drought

Iran has been facing a severe water crisis for the past few decades. The Helmand River basin, which stretches from southwestern Afghanistan to eastern Iran, has been the site of ongoing disputes between the two countries for nearly a century, but these tensions have become more prominent in recent years, following the expansion of the water crisis in Iran and the construction of a dam upstream in Afghanistan. While our research literature suggests that transboundary water resources in the Helmand River basin have been politicized and even securitized by Iran, no study has examined how Iranian government officials have considered water as a political and security issue. This study responds to this gap by analyzing Persian-language news articles from 2001 to 2019 that contain statements by Iranian officials related to the Helmand River basin, identifying the themes and discursive mechanisms behind the politicization and securitization of this issue. According to the theory of securitization, a significant proportion of these articles contained a securitization movement, the majority of which was carried out by local officials and parliamentarians. This suggests that securitization has been largely a local phenomenon and reflects broader internal tensions over the framing of water relations with Afghanistan among Iranian officials. Another key theme throughout the discourse analysis process has been the linkage between human and environmental systems, which is created by the importance of transboundary water resources through their connection to society. This study suggests that spatial scale, water scarcity, and socio-political context are importa

Drought is a natural hazard that annually causes significant economic, social, environmental, and life-threatening damage in vast areas of the Earth. The damages caused by this phenomenon are intangible but very extensive and costly.  In many circomstancs, modern remote sensing techniques can be a useful tool in monitoring drought due to high temporal accuracy, wide spectral coverage, ease of access, no need for atmospheric correction and ground referencing. In recent years, the province of Hamedan has faced many problems due to frequent droughts. Therefore, the present study focused on investigating and monitoring drought in Hamedan province using the Temperature Condition index and its impact on the vegetation cover of the province using Advanced Very High Resolution Radiometer (AVHRR) and National Oceanic and Atmospheric Administration (NOAA) remote sensing data. First, the relevant data was extracted from the Nova star database, and finally, the spatiotemporal behavior of the vegetation cover drought index was examined on 1528 pixels in Hamedan province. The spatial resolution of the data used in this study is 4 kilometers. First, the relevant data were extracted from the Navstar database and ultimately, the spatiotemporal behavior of the drought index and vegetation cover was examined. The results indicate that drought has significantly increased the vegetation cover of Hamedan province based on remote sensing data. Kendall's coefficients indicate the presence of decreasing trends in vegetation cover at a 95 Percent confidence level. Only in May, June, and December has there been a slight decrease in vegetation cover within the extent of drought in the province. The spatial behavior analysis of the drought index on vegetation cover showed that February, March, as well as April have experienced more severe droughts within Hamedan province.

Drought is a significant natural disaster that requires monitoring to control and minimize its damages. In addition to climate-based drought indices, remote sensing drought monitoring indices are widely used today, especially in regions with limited climate data. These indices utilize satellite images and provide valuable information, resulting in relatively good performance. Furthermore, composite drought indicators are relatively new and multi-variable indices that combine remote sensing indicators for monitoring drought. Studies have shown that the effectiveness of these indicators can also be influenced by the study region. Given the importance of evaluating the performance of new methods in monitoring drought, this study compared the performance of a composite drought monitoring index, CDI, with the VCI, TCI, VHI, and PCI in Chaharmahal and Bakhtiari Province, Iran. CDI is a combination of VCI, TCI, and PCI. The values of the indices were compared with the SPI for the period of 2001-2020, with a time lag of 0 to 8 months by calculating the determination coefficient. For each index, the lag time that provided the highest R2 was identified. Precipitation data from 19 rain gauge stations in the study area were used to calculate the SPI on 3 and 6-month time scales. The results showed that the CDI presents by far the highest correlation with SPI values. The coefficient of determination for the VCI on a 6-month time scale with a 3-month time lag was on average 0.30. For the TCI, the average R2 is 0.50 in both the 3 and 6-month time scales without a time lag. The average R2 for the VHI on a 6-month time scale with a 2-month time lag was 0.41. The average coefficient of determination for the PCI index on a 3-month time scale without a time lag was just 0.32. The CDI index provided the best performance, with an average R2 of 0.73 in both the 3 and 6-month time scales without a time lag. While VCI, TCI, and PCI individually showed weak matching with the SPI, combining them into the CDI resulted in a significant correlation with the SPI.

