Indian Cloud-seeding Project Aims to Produce Rain to Clear Pollution

2023-11-23 14:40:11来源：网络

Indian Cloud-seeding Project Aims to Produce Rain to Clear Pollution

印度的人工增雨项目旨在产生雨水以清除污染

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　　By Bryan Lynn

　　22 November 2023

　　Indian scientists plan to add substances to clouds above the capital New Delhi in an effort to produce rain to reduce pollution.

　　The method to artificially produce rain is called cloud seeding. The process involves adding different chemicals to clouds to cause rain. When rain falls from the sky, water droplets can attach to pollution particles and bring them down to the ground.

　　New Delhi has been rated the city with the most air pollution in the world. Reports say the problem has worsened across the city in recent weeks.

　　Air quality decreases in the city ahead of winter each year. During this time, cold air can trap many pollutants, including gases from vehicles, industry, building projects and agricultural burning.

　　Scientists expect some clouds over the city around November 20. They hope the clouds will result in heavy rainfall – when sprayed with a salt mixture.

　　The project is being led by Manindra Agrawal, a scientist at the Indian Institute of Technology in the central city of Kanpur. He told Reuters news agency the salt mixture will include silver iodine to help produce rain. It is to be sprayed on clouds over a 100 square kilometer area. Agrawal said the project will cost about $120,000.

　　The local government in New Delhi, a city of 20 million people, has already closed schools, stopped building activities, and said it will place restrictions on vehicle use to control pollution.

　　The air quality index in the city was 506 on November 9. This level is considered "hazardous" by IQAir, a Swiss company that describes itself as an "air quality solutions" business.

　　Gufran Beig is head of the Indian government's air-quality measuring agency SAFAR. He told Reuters the city needs heavy and widespread rain to wash away the pollutants. Beig added that light rain could worsen the situation.

　　The SAFAR head said current airflow is carrying smoke from crop burning in the states of Punjab and Haryana to Delhi. This smoke adds to the city's existing pollution sources. "So, unless a huge pressure is established by intense rain, this chain of transport from Punjab to Delhi will not be broken," Beig said.

　　About 38 percent of pollution in the capital has been caused by stubble burning in Punjab and Haryana, a recent government statement said. Farmers carry out stubble burning to clear material left behind from rice harvests so they can plant other crops. Indian officials directed leaders in both states to "take effective actions" to identify and limit stubble burning, the statement added.

　　Officials in New Delhi are seeking approval for the project from the Supreme Court, Reuters reported.

　　Several countries have used cloud seeding in an effort to produce rain, improve air quality and water crops in times of extreme dryness. These include Mexico, the United States, China, Indonesia and Malaysia.

　　I'm Bryan Lynn.

　　Reuters reported this story. Bryan Lynn adapted the report for VOA Learning English.

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　　作者：Bryan Lynn

　　日期：2023年11月22日

　　印度科学家计划在首都新德里的云层上添加物质，以产生雨水来减少污染。

　　这种人工产生雨水的方法被称为人工增雨。这个过程涉及向云层添加不同的化学物质以引发降雨。当雨水从天空落下时，水滴可以附着在污染颗粒上，将它们带到地面。

　　新德里被评为全球空气污染最严重的城市。报道称，近几周这个问题在整个城市中都有所恶化。

　　每年冬季来临之前，该城市的空气质量都会下降。在这个时候，冷空气可以困住许多污染物，包括来自汽车、工业、建筑项目和农业燃烧的气体。

　　科学家预计大约在11月20日左右，城市上空会有一些云。他们希望这些云在被盐混合物喷洒后会产生大雨。

　　这个项目由位于卡纳普尔市的印度理工学院的科学家Manindra Agrawal领导。他告诉路透社，盐混合物将包括碘化银以帮助产生雨水。这种混合物将被喷洒在一个100平方公里的区域上的云层上。Agrawal说，这个项目的成本将约为120,000美元。

　　新德里的地方政府已经关闭了学校，停止了建筑活动，并表示将限制车辆使用以控制污染。新德里是一个有2000万人口的城市。