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Comparison And Research On The Daily Variation Of Land Surface Radiation Balance In Artificial Vegetation And Nature Desert In Taklimakan Desert

Posted on:2018-08-18Degree:MasterType:Thesis
Country:ChinaCandidate:W L MuFull Text:PDF
GTID:2310330536965033Subject:Physical geography
Abstract/Summary:PDF Full Text Request
The Taklimakan desert is the world second large flowing desert,simultaneously is also Chinese desert typical representative.Can promote the development of desert land surface process,the research to Land Surface Radiation Balance in Artificial Vegetation and Nature Desert in Taklimakan Desert.The data of three-dimensional wind speeds,temperature and water vapor pulsation in May and June 2015 in Tazhong station are calculated by the vortex correlation method to obtain the sensible heat flux and the latent heat flux in artificial vegetation and nature desert.And the characteristics of the land surface radiation balance in Taklimakan Desert Atmosphere and Environment Observation and Experiment Station are analysed by using the data observed over the Taklimakan desert hinterland from May,2014 to September,2014.The diurnal variation of the land surface radiation is analysed in artificial vegetation and nature desert in Tazhong,stressed the otherness of budget in the different types of synoptic conditions,,drawed the following main conclusions:(1)The result shows that the surface heat primarily transfers by the sensible heat flux in artificial vegetation and nature desert in Tazhong area.The maximum heat fluxes vary in the range of 160-220 W·m-2 in artificial vegetation,and the maximum heat fluxes vary in the rang of 170-270W·m-2 in nature desert.The sensible heat flux in nature desert is higher than artificial vegetation,and chang is bigger,negative before the sensible heat fluxes at 6:00,and comes as,then the sensible heat flux becomes negative at 19:00,that is to say,the sign changes at around sunrise or sunset.(2)Artificial compared with nature desert of the latent heat flux,the artificial vegetation of latent heat flux is higher than that of nature desert.The maximum latent heat flux vary in the range of 10-80W·m-2 in nature desert,and the maximum latent heat flux vary in the rang of 30-80W·m-2 in artificial vegetation,and the change of nature desert in latent heat flux amplitude is bigger.(3)The results show that the appear time were different in each land surface radiation balance components.The land surface radiation balance components of artificial vegetation and nature desert in Tazhong are the least in nighttime.The maximum value of global radiation and reflect radiation appear at 12:00,and the long-wave radiation often lag 1-3 hours.The diurnal fluctuation of atmosphere long-wave radiation is small and the ground long-wave radiation and appears as asymmetric distribution.(4)The variation of global radiation and net radiation in artificial vegetation and global radiation is small in clear day and global radiation is bigger in global radiation than that in artificial vegetation.The solar radiation and net radiation are obviously reduced in cloudy weather,the ground long wave radiation is decreased slightly and a slight increase of atmospheric long wave radiation.The global radiation and reflect radiation are decreased and the change of net radiation under the influence of tatal radiation but decreased amplitude is less than the global radiation.The diurnal variation of land surface radiation balance is irregular under sandstorm weather and the land surface radiation components are obviously influenced by dust in artificial vegetation and nature desert.(5)Change the components in the different height of radiation is an obvious difference,global radiation overall trend of unimodal symmetric,and maximum in sunny days,80 m global radiation above 1.5 m global radiation in sandstorm weather,reflected radiation and global radiation changing trends are similar,atmospheric long-wave radiation change trend is not stable and the minimum value before sunrise,after increase slowly,in the middle of the day before and after the maximum,then decreases,and the ground long-wave radiation change is larger,1.5 m long wave radiation on the ground is greater than 80 m ground long-wave radiation in different weather conditions,net radiation in sunshine duration,the largest overall 80 m net radiation is greater than 1.5 m net radiation.
Keywords/Search Tags:Taklimakan Desert, Artificial vegetation, Nature desert, land surface radiation balance
PDF Full Text Request
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