Predicting The Long-term Effect of Climate Change on Climatic Variables in Humid Region

Water shortage as well as negative effects of climate change on it is a global concern. Long-term variations of the climatic variables due to greenhouse gases emission has a significant effect on the volume of renewable water resources and consequently, on the planning for water allocation to important sectors. Thus, in this research, the long-term effect of climate change on precipitation, temperature and potential evapotranspiration (ETp) was investigated under A1B, A2 and B2 scenarios until 2100 in Mazandaran province. First, using weather data in three stations of Noshahr, Ramsar and Babolsar during base period of 1981-2010, the potential evapotranspiration was calculated based on FAO-Penman Monteith equation. Then, the ability of ANFIS model for estimating potential evapotranspiration using the least data was evaluated. LARS-WG was used to downscale the HADCM3 atmospheric general circulation model data and thereafter, it was used for predicting the climatic variables under A1B, A2 and B2 scenarios up to 2100. A significant increase in minimum and maximum temperature led to a significant increase in potential evapotranspiration during 1981-2100. This incensement was higher under A2 scenario. More incensement in the cardinal temperatures in the cold seasons would change crops cultivation calendar. Totally, it could be concluded that despite the existence of a humid climate in the study area during the base period, significant increase in potential evapotranspiration during the whole year specially, during the cultivation seasons of agricultural products, would cause a severe water crisis in the study area. Regarding a significant relation between crop water use and yield, inattention to increased potential evapotranspiration would threaten food security due to applying severe economic loss.