Posgrado en Ingeniería, Universidad Nacional Autónoma de México, Campus Instituto Mexicano de Tecnología del Agua, Paseo Cuauhnáuac 8532, Jiutepec, 62550, Mor., Mexico.
Instituto Mexicano de Tecnología del Agua, Paseo Cuauhnáhuac 8532, Jiutepec, 62550, Mor., Mexico.
Environ Sci Pollut Res Int. 2018 Jul;25(21):20497-20509. doi: 10.1007/s11356-017-0334-2. Epub 2017 Oct 4.
Since nutrients are emitted and mobilized in river basins, causing eutrophication of water bodies, it is important to reduce such emissions and subsequent nutrient loads. Due to processes of attenuation, nutrient loads are reduced during their mobilization in river basins. At the mouth of the Río Verde basin in western Mexico, the El Purgatorio dam is being constructed to supply water to the metropolitan area of the second most populated city in the country, Guadalajara. To analyze situations that allow protecting this future dam from eutrophication, nutrient loads in the mouth of the river basin were determined and their reduction scenarios evaluated by using the NEWS2 (Nutrient Export from Watersheds) model. For this, a nutrient emissions inventory was established and used to model nutrient loads, and modeling results were compared to an analysis of water quality data from two different monitoring sites located on the river. The results suggest that 96% of nitrogen and 99% of phosphorus emissions are attenuated in the watershed. Nutrient loads reaching the mouth of the river basin come mainly from wastewater discharges, followed by livestock activities and different land uses, and loads are higher as emissions are located closer to the mouth of the river basin. To achieve and maintain mesotrophic state of water in the future dam, different nutrient emission reduction scenarios were evaluated. According to these results, the reduction of 90% of the phosphorus loads in wastewater emissions or 75% of the phosphorus loads in wastewater emissions and at least 50% in emissions from livestock activities in the river basin are required.
由于营养物质在流域中释放和迁移，导致水体富营养化，因此减少这些排放和随后的营养负荷非常重要。由于衰减过程，营养负荷在流域中迁移过程中会减少。在墨西哥西部 Verde 河流域的河口处，正在建造 El Purgatorio 大坝，为该国第二大人口城市 Guadalajara 的大都市区供水。为了分析允许保护这座未来大坝免受富营养化的情况，通过使用 NEWS2（流域养分输出）模型来确定河流流域河口的养分负荷及其减少方案。为此，建立了一个养分排放清单，并使用该清单对养分负荷进行建模，将建模结果与位于河流两个不同监测点的水质数据分析进行了比较。结果表明，氮的 96%和磷的 99%排放物在流域中被衰减。到达河流流域河口的养分负荷主要来自废水排放，其次是牲畜活动和不同的土地利用，并且排放物越靠近河流流域的河口，负荷就越高。为了实现和维持未来大坝的中营养状态，评估了不同的养分减排方案。根据这些结果，需要减少废水排放中 90%的磷负荷，或减少废水排放中 75%的磷负荷，以及流域中牲畜活动的至少 50%的磷负荷。
