National Marine Data and Information Service, Ministry of Natural Resources, Tianjin, 300171, China.
Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
Environ Sci Pollut Res Int. 2023 Jan;30(2):2450-2468. doi: 10.1007/s11356-022-21943-y. Epub 2022 Aug 5.
Since the millennium, China has economically taken off with rapid urbanization, and anthropogenic nitrogen emission intensity has undergone remarkable changes. To better understand the impact of urbanization on anthropogenic nitrogen, this study calculated the spatio-temporal heterogeneity of anthropogenic nitrogen in the Yangtze River Economic Belt (YREB) since 2000, based on the estimation, using obstacle analysis to quantify the driving of industry and agriculture on N growth and using the gray model to analyze the impact of urbanization on N changes. Additionally, using the environmental pressure model to predict the future N load. The results indicated N load in the YREB increased rapidly from 21.4 Tg in 2001 to a peak of 24.5 Tg in 2012 and then decreased to 22.2 Tg in 2019. Although N flux gradually increased from the west to the east of the YREB, the growth rate had an opposite trend with a negative growth in the eastern region. Hotspots are mainly concentrated in urban agglomerations, which contributed to ~ 60% N load of the YREB, and the YREB contributed to ~ 90% N load of the Yangtze River Basin. Obstacle degree scores indicated wastewater was a major industrial driver of N growth before 2010, and then became waste gas; increased mechanization and fertilizer control effectively reduced nitrogen emissions during agricultural development. The gray analysis of urbanization indicated urban population, industry, and services had the strongest correlation with N load changes. Scenario simulations suggest N loads of the YREB remain at a high level by 2030; however, there are still opportunities to effectively control N growth through high technological innovation and reducing the proportion of industry under an enormous population. This research contributes to a better understanding of the impact of urbanization on anthropogenic nitrogen and helps developing countries to precisely control nitrogen hotspots and sources.
自千年之交以来，中国经济腾飞，城市化进程迅速推进，人为氮排放强度发生了显著变化。为了更好地了解城市化对人为氮的影响，本研究基于估算，采用障碍分析量化工业和农业对氮增长的驱动作用，利用灰色模型分析城市化对氮变化的影响，并利用环境压力模型预测未来氮负荷，计算了 2000 年以来长江经济带（YREB）人为氮的时空异质性。结果表明，YREB 的氮负荷从 2001 年的 21.4Tg 迅速增加到 2012 年的峰值 24.5Tg，然后下降到 2019 年的 22.2Tg。尽管氮通量从 YREB 的西部逐渐增加到东部，但增长率呈相反趋势，东部地区呈负增长。热点主要集中在城市群，对 YREB 的氮负荷贡献了约 60%，而 YREB 对长江流域的氮负荷贡献了约 90%。障碍度得分表明，废水在 2010 年前是氮增长的主要工业驱动因素，然后变成废气；农业发展中，机械化和化肥控制的增加有效地减少了氮排放。城市化的灰色分析表明，城市人口、工业和服务业与氮负荷变化的相关性最强。情景模拟表明，到 2030 年，YREB 的氮负荷仍将处于较高水平；然而，通过高技术创新和降低庞大人口下工业的比例，仍有机会有效控制氮的增长。本研究有助于更好地了解城市化对人为氮的影响，并有助于发展中国家精确控制氮热点和来源。
