دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 57 4 2025 12 23 Determining the temporal and spatial trend and the change point of precipitation and maximum temperature in Tehran تعیین روند زمانی و مکانی و نقطه تغییر بارش و دمای بیشینه تهران 1 22 104608 10.22059/jphgr.2025.399196.1007896 FA اباذر اسمعیلی محمودآبادی گروه جغرافیای طبیعی، دانشکده جغرافیای دانشگاه تهران، تهران، ایران علی اکبر شمسی پور گروه جغرافیای طبیعی، دانشکده جغرافیای دانشگاه تهران، تهران، ایران حسین محمدی گروه جغرافیای طبیعی، دانشکده جغرافیای دانشگاه تهران، تهران، ایران Journal Article 2025 07 06 ABSTRACT This study aimed to analyze trends and assess the homogeneity of maximum temperature and precipitation during the cold seasons (autumn and winter) at four synoptic stations in Tehran over the period 1994–2023.The non-parametric Mann–Kendall test was employed to detect trends, and the Sen’s slope estimator was used to quantify the annual rate of change. To evaluate temporal homogeneity and identify potential structural shifts in the time series, four statistical tests—Pettitt, SNHT, Buishand, and Von Neumann—were applied. The results indicated that maximum temperature in both seasons exhibited a statistically significant increasing trend at most stations. In particular, in stations such as Shemiran and Geophysics, the average post-change temperature rose by more than 2°C. In contrast, autumn precipitation showed no significant trend, while winter precipitation at Mehrabad and Chitgar stations experienced a notable decreasing trend. The homogeneity tests also confirmed the occurrence of structural breaks in temperature data and, in some cases, in winter precipitation series. These findings reflect a clear pattern of seasonal warming, climate variability, and a relative decline in winter water resources in Tehran—issues that may have important implications for urban management, water resource planning, and climate adaptation strategies in the near future. Extended Abstract Introduction In recent decades, climate change has become one of the major challenges for urban management in megacities such as Tehran. Rising temperatures, declining precipitation, temporal fluctuations in climatic patterns, and the expansion of urban heat islands are among the visible consequences of climate change at the urban scale. Tehran, because of its high population density, unique geographical location, and rapid physical development, is highly vulnerable to climatic variations. Particularly in the cold seasons, fluctuations in temperature and precipitation can significantly impact water resources, energy consumption, and service infrastructure. Despite numerous global studies and some national research efforts, a precise and integrated examination of trends and homogeneity in Tehran’s climatic variables (especially at the seasonal scale) has received limited attention. Furthermore, analyzing trends and the statistical structure of these data can play a critical role in climate policy-making, drought management, and water resource planning. This study aims to analyze trends and assess the homogeneity of maximum temperature and precipitation during the cold seasons (autumn and winter) at four synoptic stations in Tehran from 1994 to 2023. The main focus is to identify statistically significant trends and structural breakpoints in the time series of climatic variables to better understand the behavior of Tehran’s urban climate in recent decades. Accordingly, the research addresses the following questions: Is there a statistically significant trend in maximum temperature and precipitation during autumn and winter in Tehran?Are the time series of these variables homogeneous, or have they experienced structural breaks over time? Which stations have undergone the most significant statistical changes, and what are the implications of these changes for Tehran’s climate management? Methodology This study employs an applied, quantitative, and analytical approach, utilizing daily maximum temperature and precipitation data from four synoptic stations Geophysics, Shemiran, Mehrabad, and Chitgar in Tehran. The data were collected for the autumn and winter seasons over a 30-year period (1994–2023). Following rigorous quality control procedures and removal of missing or erroneous data, the datasets were organized into seasonal time series. To analyze trends, the non-parametric Mann-Kendall test was applied, a widely accepted and robust method for detecting monotonic trends in climatic time series. Additionally, Sen’s slope estimator was used to quantify the annual rate of change, providing a reliable measure of trend magnitude. To assess homogeneity and detect structural breaks in the time series, four statistical tests were employed: Pettitt, Standard Normal Homogeneity Test (SNHT), Buishand, and Von Neumann tests. Pettitt and Von Neumann tests are non-parametric tests capable of identifying sudden changes and non-random structures without requiring assumptions of normality. Conversely, SNHT and Buishand tests assume normality and are designed to detect shifts in the mean and variance. These methods were applied separately for each variable, season, and station. Results and discussion Statistical analysis of maximum temperature and precipitation in the cold seasons at synoptic stations in Tehran revealed significant climatic changes. In autumn, the Mann-Kendall test indicated a statistically significant increasing trend in maximum temperature at most stations, with Shemiran showing the highest Kendall’s tau (0.49) and Mehrabad the lowest (0.25). Sen’s slope ranged from 0.04 to 0.09 °C per year. During winter, all stations exhibited significant positive trends, with p-values mostly below 0.01, confirming high confidence in these trends. Homogeneity tests, including Pettitt, SNHT, Buishand, and Von Neumann, detected structural breaks in maximum temperature data at Shemiran, Geophysics, and Chitgar. For instance, Shemiran’s mean temperature increased by 1.62 °C after the autumn breakpoint, and from 8.7 to 11.2 °C in winter, indicating a pronounced climatic shift in the 2000s (1380s SH). These increasing trends, particularly at Shemiran and Geophysics, are consistent with global warming patterns and are likely influenced by urbanization, enhanced heat islands, and changing energy consumption. Regarding precipitation, autumn trends were largely non-significant, while winter precipitation decreased significantly at Chitgar and Mehrabad, with Sen’s slopes of -2.27 and -1.85 mm/year and negative Kendall’s tau values (-0.29 and -0.28). Chitgar also showed the highest winter precipitation inhomogeneity, with all tests confirming structural breaks (p < 0.05), potentially affecting snow storage, runoff, and water resources during dry periods. These findings align with previous studies in Iran, including Bazgir et al. (2019) and Alipour & Malkian (2019), which reported inhomogeneity in temperature and precipitation. Overall, the simultaneous occurrence of increasing temperature trends, structural breaks, and declining winter precipitation demonstrates that Tehran is experiencing significant climate-related changes consistent with global trends. Conclusion This study analyzed trends and homogeneity of maximum temperature and precipitation during autumn and winter at four synoptic stations in Tehran from 1994 to 2023, identifying seasonal climate changes and structural breakpoints. Maximum temperatures showed significant increasing trends at most stations, particularly Shemiran and Geophysics, with winter averages rising over 2 °C after breakpoints. Homogeneity tests (Pettitt, SNHT, Buishand, Von Neumann) confirmed structural changes mainly in the 2000s. Autumn precipitation remained stable, while winter rainfall decreased significantly at Mehrabad and Chitgar. Given fixed station locations, uncertainty mainly arises from natural interannual variability. Overall, findings indicate warming during cold months, reduced winter precipitation, and structural changes, with implications for water, energy, public health, and urban resilience. 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. روندها و میزان تغییرپذیری زمانی و مکانی دو عنصر اساسی جو یعنی بارش و دما، اثرات محیطی، اقتصادی و اجتماعی بسیار شدیدی دارد. پژوهش حاضر باهدف تحلیل روند و بررسی همگنی دمای بیشینه و بارش در فصل‌های سرد سال (پاییز و زمستان) در چهار ایستگاه سینوپتیک شهر تهران طی دوره آماری 1994 تا 2023 انجام‌شده است. برای تحلیل روند، از آزمون ناپارامتری من کندال استفاده شد و میزان شیب تغییرات فصلی با استفاده از تخمین‌گر شیب سن محاسبه گردید. همچنین، به‌منظور شناسایی نقاط تغییر ساختاری در سری‌های زمانی، چهار آزمون آماری شامل پتی، نرمال استاندارد، بیشاند و فان نیومن به کار گرفته شد. نتایج حاصل از آزمون من کندال نشان داد که دمای بیشینه در هر دو فصل موردمطالعه، در اغلب ایستگاه‌ها دارای روند افزایشی معنادار بوده است. در برخی ایستگاه‌ها مانند شمیران و ژئوفیزیک، میانگین دما پس از نقطه تغییر تا بیش از ۲ درجه سانتی‌گراد افزایش‌یافته است. در مقابل، بارش پاییزه در هیچ‌یک از ایستگاه‌ها روند معناداری نداشت، اما در زمستان، ایستگاه‌های مهرآباد و چیتگر با کاهش معنادار بارش مواجه بودند. نتایج آزمون‌های همگنی نیز وقوع شکست‌های ساختاری در داده‌های دمایی و در برخی موارد بارش زمستانه را تأیید کردند. این یافته‌ها بیانگر وجود روندهای اقلیمی معنادار در تهران طی سه دهه گذشته هستند و نشان می‌دهند که شهر تهران در معرض گرمایش فصلی و کاهش نسبی منابع آبی در زمستان قرارگرفته است؛ موضوعی که باید در برنامه‌ریزی شهری و مدیریت منابع آب و انرژی موردتوجه قرار گیرد.

