Recent Changes in Annual Rainfall over Southern Taif Province, Saudi Arabia.

This study has primarily aimed at determining recent changes in rainfall over southern Taif province, Saudi Arabia. Interest has been focused on trend detection of annual rainfall at selected stations for the last four decades ending in 2004. The study has been introduced by a brief summary of the general characteristics of rainfall on the annual, seasonal, and monthly levels as well as inter-annual variations. Rainfall trends were calculated by means of the linear model of the Least Squares Method. The importance of the study lies from the fact that it is considered as a contribution to the subject of climate change in this part of the world. In addition, it can be viewed as an introduction to more comprehensive and detailed studies in the field of Environmental Assessment studies especially as they relate to climatic changes. Results have shown negative trends for the majority of the stations in the study area, with Al-Shafa station as the only exception where annual rainfall showed a positive direction of 1.03% over the study period. The results have also indicated negative rainfall trends which ranged between (- 0.32%) and (- 44.80%). Due to such a wide range, it is expected that similar levels of variations would have been resulted in regards to the extent to which the ecology, hydrology, and soil conditions are affected due to such decreasing trends of rainfall in the study area. Therefore, the study concluded that further studies are to be recommended. Attention should be focused on the determination of those part(s) of the year that are mainly responsible for the decreasing trends. Special attention is also needed for determining the exact extent of environmental effects regarding such areas as the ecology, the hydrology, and the levels of agricultural production in the study area. [ABSTRACT FROM AUTHOR]