The Effect of Tree Plantations on Moderating Air Temperature in Arafat, Makkah for the Period 2002-2016

Abstract

Recently many studies have shown that average temperature has increased globally. However, temperature trends vary in different parts of the world due to local geographical, climatic, land usage and various socio-economic factors. This study focuses on temperature trend in Makkah and intends to investigate the effect of vegetations on temperature trend. Temperature trend is analyzed from two meteorological monitoring sties in Arafat and Waly Al-Ahd area for the period 2002-2016. The two sites have demonstrated opposite trends from each other for the above period. In Arafat area temperature has not increased and has rather decreased during the last 15 years (-0.05oC/year). The negative trend in Arafat was more evident since 2009 (-0.21oC/year). In contrast, Waly Al-Ahd area demonstrated positive significant trend (+0.14oC/year). In Arafat area mass tree plantation has taken place during the last couple of decades. Furthermore, Arafat has experienced no urbanization, as it is one of those Holy areas that are reserved for the purpose of Hajj. During the study period greenery in Arafat area has increased significantly since the plantation project was started in 1986. In contrast rapid urbanization, resulting in increase in energy use, road traffic, and change in land usage has led to temperature rise in most parts of the Makkah City including Waly Al-Ahd. This study shows how local factors, such as vegetation can affect local temperature trend. Arafat tree plantation project can be used as a good example to encourage more tree plantation in the Holy sites to cope with the increasing heat in the coming decades. Trees also provide shelter from the blazing sun, especially during Hajj season in Makkah, where temperature reaches as high as 50oC in summer months and probably will continue to rise in the future.