37.5 % and 42.19 %, respectively, while the channel adjustment change/trend indicators in the first segment were 70 % and 70 % in the second segment. Based on these data, the rMQI values were calculated as 45.18 % for the first segment and 47.53 % for the second segment. The morphological quality of both segments of the Vaz River was assessed as moderate. Vaz River: The study area along the Vaz River was divided into two segments. The values obtained from the pressure index parameters in the first and second segments were 31.25% and 54.39%, respectively, while the channel adjustment change/trend indicators in the first segment were 54.39% and 51.75% in the second segment. Based on these data, the rMQI values were calculated as 42.82% for the first segment and 41.5% for the second segment. The morphological quality of both segments of the Vaz River was assessed as moderate. Hablehrud River:The study area along the Hablehrud River was divided into three segments. The values obtained from the pressure index parameters were 7.87% in the first segment, 28.75% in the second, and 15.63% in the third. The channel adjustment change/trend indicators were 64.91% in the first segment, 60.53% in the second, and 67.54% in the third. Based on these data, the rMQI values were calculated as 36.39% for the first segment, 44.64% for the second, and 41.58% for the third. The morphological quality of all three segments of the Hablehrud River was assessed as moderate. Shahrud River: The study area along the Shahrud River was divided into two segments. The values obtained from the pressure index parameters were 20.31% in the first segment and 25% in the second, while the channel adjustment change/trend indicators were 30.7% in both segments. Based on these data, the rMQI values were calculated as 25.51% for the first segment and 27.85% for the second. The morphological quality of both segments of the Shahrud River was assessed as good. Discussion and Conclusion The assessment of the morphological quality of the studied river sections using the rMQI method revealed that the examined reaches of the Vaz River and Hajimahrud exhibit moderate quality. This condition is attributed to the presence of three severe and one moderate anthropogenic pressure, as well as unfavorable morphological alterations and channel functionality. Similarly, the studied reaches of the Hablehrud River were found to be in a comparable state to those of the Vaz River, resulting in a moderate morphological quality. In contrast, the examined sections of the Shahrud River demonstrated good morphological quality, owing to minimal human pressures and favorable conditions in channel planform dynamics and functionality over time. The superior morphological quality of the Shahrud River may be linked to the absence of intensive management and exploitation pressures. These studied reaches are located in mountainous areas, distant from densely populated urban and rural settlements. The findings from the Vaz, Hajimahrud, Hablehrud, and Shahrud Rivers indicate that human interventions—such as sand and gravel mining, channelization, and unsustainable water extraction—have significant adverse impacts on the hydrogeomorphological conditions of rivers. مورفولوژی رودخانه در چند دهه اخیر به طور مکرر به دلیل تغییرات آب و هوا و عوامل انسانی تغییر کرده است. در ایران رودخانه‌ها به‌واسطه‌ی مداخلات گسترده انسانی نظیر برداشت شن و ماسه، ساخت سدها، تغییرات مسیر، تثبیت سواحل و بهره‌برداری از منابع آب، تحت فشارهای شدید قرار گرفته‌اند. یکی از ابزارهای مهم در این حوزه، شاخص کیفیت مورفولوژیکی اصلاح‌شده (rMQI) است که با هدف تحلیل دقیق‌تر فرآیندهای فیزیکی رودخانه‌ها توسعه یافته است. هدف این مطالعه درک فرآیندهای پویا شکل دهنده کانال و تغییرات مورفولوژی رودخانه های واز، حاجی ماهرود، حبله رود و شاهرود در طول زمان است. در این پژوهش از روش شاخص کیفیت مورفولوژیک بازبینی شده(rMQI) به‌منظور ارزیابی از کیفیت مورفولوژیکی رودخانه های مورد مطالعه استفاده گردید. این روش با به‌کارگیری شاخص های فشار(PI) و تعدیل کانال و عملکرد کانال (AI) به بررسی وضعیت کیفی رودخانه می پردازد. بررسی کیفیت مورفولوژیکی رودخانه های مورد مطالعه با استفاده از روش rMQIنشان داد که بازه های مورد مطالعه در رودخانه واز و حاجی ماهرود دارای کیفیت متوسط است. این وضعیت نتیجه وجود سه فشار شدید و یک فشار متوسط انسانی همچنین شرایط نامناسب در تغییرات مورفولوژیک و عملکرد کانال است. در بازه های مورد مطالعه در رودخانه حبله رود نیز شرایط مشابه رودخانه واز حاکم بوده و باعث شده این بازه ها در وضعیت کیفیت مورفولوژیک متوسط باشند. بازه های مورد مطالعه در رودخانه شاهرود به دلیل وجود فشارهای انسانی جزئی و شرایط مناسب در عملکرد و تغییرات پلانفرم کانال در طول زمان دارای کیفیت مورفولوژیک خوب است. نتایج بررسی رودخانه های واز، حبله رود و شاهرود نشان داد که مداخلات انسانی مانند برداشت شن و ماسه، دیوار کشی و برداشت های نامناسب آب تاثیرات منفی زیادی بر وضعیت هیدورژئومورفولوژیکی رودخانه ها برجای می گذارد.

https://www.geomorphologyjournal.ir/article_222669_c9afbe3533afea2197d4ef31fca8402d.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Geomorphometric Characterization of Dunes in the Rig-e-Yalan, Dasht-e-Lut: Aeolian Processes and Spatial Analysis ویژگی‌های ژئومورفومتریک تلماسه‌ها در ریگ یلان، دشت لوت: فرآیندهای بادی و تحلیل مکانی 24 41 224007 10.22034/gmpj.2025.510974.1551 FA ابوالقاسم گورابی گروه جغرافیای طبیعی، دانشکده جغرافیا دانشگاه تهران، تهران، ایران. 0000-0002-2787-8687 Journal Article 2025 03 06 1. Introduction The morphology of dunes stands as a pivotal marker of aeolian processes and wind regimes in hyper-arid environments. Detailed geomorphometric analysis of dunes offers critical insights into sediment transport dynamics, wind-driven geomorphological processes, and the protracted evolution of desert landscapes. The Lut Desert (Dasht-e Lut) in eastern Iran ranks among the most hyper-arid regions globally, characterized by extreme temperatures, low relative humidity, and elevated aeolian activity. Within its eastern sector, the Rig-e Yalan sand sea showcases an extensive suite of megadune morphologies, including longitudinal (seif) and barchan forms, which have developed under the influence of prevailing and persistent wind regimes. Although this region holds substantial promise for advancing research into aeolian geomorphology, comprehensive morphometric studies leveraging remote sensing techniques remain notably limited. Further geomorphological investigation into the Rig-e Yalan sand sea could significantly enhance understanding of the interplay between prevailing wind conditions and dune morphology formation processes in hyper-arid settings. To date, the deployment of remote sensing and geospatial methodologies, such as geomorphometry, has been insufficiently explored in this context. This study aims to conduct a rigorous geomorphometric assessment of dunes within the Rig-e Yalan sand sea, employing Digital Elevation Models (DEM) and geospatial analysis techniques. The research is designed to identify the dominant wind direction, quantify dune geomorphometric characteristics, and analyze their linkage to aeolian sediment transport processes in this hyper-arid landscape. 2. Methodology This investigation integrates remote sensing, Google Earth Engine (GEE), and Geographic Information Systems (GIS)-based morphometric analysis to examine the aeolian geomorphology of the Rig-e Yalan dune field. The methodological framework encompasses data acquisition, preprocessing, geomorphometric analysis, and interpretation, structured as follows: (1) Data Acquisition: The core dataset comprises the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) with a 30-meter resolution, sourced from the United States Geological Survey (USGS). To corroborate dune morphology patterns and aeolian sediment transport, supplementary multispectral imagery from Landsat and Sentinel-2 satellites was incorporated. These datasets provide a robust foundation for analyzing topographic and surface reflectance variations across the hyper-arid landscape. (2) Preprocessing: The SRTM DEM underwent processing within Google Earth Engine (GEE) and ArcGIS platforms. To refine data quality, a Gaussian kernel filter (radius 15, sigma 2) was applied, mitigating noise while retaining critical geomorphic signatures such as dune crests and interdune troughs. The study area perimeter was demarcated using a fusion of optical and radar-based satellite imagery, ensuring accurate delineation of the Rig-e Yalan dune field amidst its complex aeolian terrain. (3) Geomorphometric Analysis: A suite of geomorphometric parameters was calculated to characterize the dune field’s morphology and its interaction with wind regimes, including: • Slope (S): Quantifies the inclination of dune surfaces, a primary control on aeolian sediment entrainment. These indices were derived through advanced spatial analysis tools within GIS, with their spatial variability mapped to elucidate geomorphological patterns across the Rig-e Yalan dune field. Statistical correlation analyses were subsequently conducted to explore the interdependencies between these geomorphometric attributes and wind-induced sediment transport dynamics, enhancing understanding of aeolian process-form relationships in this hyper-arid environment. 