https://jphgr.ut.ac.ir/article_104608_b7ac301e019c6a4e0341ac0f8fbef121.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 57 4 2025 12 23 Impact of Urban Characteristics on Nitrogen Dioxide Concentration and Urban Heat Island Intensity: A case study of Tehran تأثیر ویژگی‌های شهری بر غلظت دی‌اکسید نیتروژن و شدت جزیره گرمایی شهری مطالعه موردی: کلان‌شهر تهران 23 41 104391 10.22059/jphgr.2025.394256.1007882 FA طاهر صفرراد گروه جغرافیا، دانشکده علوم انسانی و اجتماعی، دانشگاه مازندران، بابلسر، ایران محمدرضا میاندج گروه جغرافیا، دانشکده علوم انسانی و اجتماعی، دانشگاه مازندران، بابلسر، ایران Journal Article 2025 07 06 ABSTRACT Air pollution and the Urban Heat Island (UHI) effect have become critical challenges in megacities such as Tehran, particularly as a result of rapid population growth and ongoing urban expansion. This study investigates the relationship between key urban characteristics, including built-up areas, building height, and vegetation cover, and UHI intensity as well as nitrogen dioxide (NO₂) concentration, which represents a major urban air pollutant. Data on built-up areas and building height were obtained from the Global Human Settlement Layer (GHSL), while vegetation cover was mapped using the Normalized Difference Vegetation Index (NDVI) derived from Sentinel-2 imagery. UHI intensity was assessed using nighttime MOD11A2 land surface temperature products acquired at 22:30 with a spatial resolution of 1000 m for the period 2018 to 2022, while NO₂ concentrations were retrieved from the TROPOMI sensor onboard Sentinel-5 for the period 2019 to 2024. All data processing and analysis were conducted using the Google Earth Engine platform, with Pearson correlation analysis applied to examine the relationships among variables. The findings reveal significant positive correlations between both built-up areas and building height and NO₂ concentration (R² = 0.45 and 0.18, respectively), indicating that urban growth substantially contributes to increased NO₂ levels. A weaker positive correlation was observed between vegetation cover and NO₂ concentration (R² = 0.097), which is attributed to Tehran’s topographic conditions and the accumulation of pollutants in certain densely vegetated areas. The results also indicate strong positive associations between built-up areas and building height and UHI intensity (R² = 0.45 and 0.18), highlighting their significant role in intensifying urban heat island effects. Although the relationship was not statistically significant, an inverse association was observed between vegetation density and UHI intensity, suggesting that vegetation may play a mitigating role in reducing urban heat intensity. Overall, this study underscores the strong influence of urban morphology on both air quality and thermal dynamics, while highlighting vegetation as a potential strategy for moderating UHI intensity in rapidly growing cities such as Tehran. Extended Abstract Introduction Urbanization exerts increasing pressure on environmental resources and has adverse effects on air and water quality, land availability, and local climatic conditions. Urban areas play a substantial role in the emission of greenhouse gases and, at the same time, are highly vulnerable to the impacts of climate change, including global warming and sea-level rise. Urban development alters surface radiation balance and moisture regimes, leading to changes in land use patterns and biogeochemical cycles. The present study examines the relationship between urban structural characteristics, including built-up areas, building height, and vegetation cover, and their effects on the Urban Heat Island (UHI) phenomenon and nitrogen dioxide (NO₂) emissions in Tehran. By employing multiple remote sensing datasets, this research seeks to provide an integrated assessment of urban structure, air quality, and urban heat island intensity. Methodology This study employs datasets from the Global Human Settlement Layer (GHSL) to assess the physical characteristics of the urban environment, with particular emphasis on the Global Built-up Surface dataset for quantifying built-up areas and the building height dataset for estimating building heights. These datasets are readily accessible through the Google Earth Engine (GEE) platform. Vegetation cover characteristics were extracted using the Normalized Difference Vegetation Index (NDVI) derived from Sentinel-2 satellite imagery. To address differences in spatial resolution and sample size, the study area, namely the city of Tehran, was divided into a uniform grid with a spatial resolution of 1000 × 1000 m. Within each grid cell, key variables were calculated, including Urban Heat Island (UHI) intensity, nitrogen dioxide (NO₂) concentration, mean building height, total built-up area, and vegetation cover. Subsequently, the relationships between urban physical characteristics and both UHI intensity and NO₂ concentration were analyzed using Pearson correlation coefficients. This methodological framework enables a systematic assessment of the interactions between urban structure, urban heat island characteristics, and air pollution at a consistent spatial scale. Result and Discussion Urban Heat Island in Tehran During the study period from 2018 to 2022, the highest mean annual temperature in Tehran was recorded in 2022 at 17.7 °C, while the lowest mean annual temperature was observed in 2020 at 15.3 °C. In the suburban areas of Tehran, the highest average temperature reached 12.8 °C in 2022, whereas the lowest value of 10.7 °C was recorded in 2019. Seasonal analysis indicates that temperatures within the urban core of Tehran consistently exceed those of the surrounding suburban areas throughout the year, confirming the persistent presence of the Urban Heat Island (UHI) phenomenon. UHI intensity in Tehran exhibits clear seasonal variability, reaching its maximum value of 5.2 °C during the winter months and decreasing to approximately 4.3 °C during the summer. Notably, the UHI effect intensifies during colder seasons, a pattern that can largely be attributed to increased anthropogenic activities, particularly the extensive use of heating systems in urban areas. In 2021, when the mean urban temperature declined to 14.9 °C, central districts, especially Districts 10 and 11, exhibited elevated temperature levels, with an average UHI intensity of 4.4 °C. This spatial concentration of higher temperatures highlights the influence of dense urban morphology and intensified human activities on local climatic conditions in Tehran. Nitrogen Dioxide (NO₂) Concentration in Tehran Analysis of nitrogen dioxide (NO₂) concentrations in Tehran from 2018 to 2024 indicates that Districts 7 and 8 consistently experienced the highest average NO₂ levels, whereas Districts 19 and 20 recorded the lowest concentrations. The highest overall NO₂ concentration was observed in 2021, while the lowest levels occurred during 2018 and 2019. The peak in NO₂ concentration in 2021 may be associated with post–COVID-19 