Kovacs Kent, West Grant
Department of Agricultural Economics and Agribusiness, University of Arkansas, Fayetteville, Arkansas, United States of America.
PLoS One. 2016 Dec 29;11(12):e0168681. doi: 10.1371/journal.pone.0168681. eCollection 2016.
An irrigated agricultural landscape experiencing groundwater overdraft generates economic returns and a suite of ecosystem services (in particular, groundwater supply, greenhouse gases reduction, and surface water quality). Alternative land cover choices indicate tradeoffs among the value of ecosystem services created and the economic returns. These tradeoffs are explored using efficiency frontiers that determine the least value in ecosystem services that must be given up to generate additional economic returns. Agricultural producers may switch to irrigation with surface water using on-farm reservoirs and tail water recovery systems in response to groundwater overdraft, and this has consequences for the bundle of ecosystem service values and economic returns achievable from the landscape. Planning that accounts for both ecosystem service value and economic returns can achieve more value for society, as does the adoption of reservoirs though lowering the costs of irrigation, increasing groundwater levels, and reducing fuel combustion and associated GHG emissions from groundwater pumping. Sensitivity analyses of per unit value of ecosystem services, crop prices, and the groundwater and water purification model parameters indicate tradeoff among ecosystems service values, such as the use of a high-end social cost of carbon ultimately lowers groundwater supply and water purification value by more than 15%.
一个经历地下水超采的灌溉农业景观能产生经济回报和一系列生态系统服务（特别是地下水供应、温室气体减排和地表水水质）。不同的土地覆盖选择表明了所创造的生态系统服务价值与经济回报之间的权衡。利用效率前沿来探索这些权衡，效率前沿确定了为产生额外经济回报而必须放弃的生态系统服务的最小价值。农业生产者可能会因地下水超采而改用利用农场蓄水池和尾水回收系统的地表水灌溉，这会对该景观可实现的生态系统服务价值和经济回报组合产生影响。兼顾生态系统服务价值和经济回报的规划可为社会实现更多价值，采用蓄水池也是如此，因为它能降低灌溉成本、提高地下水位，并减少地下水抽取的燃料燃烧及相关温室气体排放。对生态系统服务单位价值、作物价格以及地下水和水净化模型参数的敏感性分析表明了生态系统服务价值之间的权衡，例如使用高端社会碳成本最终会使地下水供应和水净化价值降低超过15%。