3. Results and Discussion The findings reveal distinct geomorphometric patterns linked to aeolian processes in Rig-e Yalan: 3.1 Dominant Wind Directions: Analysis of dune orientations and sediment transport indices suggests that the prevailing wind direction is from the southeast (SE) towards the northwest (NW). This is indicated by steeper lee slopes in the NW direction and windward slopes in the SE, confirming sediment transport trends. 3.2 Dune Morphometry and Spatial Patterns: - The average slope of dunes is highest in the NW region (10.79°) and lowest in the SE (7.20°), suggesting that NW dunes experience higher sediment accumulation while SE dunes undergo more wind erosion - Surface roughness values exhibit significant variation, with the highest values in NW dunes (12.83) and lower values in SE dunes (8.64), supporting the hypothesis that NW serves as a sediment deposition zone. - STI values reinforce these patterns, as NW dunes show significantly higher sediment retention (STI = 146.14), whereas SE dunes have lower STI (60.61), indicating active erosion in the SE sector. 3.3 Wind-Erosion and Sediment Deposition: The correlation between slope and surface roughness (r = 0.9325) highlights the role of wind strength in shaping dune morphology. The relationship between sediment transport index and elevation variations suggests that dunes act as dynamic sediment traps, influenced by seasonal wind fluctuations. 3.4 Influence of Secondary Winds: While SE-NW is the dominant wind corridor, secondary wind interactions from the north (N) and northeast (NE) contribute to complex dune reorganization, creating asymmetrical ridge alignments. These secondary winds lead to partial redistribution of sediments in specific sub-regions, modifying local dune morphology. The morphometric patterns observed in this study align with previous global studies on aeolian environments, such as the Namib and Thar deserts. However, the unique geomorphic setting of Rig-e Yalan, with extreme climatic conditions and complex wind interactions, presents new insights into dune evolution in hyper-arid environments. 4. Conclusion This study investigated the geomorphometric characteristics of dunes in the Rig-e Yalan sand sea, Lut Desert, to identify the dominant wind direction using SRTM digital elevation models and advanced analyses in Google Earth Engine and GIS. Findings revealed that the primary wind direction from southeast to northwest (SE-NW) shapes dune morphology, with erosion in SE slopes (mean slope 7.20°, STI=60.61) and sediment accumulation in NW (mean slope 10.79°, STI=146.14). Geomorphometric indices, particularly STI and RPI, accurately predicted wind direction by analyzing slope, surface roughness (NW: 12.83, SE: 8.64), and curvature patterns. Secondary winds (NE-SW and N-S) influence dune morphology in northeastern and southwestern sectors, respectively. Comparisons with global studies (Namib, Thar, Lut) confirmed the findings and highlighted innovations in multi-directional wind analysis and comparative morphometric matrices. However, the 30-meter resolution of SRTM data and the absence of field-based wind measurements limited the precision of fine-scale analyses. These results enhance understanding of aeolian processes and support sustainable land management, wind erosion control, and environmental planning in arid regions. Future research should integrate field wind data, multi-temporal remote sensing, and CFD modeling to refine dune dynamics models. این پژوهش به بررسی ارتباط ویژگی‌های مورفومتریک تلماسه‌ها و الگوهای بادی در ریگ یلان ، واقع در غرب دشت لوت، ایران، با استفاده از داده‌های مدل ارتفاعی رقومی پرداخته‌است. هدف اصلی این پژوهش، شناسایی جهات باد غالب و فرعی با تأکید بر ویژگی‌های ژئومورفیک تلماسه‌ها است. روابط بین شاخص‌های ژئومورفیک تلماسه‌ها و جهت‌گیری بادهای غالب با مطالعه و تحلیل آماری فضایی داده‌های مورفومتریک (شیب، زبری سطح، انحنای پروفیل، انحنای طرح، شاخص موقعیت توپوگرافی، شاخص موقعیت نسبی، تفاوت ارتفاع، و شاخص حمل رسوب تعین شده‌اند. در این راستا با بهره‌گیری از Google Earth Engine و GIS، شاخص‌های مورفومتریک از داده‌های SRTM محاسبه و با فیلتر کرنل گاوسی (شعاع 15، سیگما 2) نویزها کاهش یافتند. ارزیابی تأثیرات متقابل این شاخص‌ها نشان داد که تغییرات انحنای پروفیل و پلان تلماسه‌ها می‌تواند به‌عنوان شاخصی برای شناسایی مناطق فرسایش‌پذیر در نظر گرفته شود. یافته‌های کلیدی نشان‌دهنده جهت باد غالب از جنوب شرقی و جنوب (SE,S)، با ستیغ‌های تلماسه‌ای در راستای شمال غربی و شمال (NW,N)، و شاخص تقارن 0.21- با سطح اطمینان بالا (۹۵٪) هستند. نتایج تحلیل‌ها (میانگین شیب 11.87 درجه در NW، زبری 13.90 در NW، و STI =162.70 در NW در NW) الگوهای ستیغ‌ها و گودال‌ها را در جهت‌های NW و SE تأیید کردند. نتایج همچنین نشان دادند که تغییرات شاخص حمل رسوب در امتداد محور NW-SE همبستگی بالایی با تغییرات زبری سطح دارد، که می‌تواند در مدل‌سازی پویایی تلماسه‌ها کمک کنند. نتایج همچنین بیانگر پتانسیل بالای داده‌های دورسنجی برای پایش تغییرات مورفولوژیکی در مناطق فراخشک و جایگزین مناسبی برای داده‌های میدانی در مناطقی که دسترسی به داده‌های بادشناسی محدود و ممکن نیست، است. این نتایج اهمیت تحلیل مورفومتریک مشتق‌شده از DEMs را برای درک فرآیندهای بادی در بیابان‌ها، مدیریت منابع طبیعی، و پیش‌بینی فرسایش بادی برجسته می‌کنند. محدودیت‌هایی مانند فقدان داده‌های میدانی و بادی محلی، مسیرهای تحقیقاتی آینده را مشخص می‌کنند.

https://www.geomorphologyjournal.ir/article_224007_28dce2a63ff98d7c991e10b658b86327.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 ارزیابی و پهنه‌بندی حساسیت زمین لغزش با الگوریتم-های یادگیری ماشین (مطالعه موردی حوضه آبخیز مارگون، زاگرس فارس) 42 61 224962 10.22034/gmpj.2025.474854.1519 FA سعید نگهبان گروه جغرافیا، دانشکده اقتصاد، مدیریت و علوم اجتماعی، دانشگاه شیراز، شیراز، ایران مهری مرحمت دانش آموخته دکتری ژئومورفولوژی، گروه جغرافیای طبیعی، دانشگاه محقق اردبیلی. حمید علی نژاد دانش آموخته کارشناسی ارشد عمران مکانیک خاک و پی، دانشگاه آزاد اسلامی واحد استهبان. Journal Article 2024 08 23 زمین لغزش یکی از مخاطرات ژئومورفولوژی است که همواره در مناطق کوهستانی وجود داشته و خسارات زیادی را به باغات، سکونتگاهها و تاسیسات انسانی وارد می کند. هدف از این تحقیق ارزیابی و پهنه‌بندی حساسیت زمین‌لغزش در حوضه آبخیز مارگون در شهرستان سپیدان، استان فارس است. سه مدل یادگیری ماشین (ML) (ماشین بردار پشتیبان (SVM)، خطی تعمیم‌یافته (GLM) و جنگل تصادفی (RF)) برای شناسایی عوامل مؤثر در وقوع زمین‌لغزش استفاده شد. عوامل مؤثر (ارتفاع، شیب، فاصله از رودخانه، تراکم زهکشی، پوشش‌گیاهی، کاربری اراضی، سنگ‌شناسی، نوع خاک، متوسط بارندگی سالانه و فاصله از جاده) است و نقشه فهرست زمین‌لغزش (119 نقطه لغزش و 99 نقطه عدم لغزش است که از گوگل ارث، مشاهدات میدانی و نرم‌افزار ArcGIS) به دست آمد. هر مدل با استفاده از 70 درصد داده‌های آموزشی به طور مستقل آموزش داده شد و در مقابل 30 درصد باقی‌مانده اعتبارسنجی شد. فاصله از جاده به‌عنوان تأثیرگذارترین عامل در لغزش زمین در مدل ماشین بردار پشتیبان و مدل جنگل تصادفی و در مدل خطی تعمیم‌یافته شیب به‌عنوان تأثیرگذارترین عامل شناخته شد. برای ارزیابی عملکرد مدل‌ها از سطح زیر منحنی مشخصه عملیاتی گیرنده (AUC) و ضریب Kappa استفاده شد. مدل‌ RF (98/0، 739/0) و SVM (91/0، 638/0) بالاترین سطوح عملکرد را نشان دادند. این تحقیق می‌تواند به اجرای استراتژی‌های مدیریت خطر زمین‌لغزش مؤثر در منطقه کمک کند.

