库布齐沙漠治理对京津冀地区空气质量影响:2017年5月3-6日沙尘天气模拟

作为影响京津冀地区的沙尘途经地和发源地，对库布齐沙漠的治理工作一直在持续，成为使用科学技术手段将沙漠变废为宝、变害为利的成功案例，同时也是全球治沙范例。为研究库布齐沙漠治理工作对京津冀地区空气质量的改善效果，利用手工采样数据和城市空气质量监测数据，结合气团轨迹，筛选库布齐沙漠起沙并对京津冀地区产生影响的沙尘天气。选取2017年5月3-6日作为典型个例代表，使用嵌套网格空气质量预报模式系统（NAQPMS），设计不同的起沙权重系数敏感试验，模拟研究该地区起沙和治理对京津冀地区的空气质量影响。结果表明：（1）气象模式较好地把握天气系统的演变以及地面风场的特征，保证NAQPMS模式可合理模拟沙尘的起沙区域、影响范围以及时空演变特征；（2）受沙尘影响城市的PM₁₀浓度模拟量值及变化与观测较为一致，表明模式合理再现了沙尘的输送过程；（3）库布齐沙漠起沙对京津冀地区的PM₁₀浓度贡献为35~150 μg·m^-3，贡献比例为10%~40%；（4）库布齐沙漠治理可使京津冀地区PM₁₀浓度降低35~75 μg·m^-3，下降比例为5%~20%，受影响城市PM₁₀浓度下降比例为7%~37%，沙漠治理工作可有效降低受影响地区的PM₁₀浓度。

Influence of desertification control in Hobq Desert on air quality in Beijing-Tianjin-Hebei region: a simulation case of dust weather on 3-6, May, 2017

Hobq Desert, as one of the sand-dust transport and source areas that affect the Beijing-Tianjin-Hebei region, is a successful case of turning desert into treasure and benefit by using a series of scientific and technological means. It is also a global representative example of desertification control. In order to study the effect of Hobq Desert treatment on the improvement of air quality in Beijing-Tianjin-Hebei region, data of manual sampling and urban air quality monitoring and air mass trajectory model were used to screen out dust weather cases, which all happened in Hobq Desert and affected the Beijing-Tianjin-Hebei region. The Nested Air Quality Prediction Modeling System (NAQPMS) was used to simulate sanding and governance of the desert by designing different sensitivity tests of sand-weighting coefficient during a representative case of dust process occurred on May 3-6, 2017. The results showed that:(1) The meteorological model can better grasp the evolution of the weather system and the characteristics of the surface wind field, and ensure that the NAQPMS model can reasonably simulate the sand-sanding area, the extent of impact and the characteristics of temporal-spatial evolution; (2) The simulated values and changes of PM₁₀ concentrations in the cities which are affected by sand and dust are consistent with the observations, indicating that the model reasonably reproduces the dust transport process; (3) The contributions of PM₁₀ mass concentrations on Beijing-Tianjin-Hebei region by sanding in Hobq Desert reached 35-150 μg·m^-3 and the contribution ratios were from 10% to 40%; (4) The treatment of Hobq Desert can reduce PM₁₀ concentrations of the cities in the Beijing-Tianjin-Hebei region by 35-75 μg·m^-3, and the decrease ratios were between 5% and 20%. The PM₁₀ concentrations of decreased by 7%-37% in the cities, and desert treatment can effectively reduce the concentrations of PM₁₀ in the affected areas.