Climate Change and Climate Disaster

Abstract The desiccation of Lake Urmia, recognized as one of the most significant environmental crises in Iran, has had far-reaching economic, social, environmental, and managerial impacts on the surrounding regions. This study adopts a descriptive–analytical approach to examine the spatial consequences of Lake Urmia’s desiccation and to identify effective restoration strategies. Data were collected through library research and survey methods. The statistical population consisted of 60 experts and executive managers selected using the snowball sampling technique. Data were analyzed using the structural cross-impact analysis approach in MicMac software and the interactive cross-impact analysis approach in Scenario Wizard software. The findings indicate that the depletion of water and soil resources, declines in production, income, and investment opportunities, rising unemployment, stagnation in the housing market, the emergence of ethnic tensions resulting from population displacement, particularly the settlement of Kurdish migrant groups in the Azerbaijan region, widening socio-political divisions, spatial and physical management challenges, declining tourism, and weakened regional and national cohesion and development are among the most significant consequences of Lake Urmia’s desiccation. Furthermore, improving laws and regulations, halting dam construction, implementing watershed management projects, stabilizing dust source areas, reforming cropping patterns, and enhancing public awareness were identified as the most effective strategies for restoring the lake.

Abstract Water security poses a growing policy challenge, critically shaped by hydro-political relations—ranging from cooperation to conflict—among political-spatial units. This applied study investigates future scenarios of such relations affecting water security in Iran’s Tang Shool basin. Using a descriptive-analytical method, the research draws on library sources and field questionnaires, with data processed via Micmac and Scenario Wizard software. Seven key variables were identified: inter-village water distribution, investment in water transfer infrastructure, basin economic development, sub-national water resource management, external water dependency, enforcement of laws on water shares, and local poverty levels. Scenario analysis based on these variables yields five probable future states for sub-national hydro-political impacts on water security: “Favorable,” “Semi-favorable,” “Static,” “At the Threshold of Crisis,” and “Critical.” The current condition leans toward the critical state. The findings underscore an urgent need to reform the water governance system.

Abstract Variation is an inherent characteristic of the climate. Over time, the change in the frequency distribution of the temperature at a location can reach a point where that location leaves behind its previous climate and accepts a new type of climate. In this case, the evolution of the temperature frequency distribution can be a suitable indicator of climate change. In hot and arid climatic regions such as Iran, where water resources are already very scarce, the evolution of the temperature frequency distribution can have significant consequences for water and energy demands. A detailed understanding of the changes that have occurred in the frequency of different temperature intervals across various points of Iran over time has been the goal of this research. To achieve this goal, daily maximum temperature reanalysis data (ERA5) for 44 years were evaluated using Singular Value Decomposition (SVD). This investigation showed that over the warmer parts of Iran, the frequency of temperatures below 20°C, and over the colder parts, the frequency of temperatures below 10°C, have decreased. In contrast to this decrease, over the warmer parts of Iran, the frequency of temperatures above 40°C, and over the colder parts, the frequency of temperatures above 30 degrees Celsius, have increased.

Abstract As a prominent climate change hotspot, Iran exhibits complex and heterogeneous hydroclimatic responses to global warming. This study analyzes the temporal dynamics of temperature and relative humidity using monthly data from five representative synoptic stations (Ahvaz, Bandar-e Anzali, Tabriz, Zahedan, and Yazd) over a 38-year period (1986–2023). To model the time series behavior, a comparative framework incorporating Moving Average (MA), Autoregressive Integrated Moving Average (ARIMA), and Holt-Winters exponential smoothing models was employed. Prior to modeling, the distributional structure of the data was assessed using the Anderson-Darling test and graphical probability analysis. The results revealed a consistent and significant warming trend across all stations, confirming a convergent thermal response at the national scale. In contrast, relative humidity exhibited a profound divergence. The most significant finding was the identification of strong evidence for a climate regime shift at the Tabriz station. Here, a bimodal distribution in relative humidity, uncovered through diagnostic analysis, indicates an abrupt transition to a more stable, arid climatic state. Model evaluation confirmed the definitive superiority of the Holt-Winters approach, owing to its capability to adapt to both trend and seasonal components. These findings underscore the insufficiency of standard linear models for assessing climate change in transitioning regions, highlighting that regional adaptation strategies must be formulated based on an understanding of these non-linear and heterogeneous responses.

