Showing 727 results for Type of Study: Research
Mohammad Radman, Mohammad Saligheh, Mohammad Hossein Naserzadeh,
Volume 0, Issue 0 (3-2007)
Abstract
In order to comprehend the water flow characteristics and variations of the Karun River, we examined the Zaz, Bazoft, and Beshar sub-basins from its main branches. The reason for choosing these basins was the proximity to the catchment centers of the Middle Zagros and their location upstream of the dams.
Iran Water Resources Management Company provided all the required data (from the water year
1356-57 to 1395-96), and we analyzed them using Kolmogorov-Smirnov tests, data skewness, skewness, and Pearson correlation. Then, we performed the linear regression test to determine the effect of temperature and precipitation on river discharge, and they conducted the Mann-Kendall test to identify the trend and jump points. The results of the data analysis showed that all of them are in normal conditions, although they have some elongation and skewness. The Pearson correlation test revealed a correlation between meteorological and hydrometric data.
The regression model used shows the changes in precipitation and discharge (unlike temperature and discharge) well. The significance number of all stations in the model is less than 0.05, which shows that the changes that occurred between predictor and dependent variables are significant. We see the high performance of the model in explaining the changes in discharge compared to precipitation. According to the regression charts, the decreasing trend of precipitation and discharge and increasing temperature are clear in all three basins.
The Mann-Kendall test reveals a significant trend of increasing temperature in Bazeft and Bashar basins, a decreasing trend of discharge in Bazeft and Bashar basins, and a decreasing trend of precipitation in Zaz and Bazoft basins.except for the temperature of the Zaz basin, all variables show mutations in mutation basins.
Atefeh Rezaei Talei, Zahra , Buhlol Alijani, Hematolah Roradeh, Taher Safarrad,
Volume 0, Issue 0 (3-2007)
Abstract
| The role of regional and extra-regional forcings causes changes in the Siberian high-pressure cyclonic circulation every year. In this regard, an attempt was made to investigate the variability of the intensity of the Siberian high pressure in relation to the abnormal winter circulation of the atmosphere. For this purpose, gridded data of sea level pressure, geopotential height, orbital and meridional wind components of Center for Environmental Prediction/Atmospheric Sciences (NCEP/NCAR) between the years until 2020 (December to February) were used. After applying the Siberian high pressure intensity index, the extreme periods of this high pressure in winter were extracted. Next, the development of this system and the systems affecting the Siberian high pressure were investigated using the quantity of relative Vorticity advection. The results showed that during the winter period, the high pressure center of Siberia has undergone changes and has taken on a growing trend between 4 and 6 hectopascals. On the other hand, it was observed that the role of atmospheric systems such as dynamic ridges on the Siberian region along with advection The negative relative humidity, the location of the Siberian region in the east of the ridge, and the formation of omega bands play an important role in strengthening this system, which has caused this high pressure to develop from east to west or north to south. On the other hand, the role of the polar vortex in the cold advections of the region and the displacement towards the equator has caused the Siberian high pressure to sometimes increase by more than 11 hectopascals compared to its long-term average. Finally, it was observed that the atmospheric circulation in mid-latitudes plays a transitional role in the high pressure changes in Siberia and the polar and subpolar currents. |
Ali Nasiri,
Volume 0, Issue 0 (3-2007)
Abstract
The purpose of this study is to investigate the risk of earthquakes in the Urmia region by determining the parameters a and b of the Gutenberg-Richter magnitude-frequency relationship. For this purpose, based on the tectonic and seismographic data of the region, 4 different seismic springs were identified and zoned using geostatistical spatial analysis methods in the ARCGIS 10.3 environment. In this research, the value of b, which is the slope of the frequency-magnitude relationship of the Gutenberg-Richter relationship, was calculated using the maximum likelihood (ML) method. Also, I estimated the average return periods, the most probable maximum magnitude in the time interval of t years, and the probability of an earthquake with magnitude M => 7 in the time intervals of t years. Then we produced a map of the values of the parameters a and b using the ML method. We obtained the lowest b value of 0.414 in seismic zone 1 and the highest value in zone 2 equal to 0.96 and zones 3 and 4 respectively 0.553 and 0.72. These results are strongly supported by the probability value (90 percent) that the largest earthquake with a magnitude greater than or equal to 6 on the Richter scale occurs in zones 3 and 4. We estimated the minimum return period of such an earthquake with the mentioned magnitude to be 79 and 169 years respectively in zones 3 and 4 of the region. We estimated the most probable earthquake with a magnitude of 6 and above in the next 100 years in 4 zones of the region, and the highest value of the earthquake magnitude scale was determined in zone 4 (M=7.7). Based on the parameters of the mentioned relationship and the type of tectonic regime of the region, zones 3 and 4, which mostly cover the southwest and north of the region, are the most dangerous zones in terms of seismic risks in Urmia region.
