جستجوی مقالات مرتبط با کلیدواژه « خشکسالی » در نشریات گروه « کشاورزی »

Rural business is one of the types of businesses that nowadays, due to the reconstruction of functional patterns of many rural areas and also the design of new tourism businesses in rural areas is one of the most dynamic aspects of entrepreneurship. Activities that are formed in tourism destinations with goals such as improving livelihoods and economic well-being sound to be the best ways to deal with these risks of economic shocks and imbalances to improve their resilience. Resilience is the capacity of society to withstand risks and abnormal conditions and return to normal conditions. Considering that tourism is an important and dominant economic sector in some countries and some destinations are dependent on this sector for growth and survival, relying on this sector has put a lot of pressure on tourism managers and planners in order to protect the business and the tourism community against crises and disasters and has led to the presentation of strategic plans to deal with its possible consequences. Therefore, in an important and growing economic activity such as tourism, it is necessary to understand and recognize the dimensions of the accident and crisis and to examine strategies to stop or limit its consequences. In this regard, business resilience and resilience planning are a comprehensive approach. To realize the development of tourist communities and reduce the possibility of instability caused by the occurrence of disruptive conditions in the normal process of these businesses, the most common perspective of resilience in tourism is on the marketing of the tourism industry and the number of incoming tourists to the destination due to the rapid change of variables caused by unexpected or predictable events and its impact on the economy and tourism businesses. In fact, the resilience of tourism may pay attention to the changes in social, environmental and economic variables that make up  tourism in an integrated way, but the ultimate goal of paying attention to it should be to create the resilience of businesses related to these variables against external fragile events.

The current research is applied in terms of its nature and descriptive-analytical in terms of survey-based method. The data collection tool for each item was through a questionnaire. The required variables of this research were selected using the study of reliable scientific sources and field study from the study area. In this research, the questions related to the variables of the questionnaire are set using a 5-option Likert scale from very high to very low. The unit of analysis in this research is the business owners related to the tourism sector in the rural areas around Urmia Lake in Shabestar city. In order to determine the reliability of the questionnaire, a number of 30 questionnaires were distributed in the region and the reliability coefficient of resilience was estimated at 0.87, which indicates that the mentioned questionnaire has adequate reliability. Also, based on Cochran's sampling formula, the sample size was 350 people from business owners related to the tourism sector. The data needed for the research was also collected through a simple random sampling method.

The descriptive findings of the research, based on 350 questionnaires distributed among the sample size, indicate that 319 were men and 31 were women. The highest frequency of respondents was 156 people in the category of 41-50 years, which accounted for 45% of the sample size. In terms of level of education, among the four levels of education, elementary and illiterate, under-diploma, post-diploma, bachelor and above, the highest frequency of respondents with 194 people, equal to 55%, was in the diploma level. One sample t-test was used to investigate the resilience of villages in four dimensions. The general results of the one-sided t-test for the resilience of the villages show an average of 1.68. Considering that the average observed resilience of the villages is less than 3, which corresponds to the average level of the Likert spectrum, so it can be said that the overall resilience situation in the studied villages is evaluated at a low level of resilience. According to the results of the one-sided t-test, the average of social capital dimension was 2.11, economic 1.22, human capital 2.16, and management institution 1.23. The significance level of all the indicators is lower than the test error level of 5% and the average of all dimensions are not at the optimal level and this issue is effective in reducing the resilience of the studied villages.

The results of the research based on the one-sided t-test indicate that the general situation of resilience is not very favorable. The general results of the one-sided t-test for the resilience status of the studied villages show an average of 1.68. Considering that the average observed resilience of the villages is less than 3, which corresponds to the average level of the Likert scale, it can be said that the overall resilience situation in the studied villages is evaluated at a very low level of resilience. Dimensions of resilience from the villagers' point of view have different averages, so that the highest average is related to the institutional and human capital (2.16) and the lowest average is related to the economic dimension (1.22). The stratification of the 7 studied villages based on Mirka's decision-making technique shows that based on the score (Q) Ali Biglo, Qara Tapeh and Kafi al-Mulk villages are at the medium resilience level, Sheikh Wali and Koushak villages are at the low resilience level and Haft Cheshme and Maraghosh Qala villages are at a very low level of resilience.

