Evaluating sustainable adaptation strategies for vulnerable mega-deltas using system dynamics modelling: Rice agriculture in the Mekong Delta's An Giang Province, Vietnam
Evaluating sustainable adaptation strategies for vulnerable mega-deltas using system dynamics modelling: Rice agriculture in the Mekong Delta's An Giang Province, Vietnam
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DOI：
10.1016/j.scitotenv.2016.02.162
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发表时间：
2016-07-15
影响因子：
9.8
通讯作者：
Darby, Stephen
中科院分区：
文献类型：
--
作者：
Chapman, Alexander;Darby, Stephen
随着社会试图减缓和适应气候变化，同时维持当地的快速发展，地球仪的社会生态系统正在呈现出变化的动态。IPCC的第五次评估表明，这些不断变化的系统容易受到不可预见和危险的“紧急风险”的影响。一个典型的例子是越南湄公河三角洲（VMD），在过去十年中，该地区的河堤网络得到了加强和扩展，其双重目标是：（1）使三角洲的1800万居民及其生计适应日益严重的河流洪水，（2）通过从一年两熟到三熟的转变来发展水稻生产。这一转变带来了负面影响，特别是排除了河漫滩的河流沉积物沉积。在我们的理解的水稻-沉积物系统，其中涉及不直观的延迟，反馈和临界点的动态赤字，在这里解决，使用系统动力学（SD）的方法，告知可持续的适应战略。具体来说，我们开发并测试了一个新的SD模型，该模型模拟了农民的经济系统和他们的水稻农业操作之间的动态，并且独特地将河流沉积物沉积在他们的堤坝隔间中的作用结合起来。我们的研究结果表明，目前的主导战略（三熟制）只适用于社会中较富裕的群体，而且在短期内（约20年）是最佳的。实施后10年）。该模型表明，在高洪水年打开闸门，让稻田休耕的政策，以鼓励自然沉积和营养补充它提供的，是一个更公平和更可持续的政策。但是，即使采用这种方法，沉积物养分供应的减少以及随之而来的人工肥料补偿需求将意味着VMD中规模较小的农民更容易受到债务累积的影响。(C)2016作者由爱思唯尔公司出版。这是一篇开放获取的文章，使用CC BY许可证（http：//creativecommons.org/licenses/by/4.0/）。
Challenging dynamics are unfolding in social-ecological systems around the globe as society attempts to mitigate and adapt to climate change while sustaining rapid local development. The IPCC's 5th assessment suggests these changing systems are susceptible to unforeseen and dangerous 'emergent risks'. An archetypal example is the Vietnamese Mekong Delta (VMD) where the river dyke network has been heightened and extended over the last decade with the dual objectives of (1) adapting the delta's 18 million inhabitants and their livelihoods to increasingly intense river-flooding, and (2) developing rice production through a shift from double to triple-cropping. Negative impacts have been associated with this shift, particularly in relation to its exclusion of fluvial sediment deposition from the floodplain. A deficit in our understanding of the dynamics of the rice-sediment system, which involve unintuitive delays, feedbacks, and tipping points, is addressed here, using a system dynamics (SD) approach to inform sustainable adaptation strategies. Specifically, we develop and test a new SD model which simulates the dynamics between the farmers' economic system and their rice agriculture operations, and uniquely, integrates the role of fluvial sediment deposition within their dyke compartment.We use the model to explore a range of alternative rice cultivation strategies. Our results suggest that the current dominant strategy (triple-cropping) is only optimal for wealthier groups within society and over the short-term (ca. 10 years post-implementation). The model suggests that the policy of opening sluice gates and leaving paddies fallow during high-flood years, in order to encourage natural sediment deposition and the nutrient replenishment it supplies, is both a more equitable and a more sustainable policy. But, even with this approach, diminished supplies of sediment-bound nutrients and the consequent need to compensate with artificial fertilisers will mean that smaller-scale farmers in the VMD are more vulnerable to accruing debt. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).