Investigation On The Lake Surface Evaporation In The Badain Jaran Desert Using Multiple Methods

Using the data of Sumu Jaran South Lake automatic meteorological station and Large Aperture Scintillometer(LAS)in Badan Jaran Desert,combined with other data,this paper investigates the Sumu Jaran South Lake surface evaporation using multiple methods.Analyzing the data of E601 evaporation pan at the weather station,it is find that the maximum day evaporation is 180 mm,in August and the the maximum night evaporation is 55 mm,in March.The day evaporation is larger in summer and smaller in winter,while the night evaporation is opposite,it is larger in winter and smaller in summer. Sumu Jaran South Lake surface annual evaporation is about 1300 mm.The evaporation pan was setted up in the lake,so the pan evaporation could be regard as the lake surfer evaporation.According to the correlation analysis, the lake day evaporation is positively related with temperature, wind speed, and negative correlation between relative humidity, the night evaporation is negatively related with air temperature, relative humidity, and positively correlated with wind speed.For the seasonal variation of the surface evaporation, this paper selects the typical period of time, using the Dalton model to assess the lake surface night evaporation, and on the day evaporation of the lake is adopted a variety of methods to evaluate,including:the water balance method to assess seasonal evaporation,the United Nations Food and Agriculture Organization(FAO) recommended ETo Calculator software to calculate the potential evapotranspiration; Penmen- Montes formula for direct calculation method to estimate the day evaporation, according to the Large Aperture Scintillometer data calculate latent heat flux and sensible heat flux,etc. Results show that these methods to estimate the evaporation and the actual evaporation have almost the same change trend.The water balance simulation method can well reflect the seasonal variation of the evaporation of Sumu Jaran South Lake, it is conclude that groundwater discharge to Sumu Jaran South Lake is stable,the computation supply intensity reached 900 mm to 1900 mm according to the lake area,effectively balance the water evaporation. The day evaporation calculated byPenmen- montes formula is slightly larger in the overall simulation period.The day evaporation in summer calculated by ETo calculator software slightly smaller but error is little, while the calculated value of day evaporation in winter is slightly larger.The simulated day evaporation by dealing with Large Aperture Scintillometer data and meteorological data is just slightly smaller in the summer, and is slightly larger in winter.Analysis of the relationship between net radiation and the calculated sensible heat flux, latent heat flux, found that the net radiation is larger than the sum of the estimated sensible heat fluxes and latent heat fluxes, suggesting that water heat flux can not be ignored, need to take into consideration in the calculation model in the future. The performance of Dalton model to calculate night evaporation is not good,so we still need further study of mechanism and simulation method of evaporation on the lake surface night evaporation.