Today, the phenomenon of climate change is one of the problems that has always received attention in the world. One of the reasons for climate change is the increase of greenhouse gases, which have a significant effect on extreme phenomena. Drought forecasting is one of the management strategies that helps to plan properly for using limited water resources. It is also important to examine drought changes based on climate changes from various aspects; in many long-term plans, it is necessary to develop a vision of the future state of rainfall and drought periods for the region. The SPEI index can calculate drought in different time scales and can also include the effects of temperature changes in drought assessment and be used to monitor current and future climate changes based on climate scenarios. Also, the Standard Precipitation Index (SPI) is one of the most important indicators in drought analysis. This index is known as the most appropriate index for drought analysis due to the simplicity of calculations, the use of available rainfall data, and the ability to calculate for any desired time scale. The recent increase in droughts in the Karun 3 watershed has caused water shortages and economic and social damages. Therefore, investigating the effect of climate change and analyzing the frequency of drought is very important. In line with this goal, in this research, firstly, simulation of rainfall, maximum temperature, and minimum temperature of eight meteorological stations using three climate models EC-EARTH, CNRM-CM5, and GFDL-ESM2M under two release scenarios RCP4.5 and RCP8 5. It was forecated for the period (2055-2030).

In this research, firstly, the temperature data (maximum and minimum) and precipitation output of EC-EARTH, CNRM-CM5 and GFDL-ESM2M climate models under the CORDEX project for RCP4.5 and RCP8.5 emission scenarios with the help of CMhyd Raz software Scaled and time series of maximum, minimum and precipitation temperatures for eight meteorological stations in the future period (2055-2030) were produced. Then, the temperature and precipitation changes in the future period compared to the base period (1995-2020) were investigated. Finally, the investigation of drought (frequency and continuity) in the future period under two release scenarios of RCP4.5 and RCP8.5 by (SPI) and (SPEI) indicators in three-time scales of three, six, and twelve months using DIP software was performed. To evaluate the efficiency and accuracy of three EC-EARTH, CNRM-CM5, and GFDL-ESM2M general circulation models for simulating climate data, the monthly average of climate variables in the period (1990-2005) obtained from the output of the model was compared with the corresponding observational values. For this purpose, Nash Sutcliffe (NS), bias index and coefficient of determination (R^2) were used.

The results showed that the maximum temperature increase is related to Shushtar station. In this station, the maximum temperature will increase by 1.46 degrees Celsius in the RCP8.5 emission scenario and one degree Celsius in the RCP4.5 emission scenario compared to the base period. Masjid Sulaiman station has the highest increase in minimum temperature. At this station, the minimum temperature increase under the RCP8.5 release scenario is 2.41 degrees Celsius and under the RCP4.5 scenario, it is 1.92 degrees Celsius. Also, the rainfall in the whole range has been decreasing in the coming period. The decrease of rainfall in Kohrang in the RCP8.5 scenario is 146.3 mm and in the RCP4.5 scenario, it is 53.6 mm, which is about 11.7 and 4.3 percent, respectively. In terms of the frequency of drought in the statistical period (2055-2030) on a three-month scale, in the RCP4.5 scenario, Izeh station has the highest frequency with 14 droughts, on a six-month scale, in the RCP4.5 scenario, the maximum number of droughts in Shahrekord with 16 times and on a twelve-month scale, in the RCP4.5 scenario, Kohrang station shows the highest frequency with 15 times. In the RCP8.5 scenario, Izeh station has the highest frequency with 20 drought experiences. Also, in the upcoming period, under the RCP4.5 release scenario, on the scale of three, six, and twelve, respectively, Shahrekord, Yasouj, and Lordegan stations will have eight, 11, and 27 months, and in the RCP8.5 scenario, the drought will continue the most at Masjid Sulaiman, Shushtar, and Lordegan, respectively.