https://www.geomorphologyjournal.ir/article_224962_76d6b2aa80101af4eb8c8061b2f9e3a2.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Investigation and Monitoring dust generation ranges and forecasting desertification in Iraq's Wasit province using time series analysis (2005 to 2030) بررسی و پایش محدوده‌های زایش گردوغبار و پیش‌بینی بیابان‌زایی در استان واسط عراق با استفاده از تحلیل سری زمانی (2005 تا 2030 ) 62 80 220626 10.22034/gmpj.2025.510717.1550 FA مریم بیاتی خطیبی گروه سنجش از دور و سیستم اطلاعات جغرافیایی، دانشکده برنامه‌ریزی و علوم محیطی، دانشگاه تبریز هاله عبدالکریم گروه سنجش از دور و سیستم اطلاعات جغرافیایی، دانشکده برنامه ریزی و علوم محیطی ،دانشگاه تبریز بختیار فیضی زاده گروه سنجش از دور و سیستم اطلاعات جغرافیایی ،دانشکده برنامه‌ریزی و علوم محیطی ،دانشگاه تبریز Journal Article 2025 03 05 Because of this importance, researchers have tried to focus their research on these areas. Worldwide, some countries are experiencing severe environmental changes, and areas under desertification affect approximately 35% of the Earth's surface and 32% of the total human population. Among other countries in the Middle East, Iraq has become the most important dust-producing area due to environmental changes and desertification, and during part of the year, Iran is also affected. Given the importance of paying attention to the issue of desertification in Iraq, in the present study, with the aim of monitoring areas under desertification in Al-Wasit province, the Albedo and TGSI desertification indices extracted from MODIS sensor products for the years 1384 to 1402 (2005 to 2023) were used and trended using the ARIMA model in time series analysis for the year 1402 (2023). In the Google Earth Engine environment, the indices used for the period 1384 to 1402 (2005 to 2023) were produced by coding in computer programs. After fuzzy descaling of the indices and algebraic summation of the research indices, the desertification index (DI) was generated. For time series analysis on raster layers, libraries related to time series analysis and raster analysis were used in the R software environment. The study findings show that the extent of areas subject to desertification has changed in different years and has expanded significantly in the province under study, and given the current trend of desertification, it will continue if not managed and controlled. Important parts of the northern, northeastern and central regions of Al-Wasit province are involved in the phenomenon of desertification. The intensification of this trend will have various effects and consequences, such as dust.Desertification, which is the process of land destruction in dry, semi-arid and semi-humid areas, can lead to the loss of biological and economic productivity, and ultimately biodiversity and dust generation. This process affects approximately 35% of the earth's surface and 32% of the total human population( 8). Desertification is caused by a combination of climate fluctuations and human activities; Climate factors: Drought and climate change intensify desertification by reducing water availability and changing precipitation patterns. Human activities: excessive cultivation, deforestation, excessive livestock grazing, inappropriate irrigation practices and unsustainable land management are among the main factors(7). Desertification is recognized as an important environmental challenge that affects ecosystem services, food security, and social well-being. This phenomenon is mainly caused by changes in land use and land cover, removal of natural plant cover. In fact, desertification is a complex phenomenon and occurs in different temporal and spatial scales, and each geographical area can have its own unique factors. There are different global experiences regarding confronting and identifying this phenomenon(4). For example, in China, extensive efforts have been made, including government policies and desertification control programs, which have led to the reversal of the expansion of desert lands(4). In Iran, despite various political measures, desertification caused by meteorological drought and excessive use of water remains a serious issue. Also, in Central Asia, the phenomenon of desertification has intensified again since the 2010s . Since dry areas are often affected by rapid soil erosion, land degradation, and desertification, continuous monitoring of land use and land cover changes is necessary, and remote sensing images are valuable resources for extraction due to having continuous spatial information and time series. Time patterns are the process of changes and monitoring of this phenomenon. Until now, various remote sensing indicators have been developed and used to investigate and evaluate the process of desertification and land degradation.The indices obtained from the spectral information of satellite images have various advantages in the study of phenomena such as desertification. While most of the previous researches used the NDVI index to study vegetation changes in the study of Desertification, this research, like the researches (9,10,11)used the TGSI index, which indicates the size of the soil. It is used superficially. Like other researches, the use of several important indicators in the phenomenon of desertification can identify the areas at risk of this phenomenon. Time series analysis with Arima in the R software environment can provide quick and easy monitoring of desertification phenomenon. According to the findings in the figure (13-14, 15-16), the average trend of changes in the desertification index obtained in the studied years follows a completely non-linear pattern. So that during 2005 to 2007 this trend was increasing and from 2007 to 2009 it was decreasing and then it was increasing until 2010 and then decreasing in 2011 to 2012 and then it was increasing until 2014. In general, the analysis of changes in this index shows that compared to 2005, this index has increased. The lowest value of this index is 0.72 in 2012 and the highest value is 1.44 in 2023. The intensity of desertification in the northern areas of the Tigris River and the northern and northeastern parts of this province during the studied period is high. Desertification is one of the most well-known environmental challenges in today's world. The existence of this phenomenon not only emphasizes the necessity of studying it, but also requires appropriate and available tools to monitor and control it. Various researches have dealt with the monitoring and monitoring of Desertification, in line with the previous researches, this study also aimed to provide a simple and fast tool for monitoring the Desertification in Al-Wasit province of Iraq. And by examining the background of the research, he used two indices, Albedo and TGSI. In order to monitor and predict the desertification phenomenon, Arima model was used in time series analysis. R software environment was used to implement the model. The findings of the research show that the phenomenon of desertification in the north, northeast and parts of the center of this province is considered a serious problem and this process will continue until 2030, which requires optimal planning and management. به دلیل اهمیت محققان سعی کرده اندپژوهش‌های خود را به این محدوده ها متمرکز کنند. در سطح دنیا بعضی ازکشورها درگیر تغییرات محیطی شدی هستند ومحدوده‌های تحت بیابانی شدن تقریباً 35 % از سطح زمین و 32 % ازکل جمعیت انسانی را تحت تأثیر قرار می‌دهد.کشور عراق در بین سایر کشورهای خاورمیانه امروزه به لحاظ تغییرات محیطی و بیابانی شدن ،به عمده‌ترین محدوده زایش گردو غبار تبدیل شده است که دربخشی ازسال، کشور ایران نیز از آن بی‌بهره نمی‌ماند.با عنایت به اهمیت توجه به موضوع بیابانی شدن در کشورعراق،در پژوهش حاضر با هدف پایش محدوده‌های تحت بیابان‌زائی در استان الواسط از شاخص بیابان‌زائی Albedo و TGSI مستخرج از پروداکت‌های سنجنده مودیس برای سال‌های 1384 تا 1402 ( 2005 تا 2023 )استفاده شده و با مدل آریما در تحلیل سری زمانی برای سال 1402( 2023)روندیابی شد. در محیط گوگل ارث انجین شاخص‌های بکارگرفته شده برای دوره زمانی 1384 تا 1402(2005 تا 2023) با کد نویسی دربرنامه های کامپیوتری تولید شدند. پس از بی‌مقیاس سازی فازی شاخص‌ها و با جمع جبری شاخص‌های پژوهش، شاخص بیابان زائی(DI) تولید شد. برای تحلیل سری زمانی بر روی لایه‌های رستری از کتابخانه‌های مربوط به تحلیل سری زمانی و تحلیل رستری در محیط نرم افزاری R استفاده شد.بررسی یافته‌های پژوهش نشان می‌دهد که در سال های مختلف گستره محدوده های تحت بیابان زایی تغییر یافته و در استان مورد مطالعه گسترش قابل ملاحظه بوده است و با توجه به روند فعلی بیابان‌زائی، درصورتیکه مدیریت و کنترل بعمل نیاید،ادامه خواهد داشت. بخش‌های مهمی از مناطق شمالی، شمال شرقی و مرکزی استان الواسط درگیر پدیده بیابان‌زائی هستند.تشدید این روند اثرات و پیامدهای مختلفی مثل ریزگردها را در پی داشته باشد.

