Tuesday , 4 October 2022

Iran’s Meteorological Organization projects normal water year

PayvandNews – Iran’s Meteorological Organization (IMO) predicted normal conditions for the next water year (starting on September 23) in the country.

In a press conference, the new director of IMO, Sahar Tajbakhsh, explained that since the beginning of the current water year (September 23, 2018) the precipitation rate has increased by 17.6 percent compared to long-term averages, so it is predicted that the current desirable conditions will last in the spring as precipitations levels will hit normal and above normal levels.

Accordingly, precipitations for the next water year appear to be normal, Tajbakhsh highlighted.

However, IMO director highlighted that the increase in precipitation amounts in the current year and next year does not necessarily mean that drought spells are over in the country.

“There are different kinds of drought including meteorological, hydrological, and agricultural droughts,” she said, adding that drought spells do not solely depend on increased precipitation levels, as depletion of groundwater resources also plays a significant role in giving rise to droughts.

Sahar Tajbakhsh
New director of Iran’s Meteorological Organization (IMO)

Meteorological drought is defined on the basis of the degree of dryness, in comparison to a normal or average amount, and the duration of the dry period.

Data sets required to assess meteorological drought are daily rainfall information, temperature, humidity, wind velocity and pressure, and evaporation.

Agricultural drought accounts for the susceptibility of crops during different stages of crop development. Deficient topsoil moisture at planting may hinder germination, leading to low plant populations per hectare and a reduction of yield.

Data sets required to assess agricultural drought are soil texture, fertility and soil moisture, crop type and area, crop water requirements, pests, and climate.

Hydrological drought refers to a persistently low discharge and/or volume of water in streams and reservoirs, lasting months or years. Hydrological drought is a natural phenomenon, but it may be exacerbated by human activities. Hydrological droughts are usually related to meteorological droughts, and their recurrence interval varies accordingly. Changes in land use and land degradation can affect the magnitude and frequency of hydrological droughts.

Data sets required to assess hydrological drought are surface-water area and volume, surface runoff, stream flow measurements, infiltration, water-table fluctuations, and aquifer parameters.

Tajbakhsh went on to say that regarding meteorological and agricultural droughts, taking recent rise in rainfall levels into consideration, the conditions have improved, nevertheless in respect of hydrological drought the situation have not ameliorated yet.

Elsewhere in her remarks, IMO director explained that during the Persian New Year holidays (starting on March 21) the weather conditions may not suit travelers as “we get rainfalls and snowfalls sporadically during the two-week holiday.”

Owing to low temperatures and increased precipitation during spring, snowpack won’t start melting anytime now which is good news as the supply of water coming from melting snow will not be exhausted, she noted.

As per the data released on Monday by the National Drought Warning and Monitoring Center affiliated to IMO the whole country received 199.8 millimeters of precipitations since the beginning of the current water year (starting on September 23) which indicates a 22.9-percent rise compared to the long-term averages.

Moreover, the amount also shows a 132.8-percent increase compared to last year’s precipitations in the corresponding period.

This is while last year’s precipitation in the same period displays a sharp drop of 47.2 percent compared to the long-term means.

Provinces of Ilam, Lorestan, and Golestan have experienced the highest rise in precipitation amounts in the same period compared to long-term averages while provinces of Kerman, Sistan-Baluchestan, and Yazd on average have suffered 19 percent drop in precipitations.

It is generally hoped that precipitation deficiencies will be overcome by the rainfalls the country receive in the spring.

… Payvand News – 03/19/19 … —