Is artificial rainfall a solution?

The increase in the severity and frequency of regional droughts in our country has also increased the search for urgent solutions in some of our major cities. In this context, the Ankara Metropolitan Municipality and the Izmir Metropolitan Municipality have begun research on ‘artificial rainfall and rainfall enhancement’.

There is no clear consensus on the results obtained from this method, which has been tried in various countries. Experts on the subject indicate that this method is being implemented but also share uncertainties about its effectiveness. Water is a vital resource for which there is constant demand and for which no substitute can be found. Therefore, ensuring a continuous and sustainable water supply is of great importance.

When water supply security is at risk, water services management quickly seeks emergency solutions to overcome the crisis before it deepens. During this period, efforts are made to increase water supply, such as drawing water from the dead volume of dams, obtaining additional water from groundwater, and using water periodically from dams intended for different purposes.

These efforts are appropriate and should be implemented as crisis period measures, given the potential for a deepening water crisis to directly pose a public health risk. In addition to these measures, some emergency solutions, such as ‘artificial rainfall and packaged seawater desalination plants,’ are also being discussed as the water crisis approaches. For sustainable water management, all technological developments can be evaluated within short, medium and long-term solution alternatives. However, the most appropriate solution in social, economic and ecological terms should be implemented. In this period of increasing climate change impacts, the most important policy for water management should be the most efficient use of available water and preparation for drought risk management.

Care must be taken to ensure that emergency water supply solutions during high-risk periods do not become permanent practices that are economically and ecologically unviable, given the many steps that need to be taken in water management. It is not possible to sustainably solve emerging water problems with the ‘short-term emergency solutions’ of advanced technology, moving away from the principles of planning and efficiency. Therefore, water services management should use technological developments primarily to increase efficiency and to effectively and widely implement a planned, participatory, transparent water policy that respects the natural balance.

I present below some explanations from the conclusion section of an article on the website of the General Directorate of Meteorology on the subject of artificial rainfall, which has been much discussed recently, as I believe they will be useful.

"Cloud seeding applications form the basis of artificial rainfall studies. Cloud seeding is an air modification method used to influence the physical processes occurring in clouds by scattering various chemicals, primarily silver iodide, into the clouds to change the amount and type of rainfall. Rain enhancement operations require sufficient quantities of suitable clouds for seeding. The underlying reason for the current rainfall deficit in our country is the low cloud formation under the influence of high-pressure systems and the absence of cloud cover suitable for seeding.

Artificial rainfall through cloud seeding is an air modification process with potential for application in regions where the benefit/cost analysis is favourable and can only be applied to clouds with suitable temperature and humidity conditions.

After cloud seeding, it is not possible to control where the rainfall will fall. Even if cloud cover is suitable, it is uncertain whether the precipitation resulting from seeding will fall in the target basin. It is claimed that, under the right conditions, cloud seeding carried out in accordance with the technique can increase rainfall by 5-20 per cent. However, the extent of the increase in rainfall cannot be measured scientifically and with certainty.