The results showed that the annual long-term average of the maximum and minimum temperature in the future period compared to the base period in all eight stations had an upward trend. Also, the results showed that the maximum temperature under the 8.5RCP scenario increases more than the 4.5RCP release scenario. Also, the results showed that the Kohrang station affected by climate change will have the largest decrease in rainfall in the study area during the coming period. Also, the results showed that in all three-time scales of three, six, and 12 months in the future period, compared to the base period, there are many fluctuations in the time series of SPI and SPEI drought indices. Also, extreme drought conditions will increase in the coming period. It is expected that in the coming period, the number of dry months will be less than the number of months with normal and wet conditions. Also, when examining the drought situation using the SPEI index, it can be seen that, like the SPI index, the pattern of changes in the drought period can be recognized in the stations. It should be mentioned that the intensity of droughts calculated using the SPEI index is rarely higher than the numerical value of two. By comparing the duration and frequency of drought in the studied stations and in different time comparisons, it was found that the SPI index shows the continuity and frequency of drought in most cases compared to the SPEI index.

Rafsanjan plain in Kerman province, which is located in the arid and semi-arid region of Iran, is one of the oldest regions in the country in the field of economic pistachio cultivation, and the majority of the economy of the residents of these areas is directly dependent on pistachio crop cultivation. Indiscriminate extraction of underground water resources, mainly for the consumption of the agricultural sector and pistachio crops, has caused a sharp decrease in the quantity and quality of underground water in the region. The quantitative and qualitative reduction of underground water as the only reliable source of water in the region has caused a decrease in the area under cultivation, the amount of production and productivity of the agricultural sector as the main source of the region's economy, and many economic, social and environmental consequences. Considering the vital importance of water in the Rafsanjan Plain, in this research, the quantitative and qualitative changes (EC) of water in this area in the last two decades have been investigated and studied. Information has been collected through interviews with experts and analysis of data available in the relevant departments. The results of the study show that along with the increase in the drilling and exploitation of wells, the underground water level has decreased, the depth of the wells and the water level have increased, and the water quality has also decreased.

Critical to human survival, water resources, including groundwater and particularly rivers, are under threat from anthropogenic pollution. The major Kashafrud River, located in northeastern Iran, is a seasonal watercourse currently encountering numerous challenges. At present, a stretch of this historic river (Parkandabad to the basin's exit) carries wastewater, comprising industrial, urban, agricultural, and even livestock effluents, transforming it into a conduit for sewage. This study reviews existing research on the challenges faced by the Kashafrud River, including pollution, climate change, and its impacts, as well as reduced runoff and drought. It outlines the crisis afflicting the river and then explores solutions to mitigate the current conditions. This research process involved reviewing previous studies on the challenges of Kashafrud, conducting field visits, engaging in discussions with local residents, and validating these findings through consultation with regional water experts responsible for overseeing this water course. Research indicates that there has been a limited focus on the pollution issue in Kashafrud, underscoring the evident necessity for comprehensive scientific inquiry aimed at presenting suitable solutions to tackle river contamination. In conclusion, through analyzing solutions proposed in previous studies and summarizing their strengths and weaknesses, 13 practical solutions were presented to provide the most effective strategies for addressing the challenges of this significant river.

Drought is one of the phenomena of environmental hazards that occurs in most parts of the world but its manifestation is more in arid and semi-arid regions and also occurs over a long period of time and alternately affects human societies through negative effects. It causes problems for water and agriculture, followed by the economy. One method of assessing drought status is the use of Palmer Drought Severity Indicators (scPDSI). In this study, the scPDSI index has been used to study drought and wet season during the period 1979 to 2018. In this research, data with spatial resolution of 0.5 * 0.5 has been used. The results showed that the cities of Bojnourd, Maneh and Samolghan, Gorgan, Shahroud, Tehran, Qazvin, Arak, Hamedan, Kashan, Bandar Lengeh, Fasa, Bandar Abbas, and west of Khorramabad have experienced severe to moderate droughts; These droughts have covered Iran with 22.06% in spring and 20.12% in summer. In general, the results indicate that droughts occurred from low latitudes to 33.75 ° latitude.

The weather has an ongoing impact on human living and working environments. Drought is a natural disaster that ranks first in frequency of occurrence, financial losses, and even human casualties among natural disasters that endanger humans and their environment. Due to its complexity and imperceptibility, this phenomenon—one of the primary and recurring features of various climates—has significantly impacted the human environment more than any other hazard. Its effects can also accumulate gradually over time and last for years afterward.Drought cannot be avoided, but if its nature and characteristics are researched and understood, we may be able to forecast when it will occur, lessen its adverse effects through planning and preparation, and perhaps even control it.

