University of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Codification of indicators of the resilience of Iranian news agencies in the stage of reconstruction and rehabilitation of natural crises managementCodification of indicators of the resilience of Iranian news agencies in the stage of reconstruction and rehabilitation of natural crises management241714310.22111/jneh.2022.41642.1877FAShahabTaghikhaniPhD student of Media Management, Alborz Campus, University of Tehran, IranMajidMokhtarianpourAssistant Professor of Public Administration, University of Tehran, IranAkbarNasrollahiAssistant Professor of Media Management and Public Relations, Islamic Azad University, IranJournal Article20220216Mass media such as news agencies, due to their ability to direct public opinion, play a key role in various stages of the crisis, including the reconstruction and recovery phase, so that by defining and implementing their positive and intrinsic roles, they can increase the resilience capacity of society. However, the prerequisite for this assistance is that they can maintain their original status after the emergency and continue to provide services; In other words, be resilient. To make media resilient, the first step can be to measure how well they perform, and in fact, how resilient that media is in the face of crises. This issue is based on providing indicators that show the performance of the media in the face of crises. Therefore, the purpose of this study is to develop the performance indicators of the resilience of Iranian news agencies in natural crises in the reconstruction and recovery phase. In this qualitative research, the data were collected using a systematic review of resources and also a semi-structured interview with 12 subject matter experts and analyzed using thematic analysis. The analysis of research data led to the introduction of 3 comprehensive themes (as dimensions) including "learning development", "news continuity", and "monitoring and follow-up", under which 5 components are "monitoring the actions of officials", "take care of the environment and public opinion ", "Experience Writing", "Futuristic Education" and "Situational Reporting". Finally, 12 indicators were identified and presented as performance indicators of the resilience of Iranian news agencies in the stage of reconstruction and recovery of natural crises.Mass media such as news agencies, due to their ability to direct public opinion, play a key role in various stages of the crisis, including the reconstruction and recovery phase, so that by defining and implementing their positive and intrinsic roles, they can increase the resilience capacity of society. However, the prerequisite for this assistance is that they can maintain their original status after the emergency and continue to provide services; In other words, be resilient. To make media resilient, the first step can be to measure how well they perform, and in fact, how resilient that media is in the face of crises. This issue is based on providing indicators that show the performance of the media in the face of crises. Therefore, the purpose of this study is to develop the performance indicators of the resilience of Iranian news agencies in natural crises in the reconstruction and recovery phase. In this qualitative research, the data were collected using a systematic review of resources and also a semi-structured interview with 12 subject matter experts and analyzed using thematic analysis. The analysis of research data led to the introduction of 3 comprehensive themes (as dimensions) including "learning development", "news continuity", and "monitoring and follow-up", under which 5 components are "monitoring the actions of officials", "take care of the environment and public opinion ", "Experience Writing", "Futuristic Education" and "Situational Reporting". Finally, 12 indicators were identified and presented as performance indicators of the resilience of Iranian news agencies in the stage of reconstruction and recovery of natural crises.https://jneh.usb.ac.ir/article_7143_948a67c4cbdba837e4ba29d6b6fb11eb.pdfUniversity of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Analyzing the Role of Rural Management in Increasing Resiliency of Rural Areas against Drought from the Perspective of Rural People (Case Study: Central Part of the City of Ardabil)Analyzing the Role of Rural Management in Increasing Resiliency of Rural Areas against Drought from the Perspective of Rural People (Case Study: Central Part of the City of Ardabil)2540702210.22111/jneh.2022.41670.1878FAKiuomarsKhodapanahAssistant Professor, Department of Geography, Payame Noor University, Tehran, Iran.Journal Article20220219Effective rural management requires utilizing novel managerial and institutional approaches to help adopt strategies and solutions that will make rural families resilient against various perils, such as drought. Thus, the present research aims to investigate the role of rural management in rural peoples’ resiliency against drought. This research falls under applied research and is descriptive-analytical. The statistical population of this research consists of 32 villages in the central part of the city of Ardabil with 8038 households. The sample size was estimated to be 384 people using the Cochran formula, which was distributed in proportion to the number of the