Drought is a challenging problem that can be evaluated with multi-variable and combined perspectives. Therefore, the aim of this study is to create a comprehensive index of three indices SPI, PDSI, and SRI, which includes all aspects of meteorology, hydrology, and agriculture. For this purpose, three drought variables (severity, duration, Magnitude) were analyzed for 10 meteorological stations in Iran for the statistical period of 1990-2021, firstly using principal component analysis (PCA) and nonlinear coupling based on copula. were analyzed. The probability distribution model for constructing the MCDI composite index. It was then tested with the ability of the exact functions of Clayton, Frank, and Gamble to generate a trivariate joint distribution. The best copula function for each station was determined through the Kolmograf-Smirnov (K_S) test, and the results showed the superiority of the Gumbel function in most stations. Return period curves were drawn for all stations and for all three joints. The period of returns indicated a long-term frequency of drought with greater intensity for periods of 50 and 100 years. The shortest return period of 50 years with the superiority of Clayton's function related to Tabriz and with the superiority of Gumbel's function related to Tehran was 10 months and the longest period was 30 months related to Mashhad with the superiority of Gumbel's function, respectively with intensity of 6.53 and 8.95 and 26/34 were included. For the 100-year return period, the shortest period with the superiority of Clayton is related to Tabriz with 13 months and intensity of 13.75, and the longest period with the superiority of Gumbel's function belongs to Kerman with a duration of 48 months, and the intensity of 42.56. The results of this research show that the use of a multivariate composite index (MCDI) by using detailed functions provides the possibility of a more comprehensive and accurate assessment of drought on a national scale. This approach, taking into account the meteorological, hydrological, and agricultural aspects of drought, provides an efficient tool for managing water resources and strategic planning in the face of drought in different regions of Iran.

Due to the significance of forests in both the natural and human environment, this study aims to investigate the impact of meteorological drought on oak forest dieback in Ilam province. Specifically, the study seeks to determine the relationship between Zagros Forest drought and droughts in this particular region. The analysis utilizes the Standard Precipitation Index (SPI) to identify the frequency of droughts during different time periods. The results indicate that the years 2007, 2008, 2011, 2015, and 2016 experienced the highest occurrence of droughts. Additionally, remote sensing data from MODIS images were employed to examine the trend in tree greenness (NDVI) from 2000 to 2016. The analysis reveals a significant correlation (R2 = 0.9999) between the greenness trend and the drought index (SPI). Moreover, a land survey of oak drying points and simulation using Landsat satellite images, with a 15×15 pixel output from GIS software, indicate that approximately 17,894 hectares of forests in the region experienced drying and destruction between 2000 and 2016. By combining the oak forest drying layer with the output layers derived from drought zoning, visual indicators were created, and statistical analysis was conducted for three 5-year time series. The results demonstrate a correlation coefficient of 96.6% and an explanation coefficient of R2 = 0.985 for the 2002-2006 time series, a correlation coefficient of 95.4% and an explanation coefficient of R2 = 0.980 for the 2007-2011 time series, and a correlation coefficient of 98.8% and an explanation coefficient of R2 = 0.995 for the 2012-2016 time series. These findings illustrate the influence of drought and its variations in terms of intensity and duration on oak forests in the Zagros region of Ilam. Based on the study results, it is predicted that if the drought persists with the same trend, approximately 1,118.4 hectares of oak forests in Ilam province will dry up and be destroyed annually.

 Investigation of the relationship between droughts and the number of days associated with dust in East Azerbaijan Province. 

 First, using the correlation equation, the missing value of the number of days with dust of the synoptic stations was completed in the last 30 years. Then, the trend of this data was checked using the Mann-Kendall test. The frequency and severity of droughts were calculated using the SPEI method in the R program. The impact of droughts on the occurrence of dust was evaluated through the Spearman correlation test.

 The presence of a trend in the data series at a significant level of 0.05 has been confirmed, and Sen’s slope values also indicate that this trend is increasing. The results of the SPEI index show that drought periods are expanding, especially in the second half of the selected period in the region. On the other hand, there was a significant correlation at the 0.01 level between the number of days with dust and the SPEI-6 drought index.

 The playa of Urmia Lake is the main focus of local dust generation, and this fact is confirmed based on the correlation between the dust and the SPEI index and the observation of suspended particles with lake origin in the air of the stations near this lake.

This research aims to reveal the correlation between the occurrence of dust phenomena in connection with the continuation of droughts and the expansion of the playa of Lake Urmia, which has calculated the SPEI index based on the latest statistics of meteorological stations. Conducting such research is necessary to evaluate the tempo-spatial distribution of wind erosion, identify areas at risk of desertification, and formulate control strategies for these areas.