The political region of Iran is the subject of this study (Figure 1). Soil moisture and monthly precipitation are among the data used. The necessary data, which included 516 precipitation files and 516 soil moisture files with a spatial resolution of 0.5*0.66 in NC format, as well as drought and its characteristics calculated for all points, were acquired from the MERRA website for 43 years (1980–2022) to conduct this research. Iran's droughts were estimated over 3, 6, 9, 12, and 24 months using the MSDI. The characteristics of droughts, such as frequency, duration, severity, and magnitude, were computed, analyzed, and presented as a map in addition to examining the actual droughts.

Analyzing the drought characteristics for 1546 points across Iran revealed that the frequency and number of drought periods decrease as the time scale increases. In contrast, the values of other traits—such as continuity, intensity, and magnitude—also rise as the time scale increases. The increase in drought characteristics with increasing time scale, in terms of magnitude, duration, and severity, has been highlighted in studies by Nouri and Homai (2020) and Torabinejad et al. (2023). Geographically, the southeast and eastern parts of Iran have seen the highest frequency of droughts throughout the 43 years; in the southeastern part of the country, which is centered on the provinces of Sistan and Baluchestan, Kerman, and Hormozgan, there have been 28 to 34 periods of drought in 3 months. Conversely, the least amount of drought occurred in the northern coasts during the short-term periods of three and six months, with six to twelve periods, and in the coasts of the north and the southwestern region of the country during the long-term periods of twelve and twenty-four months, with two to six periods. The provinces of Sistan Baluchistan, Kerman, and Hormozgan in the southeast, as well as the far east of Khorasan Razavi and South provinces in the east of the country, experienced the worst droughts in terms of severity. Severe droughts lasting 12 or 24 months are concentrated in the southwest, in Bakhtiari and Chaharmahal, Kohgiluyeh and Boyer Ahmad, and part of Khuzestan.The findings from the computation and analysis of the duration and magnitude of droughts in Iran over the period under discussion indicated that, for two features, the country's northern regions, centered on the north coasts, mainly Mazandaran province, had more prolonged and severe droughts than other regions within the time scales of three and six months. By looking at the country's southwest from the perspective of location over periods of 12 and 24 months, the provinces of Fars, Bushehr, south of Kohgiluyeh and Boyer Ahmad, and Khuzestan province make up the central core of the most prolonged and most extensive droughts. 

Based on soil moisture and precipitation data, the results of a drought calculation in Iran demonstrated that droughts occur throughout the country with varying degrees of severity and weakness. Their occurrence has become a permanent feature of the country's climate, particularly in recent decades. The analysis of Iran's drought chronology revealed that, according to the MSDI index's range, most of the country's droughts are weak and moderate. It was also discovered that as time scales increase, the frequency of droughts decreases while the continuity, magnitude, and severity increase. Geographically, the country's southeast and east saw the highest frequency of droughts, while its northern coast—mainly the province of Mazandaran—and southwest—where the provinces of Chaharmahal & Bakhtiari and Kohgiluyeh & Boyer Ahmad—saw the lowest frequency. The maximum severity of drought in the country is -1.93 on the 3-month scale in the southeast and -2.2 on the 24-month scale in the southwest. Two of the study's notable findings are the continuity and high magnitude of the droughts that struck the country's north and southwest. Thus, the most extensive droughts, with values between -16 and -31 on short-term scales and between -35 and -68 on 12- and 24-month scales, have happened in the country's north and southwest, respectively. These results suggest an overall decrease in soil moisture and precipitation in these regions.