pandemic conditions. Although reductions in vehicular traffic and industrial activities during lockdown periods in 2019 and 2020 likely contributed to lower emission levels, the subsequent resumption of economic activities in 2021 appears to have led to a renewed increase in pollutant emissions. Seasonal analysis further reveals that NO₂ concentrations peak during December and January, coinciding with winter temperature inversion events that trap pollutants near the ground surface. In contrast, NO₂ levels reach their minimum between April and September, a period characterized by enhanced atmospheric dispersion and reduced emission intensity. In particular, April shows a marked decrease in NO₂ concentrations compared to March, which may reflect reduced urban and industrial activities during the Nowruz holiday period. Conclusion The results of this study indicate that the Urban Heat Island (UHI) in Tehran exhibits a distinct seasonal pattern, intensifying during the winter months as a result of increased fossil fuel consumption and weakening during the summer. In addition, UHI intensity decreases markedly during weekends and official holidays, such as Thursdays and Fridays, coinciding with reduced industrial activity, a pattern that is consistent with findings reported in previous studies. Further analysis reveals a statistically significant relationship between UHI intensity and urban physical characteristics, particularly built-up areas and building height. These urban forms contribute to heat accumulation, whereas increased vegetation cover is associated with a moderating effect on urban temperatures. Similarly, nitrogen dioxide (NO₂) emissions follow a seasonal pattern comparable to that of the UHI, reaching peak levels in winter due to intensified urban and industrial activities and declining during periods of reduced activity. Correlation analysis indicates strong associations between NO₂ concentration and built-up density, building height, and vegetation cover. Specifically, areas characterized by higher building density and taller structures exhibit elevated NO₂ levels, while areas with greater vegetation cover are associated with lower concentrations. These findings underscore the critical role of urban morphology in shaping thermal and atmospheric conditions in urban environments and highlight the importance of vegetation in mitigating urban heat and air pollution. 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. آلودگی هوا و جزیره گرمایی شهری (UHI) متأثر از رشد سریع جمعیت و گسترش شهرها در شهرهایی مانند تهران تشدید شده است. این مطالعه رابطه بین ویژگی‌های شهریِ مناطق ساخته‌شده، ارتفاع ساختمان و پوشش گیاهی و شدت UHI و غلظت دی‌اکسید نیتروژن (NO2) را به‌عنوان یک آلاینده کلیدی شهری بررسی می‌کند. مناطق ساخته‌شده و ارتفاع ساختمان از داده‌های GHSL و پوشش گیاهی با استفاده از شاخص NDVI از طریق تصاویر Sentinel-2 استخراج شدند. محصول MOD11A2 برای شب (22:30) باقدرت تفکیک 1000 متر به‌منظور اندازه‌گیری اثر UHI در سال‌های 2018 تا 2022 استفاده شد و غلظت NO₂ از سنجنده TROPOMI در ماهواره Sentinel-5 برای سال‌های 2019 تا 2024 به دست آمد. پردازش و تجزیه‌وتحلیل داده‌ها از طریق سامانه Google Earth Engine همچنین با بهره‌گیری از ضریب همبستگی پیرسون انجام شد. نتایج نشان داد هر یک از ویژگی‌های مناطق ساخته‌شده و ارتفاع ساختمان‌ها با ضریب (45/0 و 18/0)R² رابطه‌ای مستقیم و معناداری با غلظت NO₂ دارند و توسعه شهری، افزایش قابل‌توجهی در انتشار NO₂ خواهد داشت. همبستگی مستقیمی بین پوشش گیاهی و NO₂ با ضریب (097/0)R² مشاهده شد که به توپوگرافی تهران و تجمع آلاینده در مناطق با پوشش گیاهی زیاد نسبت داده شد. همچنین نتایج این پژوهش آشکار کرد که، ارتباط مستقیم و معناداری بین مناطق ساخته‌شده و ارتفاع ساختمان‌ها با UHI با ضریب (45/0 و 18/0)R² در تهران وجود دارد که نقش این ویژگی‌ها را در شکل‌گیری و تشدید پدیده جزیره گرمایی برجسته می‌کند. همچنین، این مطالعه نشان داد که رابطه معکوس (اگرچه از نظر آماری معنادار نیست) بین تراکم پوشش گیاهی و اثر جزیره گرمایی وجود دارد که نشان می‌دهد پوشش گیاهی می‌تواند نقش تعدیل‌کننده‌ای در کاهش شدت جزیره گرمایی ایفا کند..

https://jphgr.ut.ac.ir/article_104391_457a9e1e279be686c2bc90e12d91cd90.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 57 4 2025 12 24 Spatiotemporal Trend and Correlation Analysis of Climatic and Environmental Indices Associated with Desertification in Khatam and Abarkooh Counties Using Satellite Data تحلیل مکانی–زمانی روند و همبستگی شاخص‌های اقلیمی و زیست‌محیطی مرتبط با بیابان‌زایی در شهرستان‌های خاتم و ابرکوه با استفاده از داده‌های ماهواره‌ای 43 61 105500 10.22059/jphgr.2026.407281.1007912 FA زهرا بهزادی گروه جغرافیا، دانشکده علوم انسانی، دانشگاه یزد، یزد، ایران محمد شریفی پیچون گروه جغرافیا، دانشکده علوم انسانی، دانشگاه یزد، یزد، ایران Journal Article 2025 07 07 ABSTRACT Desertification in arid and semi-arid regions of Iran is accompanied by variations in climatic and environmental indicators. The aim of this study is to analyze the spatio-temporal trends and statistical relationships of climatic and environmental proxy indicators associated with desertification-related processes in Khatam and Abarkuh counties during the period 2000–2022. To this end, the Normalized Difference Vegetation Index (NDVI), as a proxy for vegetation cover conditions, was derived from MODIS data; soil moisture and actual evapotranspiration were obtained from TerraClimate; and precipitation and wind speed were extracted from the WorldClim dataset. Long-term trend analysis was performed using the non-parametric Mann–Kendall test and Sen’s slope estimator, while pixel-based Pearson correlation analysis was employed to examine statistical relationships among the indicators. The results indicated that 63% of the pixels exhibited a significant decreasing trend in NDVI (mean Sen’s slope of −0.002 per year), while precipitation showed a declining trend over 69% of the study area, with an average decrease of 1.5 mm per year. Simultaneously, soil moisture displayed a negative trend in 58% of the pixels, whereas actual evapotranspiration showed an increasing trend in 47% of low-lying and arid areas. Wind speed exhibited an increasing trend in 42% of the open eastern zones. Correlation analysis revealed significant positive relationships between NDVI and precipitation as well as soil moisture across large parts of the region, and notable negative correlations between NDVI and wind speed in dry plain areas. Overall, these findings indicate the spatio-temporal co-variation and statistical alignment of environmental indicator changes with conditions associated with desertification, rather than direct causal relationships. Extended Abstract Introduction Desertification is a complex and multi-dimensional process resulting from the interaction of climatic, environmental, and human factors, particularly in arid and semi-arid regions. Iran, due to its location within the global arid belt, pronounced climatic variability, and increasing pressure on natural resources, is highly vulnerable to desertification-related processes. The southern part of Yazd Province—especially Khatam and Abarkooh counties—because