Chapter 4. China

4.1 Overview

During the monitoring period, rainfall in China increased by 20% over average, while temperature decreased by 0.1°C and RADPAR by 8%, which is considerable. Consequently, the biomass production potential indicator (BIOMSS) was above average (+12%). At the sub-national scale, above-average rainfall occurred in all regions, with departures from +13% to +70%. Temperature was average or close to average, with departures ranging between -0.3°C and +0.1°C. The spatial distribution of rainfall profiles showed that this climatic variable fluctuated largely between July and mid-August (figure 4.1), but was relatively stable and close to average since late August for all the regions. Northeast  and Southwest China (accounting for 23.9% of planted areas) and the Lower Yangtze region (22.2% of planted areas) respectively experienced excess rainfall (more than 75 mm compared to average) in early and mid-August, indicating that these areas may have suffered from flood damage. During the reporting period, temperature continuously fluctuated in various regions.

 As shown in figure 4.3, high cropping intensity values mainly occurred in southern, southeast, southwest, and central China, with the values between 200% and 300%. On the contrary, low values (100%) are located in the northern part of China, including northeast China, Inner Mongolia, and Xinjiang. These indicate that double and triple cropping practices are distributed in the southern parts of China while single cropping is practiced in the north. The current period covers the growing and harvesting time for summer crops in China. Hence, most cropland in China was cropped, except for some regions of central Inner Mongolia, Ningxia, and Gansu. The VCIx map shows that higher values (greater than 0.8) of this indicator mainly occurred in Northeast China. In contrast, lower values (0.5-0.8) were primarily located in central Inner Mongolia, some parts of Ningxia and Gansu, western Henan, the Yangtze river delta and the Pearl river delta. CALF was average or near average for all regions, with the anomalies between -2% and 2%, as displayed in Table 4.1. The map for VHIn showed that low values (16-35) were mainly located in Sichuan Basin, southern Hebei and northwestern Henan (figure 4.6), except for Northeast China. This pattern was consistent with that of VCIx.

Table 4.1. CropWatch agroclimatic and agronomic indicators for China, July-October 2017, departure from 5YAand 15YA

Figure 4.1. China spatial distribution of rainfall profiles, July-October 2017 

Figure 4.2. China spatial distribution of temperature profiles, July-October 2017

Figure 4.3. China cropping intensity, by pixel, July-October 2017 

Figure 4.4. China cropped and uncropped arable land, by pixel, July-October 2017 

Figure 4.5. China maximum Vegetation Condition Index (VCIx), by pixel, July-October 2017

Figure 4.6. China minimum Vegetation Health Index (VHIn), by pixel, July-October 2017