Mr Hossein Amraei, Ph. D Hossein Rabiee, Mr Esmaeil Dehghan, Ph. D Zakeyeh Aftabi,
Volume 0, Issue 0 (3-2007)
Abstract
Qarabagh region and consequently Zangzor Corridor is of special importance for Iran due to its geopolitical and geoeconomic capabilities. This practical article is devoted to the explanation of the future scenarios for Iran caused by the Zangzor Corridor. The methodology governing the research is descriptive and analytical. The required data has been collected by library and field methods and analyzed using Micmac and Scenario Wizard software. The results of the research showed six variables: Israel's presence in the Karabakh region, the location of the Karabakh region in the orbit of the US and the West, Iran's gas export, especially to Turkey, Iran's territorial integrity (especially the Turkic provinces), Iran's transit role in international transportation, and Iran's geopolitical position. They were chosen as the key influencing variables of Zangzor Corridor on Iran. In this regard; The possible situations related to six scenarios with strong compatibility showed: the situations that describe the scenarios facing Iran as critical due to the impact of the Zangzor Corridor, include the most possible possible situations. On this basis, the scenario of geopolitical collapse was formulated and it was concluded that the future of Iran's security in the Caucasus depends on its ability to create an effective strategy for managing challenges and exploiting opportunities. Only by strengthening regional cooperation and adopting prudent policies, Iran can take steps to protect its national interests and ensure stable security in this region
Mehdi Feyzolahpour, Neda Kanani,
Volume 0, Issue 0 (3-2007)
Abstract
“Desertification is a form of land degradation in arid, semi-arid, and semi-humid regions caused by climate change and human activities. The purpose of this research is to investigate the desertification situation in the Sirjan Plain region in the period from 1990 to 2023. Desertification in this area threatens human settlements. The purpose of this research is to combine several indicators to evaluate the state of desertification, and for this purpose, several spectral indicators are combined with each other to select the best indicator. In this research, based on albedo, MSAVI and SFI indices, desertification monitoring index (DMI) was proposed and the spatial and temporal distribution of desertification in the west of Sirjan was estimated in 1990 and 2023. To classify the results obtained from the DMI index, Jenks classification methods and quantitative index were used. Based on the results of the Jenks index, it was observed that the areas with very low desertification in 1990 were about 59.7 square kilometers, which decreased to 127.5 square kilometers in 2023, and 47.68 percent of the area has desertification. It has been very little. Areas with high desertification have faced a significant change and have reached 118.6 square kilometers in 2023 from 465.7 square kilometers in 1990. The results showed that Jenks classification method has a higher ability than the quantitative index with an overall accuracy of 82% and a Kappa coefficient of 0.86 in 1990. Finally, it was observed that the albedo index had the highest positive correlation compared to the DMI index. So that the correlation between these two indicators in 1990 and 2023 was estimated at 0.71 and 0.82, respectively.
Dr Sadegh Allahyari,
Volume 0, Issue 0 (3-2007)
Abstract
A healthy city is a city where the quality of life of citizens is high in all areas, including physical and mental health, social welfare, economic development, and environmental protection. This study evaluates the indicators of a healthy city in Shush Daniel using the Healthy City Index from the perspective of the United Nations' 2023 Agenda. The research is applied in purpose and quantitative in nature, conducted through a descriptive-analytical method. The statistical population included experts, planners, urban researchers, and specialists with comprehensive knowledge of Shush city, from which 30 individuals were purposefully selected to answer the questions. Binary logistic regression was employed to analyze the data and information. The results revealed that among the six main components, economic density and investment had the highest impact with an influence coefficient of 0.210, followed by health, welfare, and healthy citizens (0.203), creation of neighborhoods, infrastructure, and healthy housing (0.191), and a healthy environment (0.186). These factors had the most significant influence on creating a healthy and sustainable city in Shush. Out of 38 indicators, the 10 most important ones were identified, with the top three being physical and mental health of citizens (0.393), low levels of stress and anxiety in society (0.382), and provision of urban infrastructure and equipment (0.328). These indicators were found to be the most critical in establishing a healthy and sustainable city in Shush Daniel
Hamidreza Karimi, Shariar Khaledi, Reza Borna,
Volume 0, Issue 0 (3-2007)
Abstract
Goods and currency smuggling is a widespread issue in Iran, disrupting economic, political, and social planning. While not limited to border regions, these areas are particularly vulnerable due to their unique geographical conditions. This research focuses on the natural factors influencing smuggling in border areas, examining the roles of topography, vegetation, climate, and water resources.
