In China, winter crops including winter wheat and rapeseed were growing during the current monitoring period. Overall, crop condition was favorable, according to above-average BIOMSS (+5%) on the national scale. CropWatch agroclimatic indicators show that rainfall and radiation for the whole country decreased by respectively 13% and 6% compared to average, while temperature increased 0.5°C (see table 3.1). At the regional level, as shown in table 4.1, rainfall was significantly above average in Inner Mongolia (RAIN, +60%), Loess region (+23%), and Huanghuaihai (+15%). In contrast, below-average precipitation occurred in the Lower Yangtze (RAIN, -21%), Southwest China (-17%), and Southern China (-7%). Rainfall for Northeast China was close to average (-1%). Compared to average, temperature increased in most regions of China except for Southwest China (-0.1°C) and Southern China (average temperature). Radiation was significantly below average in Southwest China, with a very significant decrease of 13%. Less severe RADPAR departures occurred in Southern China (-8%), Lower Yangtze (-7%), Loess region (-5%), and Huanghuaihai (-3%). The spatial distribution for the anomalies of agroclimatic indicators and their fluctuations over time are shown in figures 4.1 and 4.2.

According to figure 4.3, cropped areas were located in Huanghuaihai, Lower Yangtze, the southern part of the Loess region, and southern and southwestern China, while uncropped areas were in Northeast China, Inner Mongolia, and the northern part of the Loess region. Compared with the recent five-year average, the cropped arable land fraction (CALF) decreased in Huanghuaihai (CALF, -2 percentage points), Lower Yangtze (-2 percentage points), southern Loess region (-7 percentage points), and marginally in southwestern China (-1 percentage point); see also table 4.1. CALF for Southern China was average.

The maximum VCI (VCIx) on the national level was moderate, with the average value at 0.62. Among the regions, high VCIx (larger than 0.5) occurred in Huanghuaihai, Lower Yangtze, and China’s southwestern and southern regions, while lower values occurred in the Loess region and Inner Mongolia (figure 4.4 and table 4.1). As shown in figure 4.5, high values for minimum Vegetation Health Index (VHIn) were mainly distributed in Huanghuaihai and Southwest China, with lower values appearing in Lower Yangtze and Southern China.

Table 4.1. CropWatch agroclimatic and agronomic indicators for China, January-April 2017, departure from 5YA and 15YA

Figure 4.1.  China spatial distribution of rainfall profiles, January-April 2017

Figure 4.2. China spatial distribution of temperature profiles, January-April 2017                  

Figure 4.3. China cropped and uncropped arable land, by pixel, January-April 2017

Figure 4.4. China maximum Vegetation Condition Index (VCIx), by pixel, January-April 2017

Figure 4.5. China minimum Vegetation Health Index (VHIn), by pixel, January-April 2017