https://www.geomorphologyjournal.ir/article_220626_a65476219af0f732ada923069f4514de.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Determination of the Most Important Parameters Affecting the Urban Runoff in Khorramabad City using SWMM Model تعیین مهم‌ترین پارامترهای موثر بر سیلاب شهری خرم‌آباد با استفاده از مدلSWMM 81 106 224982 10.22034/gmpj.2025.518647.1557 FA حمید رضا هاشمی گروه مهندسی طبیعت، دانشکده منابع طبیعی و محیط زیست، دانشگاه ملایر، ملایر، ایران علیرضا ایلدرمی گروه مهندسی طبیعت، دانشکده منابع طبیعی و محیط زیست، دانشگاه ملایر، ملایر، ایران بهنوش فرخزاده گروه مهندسی طبیعت، دانشکده منابع طبیعی و محیط زیست، دانشگاه ملایر، ملایر، ایران Journal Article 2025 04 23 In urban watersheds, the increase in impervious levels, which due to physical development, leads to an increase in the volume of runoff, peak discharge, and a decrease in the amount of permeability and an increase in urban flooding .and this is despite the fact that most of the urban watersheds do not have hydrometric stations and runoff statistics, hence determining the hydrological response of urban watersheds is essential considering the complexity of the drainage system (Yarahmadi et al. 2018). Ghadri Dehkordi et al. (2019) using the SWMM model to determine the ability to collect and extract runoff in Babolsar city, showed that the runoff coefficient is directly related to the return period, and larger rainfalls have a higher runoff coefficient.. Yarahamdi et al. (1400) in evaluating the effectiveness of the SWMM model in order to investigate the drainage network flood nodes under the influence of climate change in the east of the six municipalities of Tehran, showed that the surface runoff collection system of the research area needs to be improved and modified, the slope of the passages and dimensions It has channels to transfer runoff caused by floods . .Zhang et al. (2020) designed and implemented a framework based on SWMM for urban runoff management. The results showed that the model can provide calculations in real-time, consistently, quickly and accurately, and can be effectively used in real-time management of urban runoff. In a research, Brown et al. (2021) investigated the impact of runoff management in small cities and showed that land use changes lead to hydrological changes in the city and will be intensify by climate change. Methodology Khorramabad city with an area of 50.28 km2 is located in Lorestan province.The purpose of this research is to simulate runoff and determine the most important parameters affecting urban flooding in parts of Khorramabad city using the SWMM model. .First, while determining the runoff values for 24-hour rainfall with different return periods, the best statistical distribution according to the intensity-duration-frequency diagrams, the flood potential of Khorramabad city was investigated.and then simulation of infiltration by SCS method and soil information layer and By using parameters of equivalent width, slope percentage,percentage of impenetrable areas Manning roughness coefficient of permeable zones and impenetrable,Pond storage depth for permeable and impervious areas and percentage of impervious areas without pond storage, SWMM model sensitivity analysis was performed. Therefore, in this research, the SWMM model was investigated and evaluated in order to simulate urban runoff and determine the most important parameters affecting the occurrence of floods in parts of Khorramabad city. Results and Discussion The results showed that there is a significant relationship between the model efficiency evaluation index related to the estimation of simulated and observed runoff height.and the evaluation of the efficiency of the model by the Kling-Gupta index provided an acceptable value and the model for simulating the resulting rainfall and runoff compared to the measured rainfall and runoff, as well as presenting the hydrological and hydraulic characteristics of urban watersheds, has an acceptable efficiency.The results of the model calibration showed that there is a significant relationship between the runoff depth produced by the model and calculated by the SCS method.and the SWMM model can simulate the runoff coefficient and flood potential well by modeling infiltration in different ways. The results of the model calibration showed that there is a significant relationship between the runoff depth produced by the model and calculated by the SCS method. and the SWMM model can simulate the runoff coefficient and flood potential well by modeling infiltration in differe.. The results showed that in Khorramabad urban watershed, which has a higher percentage of impermeability, the potential of runoff and flooding is also higher.and the percentage of impervious areas has the greatest effect in creating peak discharges.The results show that the most sensitive parameters, in order of priority, include the percentage of impervious areas, the depth of pond storage in impervious areas,equivalent width,Manning's roughness coefficient in impervious areas subbasin slope, the depth of pond storage in permeable areas, Manning's roughness coefficient in permeable area and the percentage of impervious areas without pond storage. Conclusion Today, many hydrological and hydraulic simulation models have been designed in connection with the simulation of flow and runoff patterns In the field of urban runoff, one of the best is the SWMM model, which is specially designed. Since the city of Khorramabad was built along the Khorram River channel, it is always subject to urban flooding; Therefore, in this research, the SWMM model was investigated and evaluated in order to simulate urban runoff and determine the most important parameters affecting the occurrence of floods in parts of Khorramabad city. on the results, it can be said that the SWMM model can estimate the runoff coefficient and flood potential well by modeling infiltration in different ways.In this research, considering the lack of access to infiltration data, the SCS method was used to estimate infiltration and the results showed that impervious surfaces including residential areas, roofs,the roads of asphalt etc. have the largest share in the flood potential of the study area.Theresults showed that some channels and nodes of Khorramabad urban network do not behave properly and cause risky behavior in sensitive and busy and dense situations of the city which is suggested to be improved in order to solve the hydraulic defects ,In addition, it is possible to reduce the impervious area to a minimum by measures such as reducing private parking lots and building public and multi-story parking lots, preventing the construction of very wide and unprincipled sidewalks and roads, especially in residential areas. کنترل آبگرفتگی، سیلاب و تحلیل پیچیدگی عملکرد هیدرولیکی و هیدرولوژیکی پارامترهای موثر بر سیلاب شهری‌، مستلزم استفاده از روش‌های محاسباتی پیشرفته و مدلسازی‌های جدید و کارآمدتر می باشد. هدف ازاین پژوهش شبیه‌سازی رواناب و تعیین مهم‌ترین پارامترهای موثر بر سیلاب شهری بخش‌هایی از شهر خرم‌آباد با استفاده از مدل SWMM است. ابتدا ضمن تعیین مقادیر رواناب برای بارش 24 ساعته با دوره بازگشت های مختلف بهترین توزیع آماری با توجه به نمودارهای شدت-مدت-فراوانی، پتانسیل سیلخیزی شهر خرم‌آباد بررسی و سپس شبیه سازی نفوذ از روش SCS و لایه اطلاعاتی خاکشناسی انجام و با استفاده از پارامترهای عرض معادل، درصد شیب، درصد مناطق نفوذ ناپذیر، ضریب زبری مانینگ مناطق نفوذ پذیر و نفوذ ناپذیر، عمق ذخیره چالابی برای مناطق نفوذ پذیر و نفوذ ناپذیر و درصد مناطق نفوذ ناپذیر بدون ذخیره چالابی، آنالیز حساسیت مدل SWMM انجام شد. با توجه به مقدار 994/0 رابطه نش-ساتکلیف ورابطه کلینگ-گوپتا به میزان913/0 نتایج واسنجی و ارزیابی مدل نشان داد که بین شاخص‌ ارزیابی کارایی مدل جهت برآورد ارتفاع رواناب شبیه‌سازی و مشاهداتی، رابطه معنی‌داری وجود دارد و مدل برای شبیه‌سازی بارش و رواناب از کارایی قابل قبولی برخوردار است. نتایج نشان داد به ترتیب درصد مناطق نفوذ ناپذیر، عمق ذخیره چالابی مناطق نفوذ ناپذیر و عرض معادل بیشترین تاثیر را بر تغییر عمق رواناب دارند .نتایج واسنجی مدل نشان داد بین عمق رواناب تولیدی مدل و محاسباتی روش SCS ارتباط معنا داری وجود دارد و مدل SWMM می‌تواند با مدلسازی نفوذ به روش های مختلف، ضریب رواناب و پتانسیل سیل‌خیزی را به خوبی شبیه‌سازی نماید‌. همچنین نتایج نشان داد برخی کانال‌ها و گره-هایی شبکه شهری خرم آباد به درستی رفتار نمی‌کنند و موجب رفتار مخاطره آمیز درموقعیت‌های حساس و پر رفت و آمد و متراکم شهر می شوند که پیشنهاد می شود جهت رفع نواقص هیدرولیکی بهسازی شوند

https://www.geomorphologyjournal.ir/article_224982_ff1b269e64882a1c870467ef977dffc1.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Identifying and Assessment the geoheritage of desert areas with the aim of developing geotourism (case study: desert areas of Semnan) شناسایی و ارزیابی میراث زمینی مناطق بیابانی باهدف توسعه ژئوتوریسم (مطالعه موردی: مناطق بیابانی سمنان) 107 124 180466 10.22034/gmpj.2023.380768.1444 FA مجتبی منصوری ارمکی گروه جغرافیای طبیعی، پردیس بین المللی کیش، دانشگاه تهران مجتبی یمانی گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران. ایران 0000-0002-2042-7365 مهران مقصودی گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران. ایران 0000-0002-4973-8327 Journal Article 2023 07 08 Introduction world and to some extent in Iran. A geosite is a landscape, a collection of roughness forms, a unique roughness, a rock outcrop, a fossiliferous zone, a specific fossil, caves, a crater created by a meteorite impact, a volcano, and even a mine . Geomorphological landforms have a high ability to attract tourism. The connection of landforms with the discussion of the expansion of civilization and ancient, historical, cultural monuments, as well as sports topics, doubles the capabilities of landforms in the field of attracting tourism (Yemani et al., 2013: 70). The purpose of the geomorphosite concept design is to identify landforms that have a special place and importance in describing and understanding the history of the earth's surface Also, they have scientific, ecological, cultural, aesthetic and economic values together and are exploited for the purpose of understanding and exploiting human tourism . Geomorphosites have scientific, cultural, ecological, economic, etc. values . The evaluation of geomorphosites is a topic that shows the motivation and interest of geographers around the world to try to focus on developing and maintaining the evaluation methods that they provided in the past. Identifying different forms of the earth, especially geosites, geomorphosites, geotopes, and other natural forms of the earth is one of the basic principles of nature tourism. Study area The desert and desert areas of Semnan province have the ability to be turned into geoparks due to their geomorphological heritage, but due to the spread and size of the region in the north and south of the province, research on geotourism and geoparks has been done on a case-by-case basis, and the officials at the province level cannot plan to attract tourists. have, and for this purpose, with careful identification and study, it is possible to provide the ground for geopark registration. The possession of land and natural resources, which is