Severe drought occurred in the cultivated area of the Mekong Basin from February to April 2020 By the Chinese Academy of Sciences

ANSO CropWatch-ICP

27 04, 2020

Severe drought occurred in the cultivated area of the Mekong Basin from February to April 2020 By the Chinese Academy of Sciences

At the Time of COVID-19 pandemic, people start to worry about food shortage and food security as this pandemic is likely to affect global food storage, processing, transportation, even production to various levels.

Agriculture and food security are a major focus and long-term commitment of ANSO in the promotion of the world’s sustainable development. Recently, ANSO initiated CropWatch Innovative Cooperation Programme for Agricultural Monitoring (CropWatch-ICP) to facilitate and stimulate the agricultural monitoring of the “Belt and Road” countries for the advancement of the UN SDGs of zero hunger. The CropWatch team of the Chinese Academy of Sciences has many years of experience in the monitoring and forecasting the global food production and publishes its quarterly bulletin both in Chinese and English (http://cloud.cropwatch.com.cn). It takes immediate actions to trace the food production in domestic, regional and global scale in response to the impact of COVID -19.

By this column, ANSO would like to share the concerned information with its members and beyond in combating the impact of COVID-19. As the crisis continues to unfold, we will continue to update the column with the related information. We hope this information will be useful to individuals, institutions and policymakers within ANSO and beyond. If you have any questions, please contact us at cropwatch@radi.ac.cn

The Aerospace Information Research Institute, Chinese Academy of Sciences has monitored the crop conditions affected by drought in the Mekong River Basin from February to April of 2020 through its Global Drought and Crop Monitoring Systems (DroughtWatch and CropWatch) based on the remote-sensing technology. The data sources used also include the multiple remote sensing data such as optical, thermal infrared satellite data (MODIS) and the reanalysis data of the National Center for Environmental Prediction (CFSv2) of the United States in the period between February 1 and April 20. The institute has obtained comprehensive monitoring results for the region, including Cambodia, Laos, Myanmar, Thailand, Vietnam and the Yunnan Province of China.

The results indicate that the five countries in the Mekong River Basin and the Yunnan Province of China had severe deficits of precipitation from February to April 2020, and a meteorological drought occurred (Figure 1). The precipitation deficits mainly occurred in the lower Mekong region in February, in Cambodia in March, and along the borders of Myanmar, Thailand and Laos in April.

Figure 1. Distribution and changes of Standardized Precipitation Index (SPI-3) in the Mekong River Basin in early February, early March and early April 2020

Since it is the dry season of the Mekong and Lancang Rivers in February and March, and is not yet the main season for crop planting, the severe meteorological drought leads to the deficit of soil moisture, but not produce a significant impact on agriculture (Figure 2). Table 1 shows the drought situations since February in terms of the proportion of the drought-affected area to crop planting area. Laos was hit the hardest: its average proportion reached 38.3% with a peak value of 58.5% in early March. Followed by Cambodia (27.7%), Myanmar and Thailand (18.3% and 17.1%, respectively). The drought impact on Vietnam and the Yunnan Province of China was relatively low, about 13.1% and 11.0% respectively (Table 1).

Figure 2. Spatial distribution and changes of drought in the Mekong River Basin in mid-February, mid-March and mid-April 2020

Table 1. Dekadal crop drought proportion from February to April 2020

February-April	The proportion of drought-affected area to crop planting area (%)
February-April	Cambodia	Laos	Myanmar	Thailand	Vietnam	Yunnan of China
First dekad of February	25.9	36.6	15.3	14.9	8.30	4.7
Second dekad of February	36.4	46.2	13.9	20.7	13.5	3.0
Third dekad of February	32.6	42.8	7.70	10.4	8.60	2.2
First dekad of March	26.6	58.5	17.1	25.3	13.8	11.2
Second dekad of March	28.0	42.9	20.2	18.0	18.9	23.5
Third dekad of March	28.2	35.5	27.5	18.3	8.0	21.8
First dekad of April	37.3	28.1	26.1	22.9	26.5	11.7
Second dekad of April	6.60	15.9	19.0	6.20	7.4	10.2
Average	27.7	38.3	18.3	17.1	13.1	11.0

There were differences in the temporal and spatial distribution of drought impact in the countries. The drought occurred mainly in the north of Laos and in the central and western regions of Cambodia (February). The southern and central and eastern regions in Myanmar were heavily affected by drought (February-March). The central and western Thailand (February) and the southern region (March) were hit relatively hard. The Mekong Delta and central Vietnam (February-March) and central and southern Yunnan Province of China (March) also suffered a rather serious drought. By mid-April, the drought situation in the Mekong River Basin had eased as a whole. However, the trend of drought still warrants continuous monitoring, and special attention should be paid to the drought impact as the main crop growing season starts.