The study aims to determine the extent and mechanisms by which each of these natural factors affects the control of goods and currency smuggling in the country's border regions. This is a fundamental-applied study using descriptive-analytical and quantitative methods. Data were collected through surveys of military and border guard personnel stationed in border regions and analyzed using Pearson correlation coefficient, regression analysis, and path analysis modeling.
The results indicate that topography, vegetation, and climate have the most significant impact on hindering the operations of military and border guard forces in combating smuggling. The Pearson correlation coefficient (0.620) demonstrates a strong relationship between natural geography and the military geography of anti-smuggling efforts. In regression analysis, the "climate" variable shows the highest impact with a beta coefficient of 0.350, while "water resources" has the lowest impact with a beta coefficient of 0.124. Furthermore, the path analysis model shows that vegetation, topography, and water resources, influenced by climatic conditions, affect the quality of anti-smuggling efforts in the country's border regions, thereby creating challenges for military and border guard forces in controlling, monitoring, and combating smuggling.
Mousa Kamanroudi-Kojouri, Azad Rahimzadeh, Farideh Fallah-Hosseini,
Volume 0, Issue 0 (3-2007)
Abstract
A creative city is a vibrant place that fosters cultural and intercultural learning, where every resident feels confident in their knowledge, skills, and cultural awareness. A creative city emphasizes characteristics that make the city more appealing to its residents. The objective of this research is a comparative assessment of Tehran’s metropolitan districts based on creative city indicators. This study is descriptive-analytical in terms of methodology and applied in terms of purpose. Data collection was conducted using a documentary-library method across four dimensions: quality of life, human capital, social capital, and innovation. The WASPAS decision-making model was used for ranking the districts, and the entropy model was applied to weight the indicators. The innovation of this research lies in its use of a comparative approach and a new model for identifying and evaluating creative city indicators at the urban district scale (Tehran metropolis).The results from employing the WASPAS decision-making model reveal differences among the 22 districts of Tehran concerning creative city indicators. The ranking of districts in terms of being a creative city shows that seven districts (6, 1, 12, 3, 4, 2, and 7) have favorable conditions. Eight districts were found to have moderate conditions, while seven districts (19, 18, 16, 21, 17, 10, and 9)respectively, were in unfavorable conditions and prioritized for urban development planning. Moreover, the findings showed that the economic dimension of the creative city had the highest number of districts (17) in unfavorable conditions.
Afshin Karami,
Volume 0, Issue 0 (3-2007)
Abstract
In centralized political systems, the government-municipality or government-local governance relationship follows a hierarchical structure, where the independence of municipalities is overshadowed by their financial dependence on the government or state-affiliated organizations. In Ahvaz, the metropolitan area under study in this research, in addition to this type of governmental dependence, urban management may be subject to another form of financial dependency. The prominent presence of companies and industries operating at regional and supra-regional scales – such as Khuzestan Steel Company, petrochemical industries, the National Iranian Oil Company, and its affiliated organizations in Ahvaz and Khuzestan region – and their interactions with urban management can significantly influence municipal performance. This research seeks to examine the political-economic effects of regionally and nationally scaled companies and organizations on spatial-political management and urban governance. In other words, it aims to answer the question: To what extent can the financial dependence of urban management on one or more national/regional companies affect the optimal performance of municipalities? This study employs the policy network model as its research framework. The policy network was visualized using Gephi software, followed by network analysis. The research findings indicate that the political economy of these corporations' presence can be summarized in two dimensions: a) Positive economic impacts b) Urban management challenges.
