Abstract Considerable spatial variability in soil hydraulic properties exists within a field, even in those considered homogeneous. Spatial variability of water as a major driver of crop heterogeneity gains particular relevance within the context of precision agriculture, but modelling has devoted insufficient efforts to scale up from point to field the associated ‘cause-effect’ relations of water spatial variations. Seven crop simulation models (WOFOST, DSSAT, APSIM, DAISY, STICS, AquaCrop and MONICA) and five hydrologic models (HYDRUS-1D, HYDRUS-2D, SWAP, MIKE-SHE and SWIM) were selected and their water modelling approaches were systematically reviewed for comparison. Crop models rely mainly on ‘discrete’ and empirical approaches for modelling soil water movement while hydrologic models emphasize more ‘continuous’ and mechanistic ones. Combining both types of models may not be the best way forward as none of the models consider all of the processes which are relevant for the simulation of spatial variations. Hydrologic models pay more attention to spatially variable water processes than crop simulation models, although their focus is on scales higher than the field which is the relevant scale for assessing the influence of such variations on crop behaviour. Opportunities for progress in the spatial simulation of water processes at field level will probably come from two different directions. One implying a stronger synergism between both model families by using continuous-type approaches to simulate some mechanisms in existing crop models, and the other through the integration of lateral flows in the simulation of discrete water movement approaches.

中文翻译：

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在作物田间模拟空间水变化的水建模方法和机会

摘要 田间土壤水力特性存在相当大的空间变异性，即使在那些被认为是均质的。水的空间变异性作为作物异质性的主要驱动因素在精准农业的背景下获得了特别的相关性，但建模没有付出足够的努力来从点到场扩大水空间变化的相关“因果”关系。选择了 7 个作物模拟模型（WOFOST、DSSAT、APSIM、DAISY、STICS、AquaCrop 和 MONICA）和 5 个水文模型（HYDRUS-1D、HYDRUS-2D、SWAP、MIKE-SHE 和 SWIM），并系统地审查了它们的水模拟方法用于比较。作物模型主要依赖于模拟土壤水分运动的“离散”和经验方法，而水文模型则更强调“连续”和机械模型。结合这两种类型的模型可能不是最好的前进方式，因为没有一个模型考虑与空间变化模拟相关的所有过程。与作物模拟模型相比，水文模型更关注空间变化的水过程，尽管它们的重点是高于田地的尺度，田地是评估此类变化对作物行为影响的相关尺度。田间水过程空间模拟的进展机会可能来自两个不同的方向。一个暗示通过使用连续型方法来模拟现有作物模型中的一些机制，暗示两个模型家族之间更强的协同作用，另一个通过在离散水运动方法的模拟中整合横向流动。