The Myanmar Times
Monday, 22 December 2014
The Myanmar Times
The Myanmar Times

Farmers, experts grapple with new rainfall patterns

A farmer in Yangon Region transplants paddy. (Kaung Htet / The Myanmar Times / April 04, 2011)A farmer in Yangon Region transplants paddy. (Kaung Htet / The Myanmar Times / April 04, 2011)

Complaints about the fickle weather have become a common refrain around the country’s many farms. Droughts, floods, cyclones, unseasonal rains – we’ve had it all in recent years.

While in some cases farmers lose their entire harvest – such as during cyclones Nargis and Giri – more often the result of unpredictable weather is reduced yields.

“It is rare to harvest a full yield these days,” said U Htay Thein, a farmer from rural Monywa township in Sagaing Region. “The rain does not come at the right time. In many seasons we are just hopeful of making enough back to cover our investment costs.”

“The rain is so random,” agrees Daw Mya Khin, who owns a 7-acre rain-fed farm in Pauk township, Magwe Region. “I really have no idea how to grow crops when the rain is so unpredictable. For us farmers it feels like every season we are just gambling on when the rain will come.”

Global climate change appears to be responsible for this trend, which has shown no signs of slowing down. In a country where as much as 70 percent of the population is employed in the agriculture sector, the potential consequences of large changes to rainfall patterns are serious.

The rainfall pattern that we now consider “normal” has been relatively settled here for several hundred years, influencing both economic development and culture. The latter point is illustrated by the popular children’s rhyme “Set Ni Yarthi Moe” (The Twelve Seasonal Rains), which assigns specific names to seasonal rains, listing their characteristics and benefits.

But weather expert Dr Tun Lwin, a former director general of the Department of Meteorology and Hydrology, says that “reliable” rainfall is largely a thing of the past.

“The South Asian Monsoon winds gave the country a very reliable and beneficial rainfall pattern for agriculture. Monsoon rain has a widespread distribution pattern both in terms of time and area. It is responsible for about 90 percent of the country’s total rainfall,” Dr Tun Lwin said.

“But monsoon wind patterns” – and therefore rainfall patterns – “have been distorted since 1978 and unusual weather events have occurred very often since then,” he said.

Research conducted by the Department of Meteorology and Hydrology shows that since 1978 monsoons have arrived later and withdrawn earlier from Myanmar.

Previously, the average monsoon began in the middle of May and departed in the middle of October. However, over the past three decades monsoons began arriving on average at the end of May and leaving in mid-September.

Additionally, the strength of the monsoon wind is no longer as uniform as before, which also alters the rainfall pattern.

The number of monsoon storms in the Bay of Bengal – which do not normally becomes cyclones but produce major rain-producing clouds – has also declined, reducing total annual rainfall, particularly from 1978-98.

“Starting from 1999 we saw monsoon rainfall recover to an extent but the [monsoon] period remains shorter and other factors, such as the flow and strength of wind, have also changed. The effect is higher intensity rain but not a uniform distribution,” Dr Tun Lwin said.

Changes have also occurred in the pre- and post-monsoon seasons, which have seen more cumulonimbus clouds, tornados, thunderstorms and cyclones. However, this has provided little relief to the agriculture industry.

“The nature of storm rain is that it rains only when and where the storm passes through. It can be predicted only shortly before [a storm] occurs … and the rain is usually very intense and can cause flash floods and landslides,” he said.

This was illustrated at the tail end of the monsoon season last year, when storm rain caused flooding in Mandalay Region’s Mahlaing township and Bago Region in August and September respectively. At the same time Ayeyarwady Region was experiencing a lack of rain that reduced crop yields significantly.

“We no longer see the same reliable pattern and timing of the ‘normal’ monsoon seasonal rains. It is the same elsewhere in ASEAN and other countries in the Asia Pacific region. I expect this will continue for another 20 years, completing a 30-year weather cycle,” he said. According to the World Meteorological Organisation, climate in terms of surface variables such as rainfall, temperature and wind is usually described through a 30-year average.

This new pattern of rain obviously poses many problems for the agriculture sector, and is a headache not only for farmers but the agricultural experts trying to increase efficiency and production.

“The irregular rain patterns have significantly impacted on the agriculture sector,” said U Khin Soe, director general of the Department of Agricultural Research at Yezin in Nay Pyi Taw. “We are hearing about crop failures because of irregular rain. The [increase in] temperature is not as serious but it is also starting to have an effect in some areas. We are working to find solutions to those problems.”

However, the issue of unpredictable rainfall cannot be dealt with as easily as, for example, rain-related diseases. The solution appears to be a mixture of scientific research and technology and farmers’ local knowledge.

“Agricultural problems concerning climate change are quite site-specific: the problems vary from one region to another. Farmers’ indigenous knowledge and practices are crucial to the needs of their farm,” U Khin Soe said. “But it is important to utilise this local knowledge in conjunction with more modern agricultural technology.”

Agronomist Daw Than Than Soe, the deputy director of the department’s Agronomy Division, spends much of her time researching which farming practices work best when rainfall is unpredictable. She said farmers need an “injection of scientific knowledge”.

“This would improve their traditional farming practices. From the technician’s side, we are also looking for suitable solutions to be able to help them [cope with changes in rainfall], especially for farmers on rain-fed land,” she said.

About half of all cultivated rice fields are thought to be rain fed, while another 20pc have access to water from dams. The rest pump their water from nearby rivers and underground water sources.

“Using suitable [crop] varieties and focusing more on predicting when rains will begin and use that to adjust the planting time are crucial to solving rain-related problems,” she said.

U Khin Soe said rather than rely on the 30-year average, the department uses 10-year and one-year rainfall and temperature patterns to predict what will happen in the coming 12 months. Based on this prediction, they work out what crop and variety farmers in a particular region should use and when it should be grown.

“In our experience this is the best way to predict the weather conditions. If the farmers use varieties that are tolerant to unfavourable conditions and choose the growing time based on weather predictions that combine both their own local knowledge and meteorological reports, then farmers can reduce the damage and have a better chance of harvesting a full yield,” U Khin Soe said, before adding: “That is, if there are no extreme weather events such as La Niña, El Niño and storms like Nargis and Giri.”