Abstract This research was conducted to quantify the influence of changes in biophysical parameters on the regional thermal dynamics in the Bakhtegan-Maharlu watershed during March, across the period from 1991 to 2020. To achieve this objective, Landsat 5th and 8th generation satellite data were processed utilizing the Google Earth Engine platform for the extraction of the specified indices. Subsequently, Pearson correlation analysis and multivariate regression modeling were employed to elucidate the relationship between the biophysical variables and the thermal characteristics. Furthermore, Hot Spot Analysis was implemented to identify and spatially locate high-intensity thermal clusters. Findings revealed a significant and severe decline in the NDWI index across the Bakhtegan and Maharlu lakes, concomitant with a decrease in NDVI in the surrounding areas. These land surface transformations resulted in the expansion of warmer temperature classes (from 30−40^∘C to a new class of 40−50^∘C) in the southern and central parts of the basin, underscoring an increasing trend across all investigated temperature parameters. The spatial analysis indicated that high-intensity thermal clusters were predominantly concentrated in the southern and southeastern regions of the watershed; this spatial convergence was directly correlated with areas exhibiting the highest LST values, reduced water resources, and severe vegetation destruction.

Abstract Precise elucidation of the dynamic interactions between large-scale atmospheric circulation patterns and hydro-climatic variability in mountainous and semi-arid regions is a prerequisite for environmental risk management. This study was conducted to investigate the correlation of the North Atlantic Oscillation (NAO), Arctic Oscillation (AO), and Multivariate ENSO Index (MEI) with temperature and precipitation in western and northwestern Iran over the period 1987–2022. Data from 20 synoptic stations were processed using Pearson correlation, Canonical Correlation Analysis (CCA), and Inverse Distance Weighting (IDW) spatial modeling. Pearson results indicated that the highest positive correlation of temperature was with MEI (0.21), while the highest negative correlation of precipitation was with NAO (–0.19). Although linear correlations were weak (mostly <0.20), canonical analysis revealed a significant and non-linear climatic response. The highest canonical correlation coefficients were recorded at Ardabil (0.266), Mahabad (0.232), and Khoy (0.231). Precipitation, with a canonical loading of –0.78, exhibited the highest influence from NAO (particularly at Sarab and Maku), whereas temperature, with a canonical loading of 0.64, was mainly controlled by MEI (notably at Sanandaj). Negative canonical loadings at Sardasht and Jolfa indicated a distinct circulation mechanism. The impact of teleconnections in western Iran is a function of synergy with Zagros topography, creating a spatial gradient from the north (dominated by NAO/AO) to the south (dominated by MEI).

Abstract Changes in extreme climatic patterns, as the most prominent consequence of global warming, have created serious hydrological and ecological challenges in mountain ecosystems. This study analyzes the trends of extreme climate indices at the Sardasht synoptic station by examining downscaled temporal trends of 10 temperature and precipitation extreme indices (ETCCDI) over a 40-year period (1986–2025). After daily data quality control, the Mann–Kendall test and Sen's slope estimator were applied. The findings reveal a structural transformation in the region's climate regime, as a warming signal is observed across all temperature indices with statistical certainty (95% to 99.9%). The warm spell duration index has increased with a slope of +3.115 days/year, and tropical nights with a rate of +1.081 days/year, indicating intensified heat stress and disruption of nocturnal cooling. Conversely, frost days and ice days have decreased at rates of –1.259 and –1.059 days/year, respectively, confirming the decline of harsh winters and shortening of the cold season. Regarding precipitation, although the annual total shows no significant trend, the increase in the simple daily intensity index (+0.062 mm/day per year) suggests a shift toward short, intense downpours. Overall, the climate of Sardasht is transitioning from a temperate mountain phase toward conditions with compound extreme hazards (flash floods and heatwaves).

Abstract Analysis of climatic changes in semi-arid regions requires the detection of nonlinear behaviors and structural breaks. This study was conducted with the aim of simultaneously detecting uniform trends and regime shifts in temperature and precipitation in Kermanshah Province. Annual mean temperature and precipitation data from 12 synoptic stations were extracted for the period 1989–2018. First, uniform trends were estimated using the Mann–Kendall test and Sen's slope estimator. Then, the Innovative Trend Analysis (ITA) was employed to examine the asymmetry of trends and sub-trends. In a complementary step, the Pettitt and SNHT tests were applied to identify structural breaks. The results showed that annual temperature increased at all stations, with significant structural breaks occurring in the late 1990s and mid-2000s; particularly, Qasr-e Shirin and Sonqor stations showed higher synchrony and significance in temperature breaks. In contrast, precipitation exhibited more scattered and location-dependent behavior, and only in Gilan-e Gharb was a significant break observed in both tests, which was accompanied by a jump in mean precipitation after the break. The before/after analysis showed that temperature increase was evident at most stations after the break points, whereas precipitation changes were heterogeneous in terms of sign and magnitude.