Drought is one of the natural disasters that can occur in any climate. In recent decades, Iran has been continuously affected by severe and widespread droughts and has imposed harmful effects on various economic sectors, including the country's water resources. One of the needs for the growth and development of every country is water. On the other hand, due to the lack of permanent or even seasonal surface water flows in many plains of the country, one of the most important sources of water harvesting is the use of underground water reserves. Therefore, it is very important to investigate the status of these resources and determine the influencing factors on them. In this research, it has been tried to identify the areas that are exposed to severe groundwater drought and the impact of the factors affecting groundwater drought using the maximum entropy model and using MaxEnt software in the basin. The Jiroft plain watershed should be identified. To implement the maximum entropy model, 70% of the data were used for model training and 30% for model testing. The results of this study, based on the jackknife test, showed that the most important factors affecting groundwater drought are altitude, distance from the river, and soil moisture, and the model shows the most sensitivity to these parameters. gave Also, the results showed that the model has an acceptable accuracy in identifying groundwater drought, so that the accuracy of the model was estimated at 0.76.

This research assesses and investigates the impact of automating the Abshar irrigation network's main canal using a decentralized control system on the adequacy and stability of surface water distribution. To achieve this, the study analyzes 30 years of historical discharge data at the Abshar diversion dam and selects seven representative operational scenarios. It then employs the Integral-Delay (ID) hydraulic simulation model to simulate surface water distribution in the main canal under each scenario (a total of 540 simulations). These simulations are compared with results obtained using a simplified Integral-Delay (ID) mathematical model. Additionally, the research develops a decentralized PI automatic control system model for the network. This control system model is then integrated with the Integral-Delay (ID) hydraulic simulation model within the MATLAB environment. By utilizing system identification techniques, the study determines the proportional and integral gains for each controller in the control system. Finally, the performance of the automated control system is evaluated by analyzing the simulated surface water distribution results for the chosen scenarios using performance indices related to water distribution adequacy and stability. This allows for a comparison of the automated control system's effectiveness with the pre-automation scenario.

One of the effects of droughts on the catchment area is the impact on sediment production. The purpose of this study was to investigate the effect of drought on the amount of sediment production estimated by the sediment gauge curve located at the Chamriz hydrometric station. In this study, using the long-term data of the Chamriz hydrometric station located upstream of the Darudzen dam, the rate of changes in the produced sediment discharge in each year was calculated using different methods of the sediment curve. Then, by evaluating the applied methods, the best method for performing the subsequent analyses was selected (the non-parametric method (CF2)). Then, using the station's meteorological data, two SPI and RDI drought indicators were calculated, and finally, they were compared with the average annual sediment discharge rate. The results showed that by increasing the amount of drought index (SPI) and RDI (toward tiredness), the amount of sediment discharge increased, indicating the positive effect of climate conditions on the sediment yield of a basin. Finally, by examining the state of sediment production in many years of drought, it can be concluded that during the year of the drought, due to the effect of drought on vegetation status, soil moisture, and other factors, in the years after the occurrence Drought has caused a significant increase in sediment deposition compared to years when the drought was normal on the floor, and since then it has been terrible.

This study was conducted to evaluate the real cropping pattern of Khuzestan province in a normal water year (2018-2019) in terms of water withdrawal management from surface resources. For this purpose, the actual evapotranspiration of the products was calculated from the ratio of the available yield of different products (according to the agricultural statistics of 2018-2019) to the potential yield (the highest yield according to the agricultural statistics) by applying the country's water demand line system based on 10-year meteorological data. The results showed that the total water withdrawal from surface resources for the cultivated area of the crop year 2018-2019 (except greenhouses, livestock, poultry, and some products with a small area) was 18856 MCM, so the actual consumption (net irrigation requirement) was estimated 4310 MCM. Considering the Khuzestan Water Scarcity Adaptation Program, the total demand for agriculture and the environment with a confidence level of 80% in the Karun and Karkheh basins was 36 and 23.8% lower than the river flow, respectively, while it decreased to -72% in the Jarrahi basin, which indicated the failure to achieve the minimum environmental requirement. Since the Karkheh River flow has a more severe fluctuating behavior than that of Karun, this behavior cannot be predicted in the linear analysis of average values, and in droughts, it is less than the mentioned number. Therefore, dynamic planning in the field of cropping pattern change, providing various types of drought insurance, implementing infrastructure for the temporary purchase of water rights by the government, and other support policies are suggested in basins such as Karkheh, which has a highly fluctuating behavior in water supply.

