TEHRAN –The first scientific seminar on the role of probable regional factors in lowering the volume of rainfalls in the country will be held this week.

Due to the decrease in annual precipitation, particularly this year, the Department of Environment has asked its subsidiaries to carry out a detailed study on climate change and its causes.

Despite the Meteorological Organization’s forecasts that there would be adequate autumn rainfall, the amount of rainfall reported has been very low, IRNA reported.

Salajeqeh has asked the Office for Marine Environment and Wetlands, the National Climate Change Research Center, and the Environmental Research Institute to cooperate and investigate the causes of low rainfall this year.

Climate change

In recent years, the issue of climate change has even become one of the major political issues of the world so the United Nations and many other governments have gotten involved in this issue.

Thanks to the climate change, the air temperature has increased. Warmer temperature increases the rate of evaporation, a good example of which is the Caspian Sea's reduced volume of water.

On the other hand, there has been a noticeable decrease in the amount of snowfall in the country and a change in the pattern of precipitation from snow to rain can be seen. But the total amount of rainfall has decreased as well.

Climate change has already inserted many harmful effects on our country, and if we do not take steps to adapt ourselves to the consequences of this phenomenon and observe environmental principles, in the future, more dangerous consequences will surely plague Iran and make the conditions more unfavorable for human, animal, and plant species.

Moderate to severe drought in past 3 years

According to the data released in September by the Meteorological Organization, most parts of the country were affected by moderate to severe drought over the past three crop years.

Only some provinces did experience normal precipitation.

The crop year, from September 23, 2022, to September 22, 2023, recorded a cumulative rainfall of 188.8 mm, a 6.2 percent increase compared to 177.7 mm in its preceding year.

However, in comparison to 236.1 mm long-term rainfall, the figure shows a 20.1 percent decrease.

Also, the cumulative rainfall of the country reached 180.4 mm in the crop year from September 23, 2021, to September 22, 2022, which showed a 23.3 percent increase compared to the previous year.

It was 23.9 percent less than the long-term cumulative rainfall which was 237.1 mm.

In the crop year from September 23, 2020, to September 22, 2021, the precipitation reached 143.4 mm, showing a 50.8 percent decrease compared with 291.7 mm in the previous year and 39 percent less than the long-term rainfall which was 235.2 mm.

El Niño anomaly increasing precipitation

The National Center for Drought and Crisis Management has forecasted during the coming autumn and winter, the country will likely face a moderate El Niño event.

In case of being accompanied by other effective factors, it will cause normal precipitation in different regions and heavier than normal rainfall, especially in the western half of the country.

It should be noted that "El Nino" is one of the world's famous weather cycles that causes great anomalies in the climate of the entire planet every 2 to 7 years.

Rainfall forecast for autumn

On August 16, the meteorological organization predicted normal rainfall and more-than-normal temperatures for the country in the autumn of this year.

Normal and even more than normal rainfall is predicted for the autumn, Sahar Tajbakhsh, the head of the organization, said.

“Taking into account the trend of greenhouse gas production in the world, we can expect an increase in temperature compared to the normal level,” she added, ISNA reported.

The rise in temperature also occurred during the past year, but due to the natural heat in the summer, the heat was felt more, the official noted.

The National Center for Drought and Crisis Management has predicted precipitation in the autumn of this year will be at normal levels.

“The changes that are happening in the large-scale atmospheric indicators forecast that precipitations in autumn will start on time and will be normal with a high probability,” ISNA quoted Ahad Vazifeh, the head of the National Center for Drought and Crisis Management, as saying on June 11.

In summer, there would not be much rainfall in the country and less than 10 percent of the annual rainfall would occur in this season, he added.

Iran has a dry and semi-arid climate and has an annual rainfall of 250 mm, which is about one-third of the global average.

The average rainfall of the country has been decreasing over time so the average rainfall of the country for 53 years was about 250 mm, but the average of the last 13 years has decreased to 232 mm.

In May, the National Center for Drought and Crisis Management forecasted the summer this year would be warmer than normal in the country.

In the northern and eastern provinces of the country, the rainfall is insufficient, and even the relatively normal rainfall of the remaining days of the current water year cannot compensate for the lack of rainfall.

The month of Ordibehesht (April 21-May 21) is the most important period in the spring season to receive rainfall in the country and is very important.

MT/MG