The harvest of summer crops (potatoes and rice) was almost over by the end of August, while winter crops (wheat and barley) started to be sown in September. According to the NDVI-based crop condition development graph, the crop conditions in Iran during this whole monitoring period were better than the 5-year average. The cumulative rainfall was 13% below average. The average temperature was 0.7 ℃ below average, whereas the photosynthetically active radiation was down 4%. The potential biomass was 18% higher than the 15-year average. The national maximum vegetation condition index (VCIx) was 0.84, while the cropped arable land fraction (CALF) was 26% higher than the average of the past 5-years.
The NDVI spatial patterns show that from July to October, crop conditions in 44.3% of the cropped area were average or slightly above the 5-year average (marked in red). 16.7% of the cropped areas (marked in dark and light green) experienced above-average crop conditions until the end of the monitoring period, mainly located in the provinces of West and East Azarbaijan, Ardebil, Khuzestan, and Qazvin. 5.6% of the cultivated area experienced below-average crop conditions until the end of the monitoring period, mainly located in northern and southwestern parts of Iran, including the northern parts of the provinces of Gilan, Mazadaran, Golestan, and some parts of Khuzestan. The spatial pattern of maximum Vegetation Condition Index (VCIx) was in accord with the spatial distribution of the NDVI profiles.
When comparing the proportion of NDVI anomaly categories with their 5-year averages, all of the 16-day phases had less than 10% of the cropped areas with below-average crop conditions. As for the proportion of VHIn categories compared with 5-year average, the proportion of the cultivated areas with moderate to severe droughts increased to more than 20% for the last four phases.
In general, crop growth conditions were normal.
Based on farming system, climate, and topographic conditions, Iran can be subdivided into three regions, two of which are the main growing areas for crop production, namely the semi-arid to the subtropical hilly region in the west and the north and the coastal lowland in the arid red sea plain area.
In the Western and northern semi-arid subtropical hilly areas, the cumulative precipitation during the monitoring period was 56 mm, 13% lower than average. Both temperature (-0.7℃) and photosynthetically active radiation (-5%) were below the 15YA. The potential biomass was 8% higher than average. Crop conditions were better than the 5-year average. The proportion of cultivated land was 14%, which was 22% higher than the 5YA. Cropping Intensity (CI) was slightly below the 5YA (-1%). The average VCIx for this region was 0.87, indicating a favorable crop prospect.
In the Coastal lowland and plain areas of the arid Red Sea, the temperature was 0.1℃ above average, while the accumulated precipitation was 48% below average and the photosynthetically active radiation was 2% below average. The potential biomass was 23% higher than the 15-year average. Crop conditions were generally better than the 5-year average. During the monitoring period, although CALF and CI was 60% and 2% higher than the average of the last 5-years, the VCIx was 0.63, indicating below-average crop conditions.
(b) 基于 NDVI 的作物生长过程线
(f) NDVI距平空间聚类图 (g) NDVI距平聚类过程线
(h) 基于 NDVI 的作物生长过程线（西部和北部半干旱至亚热带丘陵区域）
(i) 基于 NDVI 的作物生长过程线（ 干旱红海沿海低地和平原区域）
|当前值 (mm)||距平 (%)||当前值 (°C)||距平(°C)||当前值 (MJ/m2)||距平 (%)||当前值 (gDM/m2)||距平(%)|
表3.104. 伊朗农业生态分区2020年7月-10月与近5年 (5YA)同期农情指标