Bulletin

wall bulletin
CambodiaMain producing and exporting countries

Authors: fuzhijun,rothana,sothy | Edit: lirui

The monitoring period coincided with the rainy season in Cambodia. In this period, the sowing of medium rice, late rice, and rainy season maize was completed by August. Harvest of these crops will start in November. Floating rice, on the other hand, will be ready for harvest in January. Throughout the period, Cambodia experienced persistently above-average temperatures, although these temperatures decreased to normal levels at the end. Precipitation was below average until September, after which it gradually approached the average level. Due to the generally high rainfall levels, the initially low rainfall did not negatively impact crop growth. In fact, crop conditions rose in August, reaching their highest level in nearly five years. In September, although the crop NDVI dropped due to intense rainfall, it quickly rebounded to its peak level. As rainfall decreased, crop conditions returned to normal levels by the end of the period.

Clustering results of NDVI departure indicated that approximately 10.4% of cultivated land (red) experienced a significant increase in crop NDVI in August. These lands are primarily located along the western shore of Lake Tonle Sap and the lower reaches of the Mekong River. Around 73% of cultivated land (orange, dark green, and light green) maintained a normal crop condition, with these lands widely distributed across the country. About 16.6% of cultivated land (blue) consistently had a slightly below-average NDVI. These lands are primarily in the eastern regions of the lower Mekong River. Despite a drop in rainfall (RAIN) by about 8%, the temperature (TEMP) was 0.7 higher, radiation (RADPAR) was 4% higher, and potential biomass was 2% above average. Additionally, cropping intensity (CI) slightly decreased by 2%, while the cropped arable land fraction (CALF) increased by 1%. The VCIx reached 0.95, and the country-level production index (CPI) was 1.05, suggesting that the production in Cambodia was generally normal.


Regional analysis

Based on cropping systems, climatic zones, and topographic conditions, four sub-national regions are described below: The Tonle Sap Lake area (agro-ecological zone 117), a seasonally inundated freshwater lake which is influenced by the inflow and outflow from the Mekong River, the Mekong valley between Tonle Sap and Vietnam border (agro-ecological zone 118), Northern Plain and Northeast (agro-ecological zone 119), and the Southwest Hilly region along the Gulf of Thailand coast (agro-ecological zone 120).

In the Tonle Sap region, rainfall (RAIN) remained normal, while the temperature (TEMP) was 0.8 higher. Radiation (RADPAR) was 5% higher, and potential biomass (BIOMASS) was 3% above average. The clear and sunny weather at the beginning were favorable for the recovery of crops, which then gradually decreased to normal. The CALF in this region was slightly higher by 1%, with the VCIx reaching 0.96. The CPI stood at 1.06, and the CI showed a slight increase of 1%. Overall, the crop production in this region is normal.

In the Mekong Valley region is the most important crop-producing region in Cambodia that supports diverse ecosystems and human activities. In this region, rainfall (RAIN) was about 10% below, while the temperature (TEMP) increased by 0.9, radiation (RADPAR) was 3% higher, and potential biomass (BIOMASS) remained normal. Although crop NDVI in this region decreased due to intense rainfall in September, it quickly recovered and even approached the highest level in nearly five years. The VCIx for the region was 0.95, and the CPI was 1.05. The CI decreased by about 2%. The combination of the various indices points to a slightly above average production.

In the Northern Plain and Northeastern, rainfall (RAIN) was approximately 15% lower, temperature (TEMP) was 0.6 higher, radiation (RADPAR) was 5% higher, and potential biomass (BIOMASS) was 2% above average. Crop NDVI in this region decreased at the end of August, likely due to the below-average rainfall during the same period. Subsequently, it remained slightly below the average. The VCIx was 0.93, and the CPI was 1.01. The CI was about 8% lower than average, with an overall normal crop production.

In the Southwest Hilly region, rainfall (RAIN) was approximately 13% above average, with higher temperature (TEMP) by 0.4, higher radiation (RADPAR) by 2%, and higher potential biomass (BIOMASS) by 1%. Crop NDVI in this region was higher than the highest level in August, and by the end of the period, it had returned to near-normal levels. The VCIx for the region was 0.95, and the CPI was 1.02. The CI decreased by about 9%, with overall crop production considered normal.


Cambodia's crop condition, July - October 2024
(a) Phenology of major crops
(b) Crop condition development graph based on NDVI(c) Maximum VCI
(d) Spatial NDVI patterns compared to 5YA  (e) NDVI departure profiles
(f) Rainfall profiles(g) Temperature profiles
(h) National CPI time series graph
Crop condition development graph based on NDVI(left:Southwest Hilly region,right:Northern plain and northeast)
Crop condition development graph based on NDVI(left:Mekong valley between Tonle-sap and Vietnam border,right:Tonle-sap)


Table 3.1 Cambodia's agro-climatic indicators by sub-national regions, current season's values and departure from 15YA, July‐October 2024

Region

RAIN

TEMP

RADPAR

BIOMSS

Current
(mm)

Departure
(%)

Current
(°C)

Departure
(°C)

Current
(MJ/m2)

Departure
(%)

Current
(gDM/m2)

Departure
(%)

Tonle-sap

1157

-0

26.4

0.8

1167

5

1605

3

Mekong valley between Tonle-sap and Vietnam border

1112

-10

26.7

0.9

1158

3

1602

-0

Northern plain and northeast

1358

-15

25.7

0.6

1132

5

1634

2

Southwest Hilly region

1477

13

24.8

0.4

1116

2

1555

1


Table 3.2 Cambodia's  agronomic indicators by sub-national regions, current season's values and departures from 5YA, July‐October 2024

Region

CALF

CI

Maximum VCI

CPI

Current(%)

Departure from 5YA(%)

Current(%)

Departure from 5YA(%)

Current

Current

Tonle-sap

99

1

134

1.21

0.96

1.06

Mekong valley between Tonle-sap and Vietnam border

97

1

139

-1.56

0.95

1.05

Northern plain and northeast

99

-0

121

-7.77

0.93

1.01

Southwest Hilly region

99

0

125

-9.16

0.95

1.02