How do blue ecosystem services respond to drought resulting from climate change

Climate changes have a significant impact on the blue ecosystem especially watershed's ecosystem services. Nowadays, increasing air Temperature (Ta), Land Surface Temperature (LST) and drought are consequences of climate change affecting the access to water sources directly. The aim of this study is to evaluate the climate change effects on the ecosystem services such as Ta and LST regulation and drought reduction in the Tajan watershed, Northern Iran. Landsat ۸ OLI satellite images used to investigate LST and drought indices include Vegetation Health Index (VHI), Temperature Condition Index (TCI), Vegetation Condition Index (VCI), Soil Adjusted Vegetation Index (SAVI) and Normalized Difference Vegetation Index (NDVI) from July to September during ۲۰۱۳ to ۲۰۲۳. The results indicated that the LST minimum and maximum value at Tajan watershed had an upward trend from ۲۰۱۳ to ۲۰۲۲. In other words, the mean value of LST increased by ۸ ℃ in the watershed during the period of ۱۰ years. Also, analyzing drought indices showed that the drought has increased significantly in the central, eastern, and southeastern parts of Tajan watershed from ۲۰۱۳ to ۲۰۲۲. The drought indices results demonstrated that vegetation cover and climate change have significant effects on LST trends. Therefore, it can be said that climate change, vegetation cover destruction and also converting forests and agriculture land to residential and barren lands increase the LST and drought in Tajan watershed, hence significantly impact on its ecosystem services. Findings indicated that severe drought and heat islands will occur in Tajan watershed in the future.

کلیدواژه ها:

Vegetation ، Drought ، Land use ، Thermal islands ، Tajan watershed