Moisture and Heat Fluxes over Grassland and Bare Soil in Semi-arid Area

Sandstorm has something with inadequatesoil protection by the grasses,the shrubs,and low vegetation coverage.It's very important for us to study the moisture and heat fluxes quantitatively over the grassland and the bare soil in the semi-arid area.Eddy covariance technique is the relatively standard method,which is used to measure the moisture and heat fluxes between the different underlying surfaces and atmosphere.Therefore the two fluxes were measured over the grassland and the bare soil.The result indicated that in sunny daytime over the grassland,the latent heat flux was much greater than the sensible one.The maximum of the latent heat was twice as that of the sensible heat.On the contrary,the sensible heat was much greater than the latent heat over the bare soil.The maximum of the sensible heat was twice as that of the latent heat.However,the latent heat flux was a little greater than the sensible heat flux in cloudy daytime over the grassland.The sensible heat was still much greater than the latent heat over the bare soil.The maximum of the sensible heat was over twice as that of the latent heat.The energy imbalance existed.Grassland has the ecological effect in decreasing temperature and enhancing moisture.It will play important part in decreasing the sandstorm and maintaining ecological balance.