heads of the households in each village. To investigate the rural management, four indicators in the form of 40 components, and to investigate resiliency against drought, four indicators in the form of 40 components were used based on previous literature. The exerts examined the face validity of the questionnaire, while its total reliability was 0.784 based on Cronbach’s alpha. Findings revealed that from among rural management indicators, environment management explained 0.703 of the resiliency variances against drought. Also, based on villagers’ perspective, the average resiliency indicators of preparations, reaction, and prevention were greater than the moderate rate, as the average resiliency indicators of recovery and reconstruction were lower than the moderate level (2.80). On the other hand, the MAIRCA technique indicated that the village of Amoughin held the highest rate of resiliency against drought, while Arvanagh held the lowest rate. The study also found that a set of systematic factors could explain the roles and developments of the rural management in villagers’ resiliency, as rural management can use an all-out vision to increase the resiliency of villagers against types of natural disasters and offer necessary warnings to them so that rural sustainability is provided.Effective rural management requires utilizing novel managerial and institutional approaches to help adopt strategies and solutions that will make rural families resilient against various perils, such as drought. Thus, the present research aims to investigate the role of rural management in rural peoples’ resiliency against drought. This research falls under applied research and is descriptive-analytical. The statistical population of this research consists of 32 villages in the central part of the city of Ardabil with 8038 households. The sample size was estimated to be 384 people using the Cochran formula, which was distributed in proportion to the number of the heads of the households in each village. To investigate the rural management, four indicators in the form of 40 components, and to investigate resiliency against drought, four indicators in the form of 40 components were used based on previous literature. The exerts examined the face validity of the questionnaire, while its total reliability was 0.784 based on Cronbach’s alpha. Findings revealed that from among rural management indicators, environment management explained 0.703 of the resiliency variances against drought. Also, based on villagers’ perspective, the average resiliency indicators of preparations, reaction, and prevention were greater than the moderate rate, as the average resiliency indicators of recovery and reconstruction were lower than the moderate level (2.80). On the other hand, the MAIRCA technique indicated that the village of Amoughin held the highest rate of resiliency against drought, while Arvanagh held the lowest rate. The study also found that a set of systematic factors could explain the roles and developments of the rural management in villagers’ resiliency, as rural management can use an all-out vision to increase the resiliency of villagers against types of natural disasters and offer necessary warnings to them so that rural sustainability is provided.https://jneh.usb.ac.ir/article_7022_855b4d35554086b858b074d4445fa12c.pdfUniversity of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Spatiotemporal changes of forest fire in vegetation areas of Iran based on MODIS sensorSpatiotemporal changes of forest fire in vegetation areas of Iran based on MODIS sensor4160707910.22111/jneh.2022.41725.1881FAKobraShojaeizadehPhD student of Climatology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, IranMahmoudAhmadiAssociate Professor of Climatology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran0000-0001-8546-0361AbbasaliDadashi-RoudbariPostdoctoral Research Associate of Climatology, Ferdowsi University of Mashhad, Mashhad, IranJournal Article20220224The increase in fire activity in many regions of Iran in recent decades has raised concerns about the short-term and long-term consequences. Forest and pasture fires will affect the quantity, quality, and health of natural ecosystems. The first step in controlling and preventing forest fires is monitoring. Therefore, this study was conducted to estimate fire areas and identify the spatial-temporal changes of these events in the vegetation areas of Iran. To achieve this goal, TERRA satellite MODIS sensor data including active fire products (MOD14A1) and burned areas (MCD64A1) for 20 years (2001-2020) have been used. The results showed that the maximum extent of fires in the vegetation areas of Iran is related to July, which covers about 4100 hectares. This month, a large part of the country's forests, especially in the northwestern parts of the Arasbaran vegetation area, has caught fire. In contrast, the minimum amount of fire areas in the vegetation areas of Iran is related to April, which was observed as two limited zones in the northwest and west of the country. Due to the maximum time of forest fires in the hot and dry months of the year, including June, July, August, and September in the western part of the country in the Zagros. The linear correlation between the burned areas and the areas with active fires in Iran showed that there is a significant relationship between