Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India.
Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India.
Sci Total Environ. 2019 Nov 25;693:133577. doi: 10.1016/j.scitotenv.2019.07.383. Epub 2019 Jul 23.
This research investigates whether the vehicular black carbon emissions originated in the North-Eastern city of Guwahati are transported over and in the Brahmaputra River Valley and the Himalayas. The total black carbon was apportioned between the fossil fuel and biomass burning by real-time measurements of black carbon concentrations at two distinct locations having different traffic volumes in 2016-17. The average observed BC concentrations were 20.58, 6.42, 3.50 and 5.29 μg/m at the low traffic location and 22.44, 17.14, 9.2 and 16.87 μg/m at the high traffic location in winter, pre-monsoon, monsoon and post-monsoon seasons, respectively. Temperature, wind speed, and solar radiation were found to have significant negative correlations with BC concentrations, while relative humidity had positive correlations. It was found that vehicles contributed over 85% of the ambient black carbon at both locations. Black carbon emission from this dominant source was estimated for 2018, which showed that from vehicles it increased to 0.44-0.55 Gg in 2018 from 0.29 to 0.33 Gg in 2011, which may result in the adverse impacts on the eco-sensitive Brahmaputra River Valley and the Himalayas. The transport and deposition of black carbon under different climatic seasons was modelled using HYSPLIT. The results showed that black carbon particulates are being transported and deposited all-round the year in the Himalayas and the surrounding region. Pre-monsoon and monsoon seasons contributed to the largest amounts of deposition, and a clear relation was found between deposition and rainfall. The total BC deposited in the Brahmaputra River Valley and the Himalayas during one year was 22,142.69 kg and 1566.53 kg with average deposition rates of 0.6452 μgm day and 0.0182 μgm day, respectively.
这项研究调查了来自东北部城市古瓦哈蒂的机动车黑碳排放是否被输送到布拉马普特拉河谷和喜马拉雅山脉地区。在 2016-17 年，通过对两个具有不同交通量的地点实时测量黑碳浓度，将总黑碳在化石燃料和生物质燃烧之间进行了分配。冬季、前季风期、季风期和后季风期，低交通量地点的平均观测 BC 浓度分别为 20.58、6.42、3.50 和 5.29μg/m，高交通量地点分别为 22.44、17.14、9.2 和 16.87μg/m。温度、风速和太阳辐射与 BC 浓度呈显著负相关，而相对湿度则呈正相关。结果发现，两个地点的环境黑碳中，车辆贡献了超过 85%。对 2018 年这一主要来源的黑碳排放进行了估算，结果表明，2018 年从车辆排放的黑碳从 2011 年的 0.29 至 0.33 Gg 增加到 0.44 至 0.55 Gg，这可能会对生态敏感的布拉马普特拉河谷和喜马拉雅山脉造成不利影响。利用 HYSPLIT 对不同气候季节的黑碳传输和沉积进行了建模。结果表明，黑碳颗粒在喜马拉雅山脉及其周边地区全年都在传输和沉积。前季风期和季风期的沉积量最大，沉积量与降雨量之间存在明显关系。在一年中，沉积在布拉马普特拉河谷和喜马拉雅山的总黑碳量分别为 22142.69kg 和 1566.53kg，平均沉积速率分别为 0.6452μg/m 天和 0.0182μg/m 天。