the countries of Iran and Afghanistan. A long period of drought has happened in this area by human interventions after 1999. The objective of current study is to predict the Hamoun wetland situation in scenarios with and without human intervention using the Markov model-automated cellular for 2019 and the next forty years. Land cover maps of the study area using satellite images for 1987 as a normal year, 1991 as a wet year, and 2019 as a year with human effects were prepared. Then, prediction model for 2019 were prepared using 1987 and 1991 cover layers in four scenarios, prediction models were prepared for the next forty years in normal, drought, and wet conditions. If the natural process of watering of Hamoun wetland continues, lower than 362735 hectares of wetland should become watering in 2019, while, according this year land cover map, less than 50000 hectares of wetland have water. Also, by continuation of the current trend and the effect of human activities in the 40-year models, 11230 hectares of the area will be watering, and if the natural process of the wetland continued using the model of 2019 this amount was equal to 373311 hectares. The results of the research show the completely different situation of the Hamoun wetland in the case of no human intervention in the watering of this wetland in 2019 and the model of the next forty years.

Drought is one of the most important natural hazards in Iran that has many destructive environmental and economic effects. Drought is affected by various factors, and different indices have been developed to monitor it. Drought studies have been performed using temperature and vegetation data, but few studies have used satellite evapotranspiration data. In this research, vegetation condition index, temperature condition index, and evapotranspiration condition index have been used to study drought in Jarahi and Zohreh catchments. For this purpose, drought indices have been calculated on a monthly basis using MODIS satellite products from the 2000 to 2017 period. The six-month Standardized Precipitation Index was used to evaluate the remote sensing-based drought indices. The results showed that the evapotranspiration condition Index had the highest correlation with the six-month SPI index and was considered the most appropriate index to study the drought. The correlation of ETCI with SPI was equal to -0.57 and the RMSE was 0.47. A drought severity map was prepared using remote sensing indices to depict six classes of drought severity including severe drought, moderate drought, mild drought, near normal, and without drought for 2008, 2009, and 2016, when the study area was suffering from drought. The results of the spatial assessment showed that the central part of the basin which contains ecologically important protected areas was the most vulnerable part during dry years, and during the study period, it has experienced over 10 months of severe drought. In this period, the coastal part had the lowest drought intensities. However, during different years, the wetland area of the basin, which is one of the protected water ecosystems, has decreased. The results showed that compared to other indices, the satellite-based evapotranspiration data can provide a good tool for monitoring drought in hot areas with sparse vegetation such as Iran.

The present research aimed to investigate the crown dieback of Persian oak trees in relation to their individual and site characteristics, evaluated the changes in crown health of trees during the years 2019 to 2022 in Meleh-Siah forest in the northern half of Ilam province. Two sites were identified in the northern and southern aspects and 100 oak trees were marked in each site. The characteristics of each tree, including the diameter at breast height, tree height, max and min crown diameter and tree origin were measured and recorded. The dieback condition of tree crowns was evaluated and divided into four classes of crown dieback. The evaluation of crown dieback of trees was done during four years and in September. The results showed that the highest abundance of trees in the northern site is in the classes of declining and crown dieback up to 50%, and in the southern site is in the class of crown dieback more than 50%. The number of trees leaving the healthy and declining classes was higher, respectively, which were transferred to the higher crown dieback classes. The healthy and declining classes were associated with decreasing changes and the crown dieback less than 50% class was associated with increasing changes. dbh, height and crown area of ​​healthy trees were lower than those of other crown dieback classes. The frequency of crown dieback was higher in denser stand. The rate of crown dieback was higher in coppice trees than in standard trees; in addition, the temporal changes of crown dieback were more in coppice trees. It was concluded that individual and social traits and environmental conditions had a considerable impact on the crown health of oak trees and how they reacted to recently happened droughts.

