Rainfall Trends and Impact on Water Resources: Case of Southwestern Saudi Arabia

The various annual reports of the Intergovernmental Group of Climate Experts (IPCC) affirm that the earth has been experiencing climate change for nearly half a century, resulting in a thermal increase and a decrease in rainfall. This substantiated in several studies. In Saudi Arabia, where the climate is characterised by low rainfall and high temperatures, it has attracted the attention of several studies. Some have looked at thermal rise while others have looked at rainfall trends. In this study we seek to take stock of the evolution of rainfall quantities at different time scales in the southwest of this country during the period 1985–2020. To do this, we use the rainfall data of seven stations located in a space that is distinguished by a physical duality, and hence a rainfall duality. Indeed, contrasting a relatively rainy west opposed to an eastern area where the rainfall is low. Does this situation create a duality of water resources? Statistical processing and graphic translation are an effective way of accurately capturing and quantifying this evolution. This will allow a focus on the impact on water resources. Such resources are a necessary guarantee for any sustainable development.