|Tuesday, June 01|
Forecasting increase in irrigation water demand under different climate change scenarios (Case Study: Quebec City, Canada)
* Hossein Bonakdari, Laval Univeristy, Canada
Hamid Golabi, Canada
Bahram Gharabaghi, Canada
One of the important adverse effects of global climate warming is the increase in agricultural water demand, due to higher evapotranspiration, which causes severe challenges for already stressed freshwater water resources. The crop evapotranspiration is a crucial parameter for the crop yield simulation and the optimization of the irrigation water system design and operation. The present study investigates the potential effects of climate change on reference evapotranspiration (ET0) through an assessment of the precipitation deficit (PD) and the vapor pressure deficit (VPD) under different climate change scenarios in Quebec City, Canada. The observational data of daily temperature and precipitation for the period 1961-1995 in metrological Jean Lesage International Airport climatological station were used to investigate the effect of climate change on ET0, PD, and VPD. To perform this analysis, the CanESM2 climate model was used under RCP2.6, RCP4.5 and RCP8.5 scenarios and using a hybrid regression/weather-generator model, minimum temperature (Tmin), maximum temperature (Tmax), mean temperature (Tmean) and precipitation (P) for the periods 2021-20501 and 2051-2080 were projected. Then, using projected variables, ET0, PD, and VPD were calculated and compared with corresponding values 1961-1995. This study showed that temperatures would increase in both periods, and this increase is more in winter and spring seasons. Precipitation will increase in all seasons relative to the base period. ET0 and VPD are similar to temperatures in both periods, and this increase is higher in spring. Overall, these results show that the area's climate will become warmer and drier in the coming years. On the other hand, the increase in temperature will result in a decrease in snowfall and will reduce the storage and supply of water to the area through the gradual melting of snow in mountainous regions. Reduced snowfall results in increased heavy precipitation and floods, and leaching of fertile soils. Due to reduced precipitation and increased ETo in the spring, agricultural sectors will demand significantly more water. Therefore, to adapt to these changes in the future, managers should take the necessary measures to reduce the consequences and adapt to the new climate.