The research mostly aims to investigate the correlation analysis of the Indian Ocean Dipole (IOD) index   and drought and wet years in Iran on a monthly basis. To this aim, a correlation analysis was performed between the Standardized Precipitation Index (SPI) of 63 synoptic stations in Iran and the Indian Ocean Dipole (IOD) index values using the Pearson product-moment correlation coefficient and Spearman's rank correlation coefficient. The findings suggested that in autumn, a moderate positive correlation was noted between the Indian Ocean Dipole (IOD) Index and    drought and wet years in Iran in a one-month lag. In other words, droughts of the autumn season in Iran occurred in the negative phase while wet years in the positive phase of this index. In the winter, however, no significant correlation was noted between the drought and wet years in Iran and the Indian Ocean Dipole (IOD) index. It was also noted in springs that there was a negative correlation between drought and wet years in Iran, especially in its southern parts and the Indian Ocean Dipole (IOD) index. In other words, the droughts in this season in Iran occurred in the positive phase while the wet years in the negative phase, i.e., exactly the opposite of the relationship seen in the autumn.

Drought is a natural and global phenomenon typically defined as a period of water scarcity relative to normal levels and is considered one of the most significant meteorological hazards. In many regions worldwide, both the frequency and intensity of droughts have dramatically increased. Drought refers to the reduction in water availability over a specific period and area. This study analyzes drought fluctuations during the period 1971 to 2019 and forecasts its status for 2019 to 2044 across various cities in Iran.The SPI was calculated at different time scales (1, 3, 6, 12 months). The SPI is an index based on the probability of precipitation deficits over a given period. SPI values are calculated using long-term precipitation records (30 years or more) for a specific region. Positive SPI values indicate above-average precipitation, while negative SPI values indicate below-average precipitation.The results reveal severe fluctuations in SPI in cities like Aliabad and Gorgan, which have experienced alternating periods of drought and wet conditions. In contrast, regions such as Hashemabad and Incheh-Borun showed predominantly positive SPI values, indicating consistently wet conditions and regular rainfall. However, cities like Kalaleh and Maraveh Tappeh faced severe droughts. Forecasts for 2019 to 2044 suggest increased severe fluctuations and recurrent droughts in cities like Bandar-e-Turkmen and Gonbad-e-Kavus, while Gorgan and Hashemabad are expected to maintain relative stability.These findings underscore the urgent need for effective water resource management and climate planning to address potential droughts and climate change impacts. Overall, this study highlights the necessity of adopting preventive measures and establishing early warning systems to optimize water resource management and tackle future challenges associated with climate variability.

Drought is known as one of the environmental phenomena and is actually an integral part of climate change that can occur in any region and have major effects on that region. Iran is one of the dry regions of the world, and in recent years, due to the decrease in rainfall and severe evaporation, it has faced the problem of drought and severe shortage of water resources. The limitation of water resources in Iran's climatic conditions is the main problem in the way of increasing the production of agricultural products. Therefore, the optimal use of water plays a fundamental role in this situation. Modern irrigation methods in terms of desirability in water distribution with high efficiency are a suitable solution for optimal use of water resources. Therefore, considering the importance of this article, which is compiled in a review form and using written and internet sources, it tries to explain the concept of drought, types of drought, the effects of drought, the benefits of modern irrigation, and finally, provide solutions in this regard.