Abstract This study investigates the spatio-temporal variations in the frequency of dry days (precipitation < 1 mm) and their longest consecutive spells across Iran during the period 1970–2021, using daily data from 411 synoptic stations. Kriging interpolation was applied for spatial analysis, the Mann–Kendall test for trend detection, and the Alexandersson test (SNHT) for identifying significant breakpoints. Results indicate that the national annual mean frequency of dry days is 328 days, with a minimum of 247 days in the southwestern Caspian region and a maximum of 355 days in western Sistan and Baluchestan. Approximately 62.6% of the country's area experienced frequencies above the spatial mean. A significant increasing trend was observed over 89.12% of the territory, whereas only 10.64% showed a decreasing trend. The longest recorded consecutive dry spell (>600 days) occurred in western Sistan and Baluchestan in December 2016. The Alexandersson test identified 1998 as a significant shift point; thereafter, the mean frequency of dry days increased by approximately 8 days, and the maximum dry spell duration nearly doubled. Anomaly analysis of frequency and duration reveals that these changes predominantly occurred in central, southern, and eastern regions. This pattern aligns with alterations in the general atmospheric circulation over Southwest Asia. The findings warn that Iran is transitioning from seasonal dryness toward more extreme and persistent aridity conditions.

Abstract Climate change is a global challenge with wide-ranging consequences for the environment, the economy, and global security. Climate-induced migration at both the domestic and international levels has become a concern, especially as Africa’s vulnerability to droughts, floods, and rising temperatures drives displacement toward European Union (EU) borders. This study examines how such movements affect the EU’s political and security architecture through the Copenhagen School’s securitization framework. It argues that climate change undermines habitats and livelihoods, forcing vulnerable communities to migrate. Externally, these flows have expanded human trafficking networks, increased border pressures, and encouraged stricter asylum policies, turning migration into a security issue. Using a descriptive-analytical method and library-based sources, the research shows that internally, securitization has shifted European priorities and strengthened right-wing parties opposing refugee admission.

Abstract I In recent decades, examining precipitation trends at local and basin scales has become increasingly important for water‑resources management and climate‑vulnerability assessment. This study aims to analyze the temporal and spatial patterns of precipitation in the Qezel-Owzan Basin during the period 1994–2023. Monthly and annual precipitation data from ten selected meteorological stations were compiled, quality‑controlled, and interpolated into continuous precipitation surfaces using the IDW method within a GIS environment. To identify long‑term statistical trends, the Mann–Kendall test and Sen’s slope estimator were applied, allowing the detection of significant directional changes. Results indicate that the long‑term mean annual precipitation of the basin is approximately 350 mm. The most pronounced declines were observed in the southern and southeastern sectors of the basin, whereas stations located in the higher northern elevations recorded more moderate variations. Spatial analysis further suggests that declining precipitation patterns are associated with reduced moisture influx from Mediterranean systems, increased frequency of short‑term droughts, and shifts in winter circulation regimes. These findings highlight rising pressure on both surface and groundwater resources and underscore the need for adaptive planning based on future climate scenarios. The outcomes of this research can assist basin managers, agricultural planners, and water‑policy stakeholders in developing strategies to enhance resilience under ongoing climatic changes.

Abstract With the increase in air temperature and global warming, the behavior of atmospheric parameters has undergone significant variations. It is common to use temperature variability to estimate the rate of global warming; however, employing the equivalent potential temperature index provides a more comprehensive and informative understanding. Since this index reflects variations in the atmospheric moisture content and the latent heat resulting from the presence of water vapor in addition to temperature, it serves as a more optimal and suitable tool for analyzing global warming. Accordingly, the objective of this study was to examine the variability of equivalent potential temperature as an indicator of global warming at the Marivan synoptic station, which is located near Lake Zarivar. To achieve this goal, daily data of atmospheric parameters from the Marivan synoptic station for the period from January 1, 1993, to December 31, 2024, were used. The findings of this study showed that due to the role of atmospheric water vapor and the proximity to the water body of Lake Zarivar, the values of equivalent potential temperature at the Marivan synoptic station are higher than air temperature values. Moreover, the rate of increase in equivalent potential temperature is greater than that of air temperature, with an upward trend of 1.3°C per decade, indicating a rise in atmospheric water vapor and evapotranspiration.