HARARE - As the country continues to experience sporadic rainfall, the Meteorological Services Department has dispatched two planes in the northern and southern regions to begin its annual cloud seeding programme.
Forecaster Tich Zinyemba yesterday told the Daily News that cloud seeding is being conducted across the country.
According to Zinyemba, the national cloud seeding exercise will be conducted for the whole duration of the 2016 season.
“The need for cloud seeding is premised on the intent to increase precipitation (rain) over the country and augment water availability for different socio-economic purposes. It was forecast that the country would likely receive below normal rainfall for the 2015/2016 rainfall season.
“In fact, as at 13 January 2016, 95 percent of the country had received rainfall less than 75 percent of their long-term average rains,” he said.
Zinyemba added that for cloud seeding to be effective, there should be clouds that are capable of producing rains.
In cloud seeding, a chemical compound known as silver iodide is injected into the clouds, where updraft or upward-moving air currents carry the silver iodide into the passing clouds.
“The silver iodide is very hydroscopic, and water vapour immediately condenses on these microscopic seeds as ice crystals. The crystals grow larger and larger until they become large enough to overcome the forces of ‘uplift’ in the cloud and fall as rain,” he said.
As the dry spell persisted, government early this month organised traditional and religious rites in a desperate bid to conjure the much-needed rains.
The current dry spell has had an adverse effect on the country’s agricultural sector and also power generating capacity as the water levels in Kariba Dam dwindle.
Weather patterns the country is currently experiencing are attributed to the El Nino phenomenon, a climatic pattern that occurs above the Pacific Ocean every five years and causes extreme weather conditions such as droughts and floods in many regions of the world.