Dr Abed Golkarami, Dr Mohammad Yousefi Shatouri, Dr Afshin Mottaghi,
Volume 0, Issue 0 (3-2007)
Abstract
Water diplomacy, as one of the effective tools in the management of shared water resources—particularly in regions with transboundary rivers—plays a crucial role in reducing tensions and strengthening regional cooperation. This study, employing an applied approach and a descriptive–analytical method, provides a geopolitical analysis of water diplomacy in Iran’s border rivers. To better conceptualize the issue, three converging theoretical frameworks in international relations—neoliberal institutionalism, liberalism, and constructivism—are utilized. Accordingly, the main research question explores how these theoretical approaches can contribute to an effective analysis of water diplomacy in Iran’s transboundary river basins. The central hypothesis posits that an integrative application of these theories can lead to a more accurate understanding of geopolitical relations, reduction of regional tensions, and enhancement of cooperation mechanisms between Iran and neighboring countries in managing shared water resources. The findings—drawn from the application of these approaches to three case studies (Helmand, Harirud, and Aras rivers)—indicate that despite their theoretical differences, all three frameworks emphasize institutional capacity building, economic interdependence, and the formation of shared identities and norms. These elements, in turn, can provide a solid foundation for enhancing water diplomacy across Iran’s borders. The study also highlights that adopting a synthesized approach can significantly assist policymakers in formulating comprehensive and multi-dimensional strategies for the sustainable management of transboundary water resources.
Dr Ata Ghaffari Gilandeh, Ms Homa Vaezi, Mr Navid Ghaffari Chanzanagh,
Volume 0, Issue 0 (3-2007)
Abstract
New urban fabrics in our country, despite previous planning efforts, often face quality crises. In this context, the present research evaluates the quality of urban spaces in the new urban fabric of Ardabil, emphasizing the components of environmental psychology. Initially, through a review of the theoretical literature, the effective components of environmental psychology on the quality of urban spaces were identified, comprising 20 components across three dimensions. These components were then assessed through a questionnaire. The statistical population of the research includes residents of Phase 1 and Phase 2 of the Sabalan Township, Rezvan Township, Sina Township, and Zaranas Township that its population is about 198644 people. The sample size is 384 individuals. The validity of the questions was confirmed by three university lecturers and experts in this field, and the Cronbach's alpha coefficient of 0.845 indicated the reliability of the questionnaire. For the analysis of the data obtained from the questionnaires, all statistical calculations were performed using SPSS and LISREL software, employing structural equation modeling and second-order confirmatory factor analysis methods. The results from the model fit indicated the correlation between latent variables and observed variables, as well as the calculated T-values for all first-order and second-order factor loadings, demonstrating the external validity of the research model. According to the findings, the environmental health component with a factor loading of 0.75 in the content factors category, the spatial readability component with a factor loading of 0.80 in the physical factors category, and the accessibility to daily commercial services component with a factor loading of 0.58 in the functional factors category have the most significant impact on improving the quality of urban space in the new fabric of Ardabil. The research findings indicated that the average quality of the components of environmental psychology, according to respondents, reflecting the moderate level of these components in the studied area.
Mr Masoud Safari Aliakbari,
Volume 0, Issue 0 (3-2007)
Abstract
In the current situation, artificial intelligence can improve rural management performance through optimizing resource use, predicting environmental changes, and making intelligent decisions.The aim of the present study is to investigating the impact of artificial intelligence on rural management performance with the mediating role of environmental dynamics in rural areas of Kermanshah county. This research is descriptive in terms of method, applied-practical in terms of purpose, and correlational in terms of nature. The statistical population includes 1300 village heads and council members in the villages of Kermanshah city. The sample size using the Morgan table is 297 people and the sampling method is simple random. The research tools include standard questionnaires for artificial intelligence from Carl Albrecht (2003) with 21 items, for measuring environmental dynamics, the Vera and Crossan questionnaire (2009) with 5 items, and for measuring performance, the Patterson questionnaire (1970) with 15 questions. The validity was confirmed by face, content and construct methods and the reliability was confirmed by Cronbach's alpha at 0.861. The collected data were analyzed based on structural equation path analysis in PLS software. The results showed that artificial intelligence had a positive and significant effect on rural management performance with an impact coefficient of 0.889 and a T value of 217.42, artificial intelligence had a positive and significant effect on environmental dynamics with an impact coefficient of 0.876 and a T value of 0.044, and environmental dynamics had a positive and significant effect on rural management performance with an impact coefficient of 0.273 and a T value of 4.938. Also, the results of the Sobel test showed that artificial intelligence had an effect on rural management performance with a mediating role of environmental dynamics with a T value of 9.361. Therefore, artificial intelligence can play a very important role in rural management performance, especially in optimizing resources, improving public services, environmental management and increasing agricultural productivity.
