摘要
内陆季节性湖盆是干旱区重要的粉尘来源地,其沙尘的排放会通过一系列的陆地-大气相互作用对区域气候及生态环境产生重大影响。以青土湖、南湖和红沙岗为研究对象,利用BSNE型沙尘仪采集沙尘物质,探讨不同地区沙尘水平通量和粒度特征。结果表明:5个测点平均沙尘水平通量表现为青土湖北(612.1 kg·m^(-2)·a^(-1))>青土湖南(84.6 kg·m^(-2)·a^(-1))>青土湖东(35.2 kg·m^(-2)·a^(-1))>红沙岗(11.0 kg·m^(-2)·a^(-1))>南湖(10.7 kg·m^(-2)·a^(-1)),随着高度增加,青土湖北和青土湖东沙尘水平通量快速降低,青土湖南和红沙岗的下降速度分别在0.5 m和1 m高度以上放缓,南湖先降后增;沙尘颗粒物主要为粉沙和极细沙,其次为细沙和黏土,除青土湖南外,其余测点随着高度的增加呈粉沙含量递增、细沙含量递减、平均粒径变细的趋势;5个测点总体表现为青土湖北平均粒径最粗,分选最好,峰态最窄,局地物质含量最高,随后依次为青土湖东、南湖、青土湖南、红沙岗。不同测点的沙尘水平通量和粒度特征存在差异主要是因为下垫面和沙尘来源不同,而风速、风向以及植被状况是导致沙尘水平通量和粒度特征随时间发生变化的重要原因,随风速增加,沙尘水平通量逐渐增加,平均粒径变粗。
Inland seasonal lake basins are an important source of sand-dust in arid region,and their sand-dust emissions can have a great impact on regional climate and ecological environment through a series of terrestrialatmospheric interactions.In this study,Qingtu Lake,Nanhu Lake and Hongshagang were taken as the research objects.The BSNE dust collectors were used to gather sand-dust to explore the differences of sand-dust horizontal flux and grain size characteristics among different sites.The results showed that the order of the average horizontal sand-dust flux at the five sites was as follows:Qingtu Lake North(612.1 kg·m^(-2)·a^(-1))>Qingtu Lake South(84.6 kg·m^(-2)·a^(-1))>Qingtu Lake East(35.2 kg·m^(-2)·a^(-1))>Hongshagang(11.0 kg·m^(-2)·a^(-1))>South Lake(10.7 kg·m-2·a-1).With increasing height,the horizontal sand-dust fluxes in Qingtu Lake North and Qingtu Lake East decreased rapidly,the decrease rates in Qingtu Lake South and Hongshagang slowed down above 0.5 m and 1 m height,respectively,and the horizontal sand-dust fluxes in South Lake increased at first and then decreased.The grain content of sand-dust was mainly composed of silt and very fine sand,followed by fine sand and clay.Except for Qingtu Lake South,the content of silt increased,the content of fine sand and the average particle size decreased with increasing height.Among five sites,the average particle size of the sand-dust in Qingtu Lake North was the largest,the sorting was the best,the kurtosis distribution was the narrowest and the local material content was the highest,followed by Qingtu Lake East,Nanhu Lake,Qingtu Lake South,and Hongshagang.The differences in dust horizontal flux and particle size among sites were mainly due to the different underlying surface and sand-dust sources,while wind speed,wind direction and vegetation conditions were important reasons for the temporal variation of sand-dust horizontal flux and particle size.With the increasing wind speed,sand-dust horizontal flux increased and average particle size became coarser.
作者
顿耀权
罗万银
邵梅
王芳
逯军峰
李得禄
满多清
车雪华
Dun Yaoquan;Luo Wanyin;Shao Mei;Wang Fang;Lu Junfeng;Li Delu;Man Duoqing;Che Xuehua(Key Laboratory of Desert and Desertification,Northwest Institute of Eco Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China;Gansu Desert Control Research Institute,Lanzhou 730070,China;Center for Glacier and Desert Research,College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China)
出处
《中国沙漠》
CSCD
北大核心
2023年第6期166-175,共10页
Journal of Desert Research
基金
甘肃省重点研发计划项目(20YF8WA005)
国家自然科学基金项目(42171013)。
关键词
内陆湖盆
沙尘水平通量
粒度特征
inland lake basin
sand-dust horizontal flux
grain size characteristics