these two satellite products. This connection shows that the burned areas in the vegetation areas of Iran are among the active centers of forest fires.The increase in fire activity in many regions of Iran in recent decades has raised concerns about the short-term and long-term consequences. Forest and pasture fires will affect the quantity, quality, and health of natural ecosystems. The first step in controlling and preventing forest fires is monitoring. Therefore, this study was conducted to estimate fire areas and identify the spatial-temporal changes of these events in the vegetation areas of Iran. To achieve this goal, TERRA satellite MODIS sensor data including active fire products (MOD14A1) and burned areas (MCD64A1) for 20 years (2001-2020) have been used. The results showed that the maximum extent of fires in the vegetation areas of Iran is related to July, which covers about 4100 hectares. This month, a large part of the country's forests, especially in the northwestern parts of the Arasbaran vegetation area, has caught fire. In contrast, the minimum amount of fire areas in the vegetation areas of Iran is related to April, which was observed as two limited zones in the northwest and west of the country. Due to the maximum time of forest fires in the hot and dry months of the year, including June, July, August, and September in the western part of the country in the Zagros. The linear correlation between the burned areas and the areas with active fires in Iran showed that there is a significant relationship between these two satellite products. This connection shows that the burned areas in the vegetation areas of Iran are among the active centers of forest fires.https://jneh.usb.ac.ir/article_7079_f1b6d1367ad8478c20ab02fe74d47b0e.pdfUniversity of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Investigation of the effects of dust storms caused by wind speed on the migration of rural population in the Sistan regionInvestigation of the effects of dust storms caused by wind speed on the migration of rural population in the Sistan region6178723510.22111/jneh.2022.41858.1885FAAhmadHosseiniAssistant Professor of Geography, Payame Noor University of IranAliJafarizadehGraduated from Geography and Rural Planning, Payame Noor University, IranJournal Article20220312Migration is a form of geographical or spatial mobility of a population that takes place between two geographical units. Research shows that environmental hazards such as wind speed, drought, and floods affect regional migration. The average annual wind speed in the Sistan region shows that from 1989 to the end of 2018, the wind speed increased by approximately 4.7 meters per second. The results of the data prediction showed that wind speed has a significant effect on rural population migration in the Sistan region. According to the census of 1335, the rural population increased from 92% to 56% in 1395, The calculation of the coefficient of determination shows that 85% of the decrease in rural population was related to wind speed and its results، Predicted values show that from 1398 the rural population will reach 55.39%, in 1399 to 54.88% and in 1400 and 1401 to 54.32% and 53.22%, respectively. Also, during the predicted years, i.e. from 1398 to 1401, 96% of the cause of rural migration was related to wind speed and its destructive effects, and 4% of it was related to other migration factors, the output shows that the coefficient of variable t statistic is equal to 2.507 in the positive model. This indicates that with increasing wind speed, rural migration also increases, which indicates the criticality of the region. Therefore, in the coming years, we have to wait for the evacuation of a larger percentage of the rural population in the Sistan region, and to solve this problem, control measures must be taken regarding the consequences of wind speeds and population stabilization.Migration is a form of geographical or spatial mobility of a population that takes place between two geographical units. Research shows that environmental hazards such as wind speed, drought, and floods affect regional migration. The average annual wind speed in the Sistan region shows that from 1989 to the end of 2018, the wind speed increased by approximately 4.7 meters per second. The results of the data prediction showed that wind speed has a significant effect on rural population migration in the Sistan region. According to the census of 1335, the rural population increased from 92% to 56% in 1395, The calculation of the coefficient of determination shows that 85% of the decrease in rural population was related to wind speed and its results، Predicted values show that from 1398 the rural population will reach 55.39%, in 1399 to 54.88% and in 1400 and 1401 to 54.32% and 53.22%, respectively. Also, during the predicted years, i.e. from 1398 to 1401, 96% of the cause of rural migration was related to wind speed and its destructive effects, and 4% of it was related to other migration factors, the output shows that the coefficient of variable t statistic is equal to 2.507 in the positive model. This indicates that with increasing wind speed, rural migration also increases, which indicates the criticality of the region. Therefore, in the coming years, we have to wait for the evacuation of a larger percentage of the rural population in the Sistan region, and