a suitable platform for the development of geo-tourism and eco-tourism in Semnan province, reveals the necessity of paying attention to the mentioned types of tourism and the importance of attracting tourists and exploiting its many benefits for the country and the province in this regard. By accurately identifying the geotourism capacities of Semnan Province, introducing suitable types of this tourism model in accordance with the region, Data and research methods The current research has been applied with a descriptive and analytical approach to introduce and evaluate the geotourism capabilities of the region. In this research, in order to collect the data used, theoretical studies were first conducted with the aim of clarifying the framework of the subject, and in field studies (asking the people of Fan in the region) has been used to identify geosites, and KoboCollect software was used for field visits and registration of geosites and their specifications. Using this software, 90 geosites were identified and a separate birth certificate was prepared and completed for each of the geosites. After examining the birth certificate of geosites by expert experts and professors, 30 potential geosite points (Figure 2) were selected according to the criteria introduced as representatives of geosites, and based on the indicators in the models of Reynard (2013) and Brillha (2016), their valuation and geotourism position was determined. Data anaysis Reynard's model and Braille's model describe the relationship between geomorphology and tourism by stating that geomorphology may be the primary or primary source of tourism or as a secondary source, as long as tourism infrastructure, tools (such as educational manuals) or services are used effectively for the primary purpose. will be examined. Final evaluation and comparison of Reynard and Braille models In general, the oil well geosite is the most valuable geosite in both Reynard and Brill models; With its unique conditions, this geosite has received the highest possible points in both models. Geosite-73 is the second most valuable geosite among the studied geosites with 970 points in the Braille model and 3.93 points in the Reynard model. On the other hand, geosite 37 ranked 29th in the Braille model with 625 points and 30th in the Reynard model with 1.4 points, and it has the lowest overall value among the surveyed geosites. The first method, which was used by Brills (Zafiropoulos and Dernia, 2022), is considered a general-purpose method designed to evaluate any type of geosite considering a wide range of criteria. The inclusion of 12 criteria to evaluate the heritage value of the studied geosites leads to more objective results. On the other hand, Reynard's method includes public views, which in the present study clearly shows the lack of geo-environmental awareness and knowledge. These two methods provide different perspectives on the geoenvironmental value of a given geosite. The first method further deals with the geosite heritage of geological and tourism important places in a broader and deeper way. The second method, while it does not consider many parameters, also includes the opinion of visitors and the general public and education. The braille model is a model for measuring the capabilities of geosites in the scientific, educational, tourism and destruction risk sectors. Each of these sections have their own minimum and maximum points and coefficients, which should be taken into account in scoring. In the evaluation of the Braille model, geosites 68 and 73 both scored 970 points, and the geosite 33 scored the lowest. Conclusion: In the current research, the existing geomorphological capabilities were evaluated and ranked from the geotourism point of view. In the meantime, the oil well geosite received the highest score in two methods and was ranked first, and this same geosite is ranked at the bottom with a score of 195 from the point of view of destruction risk. In general, it can be said that the reasons why the oil well got the most points in both methods is the scientific value in both methods, although other cases also have good points, but the important point is the lack of protection of all geosites in the study area. امروزه ژئومورفولوژی در زمینه‌های، اقتصادی، تاریخی، مطالعات فرهنگی، اکولوژی و گردشگری می‌تواند مبنای برنامه-ریزی صحیح، مدیریت پایدار گردشگری و توسعه اقتصادی باشد. استان سمنان به دلیل داشتن لندفرم‌های بیابانی متنوع و مناظر شاخصی مانند لندفرم‌های کلوت و اشکال دشت‌های نمکی این منطقه را متمایز کرده و می‌تواند گردشگران علاقه‌مند و ماجراجو را از مناطق مختلف جذب کند. هدف از این پژوهش، تعیین و مقایسه مناسب‌ترین ژئومورفوسایت‌ها برای برنامه‌ریزی گردشگری پایدار با استفاده از دو روش ارزیابی ژئوتوریسم پیشنهاد شده توسط بریل‌ها و همکاران، رینارد و همکاران بوده است. طی کارهای میدانی ابتدا 90 مکان لندفرمی شناسایی شد که پس بررسی‌های کارشناسی 30 ژئوسایت شاخص از بین آن‌ها انتخاب شد. سپس این ژئوسایت‌ها با مدل‌های مذکور مورد ارزیابی قرا رگرفتند. به‌صورت کلی ژئوسایت چاه نفت(شماره 68) ارزشمندترین ژئوسایت در هر دو مدل رینارد و بریل‌ها می‌باشد؛ این ژئوسایت با شرایط منحصربه‌فرد خود، بیشترین امتیاز ممکن را در هر دو مدل به خود اختصاص داده است. ژئوسایت هزار دره در شمال چاه نفت(شماره73) در مدل بریل‌ها و دره آرزوها (شماره71) درمدل رینارد، دومین ژئوسایت ارزشمند در میان ژئوسایت‌های موردبررسی شناسایی شد. در طرف مقابل، ژئوسایت جنوب چشمه استالیه (شماره 33) در مدل بریل‌ها رتبه 30 و در مدل رینارد ژئوسایت جنوب دلازیان (شماره 37)رتبه 30 را به خود اختصاص داده و مجموعاً کم‌ترین ارزش را در میان ژئوسایت‌های موردبررسی کسب کرده است.

https://www.geomorphologyjournal.ir/article_180466_13293fa9163a7081b817019240bdc4ce.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Morphoclimatic Analysis of Quaternary Climatic Fluctuations Using Polynomial Modeling in the Arpaçhay Basin, Zanjan تحلیل مورفوکلیماتیک نوسانات اقلیمی کواترنری با استفاده از مدل پلی‌نومیال در حوضه آرپاچای زنجان 125 139 225743 10.22034/gmpj.2025.529493.1567 FA حسن جعفری گروه جغرافیا، دانشکده ادبیات و علوم انسانی، دانشگاه یاسوج، یاسوج، ایران Journal Article 2025 06 09 Introduction Quaternary climatic fluctuations have played a fundamental role in shaping Earth's surface morphology and influencing the evolution of fluvial systems, especially in mountainous regions. These oscillations, characterized by alternating glacial and interglacial periods, have significantly altered hydrological regimes, erosion-deposition dynamics, and geomorphological development across diverse landscapes. In Iran, particularly in northwestern regions such as the Zanjanrud and Qezelozan basins, Quaternary climatic changes have left distinct geomorphic imprints, including U-shaped valleys, moraine ridges, and multiple terrace levels—features that suggest both glacial and periglacial activity. This study focuses on detecting and validating four stages of climatic and tectonic transformation in the Arpachai Basin using sixth-degree Pearson polynomial modeling and dimensional hypsometric analysis. Unlike traditional studies that rely on international glacial stage classifications, this research emphasizes morphometric and statistical signatures of past climatic oscillations, based on topographic inflection points preserved in the river longitudinal profile. Methodology To achieve the research objectives, a multi-stage methodology was adopted, combining field data acquisition, spatial analysis, and mathematical modeling. Data collection involved: Topographic maps (1:25,000 scale), Sentinel-2 satellite imagery, and Google Earth Pro for precise identification of cross-sections. Field GPS data (UTM Zone 39N) encompassing longitude (X), latitude (Y), and elevation (H) from three cross-sectional zones: upper, middle, and lower parts of the Arpachai Basin. Lithological and geological information derived from 1:100,000-scale geological maps provided by the Geological Survey of Iran. All collected data were used in dimensional hypsometric analyses. Unlike traditional dimensionless hypsometry, which considers only elevation along the Y-axis, dimensional hypsometry integrates both X and Y coordinates via the Pythagorean formula: D= √(x^2+y^2 ) This value (D ) was used as the horizontal axis, while elevation (H ) served as the vertical component in dimensional hypsometric diagrams, allowing for a more accurate representation of topographic structures. Three cross-sections (upper, middle, and lower) were selected based on slope variation, lithological heterogeneity, and the presence of multiple geomorphic terraces. Using the Profile Tool plugin in QGIS, topographic profiles were extracted and analyzed to detect geomorphic inflection points associated with climatic and tectonic changes. A sixth-degree polynomial model was applied to simulate the actual geomorphic profiles and identify key inflection points: Y=a^6 x^6 〖+a〗^5 x^5+a^4 x^4+a^3 x^3+a^2 x^2+ax+a_0₀ Coefficients were optimized using the Least Squares Method, and the resulting models were statistically validated using correlation coefficient (r), coefficient of determination (R²), and effect size. Due to limited accessibility in the middle section of the basin, pixel-coded digitization of field images and GIS-based coordinate extraction were employed to reconstruct the topographic profile. In the lower basin, 50 field survey points and UTM coordinates were combined using the Pythagorean structure to extract and analyze the corresponding topographic profile. Results and Discussion Analysis of the three cross-sectional profiles revealed consistent evidence of four major geomorphic edges throughout the Arpachai Basin. These edges correspond to inflection points in the river longitudinal profile and reflect significant shifts in base-level, river energy regime, and sedimentation patterns under combined climatic and tectonic influences. These results demonstrate the robustness of the method in detecting subtle but coherent geomorphic signals across the basin. Minor discrepancies in model performance among sections were attributed to local lithological variations, differential erosion rates, and sediment deposition effects. In the upper part of the basin, the final polynomial model was derived as: y=(-0.1*〖10〗^(-12) ) x^6+0.000003x^5-34.682x^4+(2*〖10〗^8 ) x^3-(6*〖10〗^14 ) x^2+(9*〖10〗^20 )x-(6*〖10〗^26) This model successfully explained over 97% of topographic variability, indicating minimal estimation error and strong explanatory power. For the middle basin, where direct field access was limited due to steep terrain and narrow width, the following model was obtained: y=-1.6x^6+39.2x^5-392.8x^4+1945.4x^3-4581.7x^2+5064.4x-615.92 This equation accurately simulated four geomorphic inflection points, interpreted as evolutionary stages linked to paleoclimatic oscillations. In the lower basin, data from 50 field survey points were used to generate the following polynomial function: y=(2*〖10〗^(-12) ) x^6-(4*〖10〗^(-5) ) x^5+408.55x^4-(2*〖10〗^9 ) x^3+(7*〖10〗^15 ) x^2-(1*〖10〗^22 )x+(8*〖10〗^27) Here, the model achieved the highest performance, with an R² value of 98%, confirming the stability and reliability of the