Drought as a creeping natural disaster is one of the main hazards that affects agriculture, food security, and the general livelihood of the population worldwide. Temporal-spatial variations of drought in a watershed can have numerous effects on the engineering, management, and planning of water resources. Drought is a complex phenomenon with different effects. Drought is a chronic, potential natural disaster characterized by a prolonged, abnormal water shortage. However, determination of drought onset, duration, and recovery is often difficult due to the differences in hydro-meteorological variables, socioeconomic issues, and the complex nature of water demands in different areas over the world. Drought occurrences cause serious problems to different parts of society, such as agriculture, energy generation, recreation, and ecosystems Therefore, drought indices are used to determine the severity and extent of drought. Most of these indices are based on meteorological criteria and take into account variables such as such as soil moisture, temperature, and precipitation. Precipitation is one of the most important parameters used in the calculation of drought indices. Accordingly, drought occurs when rainfall falls below normal for a period of time. In 1993, McKay et al. proposed a new definition of drought called the Standardized Precipitation Index (SPI), which believed that it was dimensionless and applicable at any time and place. Because rainfall measuring stations are scattered and access to rainfall measurement is often do with a time delay, other methods for drought monitoring are essential. In this regard, satellite information and remote sensing data can be used. Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to on-site observation, especially the Earth. Remote sensing is used in numerous fields, including geography, land surveying, and most Earth science disciplines (for example, hydrology, ecology, meteorology, oceanography, glaciology, geology); it also has military, intelligence, commercial, economic, planning, and humanitarian applications. In current usage, the term "remote sensing" generally refers to the use of satellite or aircraft-based sensor technologies to detect and classify objects on Earth. It includes the surface and the atmosphere and oceans, based on propagated signals (e.g. electromagnetic radiation). With the provision of different satellite data and the widespread use of them, it is possible to study drought using this technology. The advantages of satellite images include increasing the sampling points, wider coverage area, higher resolution and lower cost. The purpose of this study is the spatial and temporal drought monitoring in East Azerbaijan province using ground stations and satellite data. Therefore, indices (VCI and SPI) were used during the years 1993-2016. Rainfall and vegetation conditions were two variables used. These two variables were evaluated in two periods of dry and wet time. The SPI and VCI indexes were calculated using ground stations and satellite data. The SPI index has statistical consistency and is capable of showing both short and long-term drought effects in variable timescales of precipitation anomalies. The use of different time scales allows the effects of a precipitation deficit on different water resource components (groundwater, reservoir storage, soil moisture, streamflow) to be investigated. Due to SPI's probabilistic nature, its comparison in various regions is possible. The Vegetation Condition Index (VCI) compares the current NDVI to the range of values observed in the same period in previous years. The VCI is expressed in percent and gives an idea of where the observed value is situated between the extreme values (minimum and maximum) in the previous years. These two variables were evaluated in both dry and wet years. Also, the trend of drought variations in the selected period and the efficiency of the mentioned indices were investigated.The results showed that during the statistical period, the study area was faced with different classes of drought, but most stations had slight to moderate drought conditions. Dry and wet years were obtained based on SPI and VCI indices and it was observed that 2007 is the driest year and 2009 is the wettest year. The results of regional zoning showed that drought is one of the climatic characteristics of the region and the southern parts of the province often had more critical conditions. It was observed that the frequency of mild drought in the northern regions of the province and the occurrence of severe drought in the southern regions of the province were more likely. Also, the trend of variations in the SPI index in terms of Shen line slope and Menkendal values was positive. The results showed that the VCI index was a very suitable method for estimating drought through remote sensing techniques. There was a good agreement between the results obtained from ground stations and satellite data. Therefore, in areas where meteorological stations are scattered or non-existent, satellite data can be used to estimate drought.

Drought is a complex meteorological phenomenon that depends on several environmental factors. This phenomenon is a common natural disaster that is recognized as one of the ydrological, agricultural, and economic concerns of humanity. In this study, ecological, hsatellite data and Google Earth Engine were used to investigate the drought phenomenon in I, West Azerbaijan province. In order to achieve this research goal, four indices, namely SPyear period from satellite images -23NDVI, VCI, and TCI, were selected and utilized for a images were used for the NDVI, VCI, and TCI 526In this study, . 2022 to 2000of the years ch results showed images were used to calculate the SPI index. The resear 8081indices, and that severe and moderate droughts were experienced in most parts of the province in the Additionally, various levels of drought . 2022and , 2021, 2017, 2015, 2008, 2000 years , 2006, 2002ince in the years existed in the central, northern, and southern parts of the prov 2009 , 2010 , 2011 , Moreover, normal conditions were observed in all areas of . 2019and and 2014to 2012and from , 2007, 2005, 2004, 2001the province in the years 2016. t the VCI and SPI indices were the Comparing the results of the indices, it can be stated thamost sensitive indices for drought identification in the West Azerbaijan province, as they were able to effectively identify different types of droughts. Furthermore, the NDVI index, for drought identification, can indicate a decrease in due to its relatively good sensitivityvegetation cover during drought years. Overall, the results of this study demonstrated that West Azerbaijan province is at risk of drought.

The low adoption of climate-smart agriculture (CSA) technologies by farmers in developing regions where agrarian livelihoods are threatened by climate-related disasters such as drought remains a concerning enigma. Adoption patterns are not commensurate with merits of CSA on food security and climate resilience and attention to Socio-psychological features in relation to behavioral and attitudinal patterns in CSA adop-tion remains scarce. Accordingly, this research aimed to study adoption of CSA using the extended technology acceptance model in Sistan plain. The study was conducted on the farmers in the Sistan plain in Sistan and Baluchistan province (N = 6000). The sample (361 farmers) was taken by the proportionally allocated stratified random technique. The results revealed that variables of perceived usefulness, perceived ease of use, farmers’ subjective norms, and attitude had significant effects on their intention to apply CSA practices. In addition, farmers’ subjective norms and attitude towards CSA had significant effects on perceived usefulness, perceived ease of use. This shows the critical role of social influences in shaping attitudes and behavior for CSA adoption and could be useful in educating farmers on climate change.

