Early Initiatives
Artificial Rain Experiments in Tamil Nadu: Tamil Nadu began exploring artificial rain-making in 1970 through discussions between the India Meteorological Department (IMD) and the State government. The first trials were conducted in 1973 around Tiruvallur by the Indian Institute of Tropical Meteorology (IITM). These initial efforts, however, did not yield conclusive results.
Static GK fact: The Indian Institute of Tropical Meteorology is headquartered in Pune and specializes in climate research and monsoon studies.
International Trials
In 1975, a Canadian firm carried out cloud-seeding operations over Chennai and the Nilgiris at a cost of ₹12 lakh, reporting approximately a 20% increase in rainfall. Further operations were undertaken in 1983 by an American team led by Thomas Henderson, costing ₹26 lakh, followed by additional trials in 1984.
Static GK Tip: Cloud seeding involves dispersing substances like silver iodide or sodium chloride into clouds to stimulate rainfall.
State Government Initiatives
To strengthen its cloud-seeding capacity, the Tamil Nadu government purchased an aircraft in 1983 specifically for artificial rain experiments. In 1993, new trials were conducted, but scientists observed that the rainfall increase did not exceed 20% above normal levels.
Later Developments
Plans to resume artificial rain-making were announced in 2003 under Chief Minister J. Jayalalithaa, but these were not implemented due to unsuitable weather conditions. Over the years, with the construction of Krishna water projects, the Veeranam tank, and desalination plants, the reliance on artificial rain-making has become less critical for the State’s water security.
Static GK fact: The Veeranam tank, one of the largest in Tamil Nadu, was originally built during the Chola period and continues to serve water needs for Chennai city.
Impact and Relevance
Artificial rain experiments in Tamil Nadu provided valuable data for meteorological research and demonstrated the challenges of cloud-seeding under variable weather conditions. While initial trials showed moderate success, modern water infrastructure has reduced the State’s dependence on artificial rainfall methods.
Static GK Tip: Desalination plants in Chennai, such as Minjur and Nemmeli, contribute significantly to urban water supply, especially during dry seasons.
Static Usthadian Current Affairs Table
Artificial Rain Experiments in Tamil Nadu:
| Topic | Detail |
| First cloud-seeding trial | 1973, Tiruvallur by IITM |
| Canadian operation | 1975, Chennai and Nilgiris, ₹12 lakh, ~20% rainfall increase |
| American operation | 1983, led by Thomas Henderson, ₹26 lakh |
| State aircraft purchase | 1983 for cloud-seeding |
| 1993 trials | Rainfall increase ≤ 20% |
| 2003 plan | Announced by CM J. Jayalalithaa, not implemented |
| Modern water sources | Krishna water, Veeranam tank, Desalination plants |
| Cloud seeding method | Dispersing silver iodide or sodium chloride |
| Veeranam tank | Built during Chola period, serves Chennai |
| Desalination plants | Minjur and Nemmeli, urban water supply |
