The need for explicitly considering equity in climate change adaptation planning is increasingly being recognized. However, evaluations of adaptation often adopt an aggregated perspective, while disaggregation of results is important to learn about who benefits when and where. A typical example is adaptation of rice agriculture in the Vietnam Mekong Delta (VMD). Efforts focused on flood protection have mainly benefitted large-scale farmers while harming small-scale farmers. To investigate the distributional consequences of adaptation policies in the VMD, we assess both aggregate total output and equity indicators, as well as disaggregated impacts in terms of district-level farming profitability. Doing so requires an adequate representation of the multisectoral dynamics between the human and biophysical systems which influence farming profitability. We develop a spatially explicit integrated assessment model that couples inundation, sedimentation, soil fertility and nutrient dynamics, and behavioral land-use change and farming profitability calculation. We find that inter-district inequality responds in a non-linear way to climatic and socio-economic changes and choices of adaptation policies. The patterns of who wins and who loses could change substantially when a different policy is implemented or if a slightly different uncertain future materializes. We also find that there is no simple ranking of alternative adaptation policies, so one should make trade-offs based on agreed preferences. Accounting for equity implies exploring the distribution of outcomes over different groups over a range of uncertain futures. Only by accounting for multisectoral dynamics can planners anticipate the equity consequences of adaptation and prepare additional measures to aid the worse-off actors.

中文翻译：

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支持公平适应计划的多部门动态核算：以越南湄公河三角洲的水稻农业为例

人们越来越认识到在气候变化适应计划中明确考虑公平问题的需要。但是，适应性评估通常采用汇总的观点，而结果的分类对于了解谁在何时何地受益则很重要。一个典型的例子是越南湄公河三角洲（VMD）的水稻种植适应。致力于防洪的努力主要使大型农民受益，同时又损害了小型农民。为了调查VMD中适应政策的分配结果，我们评估了总产出和公平指标，以及区域级农业获利能力的分类影响。这样做需要充分体现人与生物物理系统之间影响农业获利能力的多部门动态。我们开发了一个空间明确的综合评估模型，该模型将淹没，沉积，土壤肥力和养分动态以及行为性土地利用变化和农业获利能力计算耦合在一起。我们发现，地区间不平等以非线性方式应对气候和社会经济变化以及适应政策的选择。当实施不同的政策或实现一个略有不同的不确定的未来时，谁赢谁输的模式可能会发生重大变化。我们还发现，替代性适应政策没有简单的排名，因此应根据商定的偏好进行权衡。会计核算意味着在一系列不确定的未来中探索结果在不同群体中的分布。