Syria has been involved in a full-scale war since the beginning of 2013. Researchers and experts in political, social and military sciences have examined the different angles of this war. The current research has investigated the relationship between drought and the start of war in Syria using the theory of relative deprivation. The droughts between 2003 and 2009, which were rare in the history of Syria, severely affected the farmers and herdsmen in the provinces of Hasakah, Deir Ezzor and Raqqa, and unemployed people migrated to other provinces, especially Damascus, Daraa and Homs. and this issue increased livelihood problems such as high housing prices, increase in food prices and unemployment in different regions of Syria and provided grounds for dissatisfaction and unrest. The method used in this article is descriptive and analytical, and reliable internal and external library sources and internet databases have been used. The findings of this research indicate that the occurrence of successive droughts in Syria and Turkey's water policy in building dams on the Tigris and Euphrates rivers and the failure to properly manage this crisis by the Syrian government as a factor in the dissatisfaction of the Syrian people. It has been influential.

The consecutive droughts experienced in Iran over recent years have highlighted the need to analyze atmospheric structures and their effects on precipitation patterns and drought conditions. This study investigated the location and spatial variations of key atmospheric circulation components, particularly synoptic systems, such as ridges and troughs, in relation to the extent of monthly droughts across Iran. Using ERA5 data, which included 500 hPa geopotential heights and precipitation data with a spatial resolution of 0.25°, the analysis covered the period from 1979 to 2021. Monthly drought extent percentages (September to May) were calculated using the Rainfall Anomaly Index (RAI) and categorized into 5 levels. The axes, as well as the southern and northern limits of ridges and troughs, were extracted and mapped from western Iran to the eastern Atlantic. The results indicated that during periods of widespread drought, the trough axis shifted from 30°E in September and May to 10°E in other months, while the ridge axis remained centered over central to western Iran throughout the year. Conversely, in months without drought, the trough axis was located between 30° and 40°E and the ridge axis spanned from 0° to 20°E. Notably, during widespread droughts, the southern limit of troughs was observed over North Africa, while the northern limit of ridges extended from Russia to Central Asia. The displacement of ridge axes between drought and non-drought months (approximately 50°) was significantly greater than the shifts observed in the trough axes. This displacement, particularly of the southern trough limit and the northern ridge limit, accounted for the decreased precipitation and increased drought conditions observed in December, January, and March. The eastward and westward shifts of ridges and troughs might indicate a change in Iran’s precipitation regime influenced by variations in regional atmospheric circulation within the broader context of planetary circulation.

Among the ten threatening factors that threaten humanity in the 21st century, the phenomenon of climate change ranks first. The main issue in the emergence of this phenomenon is its consequences for nature and human life. The purpose of this research is to identify the most important risks caused by climate change and prioritize them with multi-criteria decision making methods. In order to familiarize with climatic effects and test hypotheses, a questionnaire has been prepared for prioritizing climatic effects. In the meantime, useful information was obtained from group discussions to analyze and investigate the issue. The opinions of 25 experts and experts were used to design the questionnaire. The responses of the respondents were evaluated in the form of prioritizing climatic effects based on the fuzzy AHP method and ranking the climatic regions based on the Waspas method. The results show that the coefficient of t in all indicators is greater than zero and the average limit, thus a significant relationship is observed between all indicators and the risk of climate change. The highest coefficient belongs to environmental hazards with a coefficient of 35.9. Pearson's correlation results showed that the average of all indicators is greater than four and the relationship between all indicators is positive, which indicates the influence of each of these indicators on each other. The highest final weight of the six indicators in the AHP FUZZY method belongs to environmental hazards with a weight of 0.201, followed by water resources with a weight of 0.193, and economy with a weight of 0.170. The ranking of climatic regions using the Waspas method showed that in terms of climate change risk in six indicators, semi-arid, dry, Mediterranean, semi-humid, ultra-arid, wet and cold and mountainous regions are ranked 1-7 respectively. Among the ten threatening factors that threaten humanity in the 21st century, the phenomenon of climate change ranks first. The main issue in the emergence of this phenomenon is its consequences for nature and human life. The purpose of this research is to identify the most important risks caused by climate change and prioritize them with multi-criteria decision making methods. In order to familiarize with climatic effects and test hypotheses, a questionnaire has been prepared for prioritizing climatic effects. In the meantime, useful information was obtained from group discussions to analyze and investigate the issue. The opinions of 25 experts and experts were used to design the questionnaire. The responses of the respondents were evaluated in the form of prioritizing climatic effects based on the fuzzy AHP method and ranking the climatic regions based on the Waspas method. The results show that the coefficient of t in all indicators is greater than zero and the average limit, thus a significant relationship is observed between all indicators and the risk of climate change. The highest coefficient belongs to environmental hazards with a coefficient of 35.9. Pearson's correlation results showed that the average of all indicators is greater than four and the relationship between all indicators is positive, which indicates the influence of each of these indicators on each other. The highest final weight of the six indicators in the AHP FUZZY method belongs to environmental hazards with a weight of 0.201, followed by water resources with a weight of 0.193, and economy with a weight of 0.170. The ranking of climatic regions using the Waspas method showed that in terms of climate change risk in six indicators, semi-arid, dry, Mediterranean, semi-humid, ultra-arid, wet and cold and mountainous regions are ranked 1-7 respectively. Among the ten threatening factors that threaten humanity in the 21st century, the phenomenon of climate change ranks first. The main issue in the emergence of this phenomenon is its consequences for nature and human life. The purpose of this research is to identify the most important risks caused by climate change and prioritize them with multi-criteria decision making methods. In order to familiarize with climatic effects and test hypotheses, a questionnaire has been prepared for prioritizing climatic effects. In the meantime, useful information was obtained from group discussions to analyze and investigate the issue. The opinions of 25 experts and experts were used to design the questionnaire. The responses of the respondents were evaluated in the form of prioritizing climatic effects based on the fuzzy AHP method and ranking the climatic regions based on the Waspas method. The results show that the coefficient of t in all indicators is greater than zero and the average limit, thus a significant relationship is observed between all indicators and the risk of climate change. The highest coefficient belongs to environmental hazards with a coefficient of 35.9. Pearson's correlation results showed that the average of all indicators is greater than four and the relationship between all indicators is positive, which indicates the influence of each of these indicators on each other. The highest final weight of the six indicators in the AHP FUZZY method belongs to environmental hazards with a weight of 0.201, followed by water resources with a weight of 0.193, and economy with a weight of 0.170. The ranking of climatic regions using the Waspas method showed that in terms of climate change risk in six indicators, semi-arid, dry, Mediterranean, semi-humid, ultra-arid, wet and cold and mountainous regions are ranked 1-7 respectively.

