气候变化对河北坝上地区草地土壤风蚀扬尘季节和年排放速率的影响

以全球气候模式NorESM1-M产生的RCP2.6、RCP4.5、RCP6.0、RCP8.5气候变化情景数据和原环保部推荐的土壤风蚀扬尘计算方法,模拟分析了未来气候变化对河北坝上砂粘壤土、粘壤土、壤粘土、砂壤土、砂粘土和风沙土草地土壤风蚀扬尘总可悬浮颗粒物(Total Suspended Particle,TSP)、PM10和PM2.5的季节及年排放速率的影响。结果表明:气候变化影响下坝上地区气温上升,年降水量和风速波动较大、并存在上升和下降的趋势。相比基准情景,在RCP2.6、RCP4.5、RCP6.0和RCP8.5情景下,各土壤风蚀扬尘TSP、PM10和PM2.5季节排放速率在春季分别高15%、47%、28%和46%;秋季分别高17%、54%、45%和38%;冬季分别低36%、42%、39%和44%;夏季,在RCP2.6情景下低1%,在RCP4.5、RCP6.0和RCP8.5情景下分别高14%、3%和7%;未来气候变化情景下,各土壤风蚀扬尘TSP、PM10和PM2.5年排放速率分别高25%、54%、35%和54%。基准和未来气候变化情景下,土壤风蚀扬尘TSP、PM10和PM2.5的季节和年排放速率及其差异从高到低均依次为砂粘壤土、风沙土、砂壤土、粘壤土、壤粘土和砂粘土。表明未来气候变化将使河北坝上地区草地土壤风蚀扬尘排放速率增加,但存在季节和气候变化情景方面的差异。

Effects of climate change on emission rate of dust of grassland soil by wind erosion in Bashang area,Hebei province

Based on the data of RCP2.6,RCP4.5,RCP6.0 and RCP8.5 climate change scenarios produced by the global climate model of NorESM1-M and calculation method of dust emission by soil wind erosion recommended by former Ministry of Environmental Protection of People's Republic of China,the effects of future climate change on the seasonal and annual emission rates of dust TSP (Total Suspended Particle),PM₁₀ and PM_2.5 by soil wind erosion from sandy loam,clay loam,loam,sandy loam,sandy soil and sandy soil grasslands in Bashang area of Hebei province were analyzed.The results show that the air temperature will increase and the annual precipitation and wind speed will obviously fluctuate with increasing and decreasing trends in Bashang area.Compared with the baseline scenario,the seasonal emission rates of TSP,PM₁₀ and PM_2.5 are 15%,47%,28% and 46% higher in spring,17%,54%,45% and 38% higher in autumn,36%,42%,39% and 44% lower in winter in RCP2.6,RCP4.5,RCP6.0 and RCP8.5 scenarios,respectively.In summer,the seasonal emission rates of TSP,PM₁₀ and PM_2.5 are 1% lower in RCP2.6 and are 14%,3% and 7% higher in RCP4.5,RCP6.0 and RCP8.5 scenarios than those in the baseline scenario,respectively.Under the background of future climate change,the annual emission rates of TSP,PM₁₀ and PM_2.5 by soil wind erosion will respectively increase 25%,54%,35% and 54% in RCP2.6,RCP4.5,RCP6.0 and RCP8.5 scenarios relative to those in the baseline scenario.Under the baseline and future climate change scenarios,the seasonal and annual emission rates of TSP,PM₁₀ and PM_2.5 by soil wind erosion and their differences are in the order from large to small by sandy loam,sandy soil,sandy loam,clay loam,clay and sand soil.The results suggest that the increase of the rate of dust by wind erosion in grassland soil in Bashang area of Hebei province will be caused by future climate change,but existing differences in different seasons and climate change scenarios.