This report covers the second half of the monsoon season, which lasts from May to October. The harvest for the main maize was completed at the end of September, followed by the harvest for the main rice crop. The second maize and second rice crops started to be planted in October. Compared to average, the country suffered a small precipitation deficit (RAIN, -2%) accompanied by warmer temperatures (TEMP, +0.4℃) and higher radiation (RADPAR, +3%). In response, the biomass (BIOMASS) for the country showed a slight rise by 3% compared to average. The cropped arable land fraction (CALF) for the country was almost close to 100% and the maximum VCI value was at 0.97, which means the crop conditions were generally favorable.
According to the NDVI profile for the country, conditions were near average until October. The slight departure in early August may have been due to cloud cover in the satellite image or temporal flooding. The negative departures of NDVI starting in September can probably be attributed to the frequent typhoons. Especially the 17th typhoon Saudel and 18th typhoon Molave caused widespread flooding.
Considering the spatial patterns of NDVI, around 52.7% of cropland, mainly located in the western coast and middle area of Luzon island and most part of Mindanao island, had a stable NDVI which was close to average during the reporting period. For about 17.1% of the cropland, NDVI was close to average before October and suffered a great decrease of up to 0.4 NDVI units in October. This was mainly in the Central Luzon region, south CalgayanValley region and south Cordillera region. Although the great decrease was due to cloud cover brought by typhoon in satellite images, the vegetation there suffered a lot as well, which was reflected in a decrease of the NDVI curve. An anomaly, in which the NDVI dropped up to 0.4 NDVI units in middle October and recovered 0.35 NDVI units in late October, appeared in Southern Tagalog region and the middle of Calgayan Valley region. Another anomaly, in which the NDVI dropped over 0.35 NDVI units in early August and recovered 0.4 NDVI units in middle August was observed for the Southern Tagalog region and Southern Mindanao region, on around 18.7% of crop land. Subsequently, the NDVI for these regions decreased gradually. Both anomalies may have been caused by cloud cover in the satellite image, while the general drop of NDVI in October is probably due to the influence of typhoons. All in all, taking the NDVI without anomalies and near-average agro-climate indicators into consideration, the estimated production for the country in the reporting period is slightly below average.
Based on the cropping systems, climatic zones and topographic conditions, three main agro-ecological regions can be distinguished for the Philippines. They are the Lowlands region (northern islands), the Hilly region (Island of Bohol, Sebu and Negros), and the Forest region (mostly southern and western islands). All the regions are characterised by a stable (almost 100%) cropped arable land fraction (CALF) and a high maximum VCI value (VCIx>0.96).
The Lowlands region experienced warmer temperature (TEMP, +0.5℃) and higher radiation (RADPAR, +6%) compared to average. Although the rainfall (RAIN, -15%) for the region was lower, the potential biomass (BIOMASS, +6%) value was higher than average. In terms of the NDVI profile, the NDVI for the region was lower than average in late July and improved gradually. However, a drop of NDVI appeared in early September again and the departure of NDVI from average reached a maximum at the end of the reporting period. It seems that the typhoons had a great influence on the crops in this region. As a result, the crop conditions were not favorable.
Compared to the previous 15 years, the Hilly region (Negros and central Visayas island region) went through wetter than normal conditions, as the rainfall (RAIN +9%) and the temperature (TEMP +0.5℃) increased. Both the radiation (RADPAR, +4%) and potential biomass (BIOMASS, +4%) for the region were higher than average. As for the NDVI for the region, it was below average in July but recovered to average in middle August. However, the NDVI decreased again in September and was recovering at the end of the reporting period. Crop conditions were generally unfavorable.
The Forest region had an above-average rainfall (RAIN, +13%) and slightly warmer temperatures (TEMP, +0.2℃). The radiation (RADPAR) for the region was above average by 1% and the potential biomass (BIOMASS) was close to average. The NDVI profile shows that the NDVI for the region was below average in late July and recovered in middle August. Subsequently, the NDVI dropped to below average again in October. Although the NDVI was varying, the departures of NDVI from the average were relitevely small. As a result, the prospected crop conditions for the region were slightly below or close to average.
(b) 基于NDVI的作物生长过程线 (c) 最佳植被状况指数
（d) NDVI距平空间聚类图（与5年平均相比） (e) NDVI距平聚类过程线