Based On The Observation Of The Badain Jaran Desert Lakes Evaporation Salinity Effect Research

As the important spending part of lake water cycle, water surface evaporation observations provide data support for establishment of the lake water balance model. The Badain Jaran desert contains numerous lakes, and the lakes salinity are different, under the condition of different salinity of water under the same external evaporation is the existence of differences. In this study, through the Positioning observation in Badain Jaran desert, the water surface evaporation and climatic factors were observed, measured data obtained in the area of water surface evaporation, the analysis in the area of pan evaporation characteristics. By using multiple water surface observation system for different TDS water evaporation observation experiment, discuss the quantitative relationship between the TDS and evaporation, and the salinity effect factors. To solve the problem of lakes evaporation and water balance in the region. Through this article research mainly draw the following conclusion:(1) The days that instantaneous maximum wind speed is greater than the critical sand-moving velocity more than 50% in one year. The evaporating dish observations will be significantly lower than the actual value of the pan-evaporation. But, the daily pan evaporation and eddy covariance system observed daily evaporation have the same trend on time. Indicating that the pan evaporation has the same trend with actual value, Can reflect the characteristics of evaporation pan evaporation of the region.(2) The Badain Jaran desert pan evaporation characteristics change significantly, a large floating during of the daily evaporation, evaporation showing an overall downward trend after the first rise. Summer evaporation is the largest, accounting for about half of the annual evaporation.Long freshwater ice period, nearly four months, ice period evaporation minimum, only 64mm, less than 5% of the annual evaporation. Estimated from the pan evaporation in the region is about 1497mm. Another analysis found that wind speed is the main factor affecting of the desert lake evaporation.(3) TDS and evaporation of water showed a negative correlation, regression analysis found that with the increase of TDS, monthly evaporation places corresponding decline. The decrease in the amount of the monthly evaporation increases with TDS is different, when every drop 100g/1, the evaporation of each month to the range of 49.01mm to 82.09mm decline. Calculated by regression equation, in summer, TDS increased by 100g/1, evaporation decreased 221.43mm, when the water reaches the TDS 348.7g/l, the water evaporation process may tend to stop; in autumn, TDS is increased 100g/l, the evaporation decline 155.61mm, when TDS water reached 291.9g/l, the water evaporation process may tend to stop. Effects of salinity effects on lake evaporation can’t be ignored in the calculation of the area lakes evaporation, salinity effects should be taken into account.(4) The strength of the effect of salinity and pure water evaporation does not exist consistency. The change trend between the effect of salinity and various factors affecting on monthly scales analysis showed that the relative humidity, or vapor pressure may be the main factors influencing the effect of salinity strength.