The head of Iran Meteorological Organization has denied the speculations that the recent downpours across Iran have resulted from cloud seeding projects or other human efforts.
"Over the current water year [started Sept. 23] no cloud seeding project has been carried out… The low precipitation in winter and favorable rains in spring cannot be attributed to human efforts," Davoud Parhizgar was quoted as saying by IRNA.
The official noted that the present condition stems from natural atmospheric and oceanic oscillations across the Arctic and the tropical eastern Pacific Ocean.
"The phenomenon had a negative impact on Iran in the cold season which gradually recovered in the spring. The condition is expected to continue by the end of the season and slightly make up for the water year's below-normal precipitation," he said.
The abundant springtime rainfall following a rather dry fall and winter have come as a surprise to many who attribute it to human efforts such as cloud seeding.
Cloud seeding involves the dispersion of certain substances into the clouds to induce rain.
History of Practice
The use of the technique dates back about 70 years and the first operation was conducted in Iran around 40 year ago across the catchment area of Karaj Dam, 63 kilometers northwest of Tehran.
Later, a center for cloud seeding was established in Yazd Province and carried out its first project in the Shirkouh region in cooperation with a Russian company.
The plan then covered many of the provinces around Zagros Mountains range.
However, the effectiveness of the method is open to question.
According to Parhizkar, the practice did not eventually manage to address the constant drop in precipitation levels.
"In provinces such as Yazd, Fars, Isfahan, Kohgiluyeh-Boyer Ahmad and Chaharmahal-Bakhtiari, the shortage has even worsened," he said.
Local Climate at Issue
He maintained that the method has been proven ineffective in various analyses, especially given the climatic conditions of the region.
"Dispersing ice nuclei into the cloud is only justifiable when the natural amount of the substance is insufficient. This is while in many cases in Iran, the clouds that are naturally expected to cause heavy rains are rendered non-productive by dust particles and pass over the country without pouring down," he said.
Vain Hope
He referred to cloud seeding as "superficial approach" that only creates false optimism, eventually causing the public and authorities to take the issue less seriously.
Besides, the potential effect of the practice is meager and unworthy of spending money.
Parhizkar said at the best conditions, it can only increase rainfall by an average of 10%.
In Iran, "if operated precisely and with the best possible technology, it can only boost precipitation by 3% or even less by 1%, considering the high rates of evaporation that reach 10 times the amount of rain," he predicted.
Substitutes
Many countries have abandoned cloud seeding and put more logical methods on the agenda.
Management of consumption based on the amount of renewable water, treatment and recycling water, improvement in irrigation systems, cultivation of appropriate crops and importing water intensive products, sustainable agricultural practices and raising public awareness through the media are among alternative methods according to the official.
