Dissertation
Dissertation > Astronomy,Earth Sciences > Physical Geography > Department of Physical Geography > Geomorphology ( topography ) > Desert geomorphology,dry and geomorphology

The Research on Wind-Sand Observations in Spring in Guaizi Lake Region of Badain Jaran Desert

Author HuWenFeng
Tutor HeQing
School Xinjiang Normal University
Course Physical Geography
Keywords Guaizi Lake dust emission by wind Erosion wind sand fluid parameters
CLC P931.3
Type Master's thesis
Year 2012
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In this paper, based on the wind-sand observational date which gained fromGuaizi Lake of Badain Jaran Desert in Inner Mongolia, the change of meteorologicalelements, wind profile, sand flow structure characteristic and so on have beensystematic researched, and calculated the relevant parameters.The results are asfollows:(1)Hot and dry atmosphere, the surface high temperature and low humidity,pressure drop and wind speed increase are precursor to the coming storms; during thedust storms the pressure,the vapor pressure and relative humidity are decreased,slower rate of decline of ground temperature, soil moisture increased slightly. Thewind plays a major role in the development of dust storm.(2) Find that although both the free wind and sand flow can be scattered by the formZ=A*EXP (-X/T)+Z1,they have higher fitting ratio in the sand flow. Under theheight of20cm, the percentage of sediment transport rate, sediment concentrationand the energy of moving particles are in the trend of increasing. Up the height of20cm, the percentage of sediment transport rate will decrease. The sedimentconcentration in the sand flow is mainly concentrated in the area within20cm fromthe ground. In the vertical direction of sand flow, the height is negatively related withthe average particle size; while the wind speed is positively related with the averageparticle size of wind stream sediment. Saltating sand particles spatial distribution ofsediment discharge frequency of both the similarities and the wind direction, thereare differences too; direction of creeping distribution of sediment load is morecomplex, with significant differences in wind direction. The results was instructive toforecasts of sand dust storm and resistance to wind-sand.These conclusions are ofgreat guiding importance to the windbreak and sand fixation in Guaizi Lake.(3) he aerodynamic roughness length z0is ranged from1.010-7~9.010-1cm, andits mean value is0.942cm. The threshold friction velocity is ranged from0.30~0.40cm, and the threshold wind velocity of2m height is about4.55m/s. The frictionvelocity of sand was positively related with wind speed, and the influence of changeof friction velocity on wind erosion.(4) April5,2011, a process of dust storm,the average horizontal sand flux and windVertical sand flux were estimated that1.7E-02kg.m-1.s-1and1.38E-07kg.m-2.s-1,respectively.The horizontal sand flux to be much larger than the vertical. Theobtained parameters have great significance to wind prevention and sand control. (5)In the April, the ground surface temperature, temperature and wind speed werethe primary factors to wind erosion of sand, it has contributed a lot to the winderosion of sand; the secondary factors is the relative humidity of air and surfacewater content, In the process of wind and sand control, not focus only on wind speedand ignore the other factors.

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