23451

GEOG2 1099

كارشناسي ارشد

آب و هواشناسي - سينوپتيك

علوم جغرافيايي و برنامه ريزي

بهمن ما 1402

105 ص.

داريوش رحيمي

تغيير اقليم , روند اقليمي , تغيير پذيري اقليمي , زير حوزه لجنات

اين پژوهش با هدف بررسي تاثير گرمايش جهاني و تغير اقليمبر عناصر اقليمي دما و بارش با تاكيد بر منابع آب در زير حوزه لجنات تدوين شده است.در ابتدا به بررسي تغييرات اقليمي در منطقه به كمك روش هاي واكاوي روند پرداخته و روند دما و بارش در سطح اين زير حوزه بررسي شد. براي واكاوي روندسريهاي زماني دما و بارش ايستگاه هاي مورد نظر در دما و محدودهو مجاورت زيرحوزه لجنات در مقاطع زماني سالانه، فصلي و سالانه از روش ناپارامتري آماري من كندال استفاده گرديد.

1403/02/22

همدم نوروزي

Climate change , climate trend , climate variability , Lanjanat sub-basin

Assessment Climate Change on Water Resources (Lenjanat Sub-basin)

جغرافياي طبيعي

This research was compiled with the aim of investigating the effects of global warming and climate change on the climatic elements of temperature and precipitation, with an emphasis on water resources in the Lanjanat sub-basin. At first, the climatic changes in the region were investigated with the help of trend analysis methods, and the temperature and precipitation trends in this sub-basin were investigated. Non-parametric Mann-Kendall statistical method was used to analyze the trend of time series of temperature and precipitation of the desired stations in the area and vicinity of Lanjanat sub-basin in annual, seasonal and monthly periods. Also, the Sen’s slope estimator was used to estimate the slope of the trend line. The results of trend analysis on the time series of annual average air temperature show a significant increase in air temperature in most of the stations under study. So that in all the studied stations, the time series of the average annual temperature has a trend at the significance levels of 99% and 95%. The increase in temperature in the past years has had a negative impact on water resources through increased evaporation and transpiration. On the other hand, the increase in winter temperature has caused a decrease in the ratio of solid precipitation to total precipitation, and in this way, sustainable feeding of underground water sources has been challenged. The decrease in winter rainfall and the consequent increase in precipitation in other seasons also confirm the decrease in the ratio of solid precipitation to the total precipitation, and as a result, the lack of effective and sustainable feeding of underground water resources. The results of investigating the effects of precipitation on the river discharge indicate that 93% of the annual changes in the Zayandeh Rood river discharge in the subbasin are explained by the annual variable of the sub-basin and upstream precipitation. The results of the LARS-WG converter on the output of the selected Earth system model, in the near future time periods of 2040-2021, 2060-2041 middle future and 2061-2080 far future for Lanjanat sub-basin, under different climate change scenarios, indicate a decrease in annual rainfall by 5.7 to 7.5 percent in the period of 2040-2021, 5 to 8.2 percent in the period of 2060-2041 and 2.4 to 6.9 percent in the period of 2061-2080 compared to the base period. These changes will decrease the average annual discharge of Zayandeh Rood by 117 1.5 to 1.9 percent in the period of 2040-2021, 1.3 to 2.1 percent in the period of 2060-2041, and 0.6 to 1.8 percent in the period of 2080-2061. The annual temperature forecast also indicates an increase in the average annual temperature by 0.4 to 0.7 Celsius degrees in the period 2040-2021, 1.1 to 1.7 Celsius degrees in the period 2041-2060, and 1.8 to 3.7 Celsius degrees in the period 2061-2080. This increase in temperature will increase annual evaporation and transpiration by 2.8% to 3.3% in the period of 2040-2021, 4.9% to 6.9% in the period of 2060- 2041, and 6.8% to 13.4% in the period of 2080-2061 compared to the base period. This increase in evaporation and transpiration will also have a negative impact on the water resources of the region

5

فاطمه بشيريان

31144