Dr Saeed Zanganeh Shahraki, Mr Amin Mahmoudiazar, Mr Mostafa Tavakoli,
Volume 0, Issue 0 (3-2007)
Abstract
Official statistics show that the housing situation in many countries of the world, including Iran, cannot be defended. Despite global issues in the field of housing and the environment, the necessity of developing "sustainable affordable housing" has been widely accepted among urban thinkers. This necessity is intensified with the expansion of urbanization and population growth. To realize this, there is a need to identify the components of affordable-sustainable housing, which has been investigated in this study in the neighborhood, which is the most important place of residential use. In this research, the aim is to investigate sustainable affordable housing indicators in different urban areas. Using Cochran's formula, the number of samples in various locations is determined and finally, sampling is done using the systematic sampling method. The validity of satisfaction questionnaires that include the perceptions section has been confirmed by 5 professors and its reliability has been measured using Cronbach's alpha. The resulting studies show that 36 quantifiable indicators in the field of attaining affordable housing can be identified from various articles using the synthesis method, and by examining them in different planned areas, the program unplanned and old in the city of Urmia, it can be concluded that Urmia's neighborhoods with an average score of 3.87 have a good status in the social sector and with an average score of 2.23 in the economic sector, they have an unfavorable situation and the environmental indicators and Physically, they have different statuses between the localities and have marked the differences. In this way, the planned neighborhoods have a good situation in obtaining affordable housing, and the old and unplanned neighborhoods are placed in the next position.
Miss Fatemeh Salehi Janati, Dr Hamid Saberi, Dr Shirin Toghyani, Dr Hojat Mahkouei,
Volume 0, Issue 0 (3-2007)
Abstract
Tactical urban planning, which depends upon quick and participatory interventions within small-scale areas, creates a platform for citizen creativity and, by reinforcing neighborhood resilience, redefines models of urban sustainability. This study aims to provide a systematic and comprehensive overview of the composition and research trends within the area of tactical urban planning from a bibliometric perspective. Based on data from 764 papers listed in the Web of Science database between 2000 and 2025 and utilizing VOSviewer software, three bibliometric maps (network, temporal, and density) were created and analyzed. The findings indicated that tactical urban planning, as an innovative and participatory strategy, occupies the center of the theoretical network of urban planning and urbanism scholarship, with deep connections to concepts such as public space, urban policy, and innovation. The temporal trends of papers indicate a significant increase in concern with issues such as participatory design, smart urbanization, and urban resilience in recent years. Moreover, the density map indicated that priority of investigations is assigned to the axes of tactical urban planning interaction with sustainable development, and citizen involvement. Identifying thematic clusters, scientific collaboration networks, and knowledge gaps, this article provides an overall view of the existing status and further research directions within the area. Researchers and urban policymakers can use it to improve urban quality of life and promote sustainable development.
Dr Marjan Badiee Azandahi, Mr Ehsan Motaghian,
Volume 0, Issue 0 (3-2007)
Abstract
In recent decades, advancements in artificial intelligence (AI) technology and its expanding applications in human life have brought about extensive transformations across various sectors, particularly in the economic sphere. This has significantly heightened the importance of developing this technology for major global powers. Mineral resources serve as the essential raw materials for manufacturing AI-related hardware; consequently, access to these resources is crucial for nations and companies active in this field. Within the geopolitical competition to acquire these mineral resources, the means of controlling and accessing them can be utilized as leverage to exert pressure and impose restrictions on the development of AI technologies. Consequently, countries possessing these resources are pursuing stockpiling and even exploiting resources from other nations to not only increase their own influence and control but also to secure their future access to these materials.
