Increasing population and a severe water crisis are imposing growing pressure on Iranian cropping systems to increase crop production to meet the rising demand for food. Little is known about the separate contribution of trends and variability of the harvested area and yield to crop production in severely drought-prone areas such as Iran. In this study we (a) quantify the importance of harvested area and yield on trends and variability of crop production for the 12 most important annual crops under rainfed and irrigated conditions and (b) test how well the variability in annual crop areas can be explained by drought dynamics. We use remote sensing based land cover and evapotranspiration products derived from the Moderate Resolution Imaging Spectroradiometer to quantify the extent of cropland and drought severity as well as survey-based, crop-specific reports for the period 2001–2016 in Iran. The intensity of drought stress was estimated using the annual ratio between actual and potential evapotranspiration. We found that trends in the production of specific crops are predominantly explained by trends in harvested crop area. Besides, the variability in the harvested area contributed significantly more to the variability in crop production than the variability in crop yields, particularly under rainfed conditions (seven out of nine crops). In contrast, variability in the production of heavily subsidized crops such as wheat was predominantly explained by yield variability. Variability in the annual cropland area was largely explained by drought, in particular for the more arid regions in the south of the country. This highlights the importance of better and proactive drought management to stabilize crop areas and yields for sufficient food production in Iran.

不断增加的人口和严重的水资源危机给伊朗的种植系统带来了越来越大的压力，需要增加作物产量以满足不断增长的粮食需求。在伊朗等严重干旱地区，人们对收获面积和产量的趋势和变化对作物生产的单独贡献知之甚少。在这项研究中，我们 (a) 量化了在雨育和灌溉条件下，12 种最重要的一年生作物的收获面积和产量对作物产量趋势和变异性的重要性，以及 (b) 测试了一年生作物面积变异性的解释程度通过干旱动态。我们使用来自中分辨率成像光谱仪的基于遥感的土地覆盖和蒸发蒸腾产品来量化农田和干旱严重程度的范围以及基于调查的，伊朗 2001-2016 年特定作物报告。干旱胁迫的强度是使用实际和潜在蒸散量之间的年度比率来估计的。我们发现特定作物的生产趋势主要由收获作物面积的趋势来解释。此外，收获面积的可变性对作物产量的可变性的影响比作物产量的可变性要大得多，特别是在雨养条件下（九种作物中有七种）。相比之下，小麦等获得高额补贴的作物产量的变化主要是用产量变化来解释的。一年生耕地面积的变化主要是由干旱引起的，特别是在该国南部较为干旱的地区。