to solve this problem, control measures must be taken regarding the consequences of wind speeds and population stabilization.https://jneh.usb.ac.ir/article_7235_9ea831827c60080f35c97f1efc836960.pdfUniversity of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Investigation of Vulnerability and Spatial Analysis of Drought Risk in the Agricultural Sector in IranInvestigation of Vulnerability and Spatial Analysis of Drought Risk in the Agricultural Sector in Iran7998707810.22111/jneh.2022.41968.1892FAHossainMohammadiProfessor of Climatology, Faculty of Geographical Sciences, Tehran University, IranNaserIizadiPhD Student of Climatology, Faculty of Geographical Sciences, Tehran University, IranElaheGhasemi GarkaniPhD Student of Climatology, Faculty of Geographical Sciences, Tehran University, IranJournal Article20220401The nature of the drought is multidimensional and dynamic, and drought risk management plays a vital role in studying drought risk and vulnerability. Iran is always facing this meteorological phenomenon by being in the middle latitudes. Drought risk is defined as the risk index and vulnerability index function. In this study, vulnerability index with physical components including altitude, water system, land use and socio-economic components, the ratio of net production to total production, population density in agriculture, population density, the ratio of rainfed land to total land and number of livestock (1000 heads Per square meter) using standardized fuzzy membership functions and criteria, and each is given a specific weight according to the AHP method. All the maps are combined, and the map of land vulnerability to drought is obtained. According to the results, the southern, southeastern, and central regions are relatively less vulnerable to drought. As we move west, north, and northeast of the country, the number of vulnerabilities increases, the causes of which can be significantly affected by the characteristics. He knew the climate and physics of these areas. Finally, the drought risk map was drawn with the SPI index for 12 months, and after weighing and converting it into a fuzzy map, it was combined with the vulnerability index map. The drought risk map indicates the prevalence of relatively high drought risk in a large area of Iran. With the help of these maps, it is possible to develop micro or macro development plans, especially in the agricultural sector for each part of the country.The nature of the drought is multidimensional and dynamic, and drought risk management plays a vital role in studying drought risk and vulnerability. Iran is always facing this meteorological phenomenon by being in the middle latitudes. Drought risk is defined as the risk index and vulnerability index function. In this study, vulnerability index with physical components including altitude, water system, land use and socio-economic components, the ratio of net production to total production, population density in agriculture, population density, the ratio of rainfed land to total land and number of livestock (1000 heads Per square meter) using standardized fuzzy membership functions and criteria, and each is given a specific weight according to the AHP method. All the maps are combined, and the map of land vulnerability to drought is obtained. According to the results, the southern, southeastern, and central regions are relatively less vulnerable to drought. As we move west, north, and northeast of the country, the number of vulnerabilities increases, the causes of which can be significantly affected by the characteristics. He knew the climate and physics of these areas. Finally, the drought risk map was drawn with the SPI index for 12 months, and after weighing and converting it into a fuzzy map, it was combined with the vulnerability index map. The drought risk map indicates the prevalence of relatively high drought risk in a large area of Iran. With the help of these maps, it is possible to develop micro or macro development plans, especially in the agricultural sector for each part of the country.https://jneh.usb.ac.ir/article_7078_267cba28daddb21f83ea6bcccc71bba0.pdfUniversity of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Modeling of groundwater resources in Sirjan Basin using the dynamics systems methodModeling of groundwater resources in Sirjan Basin using the dynamics systems method99114720010.22111/jneh.2022.42067.1893FAMohsenPourkhosravaniAssociate Professor Department of Geography Shahid Bahonar University of Kerman, Kerman, IranFatemehJamshidi GohariMA student of natural hazard, Department of Geography Shahid Bahonar University of Kerman, Kerman, IranNasrinSayariAssistant Pprofessor Department of Water engineering. Faculty of Agriculture. Shahid Bahonar University of Kerman, Kerman, IranSaeedehAbedzadehMaster scientist of Water Resources Engineering, graduated from Department of Irrigation and Drainage Engineering, Aburaihan Campus, University of Tehran, Tehran, IranJournal Article20220410Due to the scarcity of surface water resources, groundwater plays an important role in human life, especially in arid and semi-arid regions. Since more than 60% of Iran is arid and semi-arid regions, the water supply in these areas, and especially the study area, depends on groundwater resources, so over-extraction of these valuable resources causes many crises. Therefore, modeling