پیش‌بینی تغییر اقلیم در مناطق خشک و نیمه‌خشک (مطالعه موردی جنوب استان کرمان)

تغییرات آب و هوایی ممکن است به یک سلسله حوادث مکرر شدید از جمله خشکسالی، باران شدید و درجه حرارت بالا منجر شود که در پی آن، دو افق هیدرولوژیکی خشکسالی و سیل را به همراه داشته باشد. بنابراین، بررسی تغییرات اقلیمی در مناطق خشک و نیمه خشک بیش از پیش ضروری است. هدف از این تحقیق، بررسی تغییرات اقلیمی جنوب استان کرمان با استفاده از مدل canesm2 با استفاده از نرم افزار sdsm4.5 ، و بررسی روند این تغییرات با استفاده از آزمون من کندال طی دو دوره 2050-2021 و 2080-2051 در ایستگاه های سینوپتیک کهنوج و جیرفت است. تغییرات دمایی در ایستگاه سینوپتیک جیرفت حاکی از آن است که در دوره 2050-2021 تحت سناریوهای rcp2.6، rcp4.5 و rcp8.5، دما به ترتیب به میزان 1.63، 1.61 و 2.06 درجه سانتی‌گراد افزایش می‌یابد. این تغییرات دمایی در دوره 20512080 نیز مثبت است و منطبق بر سناریوهای ذکر شده به ترتیب به میزان 2.02، 2.88 و 4.23 درجه سانتی‌گراد افزایش می‌یابد. این تغییرات در ایستگاه سینوپتیک کهنوج نیز همانند ایستگاه جیرفت افزایشی است و در طی دوره 2050-2021، برمبنای سناریوهای rcp2.6، rcp4.5 و rcp8.5 به ترتیب به میزان 1.54، 1.52 و 1.98 درجه سانتی‌گراد و در دوره 20802051، به ترتیب تحت سناریوهای rcp2.6، rcp4.5 و rcp8.5 به میزان 1.93، 2.78 و 4.13 درجه سانتی‌گراد افزایش دما می‌ یابد. همچنین در ایستگاه سینوپتیک جیرفت، بارندگی تنها در دوره اول در سناریوهای rcp2.6 و rcp4.5 به میزان 5 و 8 درصد در فصل زمستان افزایش دارد؛ اما در سناریوی rcp8.5، به میزان 14 درصد کاهش دارد. همچنین بارندگی در این ایستگاه در دوره دوم در فصل زمستان تحت سناریوهای rcp2.6، rcp4.5 و rcp8.5 به ترتیب به میزان 17، 14 و 23 درصد کاهش می ‌یابد. از طرفی، بارندگی در ایستگاه سینوپتیک کهنوج نیز در هر دو دوره در تمامی فصول افزایشی است.

Prediction of climate change in arid and semi-arid regions of the western basin of Jazmourian Wetland

Extended Abstract1. IntroductionGlobal warming has occurred in recent decades, and its warming trend will continue due to increasing concentrations of atmospheric greenhouse gases from human activities. Changes in the average rainfall in many areas have also been recorded in connection with global warming due to rising atmospheric humidity. Climate change is another threat to the security of water resources. Therefore, climate change has a significant impact on the hydrological cycle on a global and local scale. The issue of understanding climate change is of particular importance for areas dependent on seasonal water availability and areas exposed to vulnerable climates. On the other hand, Iranchr('39')s geographical location in the subtropical region has caused it to be located in the dry belt of the world. Due to this geographical location, the average rainfall in Iran (255 mm) is much lower than the global average (860 mm). A noteworthy point about Iranchr('39')s rainfall, in addition to low rainfall, is its high variability. On the other hand, in the last century, global climate change has been reflected in increasing temperatures, increasing precipitation changes, and decreasing glacial and snow regions.2. Materials and MethodsThis study was conducted in the southern region of Kerman. In this study, the first daily temperature and rainfall data of Jiroft and Kahnooj synoptic stations were prepared by the Kerman Meteorological Organization to investigate climate change during the period (19892017). After collecting data, SDSM4.5 software was used to study climate change and the trend of these changes.3. ResultsThe results of the performance of the CanESM2 model for its ability to microscale exponential parameters of precipitation and average temperature during the base period indicate that this model has a high capability in simulating climate change in the south of Kerman province for the period (20502021 and 20802021) .According to the exponential microscale results, the average temperature has the best performance relative to the daily precipitation, which can be one of the reasons that the temperature changes relative to the precipitation change over a period of time, while the precipitation parameter fluctuates widely. According to the three evaluation criteria of NSE, RMSE, and R2, the performance of the CanESM2 model is in a very good and good class. The results show that the temperature changes in both periods and both stations are incremental. However, the changes in rainfall in each of the scenarios did not follow a specific rule and are increasing and decreasing.The results show that the average temperature during the period (20502021) in Jiroft synoptic station indicates that under the scenarios of RCP2.6, RCP4.5, and RCP8.5, respectively, 1.63, 1.61 and It rises to 2.06 ° C. These temperature changes in the period (20802051) are also positive. Following the mentioned scenarios, the temperature will increase by 2.02, 2.88, and 4.23 ° C. The results of temperature change and precipitation in the base period (19892017) showed that in the base period for synoptic stations of Jiroft and Kahnooj, the temperature parameter due to the Pvalue value is less than 0.05, which means that this trend also includes Kendallchr('39')s tau and age line slope. The trend of temperature changes in the future in both stations is significant and indicates an increase in temperature in the future. Also, changes in precipitation in the base period in Jiroft synoptic station are without trend.On the other hand, these changes in Kahnooj synoptic station are significant and decreasing. In the next period, rainfall in Jiroft synoptic station is without trend. The results also show that only in the period (20802051) in the RCP4.5 scenario in Kahnooj station, its precipitation trend is significant and decreasing.4. ConclusionIn the present study, to study climate change in the south of Kerman province, the model of the fifth report of the International Board of Climate Change CanESM2 and new release scenarios in the next two periods (20802051 and 20502021) were used. Also, to clarify the trend of annual changes in temperature and precipitation components as inputs of hydrological models, a nonparametric MannKendall test was used. The results of evaluating the accuracy of the CanESM2 model showed that this model has good accuracy in both temperature and precipitation components in both synoptic stations.. On the other hand, the trend of temperature changes in the future indicates that temperature changes have had an increasing trend.