One of the main challenges in monitoring drought is determining an index that is highly reliable based on the monitoring objective. Assessment and drought monitoring is considered one of the most important tools for drought management, as it can determine the start and end, spatial extent, and intensity of its effects. It can also help in identifying the need for drought response plans and determining the formation time of a drought monitoring and response committee. In this study, the meteorological drought was investigated using drought indices such as ZSI, MCZI, CZI, PN, DI, and SPI in the Aleshtar plain. Daily precipitation values from three stations, Aleshtar, Kaka Reza, and Sarabsead Ali, were collected for the period 2001-2021. After analyzing the annual precipitation trend at each station, the duration and maximum severity of drought were determined using meteorological drought indices. To evaluate the performance of these indices and select the most applicable index for the region, the minimum hypothesis was used. According to the results, the CZI index performed better than the other indices by correctly estimating one out of four cases. following Spearman's correlation between precipitation parameters and drought indices was investigated, the results showed a significant correlation between all indices at all stations except for MCZI, which had poor performance. Finally, considering the total scores, the CZI index, which obtained 21 points out of the total tests, was selected as the superior index for the region. The SPI and ZSI indices also yielded satisfactory and accurate results in this area.

The present research was conducted in order to investigate the effective factors on reducing the effects of drought in corn cultivation and to provide extensional-educational solutions in Azadi village (of Andimshek county). The statistical population was formed by all the corn growers of Azadi district in the crop year of 2021-2022, which were equal to 600 people. The sampling method was random and the samples were selected from among the people of the society in a simple random manner. To determine the sample size due to the limited statistical population, the Karjesi-Morgan formula was used, and according to the Karjesi-Morgan table, 237 people were selected. The data collection tool is a researcher-made questionnaire Data analysis using software SPSS Ver. 26 was done. The results of the T test showed that there is a significant difference at the level of 95% between farmers' knowledge and awareness (technical knowledge), human factors, management factors, economic factors, extensional-educational strategies and farmers' attitude towards reducing damage caused by drought with mean average of the population. They can minimize the damage caused by drought. Based on the structural model (PLS), the technical knowledge of corn farmers, management factors and educational-promotional strategies had the greatest effect on reducing the damage caused by drought, so that the value of the path coefficient for them was equal to 0.378, 0.359 and 314. Also, the path coefficient of human factors and economic factors were equal to 0.142 and 0.129, respectively, which had less effect on reducing the effects of drought.

The purpose of this research is to model scenarios for the protection of underground water resources in South Khorasan province in drought conditions.

In this regard, this problem was followed using the system dynamics approach and the behavior of the reference variable "Volume of underground water resources of South Khorasan Province" was simulated against different scenarios during the years 2013 to 2014 through the use of Vensim software. The required information was collected by referring to relevant organizations such as South Khorasan Regional Water Organization, South Khorasan Agricultural Jihad Organization and Iran Statistics Center, and the input data of the model was called into the model in the form of an Excel file.

The results of the research showed that applying the control scenario of water resources exploitation in normal drought conditions and drought with low intensity is useful, but applying this scenario in drought conditions of more than 20% will have negative effects on the economic indicators of the agricultural sector. Also, the fourth scenario of the cultivation pattern (emphasis on strategic crops) along with the fifth scenario of the cultivation pattern (drought-resistant crops) have brought the least pressure on underground water resources. Nevertheless, considering that cultivation pattern No. 4 has created the least added value, it cannot be an efficient pattern.

According to the results of the research, if the severity of droughts increases in the coming years, but the current agricultural conditions of South Khorasan province continue in terms of cropping patterns, droughts will not have an effect on economic indicators, because in these conditions, farmers By breaking the ground and extracting more from underground water sources, they will compensate for the lack of rainfall and will show the negative effects of drought on the stock of underground water resources. Considering the effect of the cultivation pattern on underground water resources and economic indicators, it is necessary to think of measures to change the cultivation pattern.