of extremely low precipitation, high evapotranspiration rates, wide bare surfaces, and frequent erosive winds, represents one of the most environmentally sensitive areas in central Iran. In the scientific literature, desertification is conceptually distinguished from short-term droughts and climatic fluctuations; however, it is not measured directly in most regional-scale studies. Instead, variations in environmental and climatic conditions are commonly assessed using proxy indicators. In this regard, vegetation cover (NDVI), soil moisture, precipitation, actual evapotranspiration, and wind speed are widely applied as proxy indicators for evaluating conditions associated with desertification-related processes. Due to the limited spatial coverage of meteorological stations, remote sensing data provide an indispensable means for capturing the spatio-temporal variability of these indicators at regional scales. Accordingly, the objective of this study is to analyze the spatio-temporal trends and statistical relationships among climatic and environmental proxy indicators associated with desertification-related processes in Khatam and Abarkooh counties over a 22-year period (2000–2022), with an emphasis on identifying dominant spatial patterns and statistically significant associations rather than causal relationships. Methodology This study was conducted in Khatam and Abarkooh counties, located in the southern part of Yazd Province. The conceptual framework and required datasets were compiled using scientific literature, digital databases, and satellite-based products. NDVI data were obtained from the MODIS sensor as a proxy for vegetation cover conditions, while soil moisture and actual evapotranspiration were derived from the TerraClimate dataset. Precipitation and wind speed data were extracted from WorldClim. All datasets were processed within a pixel-based spatio-temporal framework to ensure consistency across spatial and temporal scales. Long-term trends were assessed using the non-parametric Mann–Kendall test and Sen’s slope estimator, which are robust against non-normal distributions and missing values. To investigate statistical relationships among variables, pixel-wise Pearson correlation analysis was performed, with NDVI considered the reference indicator. Google Earth Engine was employed as the primary platform for managing large datasets and conducting time-series and pixel-based analyses, while ArcGIS and R were used for visualization and supplementary processing. Results and discussion The 22-year trend analysis revealed that 63% of the pixels exhibited a statistically significant decreasing trend in NDVI, with the most pronounced declines occurring in central Khatam and the plains of Abarkooh. Precipitation displayed a significant negative trend over 69% of the study area, with an average annual decrease of approximately 1.5 mm. Declining precipitation was statistically associated with reduced soil moisture, and 58% of the pixels showed a negative soil-moisture trend. In contrast, actual evapotranspiration exhibited an increasing trend in 47% of the low-lying and arid areas, while wind speed increased in 42% of the open eastern zones, indicating conditions conducive to enhanced wind erosion. Correlation analysis demonstrated strong and statistically significant positive relationships between NDVI and both precipitation and soil moisture across large portions of the region, highlighting the importance of moisture availability for vegetation dynamics in dry environments. Conversely, negative correlations between NDVI and wind speed predominated in eastern and central plains, suggesting an inverse association between vegetation cover and wind activity. The relationship between NDVI and actual evapotranspiration varied spatially, reflecting differences in moisture availability and surface conditions. Overall, these findings indicate a clear spatio-temporal co-variation and statistical alignment among environmental proxy indicators, which collectively reflect conditions associated with desertification-related processes, rather than direct causal mechanisms. Conclusion The results of this study demonstrate that the dryland ecosystems of southern Yazd Province are characterized by concurrent trends of declining vegetation cover, decreasing precipitation and soil moisture, increasing evapotranspiration, and rising wind speeds. The significant reduction in NDVI across more than half of the study area, accompanied by unfavorable trends in key climatic variables, indicates increasing environmental vulnerability and declining land stability. Statistical relationships suggest that precipitation and soil moisture exhibit the strongest positive associations with vegetation dynamics, while wind speed and evapotranspiration show inverse or spatially variable relationships with NDVI in arid and low-lying areas. Although these findings do not imply direct causality, they highlight the potential reinforcement of desertification-related conditions if current trends persist. Therefore, continuous monitoring of climatic and environmental proxy indicators using satellite-based data, along with targeted land and water management strategies, vegetation restoration programs, and wind erosion control measures, is essential for supporting sustainable land management and mitigating environmental degradation in one of Iran’s most sensitive dryland regions. Funding There is no funding support. Authors’ Contribution Authors contributed equally to the conceptualization and writing of the article. All of the authors approved thecontent of the manuscript and agreed on all aspects of the work declaration of competing interest none. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. بیابان‌زایی در مناطق خشک و نیمه‌خشک ایران با تغییرات شاخص‌های اقلیمی و زیست‌محیطی همراه است. هدف این پژوهش، تحلیل مکانی–زمانی روند و روابط آماری شاخص‌های جانشین اقلیمی و زیست‌محیطی مرتبط با فرآیندهای بیابان‌زایی در شهرستان‌های خاتم و ابرکوه طی دوره ۲۰۰۰ تا ۲۰۲۲ است. بدین منظور، شاخص پوشش گیاهی NDVI به‌عنوان نماینده وضعیت پوشش گیاهی از MODIS، رطوبت خاک و تبخیر–تعرق واقعی از TerraClimate و بارندگی و سرعت باد از WorldClim استخراج شد. تحلیل روند بلندمدت با استفاده از آزمون ناپارامتری من–کندال و برآوردگر شیب سن انجام گرفت و روابط آماری بین شاخص‌ها با ضریب همبستگی پیرسون در مقیاس پیکسلی بررسی شد. نتایج نشان داد که ۶۳ درصد از پیکسل‌های منطقه روند کاهشی معنی‌دار در NDVI داشته‌اند (میانگین شیب سن 002/0- در سال) و بارندگی نیز در ۶۹ درصد از منطقه با کاهش متوسط 5/1 میلی‌متر در سال همراه بوده است. هم‌زمان، رطوبت خاک در ۵۸ درصد از پیکسل‌ها روند منفی و تبخیر–تعرق واقعی در ۴۷ درصد از نواحی خشک و پست روند افزایشی نشان داد. سرعت باد نیز در ۴۲ درصد از مناطق باز شرقی روند افزاینده داشت. تحلیل همبستگی بیانگر وجود روابط مثبت و معنی‌دار بین NDVI و بارندگی و رطوبت خاک در بخش عمده منطقه و روابط منفی قابل‌توجه بین NDVI و سرعت باد در دشت‌های خشک است. این نتایج بیانگر هم‌زمانی و هم‌راستایی تغییر شاخص‌های محیطی با شرایط مرتبط با بیابان‌زایی بوده است..

