Yangon RainfallRain Yangon
Growers, pundits struggle with new precipitation pattern
Drought, flooding, hurricanes, un-seasonal rainfall - we have had all this in recent years. Whilst in some cases growers are losing their whole crop - such as during hurricanes Nargis and Giri - the consequence of unforeseen climatic conditions is more often a reduction in yield. The possible effects of major changes in precipitation pattern are serious in a land where up to 70 per cent of the workforce is engaged in farming.
Precipitation patterns, which we now regard as "normal", have been relatively stable here for several hundred years and influence both the economy and society. This is exemplified by the famous nursery-rhyme " Set Ni Yarthi Moe " (The Twelve-Seasonal Rains ), which mentions the properties and advantages of year-round rain.
However, meteorologist Dr. Tun Lwin, former general manager of the Department of Meteorology and Hydrology, says that "reliable" precipitation is largely a thing of the past. "South Asian monsoon breezes gave the land a very dependable and favourable rainfall patterns for agronomy. The monsoon rains are very common in space and temporal conditions.
The rainfall is about 90 per cent of the country's rainfall," said Dr Tun Lwin. "However, winds of monsoon" - and thus precipitation pattern - "have been biased since 1978, and very often extraordinary meteorological incidents have taken place since then," he said. Earlier, the monsoons began in mid-May and broke off in mid-October.
In addition, the winds of the monsoons are not as even as in the past, which also changes the precipitation patterns. There has also been a reduction in the number of the monsoons in the Bay of Bengal - which normally do not turn into cyclions, but generate large rain-generating clouds which reduced the overall rainfall, particularly from 1978-98.
"From 1999 on, monsoons have recovered to some degree, but the season is still short, and other elements, such as the current and the force of the winds, have also altered. As a result, the water is raining at a higher level of intensitiy, but not evenly distributed," said Dr. Tun Lwin. "is that it only drizzles when and where the gale comes through.
It' can only be forecast just before a gale comes... and the rains are usually very heavy and can cause torrential waters and landslides," he said. That was evident at the end of last year's rainy period, when storms in August and September led to floodings in the community of Mahlaing in the Mandalay region and in the Bago region.
The Ayeyarwady region experienced a shortage of precipitation at the same period, which significantly decreased harvesting. "Now we no longer see the same patterns and the same point in the"'normal' rainy season. The World Meteorological Organization states that the atmosphere is generally described by a 30-year mean in the form of superficial variations such as precipitation, temperatures and winds.
Obviously, this new rainy season rains cause many difficulties for the farming industry and are a major concern not only for growers but also for the farming professionals who are trying to improve efficiencies and productivity. The problem of unforeseeable precipitation, however, is not as easy to deal with as, for example, rain-related illness. It seems that the answer is a mix of science and science and the skills of growers at grassroots level.
Agricultural scientist Daw Than Than Than Soe, Assistant Head of the Agronomy Division, is working intensively on the question of which cultivation methods work best in the event of unforeseen rainfall. It said growers need an "injection of science". We are also looking for appropriate technical assistance to help them deal with rainfall, especially for rainy farmer," she said.
Approximately half of all cultured paddy is considered rain-fed, while another 20 pcs. have a dam system for accessing irrigation canals. "The use of appropriate strains and the focus on forecasting when the storm will start are critical to resolving rain-related problems," she said.
Mr U Khin Soe said that instead of relying on the 30-year mean, Division uses 10-year and one-year precipitation and temperatures samples to forecast what will occur in the next 12month. On the basis of this forecast, they work out which crops and varieties are to be used in a particular area and when they are to be cultivated.