This study is applied research conducted using a descriptive-analytical method. The main research questions are: What role do mineral resources play in the development of AI technology, and how does the geopolitical competition among great powers for acquiring these resources unfold? Based on the research findings, mineral resources, as critical raw materials for manufacturing equipment and a source of capital, significantly impact the production of AI technology hardware. The competition among great powers for these mineral resources often manifests through strategies such as stockpiling, price manipulation, and resource processing. The results indicate that access to, control over, and supervision of the mineral mines used in AI hardware production enable major powers like the United States and China not only to influence the global trajectory of this technology's development and utilization but also to prevent the entry of rival actors into this arena or diminish their potential role.
Hadith Asemani Kenari, Aliakbar Jafari,
Volume 0, Issue 0 (3-2007)
Abstract
The South Caucasus is a semi-mountainous region located between the Caspian and Black Seas which has always enjoyed a geopolitical and geostrategic position throughout history. The conflicts between the Republic of Azerbaijan and Armenia in the South Caucasus, which led to remove the seizure of the disputed territory of Karabakh by the Republic of Azerbaijan, have made it difficult to reach a lasting peace in the South Caucasus due to some fundamental differences such as how to access Nakhchivan region. The Republic of Azerbaijan wants unhindered extraterritorial access, which Armenia and Iran strongly oppose due to the severance of land communication between the two countries and the creation of a geopolitical bottleneck. Given the importance of the South Caucasus and the impressionability of Iranian policies from any geopolitical changes and developments in the region, the present study, using a descriptive-analytical method, seeks to answer the question: "What strategies has the Iranian foreign policy apparatus adopted since the beginning of the conflicts to manage the post-Karabakh war developments in order to prevent any border changes and becoming it into a lasting geopolitical bottleneck?" The result of research show that the foreign policy of the Islamic Republic of Iran has been a combination of declaring a firm position in oppositing to any border changes and while avoiding tension and increasing cooperation in order to prevent any change in the geopolitical situation to the detriment of Iran's interests, especially in the North-South Corridor. These policies have been pursued at various economic, military, and political levels in interactions with the Republic of Azerbaijan and Armenia.
Behrouz Mohamadrezapour, Hassan Heidari,
Volume 0, Issue 0 (3-2007)
Abstract
In recent decades, environmental crises have become one of the fundamental challenges for developing countries, and the need to adopt coordinated and regional policies to address these crises has become increasingly evident. Iran and the Arab League member states possess significant capacity for environmental cooperation due to their geographical, climatic, and economic similarities. However, differences in their environmental policies and practices necessitate a careful comparative study. Therefore, the purpose of this study is to conduct a comparative analysis of the environmental policies of Iran and eight selected Arab League countries (Egypt, Algeria, Iraq, Yemen, Morocco, Saudi Arabia, the United Arab Emirates, and Kuwait), with an emphasis on responsible regionalism and its impact on sustainable development. For this purpose, official UN data for two points in time, 2020 and 2024, were used as the basis for the analysis, and 31 key indicators were extracted within three dimensions: environmental, social, and economic. The research method is mixed, combining quantitative analysis (using Shannon entropy to weight indicators and the TOPSIS model to rank countries) with qualitative library research. The findings are presented in three stages: first, an assessment of environmental policies in 2020; second, a review of developments up to 2024; and third, an analysis of indicator trends in Iran and the eight selected Arab League countries. The results show that, based on the TOPSIS model, Iran ranked fifth among the countries studied in 2020 with a Ci value of 0.339, and second in 2024 with a Ci value of 0.452, representing the most significant development advancement with a three-rank improvement. This advancement was associated with increases in the weight of certain social (such as managed drinking water), economic (such as GDP per capita), and infrastructure indicators, although challenges such as rising greenhouse gas emissions and biological threats persist. The study highlights the need to strengthen environmental policies and design regional cooperation mechanisms to achieve sustainable development.
