According to the crop condition development graph based on NDVI, crop condition was generally better than last year's in the Loess region except during the second half of April. The main crops in the region are spring wheat and winter wheat. Spring wheat was sowed during late March to early April, while winter wheat was sowed in October and will be harvested in early June. During the monitoring period, rainfall (RAIN) exceeded average by 23%, while temperature (TEMP) was 0.4°C above. Radiation (RADPAR) was 5% below average, which is consistent with the excess precipitation. The additional detail provided by the NDVI clusters and profiles shows that crop condition was close to average in most parts of the region until mid-April. It then deteriorated, and at the end of the monitoring period, crop condition was below average, especially in the middle and east of Gansu province. The fraction of cropped arable land (CALF) for the region decreased 7 percentage points when compared with the five-year average, which indicates less land is cropped. The potential biomass indicator (BIOMASS) was 16% above average, with above average values in particular reported in the south of Shanxi and eastern Shaanxi province. According to the VCIx map, with the exception of central Shaanxi, current crop condition in the region is unfavorable and deserves close monitoring.

Figure 5.12. Crop condition China Loess region, January-April 2017

(a) Crop condition development graph based on NDVI

(b) Spatial NDVI patterns compared to 5YA                 (c) NDVI profiles

(d) Maximum VCI                                                (e) Biomass