Rainfall amount in Saudi Arabia and a technique to increase the rainfall by cloud seeding

الملخص EN

This paper summarizes the rainfall measurements in Saudi Arabia by utilizing the rainfall data covering a 23-year period from 1970 to 1992 collected at 26 Saudi Arabian surface meteorological stations.

Investigations showed that Saudi Arabia has two different lands in term of precipitation: semi-arid in the southwest; and arid in the rest.

The main difference between these two regions is the amount of rainfall that they receive.

The observational analyses also indicated that the amount of annual rainfall measured over the southwestern part of Saudi Arabia, so called Asir region, have substantially decreased in recent years.

This mountainous region, known indeed as the rainy region of Saudi Arabia, has received less than 150 mm/year mean annual rainfall since 1987, as compared with a previous value of about 250 mm/year.

Because this study demonstrated the insufficient rainfall across the Kingdom, it is also one of the prime purposes of this paper to briefly discuss the alternative source to increase and enhance the rainfall by cloud seeding techniques in the Kingdom, particularly in the Asir region.

This region has a unique geographic setup, so that it has the highest potential to develop orographic and convective clouds throughout the year.

The seeding is generally carried out with the intent of adding to the cloud certain particles to start the reaction of raindrop development.

It involves many seeding particles and is done with the objective of enhancing the rainfall amount from the cloud.

The earlier cloud seeding experiments have indicated that 10 to 20 per cent increase in rainfall may be produced after the seeding.

Such a cloud seeding experiment program is needed, and it should be started in the Asir region of Saudi Arabia, in order to meet the demand for water supplies in the near future.