Drought has significant economic and social consequences, particularly in arid and semi-arid regions. The Mashhad Plain has recently experienced moderate to severe droughts, resulting in substantial damage to the agriculture and water sectors. This study aims to project changes in the characteristics of extreme droughts (SPI6 <-1) using outputs from the MRI-ESM2-0 model under two SSP scenarios. Additionally, the study investigated drought events through bivariate frequency analyses of drought duration and severity, based on SPI6 and the copula concept. Precipitation downscaling was performed using two methods linear scaling (LS) and distribution mapping (DM). The LS method demonstrated superior downscaling capability based on statistical criteria. Projections for the near future (2026-2050) indicated an increase in precipitation under the SSP1-2.6 and SSP5-8.5 scenarios, with a statistically significant increase under SSP5-8.5. A decrease in drought frequency was observed under the SSP5-8.5 scenario based on SPI6-DM. Assessing future changes in characteristics of drought derived from the SPI6-LS series suggested an increase in drought frequency under the SSP5-8.5 scenario. Univariate return period analysis using the LS method indicated that, under the SSP1-2.6 scenario, drought events would remain unchanged compared to the baseline period. Conversely, under the SSP1-2.6 scenario (DM method), increased values of duration and severity were projected. Joint frequency analysis results suggested that under the SSP1-2.6 scenario, seasonal joint return periods of severity and duration would be shorter than the baseline, indicating an increased risk of drought hazards in the region under study. The application of these research results will contribute to improved future planning in the water and agriculture sectors for this area.

In hydrological drought, water scarcity spreads through the hydrological cycle and can subsequently reduce groundwater levels, surface water and lake levels, and this means that hydrological drought dominates those areas, leading to long-term effects. In addition, due to climate changes and rainfall and temperature anomalies, droughts have increased in frequency and severity in many regions of the world. The predicted changes for the coming years show that climate variables will not have uniform changes in all regions and regional changes in the amount of precipitation may lead to the creation of hydrological patterns much different from the current conditions.The present study was also carried out with the aim of spatial analysis of drought effects on water level changes in the catchment area of Bakhtegan, Tashk and Maharlo lakes. In this research, an attempt has been made to identify temporal and spatial patterns of changes in the level of this lakes by using satellite images and spatial analysis models.

In the present study, Landsat 5(TM), 7(ETM+) and Landsat 8(OLI) satellite images with a resolution of 30 meters have been used in the period of 2000-2021 to investigate water level changes. Due to the fact that the water level of the studied lakes changes drastically with the rainfall of different months, therefore, it is difficult to determine the amount of water cover for a year without considering the fact that a part of this cover is seasonal and when the rainfall decreases, a part of the lake Dry may not provide accurate results. Based on this, in the present study, one image was used for each month for each year studied to evaluate the changes in the water level of the lakes in all months of the year.