polynomial modeling technique. These results indicate exceptionally high model accuracy, with all sections showing R² values above 94%, confirming the presence of four distinct geomorphic stages in the basin's evolution. The consistency of these geomorphic signatures across all cross-sections demonstrates that the detected climatic fluctuations were recorded synchronously throughout the basin, supporting the hypothesis that the observed changes were not random or isolated, but rather large-scale spatiotemporal adjustments driven by both climatic and tectonic forces. Minor discrepancies in model performance among sections were attributed to local lithological variations, sediment deposition effects, and differential erosion rates. However, the structural coherence of the inflection points across the basin confirms the morphoclimatic significance of the identified transitions. The consistency of these geomorphic signatures across all cross-sections indicates that the detected climatic fluctuations were recorded simultaneously throughout the basin. This coherence supports the hypothesis that the observed changes were not random or isolated, but rather reflected large-scale spatiotemporal adjustments driven by both climatic and tectonic forces. Conclusion This study provides strong evidence for the presence of four distinct paleoclimatic oscillations during the Quaternary period in the Arpachai Basin. These oscillations were identified through sixth-degree polynomial modeling and dimensional hypsometry, which enabled high-resolution simulation of geomorphic profiles and statistical validation using r, R², and Effect Size. The identified geomorphic edges represent transitions in river energy regime, base-level changes, and sediment transport dynamics, all indicative of climatic forcing. These features were consistently preserved across all three cross-sectional zones, demonstrating the basin-wide impact of Quaternary climatic fluctuations. This research highlights the robustness of geometric and statistical methods in detecting and interpreting paleoclimatic signals in tectonically active and climatically sensitive regions. The approach used in this study can serve as a model for similar investigations in mountainous and semi-mountainous basins in Iran and other regions with complex morphoclimatic and tectonic histories. تحلیل‌های مورفوکلیماتیک نقش برجسته‌ای در شناسایی تحولات اقلیمی کواترنری و تأثیرات آن بر توپوگرافی سطح زمین دارد. در این پژوهش، با هدف اثبات وجود چهار نوسان پالئوکلیماتیک دوره کواترنری حوضه آرپاچای، از روش‌های ژئومتریک و مدل‌سازی ریاضی پلی‌نومیال درجه ششم استفاده شد. داده‌های مورد نیاز شامل مختصات متریک (طول و عرض)، ارتفاع از سطح دریا و مقادیر جذر مجموع طول و عرص جغرافیایی به توان دو (√(X² + Y²)) جهت ایجاد هیپسومتری بعددار از سه مقطع عرضی (علیا، وسطی و سفلی) حوضه جمع‌آوری گردید. نیمرخ‌های توپوگرافیکی واقعی با استفاده از مدل پلی‌نومیال درجه ششم شبیه‌سازی شد و اعتبار مدل نیمرخ در بخش‌های مختلف مورد ارزیابی قرار گرفت. ضریب همبستگی بالا نشان‌دهنده تطابق بسیار خوب بین داده‌های میدانی و نتایج مدل‌سازی است. نتایج نشان میدهند که مدل پلی‌نومیال درجه ششم دارای دقت بالایی در شبیه‌سازی تراس‌های ژئومورفولوژیکی مرتبط با نوسانات اقلیمی است. چهار تراس مشاهده شده در نیمرخ‌ها مربوط به چهار مرحله تحولی در حوضه بوده که با چهار رویداد پالئوکلیماتیک همراهی دارد. همچنین، تطبیق الگوها در تمامی بخش‌های حوضه (علیا، وسطی و سفلی) نشان داد که این نوسانات تحت تأثیر همزمان فاکتورهای اقلیمی و تکتونیکی ثبت شده‌اند. این یافته‌ها نه تنها غنای علمی تحقیقات مورفوکلیماتیک را افزایش می‌دهند، بلکه کاربرد روش‌های ژئومتریک را در مناطق با دسترسی محدود ممکن می‌سازند.

https://www.geomorphologyjournal.ir/article_225743_577afa6890d661991ca8a2be72c9c357.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Assessment of the flow regime of the Simineh River using the Indicators of Hydrologic Alteration (IHA) approach ارزیابی رژیم جریان رودخانه سیمینه‌رود با رویکرد شاخص‌های تغییرات هیدرولوژیکی (IHA) 140 153 225936 10.22034/gmpj.2025.520164.1559 FA لیلا بابایی دانشجوی دکتری علوم و مهندسی آبخیزداری، دانشکده منابع طبیعی، دانشگاه ارومیه، ارومیه، ایران 0000-0002-7819-8470 هیراد عبقری گروه مرتع و آبخیزداری، دانشکده منابع طبیعی، دانشگاه ارومیه، ارومیه، ایران 0000-0002-3407-3297 رئوف مصطفی‌زاده گروه منابع طبیعی و عضو پژوهشکده مدیریت آب، دانشکده کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی، اردبیل، ایران 0000-0002-0401-0260 Journal Article 2025 04 29 Rivers play a crucial role as vital water resources in meeting drinking water, agricultural, and industrial needs, as well as in maintaining aquatic ecosystems. The flow regime of rivers is influenced by both natural and human factors. Human activities such as dam construction, river diversion, and land use changes have significantly impacted river flow regimes. Rivers provide essential needs for all vital activities and ecological processes. The riverbed shape, flow dynamics, and erosion-sedimentation processes are linked to the river's natural structure and function. Maintaining features such as flow rates and seasonal variations is crucial for river ecosystem sustainability. Ecologists consider river flow and its variability as key factors influencing many fundamental ecological processes in river ecosystems. However, in the context of climate change and increased human activities, the hydrological characteristics of natural rivers have undergone significant changes. Dams and reservoirs, and their impact on the diversion and regulation of flow upstream and downstream, are the main factors contributing to the loss of river continuity. In this study, the changes in the flow regime of the Simineh River at the Dashband hydrometric station in the Lake Urmia basin were analyzed using the Indicators of Hydrologic Alteration (IHA) model, and the values and variations of 33 hydrological parameters were calculated. The results showed that most monthly flow rates exhibited a significant decreasing trend. Specifically, the flows in October, November, February, and March showed a sharp decline with a negative slope and a 95% significance level over the statistical period. Although flows in June and July had a positive slope, the trend was not statistically significant. The minimum flow indices over 1-, 3-, 7-, 30-, and 90-day periods showed a significant downward trend (p < 0.01), indicating a reduction in baseflow. Maximum flows also showed a decreasing trend, although it was not statistically significant. The number of zero-flow days (slope 3.4) and the duration of low pulse events (slope 2.82) exhibited a significant increasing trend (p < 0.01), reflecting intensified hydrological drought conditions. The timing of maximum flow occurrence was delayed (slope 0.7, p = 0.005), while the changes in the timing of minimum flows were not significant. The baseflow index showed a slight decline (slope 0.001) but was not statistically significant (p = 0.25). Additionally, both the rise and fall rates of flow increased significantly (slopes 0.021 and 0.005, respectively), indicating greater flow instability. The number of flow reversals decreased significantly (slope 1.1, p = 0.01), possibly due to a reduction in the frequency of sudden flood events. The findings of this study, highlighting changes in the natural flow regime of the Simineh River, demonstrate that hydrologic alteration indices can serve as effective tools in water resource management; analyzing changes in each index (such as baseflow reduction, increase in zero-flow days, or shift in peak flow timing) provides important management applications in planning for drinking water supply, agriculture, drought control, and aquatic ecosystem protection across different dimensions of water management. The trend of changes in certain indicators shows an increase in hydrological fluctuations and instability in the river's flow regime, which may be attributed to the impacts of climate change or human activities such as water diversion, excessive withdrawals, and potential land-use changes. These results indicate that the flow regime of the Simineh River at the Dashband station has undergone significant changes in recent years, which could pose a serious threat to aquatic ecosystems and water supply in the future. The findings of this study show that the river flow in the Dashband-Bukan basin, particularly in the spring months, has significantly decreased, the number of dry days and the duration of drought periods have increased, the timing of maximum flow events has been delayed, and flow variability has increased. Additionally, the base flow of the river has consistently decreased. To complement these findings, it is suggested that the relationship between river flow changes and climatic parameters be investigated, the effects of human activities and land-use changes on the watershed’s water regime be analyzed, and flow prediction models be developed considering various climate change scenarios. From a management perspective, it is necessary to review the water allocation pattern, prioritize environmental needs, and focus on integrated management of surface and groundwater resources. Overall, water resource management policies should be updated considering climate change, and adaptation strategies should be implemented with the involvement of local communities and stakeholders to ensure greater effectiveness. Therefore, the need for water resource management and the adoption of optimal policies to protect natural and sustainable flows in this basin is essential. رودخانه‌ها نقش حیاتی در تأمین آب شرب، کشاورزی، صنعت و حفظ اکوسیستم‌های آبی دارند و رژیم جریان آن‌ها تحت تأثیر عوامل طبیعی و انسانی است. این پژوهش با هدف ارزیابی تغییرات رژیم جریان رودخانه سیمینه‌رود در ایستگاه داشبند با استفاده از مدل تغییرات شاخص‌های هیدرولوژیکی IHA و بررسی 33 پارامتر هیدرولوژیکی انجام شد. نتایج نشان داد که دبی ماه‌های اکتبر، نوامبر، فوریه و مارس با شیب منفی و سطح معناداری 95 درصد کاهش را طی دوره آماری نشان داده‌اند. دبی‌های ژوئن و جولای شیب مثبت دارند، اما این روند معنادار نیست. شاخص‌های دبی حداقل در بازه‌های زمانی 1، 3، 7، 30 و 90 روزه روند نزولی معنادار (p کمتر از 01/0) دارند که کاهش جریان پایه را نشان می‌دهد. دبی‌های حداکثر نیز روند نزولی دارند، اما معنادار نیست. تعداد روزهای صفر جریان (شیب 4/3) و مدت ضربان کم (شیب 82/2) افزایشی معنادار (p کمتر از 01/0) داشته‌اند که نشانه تشدید خشکسالی هیدرولوژیک است. زمان وقوع جریان حداکثر با شیب 7/0 و p برابر 005/0 به تأخیر افتاده، در حالی که تغییر زمان جریان حداقل معنادار نیست. شاخص جریان پایه با شیب 001/0 کاهش یافته اما معنادار نیست (p برابر با 25/0). هم‌چنین نوسانات افزایشی و کاهشی دبی با شیب‌های 021/0 و 005/0 به طور معنادار افزایش یافته‌اند که بیانگر بی‌ثباتی بیشتر جریان است. تعداد برگشت جریان با شیب 1/1 کاهش یافته و با p برابر 01/0 معنادار است که می‌تواند به کاهش وقوع سیلاب‌های ناگهانی مربوط باشد. بر اساس نتایج، شاخص‌های تغییرات هیدرولوژیکی می‌توانند ابزار مؤثری در مدیریت منابع آب باشند؛ به‌گونه‌ای که تحلیل تغییرات هر شاخص (مانند کاهش جریان پایه، افزایش روزهای بدون جریان یا تغییر زمان وقوع دبی‌های اوج) کاربردهای مدیریتی مهمی در برنامه‌ریزی تأمین آب شرب، کشاورزی، کنترل خشکسالی و حفاظت از اکوسیستم‌های آبی در ابعاد مختلف مدیریت آب به همراه دارد.

