Implications of Climate Change on Water Resources in Saudi Arabia

Effects of climate change on water resources in Saudi Arabia were investigated. Changes of precipitation, temperature, relative humidity and wind speed were predicted. Net solar radiation was estimated from solar radiation monitoring stations. Changes in reference evapotranspiration (ET_o) were estimated using Penman-Monteith approach. The estimations were performed for 49 grids (2.5° Latitude × 3.75° Longitude) covering Saudi Arabia (Latitude: 16.5 ° N-32.5 ° N; Longitude: 33.75 ° E-56.25 ° E). The averages of ET_o were estimated to be 0.245 and 0.368 m/year (0.343-0.394 m/year) in the year 2011 and 2050, respectively. The rates of ET_o were predicted to be higher in the Southern part than the Northern part of the country. The difference between ET_o and precipitation indicates that there may be a loss of soil moisture by 0.181 m/year (0.042-0.236 m/year) during the period of 2011 through 2050. Increase in temperature was estimated to be 1.8-4.1 °C, which can increase agricultural water demands by 5-15 % to obtain the current level of agricultural productions. This study anticipates significant reductions in water sources, which can impose further stress on agriculture and drinking water sources. Deterioration of source water quality is also expected. This study sheds light on the need for appropriate measures to protect water resources in Saudi Arabia.