https://jphgr.ut.ac.ir/article_105500_c3e30ff7999d5f7d24b10442ad2c3f38.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 57 4 2025 12 23 Evaluation of Urban Flood Risk Mitigation Ecosystem Service With A Long-Term Return Period Approach 25 Years: A case study of Tabriz Metropolitan ارزیابی خدمت اکوسیستمی کاهش خطر سیلاب شهری با رویکرد دوره بازگشت بلندمدت 25 ساله، مطالعه موردی: کلان‌شهر تبریز 63 83 105602 10.22059/jphgr.2026.385886.1007855 FA مهدی هریسچیان گروه برنامه‌ریزی شهری و منطقه‌ای، دانشکده برنامه‌ریزی و علوم محیطی، دانشگاه تبریز، تبریز، ایران حسن محمودزاده گروه برنامه‌ریزی شهری و منطقه‌ای، دانشکده برنامه‌ریزی و علوم محیطی، دانشگاه تبریز، تبریز، ایران Journal Article 2025 07 07 ABSTRACT Urban districts, especially metropolises, increase impervious surfaces, leading to large volumes of rainwater runoff on the ground surface rather than penetrating underground. This can result in urban hazards such as urban floods and the negative, irreparable consequences that follow. In the meantime, urban green infrastructure plays a significant role in mitigating urban flood risk due to its low cost and its provision of ecosystem regulation services. Therefore, this study aims to evaluate the ecosystem service of mitigating urban flood risk in Tabriz metropolitan with a 25-year return period. In this research, data from Landsat satellite images, land use/land cover, meteorology, a biophysical table, GIS, and the InVEST software were used. The findings showed that in 1984, during 15-, 30-, and 45-minute rainfall events, the volume of water absorbed and retained was 6.77, 5.47, and 4.72 million cubic meters, respectively, and the ecosystem service benefit of mitigating urban flood risk was 17.19, 13.89, and 11.99 million dollars, respectively. In 2002, during 15-, 30-, and 45-minute rainfall events, the volumes of water absorbed and retained were 7, 5.62, and 4.83 million cubic meters, respectively, and the ecosystem service benefits of mitigating urban flood risk were 32.08, 25.78, and 22.16 million dollars, respectively. In 2022, during 15-, 30-, and 45-minute rainfall events, it was 7.85, 6.15, and 5.20 million cubic meters, respectively, and the ecosystem service benefit of mitigating urban flood risk was 56.08, 43.96, and 37.14 million dollars for the entire Tabriz metropolitan area. The results showed that land use/land cover had a greater role in the potential for runoff absorption and retention in Tabriz than other factors, including soil hydrological group. In Tabriz metropolitan, across all three time periods, wasteland, agricultural land, and low residential density land uses had the highest runoff absorption and retention, while water and pasture land uses had the lowest. The results also showed that in Tabriz metropolis, during all three time periods, districts 6, 5, and 7 had the highest runoff absorption and retention, while districts 9 and 8 had the lowest Extended Abstract Introduction Urban districts, especially metropolitan areas, with increasing impervious surfaces, cause stormwater runoff from rain to flow on the ground surface rather than penetrate underground, thereby posing urban hazards, including urban floods and their negative, irreparable consequences. In the meantime, gray stormwater infrastructure, due to its age and cost, lacks the capacity to comprehensively address urban flooding and its negative consequences, whereas green infrastructure, due to its low cost and provision of ecosystem regulation services, plays a significant role in mitigating urban flood risk. Therefore, the purpose of this study is to evaluate the ecosystem service of mitigating urban flood risk in Tabriz metropolitan with a 25-year return period. Methodology The current research is descriptive-analytical in terms of method and has a developmental-applicative nature. The required information was collected using library, documentary, electronic sources, surveys, and field observations. In this research, the urban flood risk mitigation model from the InVEST 3.12.0 software package has been used. This model is one of the models that mitigates the risk of urban flooding based on the vector map of the study area/watershed map of the study area, rainfall (in millimeters), land use/land cover map, soil hydrological group raster map, the biophysical table, vector map of built infrastructure, and table of damage caused by urban flood estimates. Finally, this model estimates the result through the following raster and vector files: 1) It calculates the amount of runoff in the form of raster data. 2) It estimates the amount of absorption and retention of runoff (in millimeters) in the form of a raster file that shows the relative amount of rainfall (expressed as a percentage of rainfall). 3) It calculates the volume of runoff retention (in cubic meters) through a raster file. 4) It calculates the flood risk in the form of a descriptive table and the field of vector files and raster data that help to identify spatial changes in the specified local limits through the calculated values. 5) It estimates the damage caused by the flood through a monetary assessment. 6) It estimates the monetary value of the ecosystem service of urban flood risk reduction using the avoided damage cost method in the form of a descriptive table. Results and discussion The findings showed that in 1984, with a rainfall of 21.93 mm (0.000022 cubic meters) and a 15-minute rainfall and a 25-year return period, the amount of water absorbed and retained was 49 percent, the volume of water absorbed and retained was 6.77 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was $17.19 million. With a 30-minute rainfall, the amount of water absorbed and retained was 62 percent, the volume of water absorbed and retained was 5.47 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was $13.89 million. During a 45-minute rainfall event, 70 percent of the rainfall was absorbed and retained, totaling 4.72 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was $11.99 million for the entire Tabriz metropolitan area. In 2002, with a 15-minute rainfall of 14.07 mm (0.000014 cubic meters), the amount of water absorbed and retained was 51 percent, the volume absorbed and retained was 7 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was $32.08 million. With a 30-minute rainfall, the amount of water absorbed and retained was 64 percent, the volume of water absorbed and retained was 5.62 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was $25.78 million. With a 45-minute rainfall, the amount of water absorbed and retained was 72 percent, the volume of water absorbed and retained was 4.83 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was $22.16 million for the entire Tabriz metropolitan area. In 2022, with a rainfall of 10.78 mm (0.000011 cubic meters) and a 15-minute rainfall, the amount of water absorbed and retained was 57 percent, the volume of water absorbed and retained was 7.85 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was 56.08 million dollars. With a 30-minute rainfall, the amount of water absorbed and retained was 70 percent, the volume of water absorbed and retained was 6.15 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was 43.96 million dollars. With a 45-minute rainfall event and a 25-year return period, the amount of water absorbed and retained was 77 percent, the volume absorbed and retained was 5.20 million cubic meters, and the ecosystem service benefit of mitigating urban flood risk was 37.14 million dollars for the entire Tabriz metropolitan area. Conclusion The results showed that with increased rainfall duration (15, 30, and 45 minutes) across all three periods (1984, 2002, and 2022), the amount of runoff absorption and retention, and consequently the ecosystem service benefit of reducing urban flood risk, decreased. The results also showed that districts with higher population density and consequently higher residential land use had the lowest potential for runoff absorption and retention. In Tabriz metropolitan, due to the small amount of land uses related to green infrastructure, including green space, agricultural lands, and