Water Systems and Global Change Group, Wageningen University, Droevendaalsesteeg 3, 6708 PB Wageningen, the Netherlands; Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, The Chinese Academy of Sciences, 286 Huaizhong Road, Shijiazhuang 050021, Hebei, China.
School of Environment, Tsinghua University, 1 Qinghuayuan, Haidian District, Beijing 100084, China.
Sci Total Environ. 2021 Jul 10;777:146105. doi: 10.1016/j.scitotenv.2021.146105. Epub 2021 Feb 27.
Water pollution is a serious problem in China. This study focuses on equality in pollution control in the Yangtze, Yellow and Pearl. We first quantified environmental targets for nitrogen (N) and phosphorus (P) at the river mouth. We used the Indicator for Coastal Eutrophication Potential and the Model to Assess River Inputs of Nutrients to seAs (MARINA) to project river export of nutrients. Next, we allocated the environmental targets to sub-basins as allowable levels, based on a Gini optimization approach. We searched for minimum inequality in pollution per unit of GDP, population, basin area, and agricultural area. Our results indicate that without pollution control, the river export of nutrients in 2050 exceed allowable levels. To meet the allowable levels while striving for equality, total dissolved N and P exports from sub-basins need to be reduced by 60 to 97%. The required reductions are largest for sub-basins of the Yellow River. For P, reducing point source inputs to rivers (manure and sewage) may be enough to avoid that allowable levels are exceeded in many sub-basins. For N, more needs to be done. Some sub-basins need to reduce their pollution more than others. Equality considerations call for reducing both point (e.g. recycling manure resources on the land) and diffuse (improve nutrient use efficiencies in agriculture) sources of N in the rivers. Our study is the first to link a Gini based optimization approach with the MARINA model. It may support decision making aimed at cleaner production and at equality in pollution control.
水污染是中国面临的一个严重问题。本研究聚焦于长江、黄河和珠江流域的污染控制平等问题。我们首先在河口量化了氮（N）和磷（P）的环境目标。我们使用沿海富营养化指标和海洋营养物输入模型（MARINA）来预测河流的营养物输出。接下来，我们采用基尼优化方法，将环境目标分配到各个子流域，作为允许的水平。我们搜索了单位 GDP、人口、流域面积和农业面积的污染最小不平等性。我们的研究结果表明，如果不进行污染控制，到 2050 年，河流的营养物输出将超过允许水平。为了在追求平等的同时达到允许水平，子流域的总溶解氮和磷的出口量需要减少 60%至 97%。黄河流域的子流域需要减少的量最大。对于磷，减少向河流（粪便和污水）排放的点源输入可能足以避免许多子流域超过允许水平。对于氮，需要做更多的工作。一些子流域需要比其他子流域减少更多的污染。平等考虑因素要求减少河流中的点源（如回收粪便资源）和扩散源（提高农业中的养分利用效率）的氮污染。本研究首次将基尼优化方法与 MARINA 模型联系起来。它可以为清洁生产和污染控制平等的决策提供支持。
