Thursday, December 19, 2013
- The residents of Pakistan’s arid south- eastern Thar region, who had not seen rain for nearly a year, were overjoyed when it poured briefly last month.
This was not nature answering the prayers of the Thar peasants. Over the past year, one of the country’s worst droughts in living memory, has parched their tiny rain-fed farm patches and killed their livestock.
The rain in Thar, like in some other parts of Pakistan’s southern Sindh and Baluchistan regions, was the result of a government initiative to make up for the acute scarcity of rainfall.
During six weeks ending late July, the Pakistan Meteorological Department (PMD) successfully carried out low-cost cloud seeding experiments, which brought artificial rain to some of the country’s most arid areas.
The success of the initiative has raised hopes of battling the current drought, which has killed thousands of livestock and forced hundreds of thousands of people to leave their rural homes in Sindh and Baluchistan.
Announcing its success early August, the chief of the meteorological department, Qamaruzaman Chaudhry, said it was now possible to make it rain even during the summer months in the country’s arid areas.
Of the 24 experiments in the Thar and Cholistan deserts, and in parts of Baluchistan, 15 were successful. Between 30 to 45 mm of precipitation was recorded, which lasted between one to three hours.
Chaudhry told IPS that a second phase of the cloud seeding experiments would be held during the winter months from December to March.
For the last three years, these areas had not got any rain, which is the main source of water for drinking and irrigating farms for the people of Baluchistan and Sindh.
“All these years, either there was no rain, or if there was, then it could not benefit whole of the area. For example, last year, there was 100 mm of heavy rain in a short span of two days in the Thar desert. But all the water seeped into the sand,” said a PMD official.
“If the same amount of rain were spread over a whole month, like five to 10 mm every other day, the impact would have been much more beneficial,” he explained.
An estimated 21 million hectares of farm land in Baluchistan has been parched by the drought. The affected farms met 70 percent of the food needs of the province, which is Pakistan’s largest.
To add to the misery, the water table in these areas is also falling so fast that ground wells have to be sunk to a depth of 200 mt. Not long ago, water could be found just 30 mt below the ground surface.
In early June, the weather office gave a presentation of its cloud seeding plan to Pakistan’s military ruler Pervez Musharraf, who authorised the experiments. These were carried out using army aircraft. The cost of each experiment was a mere 100 U.S. dollars.
The weather office is optimistic, but also “cautious” about future plans. “We can consider using cloud seeding for rains in the catchment areas of dams and water reservoirs, ultimately enhancing drinking and irrigation water resources and the country’s hydel power generation capacity,” PMD chief Chaudhry said.
The idea is not new to Pakistan, which carried out its first cloud seeding experiment way back in the year 1953.
“The then meteorologists claimed 10 to 30 percent success in the experiments. But then the process discontinued apparently because Pakistan then had enough water resources,” said former PMD official, Ghulam Rasul.
Cloud seeding experiments were tried again, but unsuccessfully, in 1986, by the Pakistan Agriculture Research Council, he said. The reason for failure was the “lack of expertise,” according to Rasul.
Weather experts say that success depends on the correct identification of suitable clouds and accurate seeding agents.
“Considering the type of clouds, we have used indigenous and cost- effective sodium chloride, calcium chloride, ammonium nitrate and urea,” PMD chief Chaudhry explained.
Dry ice and silver iodide are used for cloud seeding in the winter months. “When used in super-cooled clouds (composed of water droplets at temperatures below freezing point), they form nuclei around which rain-droplets coalesce,” he said.
The weather office chief says that artificial rain is environmentally safe and practiced in a number of countries to boost crop productivity. It has no effect on regional weather because only a negligible amount of moisture — between one to two percent — is extracted from the clouds.
South Africa, the United States, Thailand, Malaysia, China, some Arab countries and Israel are using the technology.