pastures, which play a major role in mitigating urban flood risk, these land uses have not been able to play a significant role in mitigating urban flood risk. However, green infrastructure has played a greater role than water infrastructure in mitigating the risk of urban flooding in Tabriz. Also, land use/land cover has played a greater role than other factors, including the soil hydrological group. Despite the low capacity of Tabriz's runoff absorption and retention, the role of ecosystem services in mitigating the risk of urban flooding in Tabriz remains significant. Without this role, Tabriz would have to bear the high costs of potential flood risk. As the trend of increasing impervious surfaces in the Tabriz metropolitan area continues, which has increased continuously over recent decades, the capacity for runoff absorption and retention in Tabriz will decrease further, and as a result, the volume of possible floods and the resulting economic damage will increase significantly. Funding There is no funding support. Authors’ Contribution Authors contributed equally to the conceptualization and writing of the article. All of the authors approved thecontent of the manuscript and agreed on all aspects of the work declaration of competing interest none. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. مناطق شهری به‌ویژه کلان‌شهرها با افزایش سطوح نفوذناپذیر، رواناب‌های ناشی از باران را با حجم زیاد به‌جای نفوذ در زیرزمین در سطح زمین جاری می‌سازند و باعث به‌وجودآمدن مخاطرات شهری از جمله سیلاب‌های شهری و پیامدهای منفی و جبران‌‌‌‌‌ناپذیر ناشی از آن می‌‌شوند. در ‌‌‌‌‌‌‌‌‌‌‌‌این بین زیرساخت‌های سبز شهری به دلیل کم هزینه بودن و ارائه خدمات تنظیمی اکوسیستمی نقش زیادی در کاهش ریسک سیلاب شهری ‌‌‌‌‌‌‌‌‌‌‌‌ایفاء می‌‌‌کنند. ازاین‌رو هدف ‌‌‌‌‌‌‌‌‌‌‌‌این پژوهش، ارزیابی خدمت اکوسیستمی کاهش ریسک سیلاب شهری تبریز با دوره بازگشت 25 ساله می‌‌‌‌باشد. در پژوهش حاضر از داده‌های مربوط به تصاویر ماهواره‌ای لندست، کاربری اراضی/پوشش اراضی، هواشناسی، جدول بیوفیزیکی، GIS و نرم‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌افزار InVEST استفاده شده است. یافته‌ها نشان داد که در سال 1363 در طی بارندگی‌های 15، 30 و 45 دقیقه‌‌‌‌‌‌‌‌‌‌‌‌ای، حجم آب جذب و نگه داشته شده به ترتیب 77/6، 47/5 و 72/4 میلیون مترمکعب و میزان منفعت خدمت اکوسیستمی کاهش ریسک سیلاب شهری 19/17، 89/13 و 99/11 میلیون دلار، در سال 1381 در طی بارندگی‌های 15، 30 و 45 دقیقه‌‌‌‌‌‌‌‌‌‌‌‌ای، حجم آب جذب و نگه داشته شده، 7، 62/5 و 83/4 میلیون مترمکعب و میزان منفعت خدمت اکوسیستمی کاهش ریسک سیلاب شهری 08/32، 78/25 و 16/22 میلیون دلار و در سال 1401 در طی بارندگی‌های 15، 30 و 45 دقیقه‌‌‌‌‌‌‌‌‌‌‌‌ای، 85/7، 15/6 و 20/5 میلیون مترمکعب و میزان منفعت خدمت اکوسیستمی کاهش ریسک سیلاب شهری، 08/56، 96/43 و 14/37 میلیون دلار برای کل محدوده کلان‌شهر تبریز بوده است. نتایج نشان داد که در پتانسیل جذب و نگهداشت رواناب تبریز، کاربری اراضی/پوشش اراضی در مقایسه با سایر موارد از جمله گروه هیدرولوژیکی خاک نقش بیشتری را داشته است. در کلان‌شهر تبریز در طی هر سه دوره زمانی مذکور، به ترتیب کاربری‌های اراضی بایر، اراضی کشاورزی و ‌‌‌‌‌‌‌‌‌تراکم مسکونی کم بیشترین میزان جذب و نگهداشت رواناب و کاربری‌های آب و مرتع کمترین میزان جذب و نگهداشت رواناب را داشته‌اند. همچنین نتایج نشان داد که در کلان‌شهر تبریز در طی هر سه دوره زمانی مذکور به ترتیب مناطق 6، 5 و 7 بیشترین میزان جذب و نگهداشت رواناب و مناطق 9 و 8 کمترین میزان جذب و نگهداشت رواناب را داشته‌اند

https://jphgr.ut.ac.ir/article_105602_fd5cc0c1c5edb8891f432a7e341a7129.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 57 4 2025 12 25 Influence of Environmental Factors on the Distribution Pattern of Astragalus adscendens in Lorestan Province Using the MaxEnt Model تأثیر عوامل محیطی بر الگوی پراکنش Astragalus adscendens در استان لرستان با استفاده از مدل MaxEnt 85 106 105417 10.22059/jphgr.2026.406273.1007908 FA حدیث صادقی گروه علوم و مهندسی خاک، دانشکده کشاورزی و منابع طبیعی، دانشگاه لرستان، ایران حمیدرضا متین فر گروه علوم و مهندسی خاک، دانشکده کشاورزی و منابع طبیعی، دانشگاه لرستان، ایران Journal Article 2025 07 08 ABSTRACT Understanding the distribution pattern of medicinal plants is essential for identifying the role of climatic and environmental variables. In this study, the distribution of “Astragalus adscendens,” as one of the native species of Lorestan Province, was investigated using the Maximum Entropy (MaxEnt) model. Species presence data were collected through field sampling in the regions of Aligudarz, Azna, Aleshtar, and Nurabad during the spring and summer of 1404. The results showed that cold-season precipitation (Bio19), with a permutation importance of 49.4% and a relative contribution of 26.6%, was the most important distribution factor, and the highest probability of presence was observed within the precipitation range of 100 to 140 mm. Land slope, with a permutation importance of 31.8%, was the second most influential factor; moderate slopes (30–40%) and northern aspects exhibited the most favorable conditions. The optimal temperature for species presence was approximately 13–14°C, and the suitable elevation range was determined to be 2400–2700 m. Loamy soils also provided favorable conditions for species establishment. In general, variables such as elevation, land use, and soil texture played a complementary role, and species distribution was mainly influenced by temperature, winter precipitation, and sloping, snow-covered highlands; only 27.2 square kilometers of the province’s land, mainly in the east and southeast, exhibited moderate to very high suitability, and highly suitable habitats were located in the highlands of Qalikuh, Tamandar, and Oshtorankuh. Extended Abstract Introduction The distribution and long-term persistence of medicinal plant species in Iran are strongly influenced by a range of natural factors and human activities. In recent decades, unsustainable harvesting, extensive land-use changes, overgrazing, habitat fragmentation, and ecosystem degradation have led to a significant decline in the population size and geographic range of many valuable medicinal plants. These threats have been intensified by the absence of comprehensive national strategies for the identification, conservation, and sustainable utilization of native species. The lack of ecological data, the limited scope of long-term monitoring programs, and the absence of reliable spatial distribution maps have collectively constrained effective planning and management of medicinal plant resources at the national level. In addition to direct human impacts, climate change has emerged as one of the primary drivers of ecological transformations, accompanied by shifts in temperature patterns, precipitation regimes, and an increasing frequency of extreme climatic events such as prolonged droughts. These changes have significantly altered the habitat suitability of many plant species and have led to the degradation, contraction, or displacement of their ecological niches. Mountain ecosystems, despite their ecological importance and high biodiversity value, are highly vulnerable to these changes because of their narrow climatic tolerance range and strong dependence on seasonal precipitation. “Astragalus adscendens,” as a native perennial species in the central Zagros Mountains, is considered one of the ecologically important species adapted to high-altitude rangelands. This species plays a fundamental role in soil stabilization, erosion control, and the maintenance of rangeland structure and function. Its growth form and root system enhance soil physical properties, increase water infiltration, and reduce surface runoff. Given the ecological importance of this species and its increasing exposure to environmental stresses, identifying the factors controlling its distribution is essential for the development of effective conservation and sustainable management strategies. Therefore, the main objective of this study was to identify the most important environmental variables influencing the spatial distribution of “Astragalus adscendens” and to model its potential habitat suitability in Lorestan Province using the MaxEnt modeling approach. Methodology The potential distribution of “Astragalus adscendens” was modeled using MaxEnt version 3.3.4. This machine-learning method is widely used for species distribution modeling based on presence data. This approach estimates the most probable spatial distribution pattern based on the relationship between species presence points and a range of environmental variables. Species presence data were collected during the spring and summer of 2025 from four main habitats in Lorestan Province, including Aligudarz (Qalikuh and Tamandar), Azna, Aleshtar, and Nurabad. The geographic coordinates of each presence point were recorded using a GPS device, and associated ecological characteristics such as elevation, slope, slope aspect, soil type, and vegetation cover were documented through field observations. After data processing to prevent model overfitting, a total of 23 presence points were retained for the final modeling. To control multicollinearity among environmental variables, Pearson correlation analysis was performed, and variables with a correlation coefficient greater than 0.8 were excluded. Finally, 13 environmental variables, including five bioclimatic variables related to temperature and precipitation and eight topographic and environmental variables describing land characteristics, were selected. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) index. The relative contribution and importance of each variable were determined using the jackknife test, and habitat suitability maps were generated in a Geographic Information System environment and classified into five categories ranging from very low to very high. Results and Discussion The results showed that the MaxEnt model demonstrated high predictive accuracy in identifying suitable habitats for A. adscendens in Lorestan Province. Among all environmental variables, winter precipitation was identified as the most influential factor affecting species distribution. The highest probability of species presence was observed within the winter precipitation range of approximately 100 to 140 mm, whereas habitat suitability decreased markedly when precipitation exceeded 160 mm. This pattern indicates species adaptation to semi-arid mountainous conditions, where moderate winter moisture facilitates establishment and growth, while excessive precipitation may create unfavorable soil conditions. Slope was identified as the second most important factor in determining habitat suitability. The most favorable conditions were observed on relatively steep slopes (approximately 30 to 40%), particularly on northern and northeastern aspects. These topographic features enhance soil moisture retention, reduce evaporation, and prevent prolonged waterlogging, thereby providing suitable microclimatic conditions for plant growth. Variables related to temperature, elevation, and soil texture also contributed to the distribution pattern, although their effects were relatively weaker than those of precipitation and slope. Among temperature-related variables, seasonal temperature variation and the mean diurnal temperature range showed the greatest importance. The optimal mean temperature range for species presence was estimated to be between 13 and 14°C, whereas temperatures exceeding 15°C resulted in a considerable decline in habitat suitability. Elevation also restricted the species to the range of 2400 to 2700 m above sea level, where lower temperatures and higher relative soil moisture create favorable growth conditions. In contrast, variables related to land use and soil characteristics showed limited influence, indicating a relatively broad tolerance of the species to different soil conditions. The habitat suitability map indicated that approximately 95% of the area of Lorestan Province is unsuitable for this species. Only approximately 27.2 square kilometers fall within the moderate to high suitability class, mainly located in the highlands of Qalikuh, Tamandar, and Oshtorankuh. Conclusion This study showed that the distribution of “Astragalus adscendens” in Lorestan Province is primarily influenced by climatic and topographic factors, with winter precipitation and slope exerting the greatest influence. This species exhibits its highest growth potential in cold, relatively dry mountainous environments with moderate winter precipitation and warm summers. Given the dominant role of climatic variables, future changes in temperature and precipitation patterns may substantially alter the extent and spatial distribution of suitable habitats. Therefore, proactive conservation planning, protection of existing high-altitude habitats, sustainable grazing management, control of land-use changes, and continuous monitoring of climatic conditions are essential to ensure the long-term conservation and ecological stability of this species. Funding This article is derived from a postdoctoral research project supported financially by Lorestan University. Authors’ Contribution Authors contributed equally to the conceptualization and writing of the article. All of the authors approved thecontent of the manuscript and agreed on all aspects of the work declaration of competing interest none. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. شناخت الگوی پراکنش گیاهان دارویی برای درک نقش متغیرهای اقلیمی و محیطی ضروری است. در این پژوهش، پراکنش گونه گون گزی (Astragalus adscendens) به‌عنوان یکی از گونه‌های بومی استان لرستان با استفاده از مدل حداکثر آنتروپی (MaxEnt) بررسی شد. داده‌های حضور گونه از طریق نمونه‌برداری میدانی در مناطق الیگودرز، ازنا، الشتر و نورآباد طی بهار و تابستان ۱۴۰۴ جمع‌آوری گردید. نتایج نشان داد بارش فصل سرد (Bio19) با اهمیت جایگشتی%4/49 و سهم نسبی %6/26، مهم‌ترین عامل پراکنش است و بیشترین احتمال حضور در محدوده بارش ۱۰۰ تا ۱۴۰ میلی‌متر مشاهده شد. شیب زمین با اهمیت جایگشتی %8/31 دومین عامل مؤثر بود؛ شیب‌های متوسط (۳۰–۴۰ درصد) و دامنه‌های شمالی بیشترین شرایط مطلوب را داشتند. دمای بهینه حضور گونه حدود ۱۳–۱۴ درجه سلسیوس و دامنه ارتفاعی مناسب ۲۴۰۰–۲۷۰۰ متر تعیین شد. خاک‌های لومی نیز شرایط مطلوبی برای استقرار گونه فراهم کردند. به‌طورکلی، متغیرهایی چون ارتفاع، کاربری اراضی و بافت خاک نقش مکمل داشته و پراکنش گونه عمدتاً تحت تأثیر دما، بارش زمستانی و ارتفاعات شیب‌دار و برف‌گیر است. تنها ۲۷/۲ کیلومترمربع از اراضی استان، عمدتاً در شرق و جنوب شرق، دارای تناسب متوسط تا بسیار زیاد بوده و زیستگاه‌های بسیار مطلوب در ارتفاعات قالی‌کوه، تمندر و اشترانکوه قرار دارند

https://jphgr.ut.ac.ir/article_105417_8732a6c1193d43aed8a6d84b64ffb654.pdf

دانشگاه تهران پژوهش های جغرافیای طبیعی 2008-630X 57 4 2025 12 25 Assessment of Geotourism Susceptibility of Karstic Geosites: A Case Study of the Hawraman District ارزیابی پتانسیل ژئوتوریستی ژئوسایت‌های کارستیک مطالعه موردی: بخش هورامان، استان کردستان 107 124 106396 10.22059/jphgr.2026.410354.1007916 FA محمد صدیق قربانی گروه جغرافیا ، دانشکده حقوق و علوم اجتماعی ، دانشگاه پیام نور، تهران، ایران فرزاد ویسی گروه ژئومورفولوژی، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج، ایران فاطمه صالحی گروه جغرافیا، دانشگاه پیام نور، تهران، ایران Journal Article 2025 07 08 ABSTRACT Today, geotourism, as a subset of tourism, plays a significant role in tourism development. Karstic regions are one of the areas prone to geotourism and tourism development. Since the majority of geotourism attractions in the Zagros regions of Iran are composed of karstic phenomena, this research evaluated the geotourism potential of the karst area in the Hawraman region of the High Zagros. Utilizing library and field data, valuable geosites in terms of geotourism development were identified. Due to the non-uniform value and importance of the geosites, the prone geosites in the region were valued using two methods: Reynard and GAM. In addition to valuing each geosite using these two methods, the resulting values from both models were combined to determine the final value of the geosites. The final value for each geosite was calculated based on its characteristics. The value obtained for each geosite was calculated as a percentage. Based on these percentages, the final value of each geosite was calculated according to both the Reynard and the GAM evaluation models. These values showed close similarity in both models, with slight differences. Based on the results of this study and the average percentage obtained from both models, the Belbar Waterfall Spring had the highest value with 77.64% of the total score, followed by the Selin Grand Lapies with 69.04%, the Sirwan River with 67.48%, and the southern slopes of Kousalan with 64.24% of the total score.”