https://www.geomorphologyjournal.ir/article_225936_ed1484cc45f096964ac37dede1ee7fb9.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Analysis of Earthquake Ground Motion Parameters and Seismic Hazard Zonation in Sanandaj City Using Deterministic Methods and GIS تحلیل پارامترهای جنبشی زلزله و پهنه‌بندی خطر لرزه‌ای در شهر سنندج با استفاده از روش‌های تعیینی و GIS 154 168 225480 10.22034/gmpj.2025.516193.1556 FA شیدا شریفی گروه ژئومورفولوژی، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج. ایران هادی نیری گروه ژئومورفولوژی، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج. ایران عبدالله نصرتی گروه ژئومورفولوژی، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج. ایران Journal Article 2025 04 11 Earthquakes pose significant threats to urban and rural infrastructure, necessitating detailed seismic hazard assessments. This study analyzes the Ground Motion Parameters of earthquakes, specifically Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV), in Sanandaj, Iran, a city located within the seismically active Zagros zone. Employing deterministic methods, the research integrates historical seismic data, active fault characteristics, and local geotechnical properties to estimate these parameters. The attenuation model by Chandra et al. (1979) was utilized to assess spatial variations in seismic intensity, while Geographic Information Systems (GIS) and the Inverse Distance Weighting (IDW) interpolation method facilitated seismic hazard zonation across an 18×15 km urban area. Results indicate that southwestern Sanandaj faces the highest seismic risk, with PGA values ranging from 0.34g to 0.36g and PGV between 35 and 39 cm/s, reflecting significant potential impacts on infrastructure. The study reveals a heterogeneous seismic hazard distribution, with southern and southwestern zones most vulnerable due to proximity to active faults. These findings exceed the baseline PGA of 0.3g outlined in Iran’s seismic design code (Standard 2800), underscoring the need for localized revisions to enhance urban resilience. The integration of GIS-based mapping highlights its efficacy in visualizing hazard patterns, aiding urban planning and disaster management. Recommendations include revising Standard 2800 with region-specific data and adopting probabilistic methods in future studies to improve accuracy. This research provides a critical foundation for mitigating seismic risks in Sanandaj, offering insights applicable to other seismically active regions in Iran. Keywords: Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), Seismic Hazard Zonation, Sanandaj Methodology and Results Aims This study aims to evaluate the Ground Motion Parameters of earthquakes—Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV)—in Sanandaj, Iran, to assess seismic hazard distribution and inform urban planning and infrastructure resilience. Located in the seismically active Zagros zone, Sanandaj’s proximity to over 40 active faults within a 70 km radius necessitates precise hazard analysis. The research seeks to: (1) estimate PGA and PGV using deterministic methods, (2) map seismic hazard zones across an 18×15 km urban area using GIS, and (3) compare findings with Iran’s seismic design code (Standard 2800) to propose enhancements for local applicability. Procedure The research proceeded in stages: (1) data compilation and fault selection, (2) magnitude estimation for each fault, (3) intensity calculation and attenuation modeling, (4) conversion to PGA and PGV, and (5) GIS-based zonation. Fault lengths were measured from geological maps, and magnitudes were averaged across multiple relationships. Intensity attenuation was calculated for each grid cell, followed by PGA and PGV estimation. GIS mapping visualized spatial trends, validated by low RMSE values from IDW interpolation. A deterministic approach was adopted to estimate seismic parameters, leveraging historical and instrumental earthquake data, fault characteristics, and geotechnical conditions. Data were sourced from multiple authoritative repositories: historical seismicity from Mirzaei et al. (2002), instrumental records (2000–2020) from Iran’s National Seismological Center, fault maps from the Geological Survey of Iran (2019), and geotechnical data from the National Cartographic Center (2021). Active faults were selected based on criteria including a minimum length of 10 km, evidence of activity within the last 10,000 years, and proximity (<70 km) to Sanandaj, as per Iran’s Dam Construction Committee standards (2016). Earthquake magnitude (M) was calculated using empirical relationships linking fault length (L) to magnitude, including Wells and Coppersmith (1994: M = 5.08 + 1.16log(L)), Nowroozi (1985: M = 4.86 + 1.32log(L)), and Ashjaei (1981: M = 4.5 + 1.5log(L)). A mean magnitude was derived to reduce uncertainty. Seismic intensity (Io) at the epicenter was estimated using Zare et al. (2009: Io = 1.3Ms + 0.09), followed by attenuation modeling with Chandra et al. (1979: IR = Io + 6.453 − 0.00121R − 4.960log(R+20)), where IR is intensity at a site and R is epicentral distance. PGA and PGV were then derived from intensity using log10(PGA) = 0.33MMI − 1.2 and log10(PGV) = 0.31MMI − 0.7, respectively. The study area was discretized into a 1×1 km grid (270 cells), and GIS (ArcGIS 10.8) was employed for spatial analysis. Epicentral distances were computed using the Point Distance tool, and the IDW method (RMSE = 0.0248) interpolated point data into continuous hazard maps, chosen for its simplicity and accuracy in local variation modeling. Results and Discussion Results reveal a non-uniform seismic hazard distribution in Sanandaj. Southwestern zones exhibit the highest risk, with PGA ranging from 0.34g to 0.36g and PGV from 35 to 39 cm/s, corresponding to an intensity of VIII on the Modified Mercalli Intensity (MMI) scale. These values decline northward (PGA ~0.30g, PGV ~30 cm/s), reflecting increased distance from active faults concentrated in the southwest. The elevated PGA exceeds Standard 2800’s 0.3g baseline, suggesting that current design parameters may underestimate local risk. This discrepancy arises from the study’s detailed fault inventory (40 faults) compared to the code’s broader regional approach. Comparisons with prior studies show consistency with Panahi and Motasharrei (2013) (PGA = 0.34g) and partial alignment with Zare et al. (2009) (0.25–0.35g), though Yazdani and Khaji (2015) report a lower 0.25g due to fewer seismic sources. The precision of GIS-based IDW interpolation (RMSE = 0.0248) enhances result reliability, highlighting southwestern Sanandaj’s vulnerability, particularly to infrastructure like water networks, where PGV strongly correlates with pipe failure (O’Rourke & Liu, 2012). Conclusion This study underscores Sanandaj’s heterogeneous seismic risk, with southwestern areas most threatened due to fault proximity. The findings advocate for revising Standard 2800 with localized data and integrating probabilistic methods in future research to refine hazard estimates. GIS-based zonation proves effective for urban planning, offering a replicable model for other Zagros cities. زلزله یکی از مخاطرات طبیعی مخرب است که تأثیرات گسترده‌ای بر زیرساخت‌های شهری و روستایی دارد. این پژوهش به تحلیل پارامترهای جنبشی زلزله از جمله شتاب اوج زمین (PGA) و سرعت اوج زمین (PGV) در شهر سنندج پرداخته است. به‌منظور برآورد این پارامترها، از رویکردهای تعیینی و تجربی بهره گرفته شده و داده‌های لرزه‌ای تاریخی، مشخصات گسل‌های فعال و ویژگی‌های ژئوتکنیکی منطقه مورد بررسی قرار گرفته‌اند در این پژوهش، به‌منظور تحلیل تغییرات فضایی پارامترهای لرزه‌ای، از مدل‌های کاهندگی شدت زلزله همچون رابطه چاندرا (۱۹۷۹) استفاده شده است. همچنین، به‌منظور پهنه‌بندی خطر لرزه‌ای، از سیستم اطلاعات جغرافیایی (GIS) و روش درونیابی وزن‌دهی معکوس فاصله (IDW) بهره گرفته شده است. نتایج حاصل از تحلیل‌ها نشان می‌دهد که محدوده جنوب‌غربی سنندج بیشترین مخاطره لرزه‌ای را تجربه می‌کند، به‌طوری که مقدار PGA در این نواحی 34/g تا 36/g و PGV در بازه ۳۵ تا ۳۹ سانتی‌متر بر ثانیه برآورد شده است. این مقادیر نشان‌دهنده تأثیرات بالقوه بالا زلزله بر زیرساخت‌های منطقه هستند.بررسی کلی نتایج نشان می‌دهد که توزیع خطر لرزه‌ای در سنندج ناهمگن بوده و نواحی جنوبی و جنوب‌غربی شهر بیشترین تأثیر را از لرزه‌های احتمالی خواهند داشت. یافته‌های این پژوهش بر لزوم بازنگری در آیین‌نامه ۲۸۰۰ ایران با توجه به داده‌های محلی تأکید دارند. همچنین، پیشنهاد می‌شود در مطالعات آینده، از روش‌های احتمالاتی و تحلیل‌های دینامیکی جهت افزایش دقت برآورد خطر لرزه‌ای استفاده شود.