Statistics show that the occurrence of severe and long-term droughts, especially in sensitive and fragile areas of the country has caused severe economic and social losses, and the occurrence of drought, increased dust, storms, and desertification has caused a decrease in agricultural production. Extensive and dynamic monitoring of dryness by traditional methods is very difficult and costly due to the lack of soil moisture display points. Remote sensing technology is a practical and applied method for large-scale land monitoring. In this study, we tried to identify the drought in the Siah Kooh watershed area with TVDI dryness-temperature indices and the NDVI index resulting from MODIS sensor images and to investigate the relationship between drought and atmospheric elements in the region. The results of correlation as a total showed that the correlation values of TVDI index SPI6 and SPI12 are 0.68 and 0.71, respectively, and the correlation rates of NDVI values with SPI6 and SPI12 are 0.49 and 0.51, respectively. As a result, it can be said that the TVDI index, due to the use of thermal and reflective bands and soil moisture, is more accurate than the NDVI index, which considers only the amount of vegetation in the region. The TVDI index had an inverse correlation with the average of two months of rainfall of 0.54 and a direct correlation of 0.64 with the surface temperature of the earth. In contrast, the NDVI vegetation index with a two-month average rainfall has a direct correlation of 0.54 and an inverse correlation of 0.6 with the temperature. These linkages show that the correlation between vegetation and temperature is inverse (negative) and the correlation between vegetation and rainfall is direct (positive).

In the last two decades, Sistan region has been suffering from drought conditions. The fluctuation of the Hirmand River and the incorrect management of water resources in this region have caused the water crisis to intensify. In this situation, one of the solutions that can help to get out of the critical water situation is cooperative irrigation. Therefore, in this research, the feasibility of establishing water harvesting cooperatives in drought conditions in Sistan region with an entrepreneurial approach is considered. To achieve the mentioned goal, the model of similarity to the ideal option of the fuzzy logic bed has been used. To collect the necessary information, experts, experts and farmers were used through interviews and questionnaires. MCDMSolver 2018 software was used for modeling and solving the model. In this research, based on three economic, social, and attitudinal indicators, the sub-indices were divided into 12 items, and finally, the three options examined, the traditional system, the production cooperative system, and the rural cooperative system were prioritized and ranked. The results of the research showed that the production cooperative system with a weight of 0.56 was placed in the rejection rank. In the second place is the rural cooperative system with a weight of 0.40 and the traditional system with a weight of 0.29 is in the last place. According to the obtained results, water cooperative system should be given special attention in the form of production and rural systems.

For the optimal management of the surface water, it is necessary to identify the effect of meteorological drought on the river flows in terms of time. In this study, the relationship of meteorological and hydrological droughts in Sufi Chai River basin of Maragheh (East Azarbaijan province) was evaluated using SPI, RDI and SDI. The daily weather data of the Maragheh synoptic station and the daily data of Tazehkand hydrometric station (upstream of Alavian dam) were used. The statistical period of 34 years were determined (1983-2017) and 3, 6, 12, 24 and 48 month time series were created. In RDI, ETO was calculated using FAO-Penman-Monteith and Hargreaves-Samani methods. The correlation of hydrological and meteorological indices was performed for 3 to 48 month time series without delay and with delay of one-five month. The results in without delay condition showed the highest correlation between the indices is belonged to the series with similar period. The correlation between the similar RDIFPM and SDI series were less than the ones corresponding to SPI and SDI, or RDIHS and SDI. It is concluded considering the other weather parameters, in addition to rainfall, for calculating the indices, results in reduction of the correlation between the meteorological and hydrological indices. Among RDIHS and SDI values with delay condition, in the 3, 6 and 12 time series, the greatest effect of the meteorological drought on river flow was observed with the 3 month delay and in the 24 and 48 month time series, this effect was simultaneous.

Since groundwater is very important in meeting the water consumption needs of different sectors, as a result, managing and planning the consequences of drought on underground resources is considered one of the important and vital issues in the planning and administration of countries. For this purpose, in this research, using the combination of quantitative indicators of drought GRI (Groundwater Resources Index), SDWI (Standardized Well Discharge Index) and qualitative index MSECI (Modified Standad Electrical Conductivity Index) to the Hydrological drought management index HDMI in Urmia Plain during the years 2003 to 2018. The monitoring results of this drought management index in Urmia Plain show that the longest drought duration observed according to this management index is 7 years, which started from 2012 and continued until 2018, and the most severe drought observed in 2018 was -2/2. In order to observe the drought trend on the drought indicators, Mann-Kendall test was used. The results show that with the continuation of the current trend in the region, the value of the GRI index will reach less than -2 by 2026 and the HDMI drought management index will reach less than -6 by 2031. It is a sign of the state of non-exploitation and the exposure of underground resources to severe drought. If the current situation continues, it will be impossible to sustainably use the underground resources of the Urmia Plain.