. Extended Abstract Introduction The tourism industry is a highly competitive, destination-based activity that varies in every region according to its natural, cultural, and constructed resources The relationship between tourism and geological sites and their features, including geomorphological sites and landscapes, is discussed under the title of geotourism. Therefore, geotourism is one of the new fields of tourism that completely follows the principles of tourism and is a combination of geology, geomorphology, natural landscapes, topography, rocks, and minerals, with an emphasis on the processes that create these forms. One of the regions with great potential in terms of geotourism is the karstic regions, where various solutional phenomena such as sinkholes, caves, springs, canyons, and karrens (lapies) are formed, which collectively are termed karst phenomena. In Iran, the majority of karstic regions are located in the Zagros belt. Among these, the Hawraman region in Kurdistan and Kermanshah provinces has provided suitable potential for tourism due to its geological, geomorphological, climatic, and historical characteristics. Hawraman is one of the areas situated in limestone structures, and considering its geographical location and the presence of diverse landscapes, it has high potential for the development of the geotourism industry, specifically karst geotourism. Methodology "This research is based on descriptive-analytical methods, and the survey method, as well as library studies, were used to gather information. In the present study, two methods, Reynard and GAM, were used to evaluate the promising geosites in the region. Reynard Method: In this method, a geomorphosite is interpreted based on its scientific and Additional values. In fact, this method uses evaluation cards for geomorphosites that cover two parts: scientific value and Additional value. Scientific Value: In the scientific value, the indicators of rarity, interconnectedness, repeatability of observation, completeness, and paleogeography value are considered. In scientific value, the paleogeography indicator is very important due to its contribution to the analysis of earth conditions and paleoclimate. Additional Value: The Additional values section evaluates several dimensions, including environmental, aesthetic, cultural, and economic aspects. GAM Method: This method was developed for the evaluation of one of the mountains in Serbia. The GAM model uses a table structure of main and complementary values for the evaluation of geosites. Results and discussion The area is located in the High Zagros zone. Based on the 1:250,000 geological map of Marivan-Baneh, the entire study area is composed of layered to massive limestone rocks of the Bistoon Formation. The Bistoon limestones in this area have been incised by about 2000 meters by the Sirvan River, resulting in the formation of deep canyons. In addition to the main Sirvan Canyon, other secondary canyons, such as the Jivar natural-historical canyon and the Howraman Takht-Belbar Canyon, are part of the region’s karstic landscape. In this research, the characteristic karstic geosites of the region, including sinkholes, karst springs, caves, various types of lapies, and canyons, were primarily identified and examined during field visits. Geosite Evaluation: Reynard Method: In this method, geosites are evaluated based on scientific and additional values. According to the items in Table 1, the region’s geosites were evaluated based on their scientific values. Based on the results obtained, the Belbar springs had the highest value with 3.25 points out of a total of 4 points. Following this, the Selin megakarren (Selin giant karren), the Sirvan canyons, and the southern slopes of Kousalan were ranked next, with 3, 2.85, and 2.5 points, respectively. After evaluating the geosites based on scientific criteria, in order to complete the potential assessment and comprehensive evaluation of the geosites, these geosites were also evaluated for their additional value. The results of this evaluation are shown in Table 2. In this assessment, similar to the evaluation based on scientific values, the Belbar waterfall spring has the highest value with 3.25 points out of 4, and the Sirvan River, the Selin megakarren, and the southern slopes of Kousalan are next with 3, 2.5, and 2.25 points, respectively. GAM Method: The results of the GAM evaluation indicate that, similar to the Reynard method, the waterfall spring has the highest value with 19.25 points out of a total of 26 points. Following this, the Selin Grand lapies, the southern slopes of Kousalan, and the Sirvan River are ranked next with 18.25, 18, and 17.25 points, respectively. It should be noted that this method considers features such as aesthetics, visual diversity, extent, infrastructure, accessibility, etc., so geosites with better status in these respects have higher values." Conclusion "Following the library and field studies in this research, finally, 15 geosites were selected and evaluated as the final and potential geosites for investigation using the two methods, Reynard and GAM. The main goal was to evaluate the geotourism potential of the region’s geosites based on combining the results obtained from these two methods. To determine the final value of the geosites, the set of information obtained from both methods was combined to determine the final value of each geosite. To do this, in the Reynard method, the average of the scientific and additional scores for each geosite was calculated, and the average score of each geosite based on both criteria was determined as a percentage. In the GAM method, based on the multiple values of each geosite, their final rank was also determined as a percentage. Then, to determine the final value of each geosite in the Reynard and GAM methods, the obtained scores, which were converted to percentages, were averaged, and finally, the final value of each geosite was specified. Based on the combined results obtained (Table 5), the Belbar waterfall spring has the highest value with 77.64% of the total score, followed by the Great Selin Lapies with 69.04% in second place. The geotourism value of the other geosites is in the following ranks. Funding There is no funding support. Authors’ Contribution Authors contributed equally to the conceptualization and writing of the article. All of the authors approved thecontent of the manuscript and agreed on all aspects of the work declaration of competing interest none. Conflict of Interest Authors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper. امروزه ژئوتوریسم به‌عنوان زیرمجموعه گردشگری سهم زیادی در توسعه گردشگری دارد. یکی از مناطق مستعد توسعه ژئوتوریسم و گردشگری، مناطق کارستیک هستند. ازآنجایی‌که بخش اعظم جاذبه‌های ژئوتوریستی نواحی زاگرس در ایران را پدیده‌های کارستی تشکیل می‌دهد؛ در این تحقیق به ارزیابی پتانسیل ژئوتوریسم کارست منطقه هورامان در زاگرس مرتفع پرداخته شد. با بهره‌گیری از اطلاعات کتابخانه‌ای و میدانی، ژئوسایت‌های ارزشمند ازنظر توسعه ژئوتوریسم شناسایی شدند. با توجه به یکسان نبودن ارزش و اهمیت ژئوسایت‌ها، با استفاده از دو روش رینارد و گام، ژئوسایت‌های مستعد منطقه ارزش‌گذاری شدند. علاوه بر ارزش‌گذاری هر یک از ژئوسایت‌ها در این دو روش، به‌منظور تعیین ارزش نهایی ژئوسایت‌ها، ارزش‌های به‌دست‌آمده از دو مدل باهم ترکیب شدند. ارزش نهایی هر ژئوسایت بر اساس ژئوسایت مربوطه محاسبه شد. میزان ارزش به‌دست‌آمده برای هر ژئوسایت به‌صورت درصد محاسبه شد. بر مبنای این درصدها ارزش نهایی هر ژئوسایت بر اساس دو مدل رینارد و ارزیابی ژئوسایت محاسبه گردید. این ارزش‌ها در هر دو مدل با اندکی تفاوت مشابهت نزدیکی را نشان می‌دهد. بر اساس نتایج این پژوهش و میانگین درصدی حاصل از هر دو مدل، چشمه آبشاری بلبر با 64/77 درصد از مجموع امتیازات دارای بالاترین ارزش بود و بعدازآن بزرگ لاپیه‌های سلین با 04/69 درصد، رودخانه سیروان با 48/67 درصد و دامنه‌های جنوبی کوسالان با 24/64 درصد از مجموع امتیازات در رده‌های بعدی قرار دارند.

https://jphgr.ut.ac.ir/article_106396_178bd676965bacd2f2e2f80cd6aa891e.pdf