The grain-size distribution characteristics and grain-size parameters of sediment in two vertical sections of Daniugou peatland in the Changbai Mountains were systematically investigated.A comparative analysis of the ...The grain-size distribution characteristics and grain-size parameters of sediment in two vertical sections of Daniugou peatland in the Changbai Mountains were systematically investigated.A comparative analysis of the sediment granularity using a discriminative function with Hongyuan peat,red clay,loess-paleosol,fluvial deposit as well as lacustrine deposit was also conducted.It turns out that the vertical section of Daniugou peat ash is primarily constituted by clay and silt particles,and the content of sand is relatively small.Grain-size frequency curves generally show a single-peak modality while a bimodal pattern is detected in the upper layer.The grain-size component and peak pattern of grain-size frequency curves also illustrate that peat ash materials were transported to the peatland by long-range aeolian dust during the deposition process,while there existed short-distance dust influence in peat deposition of the upper layer.Comparisons of grain-size parameters and the discriminative Y-value of Daniugou peat ash with those of typical aeolian sediments show close similarities,suggesting the possibility that atmospheric dust transport processes were involved in the accumulation of peat again.Moreover,the variations of grain-size distribution suggest the local environmental deterioration which is just the driving force of local dust elevation.Grain-size analysis of peatland sediment is demonstrated to be one effective method to extract information about regional and global environmental evolution,and more attention should be paid to current local ecological environment and to seeking a balance between economic development and environmental protection in Northeast China.展开更多
Dustfall is a major threat to agricultural and industrial infrastructures, as well as to other aspects of livelihood. Dustfall associated to a severe dust storm that hit the Al-Ahsa Oasis of Saudi Arabia during 12-13 ...Dustfall is a major threat to agricultural and industrial infrastructures, as well as to other aspects of livelihood. Dustfall associated to a severe dust storm that hit the Al-Ahsa Oasis of Saudi Arabia during 12-13 March 2014 is discussed in this paper. The storm caused widespread and heavy dust deposition. A dramatic decrease in the visibility coincided with the storm, and the average dust concentrations recorded during a peak 10-hour period were 6772, 5862.4 and 451.1 μg/m3 for total suspended particles (TSP), particulate matter smaller than or equal to 10 μm (PM10) and those smaller than or equal to 2.5 μm (PM2.5), respectively. The lowest visibility was 200 m, and the wind speed increased to 17.5 m/s from the north. The average daily dust deposited in the study area during the event was 12.84 (SD = 1.2) g/(m2?d). The dust samples comprised insoluble dust (48.5%) and soluble dust (51.5%). Based on the Munsell color system, the final color description of the falling dust was 10 YR/6/3. A microphotograph of the dustfall (settleable particulate matter) captured by a stereo dissection microscope shows that the dust particles had various colors and sizes, and they contained fibers and vegetative debris).展开更多
基金Under the auspices of National Natural Science Foundation of China (No 40871089, 40830535)State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment, Chinese Academy of Sciences (No SKLLQG0910)
文摘The grain-size distribution characteristics and grain-size parameters of sediment in two vertical sections of Daniugou peatland in the Changbai Mountains were systematically investigated.A comparative analysis of the sediment granularity using a discriminative function with Hongyuan peat,red clay,loess-paleosol,fluvial deposit as well as lacustrine deposit was also conducted.It turns out that the vertical section of Daniugou peat ash is primarily constituted by clay and silt particles,and the content of sand is relatively small.Grain-size frequency curves generally show a single-peak modality while a bimodal pattern is detected in the upper layer.The grain-size component and peak pattern of grain-size frequency curves also illustrate that peat ash materials were transported to the peatland by long-range aeolian dust during the deposition process,while there existed short-distance dust influence in peat deposition of the upper layer.Comparisons of grain-size parameters and the discriminative Y-value of Daniugou peat ash with those of typical aeolian sediments show close similarities,suggesting the possibility that atmospheric dust transport processes were involved in the accumulation of peat again.Moreover,the variations of grain-size distribution suggest the local environmental deterioration which is just the driving force of local dust elevation.Grain-size analysis of peatland sediment is demonstrated to be one effective method to extract information about regional and global environmental evolution,and more attention should be paid to current local ecological environment and to seeking a balance between economic development and environmental protection in Northeast China.
文摘Dustfall is a major threat to agricultural and industrial infrastructures, as well as to other aspects of livelihood. Dustfall associated to a severe dust storm that hit the Al-Ahsa Oasis of Saudi Arabia during 12-13 March 2014 is discussed in this paper. The storm caused widespread and heavy dust deposition. A dramatic decrease in the visibility coincided with the storm, and the average dust concentrations recorded during a peak 10-hour period were 6772, 5862.4 and 451.1 μg/m3 for total suspended particles (TSP), particulate matter smaller than or equal to 10 μm (PM10) and those smaller than or equal to 2.5 μm (PM2.5), respectively. The lowest visibility was 200 m, and the wind speed increased to 17.5 m/s from the north. The average daily dust deposited in the study area during the event was 12.84 (SD = 1.2) g/(m2?d). The dust samples comprised insoluble dust (48.5%) and soluble dust (51.5%). Based on the Munsell color system, the final color description of the falling dust was 10 YR/6/3. A microphotograph of the dustfall (settleable particulate matter) captured by a stereo dissection microscope shows that the dust particles had various colors and sizes, and they contained fibers and vegetative debris).