of these sources was considered by many researchers as well as the present study. This study tries to evaluate the stability of the aquifer in the future. Also, investigate the factors affecting the instability of groundwater resources in the study area. For this purpose, the study area was modeled using the dynamics method of systems, resources, and water consumption. Then, the results of model validation were presented using limit condition tests and sensitivity analysis. After determining the degree of reliability of the model, the scenarios were explained and the model was implemented to predict the groundwater level in the coming years. In the end, the sustainability index was calculated in each scenario, to examine the status of water sustainability in the coming years. The results of limit condition tests and sensitivity analysis showed that the model was in good agreement with reality. Also, after applying the scenarios, the results showed that the aquifer will become more unstable as the current situation continues. Agricultural consumption is one of the variables affecting the resource and consumption model, so by reducing this variable, the amount of sustainability will improve.Due to the scarcity of surface water resources, groundwater plays an important role in human life, especially in arid and semi-arid regions. Since more than 60% of Iran is arid and semi-arid regions, the water supply in these areas, and especially the study area, depends on groundwater resources, so over-extraction of these valuable resources causes many crises. Therefore, modeling of these sources was considered by many researchers as well as the present study. This study tries to evaluate the stability of the aquifer in the future. Also, investigate the factors affecting the instability of groundwater resources in the study area. For this purpose, the study area was modeled using the dynamics method of systems, resources, and water consumption. Then, the results of model validation were presented using limit condition tests and sensitivity analysis. After determining the degree of reliability of the model, the scenarios were explained and the model was implemented to predict the groundwater level in the coming years. In the end, the sustainability index was calculated in each scenario, to examine the status of water sustainability in the coming years. The results of limit condition tests and sensitivity analysis showed that the model was in good agreement with reality. Also, after applying the scenarios, the results showed that the aquifer will become more unstable as the current situation continues. Agricultural consumption is one of the variables affecting the resource and consumption model, so by reducing this variable, the amount of sustainability will improve.https://jneh.usb.ac.ir/article_7200_35cf87c2823f777d0e4a8fe94ecd9a1b.pdfUniversity of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Investigating the effect of the "sedimentation chamber" on reducing the dust pollution in house interior (Case Studies: A House in Dezful)Investigating the effect of the "sedimentation chamber" on reducing the dust pollution in house interior (Case Studies: A House in Dezful)115128724110.22111/jneh.2022.42323.1901FAMohsenBinaAssistant Professor, Architectural Department, Jundi-Shapur University of Technology, Dezful, IranNargesZadehoseinM.A., Architectural Department, Jundi-Shapur University of Technology, Dezful, IranJournal Article20220507One of the most important natural hazards in the southwest is dust pollution. Dust pollution increase in recent years and became a serious problem in the region. This pollution situation in southwestern Iran is also noticeable. The continued presence of dust pollution can impose irreparable damage on the health of the community and the environment over the next few years. Therefore, it is necessary to use measures to deal with the problem. Due to the difficulty of reducing air pollution in the city and outdoors, paying attention to the indoor area will have a major contribution to health. In these circumstances, the main goal of the research is to find a solution that can remove dust from an indoor area (without applying harmful chemicals). In this research, while studying the conventional methods of dust purification, the "sedimentation chamber" method has been selected. In this research, an experimental sample of a sedimentation chamber in the house was built and tested, and from these experiments, daily data on the amount of dust collected in different spaces (Including Inside the sedimentation chamber, the research room, the adjacent room, the yard space, the amount of wind speed entering the chamber) were collected and measured. Analyzing the data collected, the results were inspected. Eventually, the effect of the sedimentation chamber has been proven in the purification of dust inside the house (in comparison with not using it). Also, the correlation between room air purification with western wind velocity (positive pressure) in 73% of cases there was a direct correlation. As a result, the use of the chamber is suggested as a way to deal with the Dust pollution in the interior of the house.One of the most important natural hazards in the southwest is dust pollution. Dust pollution increase in recent years and became a serious problem in the region. This pollution