Dr Ali Haghizadeh, Mr Nooraldin Moridi, Mrs Leila Ghasemi, Mrs Atefeh Bosak,
Volume 0, Issue 0 (3-2007)
Abstract
Evaporation is considered a critical factor in water balance systems, accounting for substantial water loss from lakes. With advancements in remote sensing technologies and computational algorithms, the estimation of evaporation from water surfaces has undergone significant transformation. This study employed the SEBAL algorithm within the Google Earth Engine platform to estimate evaporation from the Ayvashan Dam reservoir. Landsat 8 satellite imagery was processed in Google Earth Engine (GEE) to compute pixel-level evapotranspiration using the SEBAL algorithm. The results revealed that across all three study dates (10/07/2024, 04/08/2024, and 26/08/2024), the evaporation rate near the center of the dam reservoir was consistently higher than in peripheral areas. Furthermore, this study demonstrates that implementing the SEBAL algorithm in the Google Earth Engine platform maintains reasonable accuracy despite challenges such as limited access to pan evaporation data and the 11 km distance between the meteorological station and study area - a finding supported by statistical metrics (RMSE = 2.4 and Nash-Sutcliffe coefficient of 0.83). Calculated evaporation rates for July, August, and September were 9.15 mm, 12.7 mm, and 9.34 mm respectively, indicating substantial water loss from the reservoir. These findings underscore the algorithm's effectiveness in evaporation estimation even under constrained ground data conditions. Given that precipitation in the study area occurs primarily as short-term episodic events with predominantly dry conditions throughout the year, water conservation during arid periods becomes particularly crucial.
- Elham Salehian Dehkordi, - Heeva Elmizadeh,
Volume 0, Issue 0 (3-2007)
Abstract
| Landslides represent a critical natural hazard in the Northern Tehran Basin, posing significant threats due to its complex geological setting, rugged topography, and anthropogenic activities such as road construction. This study introduces an innovative hybrid framework incorporating dynamic weighting based on Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) for landslide susceptibility zonation. Unlike conventional methods (e.g., Frequency Ratio [FR], Statistical Index [SI], and Shannon Entropy [SE]), which employ static weights, our approach dynamically adjusts factor weights (e.g., distance to rivers, slope, lithology) using PSO, accounting for temporal variables such as seasonal rainfall and human activity. We compiled rainfall data and 150 landslide events (2005–2024) from local meteorological stations and geological databases. Input parameters included eight key factors (distance to rivers, distance to roads, slope, lithology, elevation, aspect, distance to faults, and land use) alongside seasonal rainfall. Results demonstrate that dynamic weighting improves prediction accuracy by 15% (AUC-ROC = 0.923 for PSO vs. 0.804 for FR), particularly during high-rainfall seasons where river proximity weight increased (vj = 8.2 vs. 7.21 in static models). The PSO-GA hybrid outperformed traditional models, with PSO (AUC-ROC = 0.923) and GA (AUC-ROC = 0.917) showing superior precision. Dynamic hazard maps accurately identified high-risk zones (e.g., near rivers with vj = 8.23 during rainy seasons). This approach offers a robust tool for landslide risk management in urbanized mountainous regions like Northern Tehran and serves as a replicable model for similar environments globally. |
Masoud Minaei, Sylvia Tramberend, Mohammad Kamangar, Ali Reza Karbalaee, Emilio Politti,
Volume 0, Issue 0 (3-2007)
Abstract
“The global water crisis is exacerbated by significant spatial data gaps in key water stress indicators such as Baseline Water Stress (BWS), posing serious challenges for policy-making and water resource management. This study leverages the XGBoost algorithm one of the most efficient machine learning methods for regression modeling to estimate missing BWS values at the global scale. Key predictor variables include soil moisture, climatic factors (precipitation, temperature, and evapotranspiration), land use/land cover, and elevation, derived from the Aqueduct Water Risk Atlas 4.0 and remote sensing datasets. Through comprehensive data preprocessing and hyperparameter optimization, the model explains approximately 71% of the variance in observed BWS values (R² = 0.711), achieving a Mean Absolute Error (MAE) of 0.727 and a Root Mean Square Error (RMSE) of 1.143 on the standardized 0–5 BWS scale—demonstrating competitive performance compared to prior studies (R² range: 0.60–0.75). Feature importance analysis reveals soil moisture as the dominant hydrological integrator (35.41%), followed by climate variables as the primary driver of the hydrological cycle (24.58%), land use/land cover (18.30%) and population density as key anthropogenic factors (16.04%), and elevation as a topographic modulator (5.67%). The reconstructed global BWS map highlights pronounced spatial heterogeneity in water stress: critical hotspots emerge across the Middle East, North Africa, and South Asia, while higher water security is observed in tropical and temperate regions. This model provides a practical tool for policymakers to identify high-risk areas, develop early-warning systems, and support sustainable water planning. The unexplained variance (29%) underscores the need to integrate socioeconomic data and implement local-scale calibration representing a pivotal step toward addressing the global water crisis.
