عنوان مقاله [English]
Introduction: Drought is one of the climatic phenomena and is one of the events that cause a lot of damage every year. This phenomenon is in fact one of the main and recurring features of different climates and its effects are not limited to arid and semi-arid areas. This phenomenon can occur in any geographical area and cause a shortage of water resources in different sectors. Sistan and Baluchestan province is one of the southeastern provinces of Iran that is strongly affected by drought as well as fluctuations and changes in meteorological variables. Given the importance and necessity of the effect of climate change on drought and more specifically on climate parameters, this study intends to identify climate change behavior on drought and some changes in meteorological parameters in this region and answer the following question. What are the changes in meteorological parameters in the stations used in the future based on general atmospheric circulation models, and what are the changes and trends in the future of this region as a result of drought conditions?
Data and methodology: The study area in the present study is southeastern Iran, Sistan and Baluchestan province. The data of this study include two categories: The first category includes meteorological variables such as daily precipitation, minimum temperature, maximum temperature and sundial related to synoptic stations located in the region during the statistical period of 30 years (2020-1987). The mentioned data have been obtained from the Statistics and Information Center of the Meteorological Organization of the country. The second category of data includes the output of general atmospheric circulation models. In this study, HadCM model data is used. In order to use the output of atmospheric general circulation models, the use of fine-grained tools is required. One of the microdistribution methods used is the LARS-WG model. The SPI Drought Index is based on the fact that rainfall deficits have different effects on groundwater, resource storage, soil moisture, snow cover, and stream flow.
Conclusion: During the study period, the precipitation regime will shift to the end of the season, ie winter and spring. In this regard, officials should pay more attention to the impact of spring rains on onshore stations in the occurrence of flash floods on a local scale. According to the distribution of precipitation in the province, it is determined that precipitation patterns are different in different regions of the southeastern part of the country. Some areas, such as Sistan, have the lowest rainfall in the province, while others are well distributed. Therefore, the distribution of rainfall in the province, especially heavy rainfall, is affected by local factors and synoptic conditions. The heaviest rainfall in the province occurs in the southern part of the province and is affected by sea moisture. These points are considered as dry points; But if the conditions for rainfall are provided, under the influence of sea moisture, they can receive the heaviest rainfall in the province. Heavy rains have also been recorded in the central heights of the province.
Drought is one of the climates that is followed by rainfall, warming and rising temperatures and is one of the dangers that Iran has faced severe problems in recent decades. The maps shown show the years when drought was more prevalent, and studies showed that in 2001 and 2016, severe droughts were seen in the south of the province and then in the center of the province, and in the years to come. It happens in both. It gives an optimistic and pessimistic scenario of a very severe drought that could increase the temperature.
Drought is a process in which water evaporation from soil and water levels increases.In this study, the outputs of the general public circulation model with two scenarios were evaluated and scaled on 6 stations in Sistan and Baluchestan province in order to evaluate and predict climate change and drought in the statistical period. In general, it can be said that the occurrence of drought and its characteristics are associated with differences in terms of time and place in different regions of the country. Therefore, due to the positive trend of drought at different time scales in the southeastern part of the country, to reduce the effects of this climate risk, we need immediate management measures in the southeastern part of the country