国家级粮食系统可持续性的数学模型
A mathematical model of national-level food system sustainability
摘要：
全球粮食系统面临各种内源和外源、生物和非生物风险因素，包括人口不断增加、人口密度提高、价格波动和气候变化。定量模型在理解粮食系统对冲击和压力的预期反应方面发挥着重要作用。在这里，我们提出了一个程式化的数学模型，一个国家级的粮食系统，包括国内供应的粮食商品，国际贸易，消费者需求，和粮食商品价格。我们得出了一个关键的复合参数，当国内供应变得不可持续，粮食系统完全依赖进口，这将导致商品价格上涨，消费者需求下降和库存水平下降时发出信号。使用贝叶斯估计，我们应用动态食品系统模型来推断英国猪肉行业的可持续性。我们发现，英国猪肉行业目前是可持续的，但由于该行业依赖进口来满足需求，自给率下降到50%以下（目前的水平为60-65%）将导致其接近崩溃的临界边界。我们的模型提供了一个理论基础，为未来的工作，以确定更复杂的因果驱动程序的粮食系统的脆弱性。
英文摘要：
The global food system faces various endogeneous and exogeneous, biotic and abiotic risk factors, including a rising human population, higher population densities, price volatility and climate change. Quantitative models play an important role in understanding food systems' expected responses to shocks and stresses. Here, we present a stylised mathematical model of a national-level food system that incorporates domestic supply of a food commodity, international trade, consumer demand, and food commodity price. We derive a critical compound parameter signalling when domestic supply will become unsustainable and the food system entirely dependent on imports, which results in higher commodity prices, lower consumer demand and lower inventory levels. Using Bayesian estimation, we apply the dynamic food systems model to infer the sustainability of the UK pork industry. We find that the UK pork industry is currently sustainable but because the industry is dependent on imports to meet demand, a decrease in self-sufficiency below 50% (current levels are 60-65%) would lead it close to the critical boundary signalling its collapse. Our model provides a theoretical foundation for future work to determine more complex causal drivers of food system vulnerability.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
