Drought Continues in Southeast Asia

Drought conditions currently exist in many parts of Southeast Asia, particularly in Indochina [Thailand, Vietnam, Myanmar (Burma), Cambodia, and Laos]. [AVHRR Image - 10 Mar 2005] The drought has stressed rice, coffee, sugar, and other crops in the region and sharply lowered the supply of water for drinking and irrigation. The largest crop losses have been reported in Thailand, but the drought has also damaged crops in southern China, Cambodia, Vietnam, and Laos. Local authorities and farmers are now eagerly waiting for the start of the 2005 wet season, which is expected to commence in April. Abundant rainfall will be needed this summer to recharge the region's depleted reservoirs and produce a normal wet-season harvest in 2005. [AVHRR Image - Comparison]

Seasonal Percent of Normal Rainfall - October 1, 2004 to March 20, 2005

The 2004 Wet Season Ended Early

Southeast Asia (excluding Malaysia and Indonesia) has a tropical monsoon rainfall pattern characterized by a wet season that runs from roughly April through October. In 2004 the wet season ended about a month ahead of schedule, and drought conditions quickly developed across an area that stretched from central China to southern Thailand to Luzon, Philippines. By November 2004, government officials and analysts across the region warned that the drought would result in lower crop yields in 2004 and the first half of 2005. Summer/autumn crops were maturing when the drought began, and local officials were concerned that irrigation water for the upcoming dry-season crops would be inadequate. They were also closely watching the development of a warm-episode El Niño in 2004, which in past years (most recently in 1997/98) had led to poor rainfall and low crop yields in the region.

Dry Season is Drier than Normal

In southeast Asia, rainfall declines sharply during the dry season (November / March). During these months the main season (mostly rainfed) crops are harvested and another crop (winter/spring, dry season) is grown under irrigation. The early end to the 2004 wet season caused hundreds of reservoirs and rivers to drop to their lowest level in decades, which made irrigation difficult if not impossible in many areas. Local governments and farmers tried to cope with the water shortage by rationing, reducing planted area, shifting to drought-resistant crops, adjusting planting dates, digging wells, releasing stored water from reservoirs, and cloud-seeding. However, these tactics were not enough to overcome the precipitation deficit. Crop stress (indicated by vegetative indices or vins) is widespread and significant, as shown by the map and graphs below.

SPOT-veg NDVI Departure from 4-yr Average (derived from satellite imagery) March 20, 2005

Vin Graphs by Region

Cambodia and Laos - Main season vins were very high, indicating good yields, but conditions have declined since December.
Philippines - Vins are equal or better than last year, no drought damage is indicated.
Thailand - Vins have dropped sharply since November and are lower than last year and normal.
Vietnam - In the north, vins are inconclusive. In the Central Highlands, declining vins indicate serious crop stress, affecting mainly coffee trees. In the Mekong Delta, high vins in fall 2004 correspond to very good yields for the 2004 summer/autumn crop. Current vins are only slightly below normal.
This is the wet season in Indonesia and Malaysia. Vegetation conditions are generally very good and vins show no indication of drought stress.

Major Crop Losses in Thailand, Minor Losses Elsewhere

Based on reports from government and trade sources, it appears that Thailand has suffered major crop losses from the current drought. The Thai government has announced that 70 of its 76 provinces have been hit by drought this year, affecting more than 9 million farmers and almost a million hectares of paddy fields. The 2004/05 rice crop is estimated at 17.0 million tons (25.76 million tons, rough basis), down 1.0 million from last year (USDA, March estimate), and trade sources expected the sugar crop to drop by about 30 percent in 2004/05 and even more in 2005/06. In contrast, the drought has had very little effect on Vietnam's rice crop, which reached a record 22.1 million tons in 2004/05 (USDA, March estimate). The 2004 summer/autumn and 10th month crops were larger than expected due to good yields, and farmers in the Mekong Delta are expecting very high yields for their winter/spring crop, which is being harvested now. However, the coffee crop in Vietnam's Central Highlands was hit hard by the drought and the government expects production to drop by about 30 percent this year.

Cambodia, Laos, and Myanmar (Burma) all enjoyed good main-season rice harvests in 2004, but the prospects for the 2004 second crop and 2005 main season crops are uncertain.

The Cambodian government has said that up to 30 percent of the country's farmland was afflicted by the current drought, including 500,000 hectares of paddy (about 1/4 of total rice area). The government also warned that 500,000 people could suffer food shortages if the drought continued.
Harvesting has begun for Myanmar's second season rice crop. On March 17, the Myanmar government said its crops had suffered no damage from the drought: water supplies were plentiful following heavy rainfall during the 2004 wet season and the level of the Irrawaddy River was above normal.
The government of Laos said the 2004 wet-season rice crop was larger than last year but a sharp reduction in the dry season crop (about 25 percent of total production) was expected due to lower planted area and low water levels in the Mekong River..

In the Philippines, rice production in 2004 was higher than last year despite dry conditions in the second half of the year. River levels are close to normal and moisture conditions for planting have improved following recent showers. Total rice production in Indonesia and Malaysia reached near-record levels in 2004. Rainfall in Java, Indonesia's most important rice-growing region, has been very favorable for crop development this season. According to the Malaysian government, the country's rice farmers have not been affected by the drought that hurt other parts southeast Asia. Southeast Asia Rice Table

Wet Season Starts Soon

The 2005 wet season is expected to start in April / May as the monsoon strengthens and moves north from the equator. In the past 10 days, light to moderate showers have fallen over northern and central Vietnam, northern Thailand, and the Philippines, easing dry conditions and indicating that the wet season may arrive on schedule. On March 17 the Philippines was hit by the first storm of the year ("Roke"), another indication that the dry season may be coming to an end. It now appears that the current El Niño is weakening and will transition to a neutral condition during the next three months, reducing its influence on weather patterns in 2005.

USDA will make its first estimates of 2005/06 grain production on May 12, 2005.

For more weather information, visit Crop Explorer

For more information, contact Paulette Sandene
with the Production Estimates and Crop Assessment Division,
Center for Remote Sensing Analysis at (202) 202-690-0133.