situation in southwestern Iran is also noticeable. The continued presence of dust pollution can impose irreparable damage on the health of the community and the environment over the next few years. Therefore, it is necessary to use measures to deal with the problem. Due to the difficulty of reducing air pollution in the city and outdoors, paying attention to the indoor area will have a major contribution to health. In these circumstances, the main goal of the research is to find a solution that can remove dust from an indoor area (without applying harmful chemicals). In this research, while studying the conventional methods of dust purification, the "sedimentation chamber" method has been selected. In this research, an experimental sample of a sedimentation chamber in the house was built and tested, and from these experiments, daily data on the amount of dust collected in different spaces (Including Inside the sedimentation chamber, the research room, the adjacent room, the yard space, the amount of wind speed entering the chamber) were collected and measured. Analyzing the data collected, the results were inspected. Eventually, the effect of the sedimentation chamber has been proven in the purification of dust inside the house (in comparison with not using it). Also, the correlation between room air purification with western wind velocity (positive pressure) in 73% of cases there was a direct correlation. As a result, the use of the chamber is suggested as a way to deal with the Dust pollution in the interior of the house.https://jneh.usb.ac.ir/article_7241_bdb59b16ccb38381aadd8866e0024456.pdfUniversity of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Variability and trend of changes in the severity-area of drought and wet in IranVariability and trend of changes in the severity-area of drought and wet in Iran129150722810.22111/jneh.2022.42519.1905FAMostafaKarimiAssistant Professor, Department of Physical Geography, Faculty of Geography, Tehran University, Tehran, IranSousanHeidariPh.D. Students of climatology, Department of Physical Geography, Faculty of Geography, Tehran University, Tehran, Iran0000-0002-9749-9025Journal Article20220529This study aims to investigate the variability and trend of changes in area severity of wet and drought on annual, seasonal, and monthly scales in Iran. For this purpose, the ZSI index, Mann-Kendall trend test, and the monthly precipitation data (ERA5) of the European Centre for Medium-Range Weather Forecasts (ECMWF) for the period 1979-2021 were used. The results showed that, in annual wet-drought intensities, there are three distinct periods; 1980s with almost equal wet-drought area 1990s wet dominate, and the first two decades of the 21st century, which began in 2000-1999 rainy year with more than 97% of the country (70% very severe drought area) under drought conditions where the most areas of drought observed. The pattern of variability of wet-drought intensity area in winter and spring is almost similar to the annual whereas it is different in autumn from the annual pattern. However wet area increases. at the end of the period. In this season in November, the area of drought intensities, especially (moderate and severe) has been decreasing and in contrast, the area of wet intensities has been increasing. But, the trend of wet-drought intensity was reversed in winter and spring, especially in January and to some extent in March. The intensity of the index also has a trend when the increase in the intensity of drought classes (increasing the intensity of the negative index) is more pronounced. Overall, in all three scales, the incidence of consecutive weak and moderate droughts and very severe and severe wet with the low sequence was higher. Increasing the intensity and area of wet in autumn may indicate a change in the precipitation regime. In contrast, the increase in droughts, especially high-intensity droughts in the two main rainy seasons of Iran is a warning for serious water resources management in the warm period.This study aims to investigate the variability and trend of changes in area severity of wet and drought on annual, seasonal, and monthly scales in Iran. For this purpose, the ZSI index, Mann-Kendall trend test, and the monthly precipitation data (ERA5) of the European Centre for Medium-Range Weather Forecasts (ECMWF) for the period 1979-2021 were used. The results showed that, in annual wet-drought intensities, there are three distinct periods; 1980s with almost equal wet-drought area 1990s wet dominate, and the first two decades of the 21st century, which began in 2000-1999 rainy year with more than 97% of the country (70% very severe drought area) under drought conditions where the most areas of drought observed. The pattern of variability of wet-drought intensity area in winter and spring is almost similar to the annual whereas it is different in autumn from the annual pattern. However wet area increases. at the end of the period. In this season in November, the area of drought intensities, especially (moderate and severe) has been decreasing and in contrast, the area of wet intensities has been increasing. But, the trend of wet-drought intensity was reversed in winter and spring, especially in January and to some extent in March. The intensity of the index also has a trend when the increase in the intensity of drought classes (increasing the intensity of the negative index) is more pronounced. Overall, in all three scales, the incidence of consecutive weak and moderate droughts and very severe and severe wet with the low sequence was higher. Increasing the intensity and area of wet in autumn may indicate a change in the precipitation regime. In contrast, the increase in droughts, especially high-intensity droughts in the two main rainy seasons of Iran is a warning for serious water resources management in the warm period.https://jneh.usb.ac.ir/article_7228_51eee97b55108cd9b4f5a1497390c876.pdfUniversity of Sistan and BaluchestanJournal of Natural Environmental Hazards2676-4377123620230622Projection of future Precipitation changes in Tehran's water supply watershedsProjection of future Precipitation changes in Tehran's water supply watersheds151180723410.22111/jneh.2022.42622.1908FAFaezeShojaPostdoctoral researcher in climatology, Department of Physical Geography, University of Tehran, IranAliakbarShamsipourAssociate professor in Climatology, Department of Physical Geography, University of Tehran, IranJournal Article20220614This study identifies the impact of climate change on precipitation in watersheds of Tehran water supply in the horizon 2025-2050 under the scenarios of CMIP6. Therefore, first, the changes in precipitation trends in the base period were calculated using the precipitation data of the study area's 33 synoptic and rain gauge stations for the period 1989-2019. Then changes soon based on four models, CanESM5, CNRM-CM6-1, MIROC6, and MRI-ESM2-0, and under two scenarios, SSP2-4.5 and SSP5-8.5 were projected. Due to the large scale of atmospheric general circulation models, two methods of linear scaling (LS) and distribution mapping (DM) were used for downscaling selected GCMs. Finally, the DM method was chosen to produce climatic scenarios due to its higher accuracy after calculating the validation indices of the models. The trend tests showed that in a significant part of the study basin, an increasing trend (with confidence levels of 0.95 and 0.99) in autumn and a decreasing trend in winter are observed during the observation period. In spring, the eastern and northeastern regions show a decreasing trend, and the northern and northwestern regions show an increasing precipitation trend. According to the output of GCM models, spring precipitation under the SSP2-4.5 scenario increases in all stations and decreases in 17 stations according to SSP5-8.5. Changes in summer precipitation are not significant in the present and future conditions, and winter and autumn are somewhat consistent with the changes in the observation period. Thus, in winter, precipitation, according to both scenarios, is less than in the current situation and is more in autumn under the SSP5-8.5 scenario. The effect of climate change on the amount of water in the watersheds also showed that the maximum water volume in the current conditions is related to the Karaj watershed. Between 2025 and 2050, the water content of this watershed increases by 8.9% in the CNRM-CM6-1 model according to the SSP2-4.5 But in MIROC6, MRI-ESM2-0, and CanESM5 models, it decreases by 5.3, 6.3, and 59.6 percent, respectively.This study identifies the impact of climate change on precipitation in watersheds of Tehran water supply in the horizon 2025-2050 under the scenarios of CMIP6. Therefore, first, the changes in precipitation trends in the base period were calculated using the precipitation data of the study area's 33 synoptic and rain gauge stations for the period 1989-2019. Then changes soon based on four models, CanESM5, CNRM-CM6-1, MIROC6, and MRI-ESM2-0, and under two scenarios, SSP2-4.5 and SSP5-8.5 were projected. Due to the large scale of atmospheric general circulation models, two methods of linear scaling (LS) and distribution mapping (DM) were used for downscaling selected GCMs. Finally, the DM method was chosen to produce climatic scenarios due to its higher accuracy after calculating the validation indices of the models. The trend tests showed that in a significant part of the study basin, an increasing trend (with confidence levels of 0.95 and 0.99) in autumn and a decreasing trend in winter are observed during the observation period. In spring, the eastern and northeastern regions show a decreasing trend, and the northern and northwestern regions show an increasing precipitation trend. According to the output of GCM models, spring precipitation under the SSP2-4.5 scenario increases in all stations and decreases in 17 stations according to SSP5-8.5. Changes in summer precipitation are not significant in the present and future conditions, and winter and autumn are somewhat consistent with the changes in the observation period. Thus, in winter, precipitation, according to both scenarios, is less than in the current situation and is more in autumn under the SSP5-8.5 scenario. The effect of climate change on the amount of water in the watersheds also showed that the maximum water volume in the current conditions is related to the Karaj watershed. Between 2025 and 2050, the water content of this watershed increases by 8.9% in the CNRM-CM6-1 model according to the SSP2-4.5 But in MIROC6, MRI-ESM2-0, and CanESM5 models, it decreases by 5.3, 6.3, and 59.6 percent, respectively.https://jneh.usb.ac.ir/article_7234_066d8d4654a9aa7fba791041db277228.pdf