乌兰布和沙漠东北缘不同下垫面降尘特征研究  

Characteristics of Dustfall on Different Underlying Surfaces in the Northeast UlanBuhe Desert

作　　者：党晓宏 魏亚娟 蒙仲举 高永 韩彦隆 DANG Xiaohong;WEI Yajuan;GAO Yong;MENG Zhongju;HAN Yanlong(Institute of DesertContol Science and Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China;Inner Mongolia Hangjin Dsert Ecological Position Rsearch Station,Ordos 017400,China;Center and Local Co-building“Aeolian Physics”Key Laboratory of Special Dominant Discipline in University,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学沙漠治理学院,内蒙古呼和浩特010018 [2]内蒙古杭锦荒漠生态系统国家定位观测研究站,内蒙古鄂尔多斯017400 [3]中央与地方共建高校特色优势学科“风沙物理”重点实验室,内蒙古呼和浩特010018

出　　处：《应用基础与工程科学学报》2020年第5期1122-1133,共12页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(41967009);中央引导地方科技发展专项资金计划项目:内蒙古荒漠化防治创新研究中心。

摘　　要：以乌兰布和沙漠东北缘5种下垫面(流动沙丘、半固定沙地、固定沙地、花棒林地和沙拐枣林地)为研究对象,采用野外实地观测和室内分析相结合的方法,对各下垫面近地表2m和5m高度处的降尘量,降尘粒度特征,防护林地土壤粒度特征及其影响降尘量的气候因素进行了分析研究.结果表明:(1)不同下垫面近地层2m、5m高度处的降尘均以<0.25mm的区域与局地沙物质为主,占总降尘量的88.50%~90.00%,远源传输物质甚少,仅占总降尘量的10.00%~11.50%.(2)随着地表植被盖度的增加,各下垫面降尘量逐渐降低.由外到内(半固定沙丘、固定沙丘、花棒防护林地、沙拐枣防护林地)近地层2m高度处降尘量较流动沙丘分别减小45.85%、53.49%、53.68%和58.39%,5m高度处降尘量分别减少65.47%、68.84%、69.92%和73.97%.(3)各下垫面近地表2m和5m高度处的降尘量由大到小依次为:流动沙丘>半固定沙丘>固定沙丘>花棒防护林地>沙拐枣防护林地.(4)各下垫面降尘主要以冬、春季为主,近地层2m、5m高度处降尘量分别占到全年总降尘量的73.72%~87.04%.(5)平均风速、扬沙、大风和沙尘暴对大气降尘有明显促进作用,尤其是大风日数对该区域降尘量影响最大.因此,绿洲防护林的保护和沙区植被营建有利于改善该区域空气环境质量.Field observations and laboratory measurements were used to study the dust depositionat 2m and 5m height of surface layer,grain size characteristics of dust deposition and surface soils,as well as climatic factors affected dustfall of different underlying surface(mobile sand dune,semi-fixed sand dune,fixed sand dune,Hedysarum scoparium plantation and Calligonum mongolicum plantation)in the northeastern edge of Ulan Buhe Desert.The analyzed results show that less than 0.25mm sediment deposition was mainly from regional and local material,accounting for 88.50%~90.00%of the total dust deposition,but the proportion of material from the far sources material was relatively small,and accounting for only 10.00%~11.50%of total dust deposition.Dust deposition in different underlying surfaces was gradually decrease with the increasing of vegetation coverage.Dust deposition at 2m and 5m height from outside to inside was 1.46,1.53,1.54,1.58 times and 1.65,1.69,1.70,1.74 times lower than that of mobile sand dune,respectively.The dust deposition at 2m and 5m height of surface layer in underlying surface were as follows:mobile dune>semi-fixed dune>fixed dune>Hedysarum scoparium plantation>Calligonum mongolicum plantation.The precipitation of dust deposition in different underlying surface was mainly in spring and winter,and accounted for 73.72%~87.04%of the total precipitation in whole year,respectively.Average wind speed,blowing dust days,strong wind days and sandstorm days could obviously affect atmospheric dustfall,especially days of strong wind had greatest impact on the dustfall in the region.Consequently,the protection and construction of vegetation was the main means of desert control in the source areas of sandstorms in sandy areas.

关 键 词：降尘量 粒度 下垫面 近地层 地表沉积物 植被盖度 防风固沙 乌兰布和沙漠 

分 类 号：P425.55[天文地球—大气科学及气象学]