英文文献：A Detailed Hydro-Economic Model for Assessing the Effects of Surface Water and Groundwater Policies: A Demonstration Model from Brazil-用于评估地表水和地下水政策影响的详细水文经济模型:来自巴西的示范模型
英文文献作者：Maneta, Marco P.,Torres, Marcelo,Howitt, Richard,Vosti, Stephen A.,Wallender, Wesley W.,Bassoi, Luis H.,Rodrigues, Lineu N.,Young, Julie A.
英文文献摘要：
Policymakers, managers of water use associations, and many others in developing countries are considering policy actions that will directly or indirectly change the costs and availability of groundwater and surface water for agricultural users. While in many cases such actions may bring about welcomed increases in water use efficiency, little is known about the likely effects of changes in irrigation costs or water access on farmer behavior, or on farmer incomes in the short or long runs, and virtually nothing is known about the detailed immediate or knock-on effects on water resources that such policy actions might cause. This paper reports the preliminary results of research aiming to fill these large scientific gaps by developing a detailed hydrologic model and a detailed economic model of agriculture in the context of the Buriti Vermelho (BV) subcatchment area of the Sao Francisco River Basin in Brazil. A spatially explicit, farm-level, positive mathematical programming model capable of accommodating a broad array of farm sizes and farm/farmer characteristics is being developed to predict the effects of alternative water policies and neighbors' water use patterns on agricultural production. Special attention is given to precisely defining and estimating the distinct variable costs (including labor and electrical energy costs) and capital costs of surface water and groundwater, which are considered perfect substitutes for irrigation. Shadow values for non-marketed inputs (land, family labor, and water) are estimated in the first step of the modeling process. A high-resolution, spatially distributed hydrologic model (MOD-HMS) is being developed to simulate three-dimensional, variablysaturated subsurface flow and solute transport. Subsurface flow is simulated using the threedimensional Richards equation while accounting for a) application of water at the surface, b) precipitation, c) soil evaporation and crop transpiration, and d) agricultural pumping. Demonstration versions of both models are presented and tested: the economic model assesses the effects of increasing water scarcity on cultivated area, crop mix, input mix and farm profits; the hydrologic model uses two irrigation water use scenarios to demonstrate the effects of each on surface water flows and storage, and on groundwater storage and well depth. The models are not currently linked, but a detailed plan to do so is presented and discussed. The paper concludes by discussing next steps in research and policy simulations.

发展中国家的决策者、用水协会的管理人员以及其他许多人正在考虑采取政策行动，直接或间接地改变农业用户地下水和地表水的成本和可用性。虽然在许多情况下,这种行为可能带来欢迎提高水分利用效率,对灌溉成本的可能变化的影响和水对农民行为的访问,或者在短期或长期运行时,农民收入,几乎没有什么了解的详细立即或连锁反应这样的政策行动可能造成的水资源。本文报告了旨在通过在巴西Sao Francisco河流域Buriti Vermelho (BV)附属集水区开发一个详细的水文模型和一个详细的农业经济模型来填补这些巨大科学空白的研究的初步结果。一个空间明确的、农场层面的、积极的数学规划模型，能够适应广泛的农场规模和农场/农民特征，正在开发，以预测替代水政策和邻居的用水模式对农业生产的影响。特别注意精确地定义和估计地表水和地下水的明显可变成本(包括劳动力和电能成本)和资本成本，地表水和地下水被认为是灌溉的完美替代品。在建模过程的第一步中，对非市场投入(土地、家庭劳动和水)的影子值进行估计。一种高分辨率的空间分布水文模型(MOD-HMS)正在被开发用来模拟三维的变饱和地下流和溶质运移。利用三维理查兹方程模拟地下流动，同时考虑以下因素:a)地表用水，b)降水，c)土壤蒸发和作物蒸腾，d)农业抽水。介绍了两种模型的示范版本并进行了测试:经济模型评估了日益严重的水资源短缺对耕地面积、作物组合、投入组合和农业利润的影响;水文模型使用了两种灌溉用水情景来演示每种情景对地表水流量和蓄水以及地下水蓄水和井深的影响。这些模型目前还没有关联，但是已经提出并讨论了这样做的详细计划。文章最后讨论了下一步的研究和政策模拟。