The investigation of the changes in the water level of Maharlo Lake shows that in the drought of 2108 and 2017, the permanent water level of the lake has decreased to 1.8 square kilometers. Meanwhile, in the severe and very severe drought of 2005 and 2004, the permanent water level reached 170.4 square kilometers. Examining the changes in the area of Tashek Lake in 15 years of drought shows that the area of the waterless part of this lake has increased more than the seasonal and permanent water. The highest amount in this field was in 2021 with a very severe drought, which shows that this lake has more critical conditions in terms of permanent dryness than Maharlo Lake. This lake has been in a terrible state for 5 years. Comparing the changes in the area of Bakhtegan lake in different years shows that this lake has a more critical situation than its neighboring lakes (Maharlo and Tashk), so that in a significant number of years (12 years) the lake lacked permanent water and only With monthly or seasonal rains, some water has been temporarily collected on its surface, but it has a short shelf life between 2 to 6 months (November to May).

The results of the evaluation and analysis of the role of drought in the water level changes of the Bakhtegan, Tashk and Maharlo catchment lakes showed that the area of these lakes has decreased significantly during the studied period, so that over time the area of the water area has decreased. It has been permanently reduced and added to the dry and waterless area. The maximum decrease in the water level of all three investigated lakes occurred during a 6-year drought between 2008 and 2013, in such a way that the area of the part with permanent water was greatly reduced and the area of the dry part of the lakes was increased.

Extreme rainfall fluctuations are one of Iran's environmental challenges. The heavy rains of 2019 and the relative drought of 2018 and 2021 show the unevenness of rainfall.

This study utilized the daily rainfall data from 360 weather stations spanning the years 1990 to 2021, along with the synoptic indices of the winter seasons of 2019 and 2021. The geographical range of the data, spanning from latitude N 10-90 to longitude E º 10-90, was chosen to provide a comprehensive view of the Iranian climate.

The probability of drought is 42%, drought is 35.5%, and normal conditions are 22.5%. Markov chain indicated the highest probability of normal drought to drought at 57% and consecutive drought at 46.2%. ANOVA showed a significant difference between the climatic variables of wet and dry years. Observational conditions showed that in the wet year (2019) sample year, the Siberian high-pressure center operator had more pressure (1054 megabytes) in 2019 and 1032 mb in 2021. In the wet year, the frequency of cyclones and the temperature difference at the level of 500-1000 are higher, but the omega values are lower. These conditions are for the drought (2021), the amount of pressure in Siberia, the temperature difference between 500 and 1000 is less, and Omega is more (stable air).

The amount of rainfall in Iran fluctuates from year to year, and low rainfall years occur more often than high rainfall years.

Innovation: 

Planners should increase the risk of water supply and development and plan based on the minimum amount of precipitation. The physical capacity of the country's ecology should be reviewed, and population concentration in limited areas should be avoided to reduce the vulnerability of the country's geographical environment.

The aim of this research is to evaluate the viability and livelihood resilience of villagers against natural hazards with an emphasis on drought in the rural areas of Poldakhter city.This research is an applied research in terms of its purpose,which was carried out in a descriptive-analytical way.,which according to the general census of population and housing in 2015 was equal to 7358 households.In order to determine the number of samples, Cochran's formula was used,according to which 365 households were selected as samples.In order to analyze the research findings,sample t-test and multivariate regression analysis were used.In order to check the status of livability indicators against drought in the villages of Poldakhter city,a sample T-Tech test has been used.The results showed that economic index with an average of 2.779 and physical index with an average of 2.937 are in unfavorable condition,environmental index with an average of 3.103 and social index with an average of 3.103 are in favorable condition.In order to check the status of resilience indicators against drought in the villages of Poldakhter city,a sample t-tech test has been used.The results showed that job security index with an average of 2.885, economic dynamism and diversity index with an average of 2.913,economic welfare index with an average of 2.901 and insurance index with an average of 2.894 are in an unfavorable situation.Multivariate regression analysis has been used in order to investigate the effects of the livability of rural settlements on the livelihood resilience of villagers against drought.The obtained results showed that the social dimension with a beta coefficient of 0.365,the economic dimension with a beta coefficient of 0.312, the physical dimension with a beta coefficient of 0.276 and the environmental dimension with a beta coefficient of 0.210 on the The livelihoods of villagers against drought have the greatest impact respectively.