https://www.geomorphologyjournal.ir/article_225480_a34ad872471eb60666d8014330311de9.pdf

انجمن ایرانی ژئومورفولوژی پژوهشهای ژئومورفولوژی کمّی 22519424 14 2 2025 09 23 Identification and Analysis of Changes in Sand Dunes and the Boundary of the Rig-e Shotoran Desert in the Northwest of Tabas Geopark شناسایی و بررسی تغییرات تپه ماسه ها و مرز ماسه زار ریگ شتران در شمال غرب ژئوپارک طبس 169 183 225017 10.22034/gmpj.2025.525188.1561 FA نفیسه هاشمیان کاخکی گروه جغرافیای طبیعی، دانشکده جغرافیا و علوم محیطی، دانشگاه حکیم سبزواری، سبزوار ابوالقاسم امیر احمدی گروه جغرافیای طبیعی، دانشکده جغرافیا و علوم محیطی، دانشگاه حکیم سبزواری، سبزوار 0009-0008-8382-7463 محمد خانه باد گروه زمین شناسی، دانشکده علوم، دانشگاه فردوسی مشهد، مشهد، ایران 0000-0002-6724-2237 محمد باعقیده گروه جغرافیای طبیعی، دانشکده جغرافیا و علوم محیطی، دانشگاه حکیم سبزواری، سبزوار Journal Article 2025 05 21 Extended Abstract Introduction Sandy seas or Erg in Iran, Afghanistan, Pakistan and Tajikistan are also known as (Reg), (Rig) or (Rek) and the name (Registan) means accumulated sand (Abassi et al., 2019). The most important issue in identifying and changing Regs is the way of expansion and the main axis of movement of Regs, determining the direction and extent of their development or limitation. Most of the Regs in the areas where the high air temperature and intense evaporation have caused a drop in moisture on the soil surface, and as a result, have weakened the bond between the soil grains in the horizontal surface of sandy soils and increasing the activity of sands and flowing sands are formed (Dang et al., 2004). Shotoran Reg, one of the largest sandy areas of Iran, has also undergone geomorphological changes under the influence of natural and human factors. Wind processes, including the movement of sand dunes and wind erosion, are one of the most important natural factors in moving sands and changing the shape of landforms in this region. The purpose of this research is to investigate the spatial-temporal changes of the Shotoran Reg in a period of 30 years using the Landsat satellite images and ground evidence. The results show that the identification of changes can be the basis for prediction future changes. Methodology The investigation of the border changes of Shotoran Reg based on Landsat satellite images (TM, ETM+ and OLI gauges) during 3 time periods with 10-year intervals (from 1994 to 2024) was analyzed by remote sensing in geographic information system software. The satellite images used were extracted from the United States Geological Survey website. Validation of the data was done in accordance with the reference pixels of the satellite image, validation and estimation of error and accuracy was done using the Kappa coefficient method, which in short was calculated to be 90% accurate and the Kappa coefficient was 0.85, which is a very acceptable evaluation. Results and Discussion In the classification of sand dunes using Landsat images and the Random Forest algorithm, the satellite images must first be preprocessed for data preparation. The identified range using Landsat images and the Random Forest model has been provided for four periods, including the years 1994, 2004, 2014, and 2024. Temporal changes due to weather conditions are observed in the images from 2014 and 2024. Specifically, in the 2014 image, due to drought, small parts of the salt flat have dried up, and sand movement caused by wind has covered portions of the surface. As a result, the model identified these areas as sand dunes. However, in the 2024 image, due to rainfall in the study area and considering the elevation of the salt flat regions, flooding has caused those areas to become wet. Therefore, it can be concluded that the boundaries of the sand dunes may change temporarily due to weather conditions, but in the long term, a distinct boundary exists between the sand dunes and the salt flat in this region. The analysis of changes in the boundaries of the Shotoran sand dunes based on climatic data shows that the annual wind speed charts, categorized by different speed ranges, from 1990 to 2024, exhibit no significant change and lack a trend. Landsat satellite imagery and the Random Forest machine learning algorithm have been utilized. Firstly, the Landsat satellite series (5, 7, 8, and 9), with global coverage and freely available data, are highly suitable for monitoring land cover changes on a large scale. With a spatial resolution ranging from 15 to 30 meters (depending on the band) and multispectral imaging capabilities, Landsat is reliable for detecting surface features such as sand, soil, salt, vegetation, and water. Secondly, the supervised Random Forest machine learning algorithm is highly effective and robust for classifying satellite imagery, particularly in handling noisy data and spectral overlap. Analysis of satellite data indicates that the overall extent of the Shotoran sand dunes has remained largely stable over the past 30 years. Changes observed in the boundaries of the sand dunes between images do not necessarily reflect actual changes in the extent of the sand dunes. They are related to the following technical and environmental factors: Landsat 5 (TM), Landsat 7 (ETM+), and Landsat 8 (OLI) have differences in spatial resolution, spectral resolution, and signal-to-noise ratio. Landsat 8 offers improved spectral quality and accuracy compared to previous generations, enabling better differentiation between surface covers such as sand, salt, and soil. These factors contribute to the observed apparent changes in the sand dune extent. During drought periods, these areas may dry out and become covered by sand, but with the first rainfall or runoff, the white, reflective salt surfaces or moist areas reappear. Conclusion The extent of the Shotoran sand dunes is geomorphologically stabilized, and the observed changes in satellite imagery are primarily due to technical factors (differences in sensors and imaging conditions) and environmental factors (variations in surface moisture and annual climate). Natural boundaries, such as salt flats and surrounding highlands, act as natural barriers, preventing the horizontal expansion of the sands. To accurately investigate the reasons for the expansion or lack thereof of the Shotoran sand dune boundaries, field methods and morphometric analysis of the sand dunes over several years are required. However, this was beyond the scope of this study due to time and cost constraints. ریگ شتران به‌عنوان یکی از پهنه‌های ماسه‌ای وسیع در ایران، تحت تأثیر مجموعه‌ای از فرایندهای طبیعی و اقلیمی، دستخوش تغییرات ژئومورفولوژیکی شده است. به‌منظور شناسایی و پایش تغییرات مکانی تپه‌های ماسه‌ای، از تصاویر ماهواره‌ای لندست با قدرت تفکیک مکانی بین 15 تا 30 متر استفاده شد تا پوشش سطح زمین با دقت مناسبی مورد ارزیابی قرار گیرد.فرایند طبقه‌بندی اراضی ماسه‌زار با بهره‌گیری از الگوریتم‌های یادگیری و الگوریتم جنگل تصادفی (Random Forest)، در بستر سامانه‌ی Google Earth Engine صورت پذیرفت. تصاویر ماهواره‌ای مربوط به سنجنده‌های TM، +ETM و OLI طی بازه‌ای 30 ساله با مقاطع 10 ساله (از سال 1994 تا 2024) به‌کار گرفته شدند تا روند تغییرات مکانی تپه‌های ماسه‌ای و مرزهای ریگ شتران در شمال‌غرب ژئوپارک طبس تحلیل گردد.نتایج حاصل از تحلیل‌های مکانی نشان داد که در طول سه دهه‌ی گذشته، عمدتاً تغییرات موقتی در مرزهای این پهنه ماسه‌ای رخ داده که بیشتر ناشی از نوسانات اقلیمی بوده است. با این حال، به دلیل محصور بودن منطقه از سمت جنوب و شرق توسط ارتفاعات، از سمت غرب توسط دق، و نیز وجود جهت غالب باد از شمال به جنوب، امکان گسترش پایدار یا جابه‌جایی دائمی مرزهای ریگ شتران بسیار محدود است. با این وجود، در داخل این پهنه، جابه‌جایی‌های محدودی در موقعیت تپه‌های ماسه‌ای مشاهده می‌شود که بیانگر پویایی موضعی درون منطقه است. تحلیل روند زمانی مساحت تجمعی تپه‌های ماسه‌ای نشان داد که این مقدار در دوره‌ی 1994–2004 حدود ۲۳۰۰ کیلومتر مربع بوده است. در بازه‌ی 2004–2014 افزایش اندکی به میزان ۷۰ کیلومتر مربع رخ داده و مساحت به حدود ۲۳۷۰ کیلومتر مربع رسیده است. با این حال، در دهه‌ی پایانی (2014–2024) کاهش حدود ۶۰ کیلومتر مربعی مشاهده می‌شود و مساحت به ۲۳۱۰ کیلومتر مربع کاهش یافته است. این نوسانات اندک نشان‌دهنده‌ی پویایی محدود و نسبتاً پایدار تپه‌های ماسه‌ای در منطقه طی سه دهه‌ی گذشته است.

https://www.geomorphologyjournal.ir/article_225017_0a52c370451194f98b199fbfc7d84078.pdf