Groundwater aquifers support agricultural production in many parts of the world. Rapidly declining aquifer levels can have significant negative implications for the sustainability of irrigated agriculture. In this paper, we study the effects of declining well capacities on the downside risk of irrigated agricultural production, defined as the standard deviation of profits that are below the average profit. We simulate seasonal crop yield and profits for three different crops, namely, maize, wheat, and grain sorghum and five different soil types for Finney County in Kansas which overlies the high plains aquifer under current climatic conditions and under the projected climate change scenario with RCP4.5. We find that lower well capacities not only result in lower average profits for all three crops, but they also result in an increase in downside risk. However, we also find that there is significant heterogeneity in downside risk across different crops and soil types. Our results highlight the importance of downside risk for the sustainability of irrigated production under declining aquifer levels and climate change.

中文翻译：

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含水层枯竭的下行风险

地下水含水层支持世界许多地区的农业生产。含水层水位迅速下降可能对灌溉农业的可持续性产生重大负面影响。在本文中，我们研究了井容量下降对灌溉农业生产下行风险的影响，该风险定义为低于平均利润的利润标准差。我们模拟了堪萨斯州芬尼县三种不同作物（即玉米、小麦和谷物高粱）以及五种不同土壤类型的季节性作物产量和利润，该县在当前气候条件下以及在预测的气候变化情景下使用 RCP4 .5. 我们发现较低的井容量不仅会导致所有三种作物的平均利润较低，但它们也导致下行风险增加。然而，我们还发现，不同作物和土壤类型的下行风险存在显着异质性。我们的结果强调了在含水层水平下降和气候变化的情况下，下行风险对灌溉生产可持续性的重要性。