During this monitoring period, winter wheat reached flowering stage in March and was approaching maturity by the end of April. Also, the transplanting of early rice was almost concluded. According to the crop condition development graph based on NDVI, crop conditions were below the 5-year average. 

For the whole region, rainfall was below the 15YA (-24%), whereas radiation was above average (+11%). Temperature was higher than average (+1.0°C). The BIOMSS was 10% above average but with great spatial variation across the region. It was above average in Guangxi, Guangdong and southern Fujian thanks to adequate precipitation, solar radiation and suitable temperatures while it showed spatial heterogeneity in Yunnan province. Since March, the precipitation in Yunnan has been significantly below average, which hampered wheat growth.

As shown by the NDVI departure clustering map and the profiles, values were obviously below average during the reporting period. This was mainly due to the reduced precipitation which caused drought conditions in Yunnan. The favorable conditions in Guangdong and Guangxi benefitted early rice and overall crop conditions recovered to close-to-average levels at the end of the monitoring period. The cropped arable land fraction was 2% below average, a drop from the planted area of early rice in the bumper 2020. The average VCIx of the Southern China region was 0.88, and most area had VCIx values ranging from 0.80 to 1.00. Low VCIx values were mostly scattered in Yunnan province which was consistent with the below-average BIOMSS map.

Overall, the crop conditions during the monitoring period were below average for this region.

Figure4.13 Crop condition Southern China, January 2021 - April 2021

(a) Crop condition development graph based on NDVI

(b) Time series rainfall profile                                    (c) Time series temperature profile

(d) Spatial distribution of NDVI                        (e) NDVI profiles 

(f) Maximum VCI

(g) Potential biomass departure from 15YA