Assessing nutrient fluxes in a Vietnamese rural area despite limited and highly uncertain data
Assessing nutrient fluxes in a Vietnamese rural area despite limited and highly uncertain data
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尽管数据有限且高度不确定，但仍评估越南农村地区的养分通量
DOI：
10.1016/j.resconrec.2011.04.008
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Thammarat Kootattep
中科院分区：
文献类型：
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作者：
Nga Do-Thu;Antoine Morel;Hung Nguyen-Vietc;Phuc Pham-Duc;Kei Nishida;Thammarat Kootattep
物质流分析 (MFA) 是一种基于质量守恒定律描述和量化复杂系统的有用方法。它被进一步调整以适应可用数据稀缺且不确定的发展中国家的具体情况。 “适应的MFA”方法优化了参数的数量，将这些参数描述为概率分布，并通过蒙特卡罗模拟评估模型值的准确性和不确定性。这项研究说明了“适应的MFA”方法在越南北部农村的一个小型低收入地区的首次成功应用，其中包括越南北部农村的两个邻近公社，这些地区的环境卫生和传统农业实践密切相关，并对周围环境产生影响。此外，该领域的数据通常稀缺且不确定。所得结果表明，农业系统是养分（氮（N）和磷（P））的重要来源，其影响周围环境的主要原因是化肥的过度使用。每年有103±39吨氮释放到大气中，25±3吨氮淋滤到地表水，14±2吨磷积累在土壤中，全部来自化肥的施用。此外，卫生系统也是进入地表水的营养物质的重要来源。每年有 69±6 吨氮和 23±4 吨磷来自家庭，通过现场卫生系统（如厕所和化粪池）的废水直接排放到地表水。此外，整个系统每年以废水、粪便污泥、动物粪便和有机固体废物的形式产生大量营养源（214 ± 56 吨氮；58 ± 16 吨磷）。经过验证的 MFA 用于对研究地点的不同场景进行建模。第一种情景表明，如果不改善养分管理，预计到 2020 年，废水、粪便污泥和有机固体废物将比 2008 年翻一番。第二种和第三种情景揭示了显着减少环境污染和再利用预计在 2020 年可用的养分源的可能策略。
Material flow analysis (MFA) is a useful methodology to describe and quantify complex systems based on the law of mass conservation. It was further adapted to suit the specific conditions in developing countries where the available data is scarce and uncertain. The ‘adapted MFA’ methodology optimises the number of parameters, describes these parameters as probability distributions and assesses the accuracy and uncertainty of the model values by Monte Carlo simulation.This study illustrates the first successful application of the ‘adapted MFA’ methodology in a small and low-income area including two neighbouring communes in rural northern Vietnam, where environmental sanitation and traditional agricultural practices are strongly interlinked and have an impact on the surrounding environment. Moreover, data on this area is typically scarce and uncertain. The obtained results reveal that the agricultural system was a significant source of nutrients (nitrogen (N) and phosphorous (P)), which affect the surrounding environment mainly due to the overuse of chemical fertilizers. Every year, there were 103 ± 39 tonnes of N released into the atmosphere, 25 ± 3 tonnes of N leached to the surface water and 14 ± 2 tonnes of P accumulated in the soil, all originating from the applied chemical fertilizers. In addition, the sanitation system was also a critical source of nutrients that enter the surface water. 69 ± 6 tonnes of N and 23 ± 4 tonnes of P came from households through effluents of on-site sanitation systems (such as latrines and septic tanks) and were directly discharged to surface water every year. Moreover, the whole system annually generated a large nutrient source (214 ± 56 tonnes of N; 58 ± 16 tonnes of P) in the form of wastewater, faecal sludge, animal manure and organic solid wastes.The validated MFA was used to model different scenarios for the study site. The first scenario demonstrated that if nutrient management is not improved, wastewater as well as faecal sludge and organic solid waste are expected to double in the year 2020 as compared to that in 2008. The second and third scenario revealed possible strategies to significantly reduce environmental pollution and reuse nutrient sources predicted to be available in the year 2020.