عنوان مقاله [English]
Prediction of climatic variables in Sistan and Baluchestan province under the conditions of RCP scenarios
Mahsa Farzaneh 1 Sharareh Malboosi 2 Mohsen Hamidianpour 3
1- PhD in Climatology
2- Climatology Research Institute-Climatic Disasters Group-Mashhad-Iran
3- Physical Geography - Climatology, Department of physical geography, University of Sistan and Baluchestan, Zahedan, Iran
Drought is one of the climatic phenomena and is one of the events that cause a lot of damage every year. In fact, this phenomenon is 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 ad 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 circulation models (GCMs), and How does the trend of changes in meteorological variables affect the frequency and severity of droughts in the studied province?
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 GCMs. In this study, HadCM model data is used. In order to use the output of GCMs, the use of downscaling tools is required. One of the downscaling 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.
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 results of the study showed that the severity of drought in 2006 and 2016 was more severe.In addition, the results of the modeling section showed that there is a great agreement between the simulated values of the base period and the modeled period.It means that the results of the LARS-WG model have adequate confidence. The general results of the surveys for the mentioned period show that the percentage of minimum temperature changes in the province has increased by 16.02%, the percentage of maximum temperature changes has increased by 8.49% and the percentage of precipitation has decreased by 9.85%. The number of dry days increases in the studied stations. The highest frequency of the severity of droughts has been related to very severe and severe droughts. Zoning maps show that the eastern and central parts of the study area are more affected by drought than the western parts..