Study On Turbulence And Water And Heat Fluxes Based On Fuping Flux Station

Agriculture is the lifeblood of country. The study for the phenomena and rules of energy and matter's transport and migrate in farmland ecosystem is related to the increase of water use efficiency, the increase of grain yield and the sustainable development of agriculture, and further affect the stability and prosperity of country; therefore, it is particularly important to study for ours. This research is conducted based on Fuping county Lubotan district. Besides,this research is experimented on the basis of Fuping ecological system detecting test station by utilizing eddy-correlation method to study turbulence phenomenon within research area and study energy and substance exchange phenomena caused by turbulence.(1) According to the judging standard of atmospheric stability, it is divided into three different statuses,which are stable,neutral and unstable. Furthermore, it conducts a statistical characteristic analysis of meteorological elements and w' T', w' q' under different statuses. The result shows: Discretization of eddy-correlation observation indexes w'T' and w'q'becomes intense. On the one hand, as atmospheric stratification turns to unstable status from unstable status, the number of turbulences and scale increase, with contained energy increasing as well. On the other hand, it is also indicated that exchange frequency of energy and substances gets faster at each interval, and it gets stronger in complexity and randomness of atmospheric movement. However, regardless of the status of atmospheric stratification, there is a manifest relation between temperature and CO2 concentration in 30min times scales. Energy contained in low-frequency part of atmosphere turbulence is higher than in high-frequency part.(2) In observation experiments, data needs to be analyzed with quality control, outlier deletion and missing data interpolation. In this paper, data processing procedures are made in compliance with observation station's requirements and flux threshold standards are built in compliance with flux station. Regarding missing or deleted flux data, it applies MDV and LUT for interpolation and EBR to compare interpolation results. As a result, it is indicated that data control standards applied in this search are legitimate and missing data interpolation method and effect proved to be feasible, which can be used as references of follow-up studies.(3 )Concerning comparisons on meteorological elements and flux of different times, the results are as follows: in day temporal scale, elements such as temperature and soil etc changes behind solar radiation as solar radiation changes. During daytime, surface temperature is higher than atmospheric temperature and turbulences appear more intense. It is represented that under sunny weather conditions, the phenomena of energy exchange appear more obvious than cloudy(rainy) days. In long temporal scale, elements such as temperature, vapor pressure deficit, soil temperature, soil water potential, soil conductivity, energy flux, and evapotranspiration change in period of day and year. Generally speaking, they change as solar radiation changes. In terms of energy output, latent heat output accounts for about 50% of total, followed by sensible heat output and soil heat output with annual closure rate of about 0.68 and Bowen ratio of about 0.56.