气候变化对河北坝上不留茬农田土壤风蚀扬尘排放速率的影响

Effects of climate change on dust emission rate of no-stubble farmland soils caused by wind erosion in Bashang area of Hebei Province

基于全球气候模式NorESM1-M产生的RCP2.6、RCP4.5、RCP6.0和RCP8.5气候变化情景数据,利用国家原环境保护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、砂粘土和风沙土不留茬农田土壤风蚀扬尘总可悬浮颗粒物(Total suspended particle,TSP)、PM_(10)和PM_(2.5)的季节和年排放速率影响。结果显示: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,不同情景下变化趋势不同。RCP2.6、RCP4.5、RCP6.0和RCP8.5情景与基准情景下比较,不同土壤风蚀扬尘TSP、PM_(10)和PM_(2.5)季节排放速率在春季分别高15%、47%、28%和46%,夏季分别高1%、14%、3%和7%,秋季分别高17%、54%、45%和38%,冬季分别低36%、42%、39%和44%。在RCP2.6、RCP4.5、RCP6.0和RCP8.5情景下与基准情景下比较,按月排放累加计算,各土壤风蚀扬尘TSP、PM_(10)和PM_(2.5)年排放速率分别低6%、75%、72%和高103%;按年气候因子计算,则分别高25%、54%、35%和54%。在基准和未来气候变化情景下,土壤风蚀扬尘TSP、PM_(10)和PM_(2.5)的季节和年排放速率从高到低依次为砂粘壤土、风沙土、砂壤土、粘壤土、壤粘土和砂粘土。结果说明,未来气候变化将使河北坝上地区不留茬农田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。

Based on the climate change data of RCP2.6,RCP4.5,RCP6.0 and RCP8.5 produced by the global climate model of NorESM1-M and calculation method of dust emission caused by soil wind erosion recommended by the Ministry of Environmental Protection of People’s Republic of China,the effects of the future climate change on the monthly,seasonal and annual emission rates of dust TSP(Total suspended particle),PM_(10) and PM_(2.5) by wind erosion of sandy loam,clay loam,loam,sandy loam,sandy soil and sandy soil were studied on no stubble farmland in Bashang area,Hebei Province.The results showed various trends of air temperature and the annual precipitation and wind speed in different climate change scenarios,with obviously fluctuating in Bashang area.Inspring,compared with the baseline scenario,the seasonal emission rates of TSP,PM_(10) and PM_(2.5) were 15%,47%,28%and 46%were higher in the RCP2.6,RCP4.5,RCP6.0 and RCP8.5 scenarios,respectively.In summer,the seasonal emission rates of TSP,PM_(10) and PM_(2.5) were 1%,14%,3%and 7%higher in RCP2.6,RCP4.5,RCP6.0 and RCP8.5 scenarios than that in the baseline scenario,respectively.In autumn,the seasonal emission rates of TSP,PM_(10) and PM_(2.5) were 17%,54%,45%and 38%higher in RCP2.6,RCP4.5,RCP6.0 and RCP8.5 scenarios than those in the baseline scenario,respectively,and during winter,the seasonal emission rates of TSP,PM_(10) and PM_(2.5) by soil wind erosion were 36%,42%,39%and 44%lower in the RCP2.6,RCP4.5,RCP6.0 and RCP8.5 scenarios than that in baseline scenario,respectively.Based on monthly calculation,emission rates of TSP,PM_(10) and PM_(2.5) in the RCP2.6,RCP4.5 and RCP6.0 scenarios were 6%,75%and 72%lower than that in the baseline scenario,and which was 103%higher in the RCP8.5 scenario than that in the baseline scenario.Based on yearly climatic factors,the emission rates of TSP,PM_(10) and PM_(2.5) by soil wind erosion was 25%,54%,35%and 54%higher in RCP2.6,RCP4.5,RCP6.0 and RCP8.5 scenario than that in the baseline scenario.In the baseline and future climate change scenarios,the monthly,seasonal and annual emission rates of TSP,PM_(10) and PM_(2.5) caused by soil wind erosionin order of:sandy loam,sandy soil,sandy loam,clay loam,clay and sand soil.The results suggested that future climate change resulted in increased rate of wind erosion and dust emission in farmland in Hebei Province,but the rates were fluctuated in different months,seasons and climate change scenarios.