Frequent droughts are a major challenge for smallholder farmers, affecting the resilience of these households. Drought has always had a great and sometimes catastrophic impact on the activities of people and human life around the world. This phenomenon is not always considered to be a difficult disaster; it has a great impact on human life. Drought encompasses a complex and intertwined set of negative impacts on the quality of life of rural communities. While impacting various aspects of the economic and social activities of farmers and related industries, it also impacts other people in the village whose job is not agriculture, and it also influences their lives. Increasing inflation in society, reducing employment opportunities, reducing the ability to pay back agricultural loans, increasing the price of raw materials for people, drying up the water resources, competing for water, the costs of migration, and social and family breakdown are other notable consequences of drought, so in developing countries, it has a great impact on the different aspects of the livelihoods of rural households because, in these countries, agriculture is the economic activity of many rural areas, and most rural households directly benefit from the agricultural sector; if there are no risk reduction systems, their lives will be greatly reduced.Frequent and irregular droughts in South Khorasan province and especially Darmian city, which has been in existence since 1998, have had a serious impact on agricultural production and livelihoods of farmers. The development of resilience and agricultural livelihoods against droughts and water resource depletion is necessary due to the increasing number of droughts and the depletion of water resources. Droughts, in addition to reducing agricultural production, have led to a decline in farmers' incomes, the destruction of some of the city's economic foundations, and an increase in unemployment in the region.Livelihood resilience (with a focus on agriculture) refers to the ability of agricultural systems to cope with environmental changes and the impacts of the most severe climatic conditions, which is a crucial strategy for confronting and transitioning from the aforementioned circumstances. The present study was conducted to better understand the livelihood resilience of farmer households against shocks caused by drought in Darmian County. Therefore, the aim of this study is to evaluate the determinant indicators of the level of livelihood resilience of small-scale farmers in the face of recurrent droughts. The obtained information helps in identifying the target, applying appropriate adaptation strategies, adopting mitigation measures, facilitating relief interventions, and building future resilience.

This applied, and descriptive research was conducted in three stages. The first step was to determine the indicators and variables of agricultural resilience, which was done through documentary review and studying previous research. In the second step, using the indicators and variables obtained from the previous stage, a researcher-made questionnaire was first prepared and developed. After examining its validity and reliability, it was completed by rural elites through a survey method. Finally, the data was analyzed using statistical methods (t-test and binomial test) and the SPSS software. In the third step, the rural settlements under study were ranked in terms of the livelihood resilience status of farmers facing drought using the ORESTE method.The validity of the research instrument was examined through consultation with experts and specialists in rural planning, rural development, and agricultural extension and education. Its reliability was also evaluated using the Cronbach's alpha method,andsince the alpha score for the different sections of the questionnaire was more than 70% and the overall average of the questionnaire was 89%, the result confirmed the reliability of the research instrument.Agricultural resilience was considered as the target population of the study for small-scale farmers in Darmian County. Due to the lack of accessible statistics on small-scale farmers in rural settlements in the country's documents and databases, theresearcher proceeded to complete the questionnaire by referring to local elites and informants, including members of the Islamic Council and village headmen present in the villages.The statistical population at the settlement level consisted of villages with more than 20 households in Darmian County, which, according to the 2016 census, numbered 96 villages. With the guidance of experts from the County Agricultural Jihad Department, 15 prominent agricultural villages with the highest number of small-scale farmers (including the villages of Zargaz, Fazlabad, Gask, Mansurabad, Shirak, Menandebala, Kushkak, Khavan, Takhtejan, Nasraldein, Avaz, Darmian, Forog, Hendevalan, and Burrang) were selected as the sample, and 100 available respondents and key informants in these villages completed the designed questionnaire, the results of which are presented in the findings section.

The highest mean was for the absorptive capacity (52.42), and the lowest was for the transformative capacity (17.82). Determinants of Absorptive Capacity: All factors except “delayed onset or early cessation of rainfall,” “weeds,” and “soil erosion” were significant in the study villages. Friedman's test ranked “occurrence of strong winds” as the top factor and “land rent” as the least important factor in determining the absorptive capacity of farmers' livelihood resilience.Determinants of Adaptive Capacity: All components except the household head's gender, number of cultivated crops, number of livelihood activities, number of months without food shortage, farm size, remittance as an income source, and savings accounts were significant in the study villages. Friedman's test showed that “access to credit” was the top-ranked factor, while “farming experience” and “off-farm income” were the least important factors in determining the adaptive capacity of farmers' livelihood resilience.Determinants of Transformative Capacity: All factors except “access to clinics” and “pesticide use” had a significant effect on the livelihood resilience of farmers in Darmian County. Friedman's test ranked “receiving training and support” as the top factor and “recommendation and follow-up” as the least important factor in determining the transformative capacity of agricultural livelihood resilience.

The findings revealed that all the absorptive, adaptive, and transformative capacities were significant determinants of the agricultural livelihood resilience in the villages of Darmian County. This suggests that livelihood resilience is associated with absorptive, adaptive, and transformative capacities. The ranking of the studied settlements further revealed that: The village of Burrang had the highest level of livelihood resilience compared to the other villages in the study. The profound gap in the livelihood resilience of farmers among the villages underscores the need for concerted efforts to improve this indicator based on forward-looking planning.