Qi Meilan, Lin Kairong, Li Xiangzhen, Sammis Ted W, Miller David R, Wang Junming
School of Science, Wuhan University of Technology, Wuhan, Hubei, P. R. China.
Department of Water Resources and Environment, Sun Yat-sen University, Guangzhou, Guangdong, China.
PLoS One. 2015 Sep 30;10(9):e0138577. doi: 10.1371/journal.pone.0138577. eCollection 2015.
Sources of regional particulate matter (PM), particularly agricultural operations, must be understood in order to manage the air quality in irrigated dry climates. Direct monitoring measurements alone are useful, but not sufficient, to estimate regional PM source concentrations. This paper combines modeling with ground (point) and airplane (spatial) measurement methods to estimate regional PM10 (PM diameter≤10 μm) contributions from agricultural operations. Hourly data from three air quality monitoring stations positioned at a 2-m height located on the west and east mesas of New Mexico's Mesilla Valley and in the valley at Anthony, NM were acquired from the New Mexico Air Quality Bureau. The study spanned the agricultural tilling season, March 1 to April 30, for the years 2008 to 2012. One- second spatial PM10 concentrations at 200 m above the valley floor were measured during a two-hour controlled field tilling operation on April 1, 2008. The HYSPLIT 4.0 (Hybrid Single-Particle Lagrangian Integrated Trajectory version 4) model was run at the corresponding times and heights, outputting PM10 concentrations from all potential agricultural tilling operations. The calculated percentage contribution (modeled PM10 concentration/measured PM10 concentration) indicated that the near-surface (2-m height) proportion from the agricultural operations for five seasonal averages ranged from 0.7% to 1.5% on the west and east mesas and 1.3% for the valley site at Anthony. There were 71 hourly high values of contribution ratios ranging from 30 to 100% at the three sites, depending on the wind speed and direction.
为了管理灌溉干旱气候下的空气质量，必须了解区域颗粒物（PM）的来源，尤其是农业活动。仅靠直接监测测量对于估算区域PM源浓度是有用的，但并不充分。本文将模型与地面（点）和飞机（空间）测量方法相结合，以估算农业活动对区域PM10（PM直径≤10μm）的贡献。从新墨西哥州空气质量局获取了位于新墨西哥州梅塞拉谷东西台地以及安东尼山谷2米高度处的三个空气质量监测站的每小时数据。该研究涵盖了2008年至2012年3月1日至4月30日的农业耕作季节。在2008年4月1日两小时的受控田间耕作操作期间，测量了山谷地面上方200米处的每秒空间PM10浓度。在相应的时间和高度运行了HYSPLIT 4.0（混合单粒子拉格朗日积分轨迹版本4）模型，输出所有潜在农业耕作操作的PM10浓度。计算得出的贡献百分比（模拟的PM10浓度/测量的PM10浓度）表明，在东西台地，五个季节平均值中农业活动在近地表（2米高度）的比例为0.7%至1.5%，安东尼山谷站点为1.3%。根据风速和风向，三个站点有71个每小时贡献比的高值，范围从30%到100%。
