| In the background of current global warming and the growing shortage of global freshwater resources, as one of the major freshwater resource consumption patterns, the significance of evapotranspiration for the global ecological environment becomes increasingly obvious. The evapotranspiration study has become the hot topic of hydrological disciplines. Under the background of different regional climate, evapotranspiration study an be more accurately reveal the process of regional hydrological cycle, provide a reference for the optimal allocation of regional water resources.This study takes the GIS technology as the mainly mains, conducted the terrain correction on the SEBAL model with the DEM data;Take the Landsat 8 images as the data source, combined with ground observation data inversion the energy components of the key parameters and in the energy balance(net radiation flux, soil heat flux and sensible heat flux) of Minqin Oasis. Analysied the temporal and spatial distribution pattern; This study using the calibrated SEBAL model to estimate the surface evapotranspiration in 2014 6-10 month of Minqin oasis. Then the parameters and the daily evapotranspiration were analyzed by correlation analysis method, according to investigate the relationship between the amount of evapotranspiration and the parameters of the two-dimensional point spread. This study also analysis the temporal and spatial distribution characteristics of daily evapotranspiration and the amount of the monthly variation characteristics. Besides, This study made statistics on average daily evapotranspiration and the total evapotranspiration of the different land use types. The main conclusions are as follows:(1) This study conducted the terrain correction on the SEBAL model with the DEM digital elevation model and used the correlation method to carry on the calibration and correction for some affecting atmospheric stability factors, which makes the SEBAL model has higher operation accuracy, easily obtained elatively more accurate simulation results.(2) In order to verify the reliability of the simulation results, this study take the measured evapotranspiration data of weather stations and the reference crop evapotranspiration data calcuiated with the Penman-Monteith model compared with the results of this study to verified. Both of the two verification results show that the retrieval accuracy of the SEBAL model were more than 85%. It is indicated that simulation results of this study is reasonable and credible. After correction, the SEBAL model can be applied to estimate the surface evapotranspiration in the arid oasis regions.(3) This study compared and analyzed for daily evapotranspiration deeply on 6-10 months in 2014, the results shown that the monthly variation of evapotranspiration are sharply, it is the highest in July, and the lowest in the middle ten days of October., surface evaporation distributed spatial distribution pattern has a large difference in the whole study area. In the Baqu central, the West of Quanshan qu and East of Huqu regions, the daily evapotranspiration value is high, whileit is lower in northwest of Baqu, eastern of Quanshanqu and northernof Huqu regions.(4) After the correlation analysis, found that NDVI, f, ? and lc were positively correlated with the daily evapotranspiration, in which it is shown a significant positive correlation between NDVI and daily evapotranspiration(r = 0.846, P < 0.001). Ts, ? and ?s were negative correlated wit the daily evapotranspiration, in which it is shown a significant negative coefficient between Ts and daily evapotranspiration(r=-0.861, P < 0.001).(5) Based on the map of land classification, the studycompared and analyzed daily evapotranspiration and total evapotranspiration of each type land. All kinds of daily evapotranspiration hair quantity is as follows: the cultivated land, abandoned farmland, woodland, high coverage grassland, residents, shrub and woodland, waters, low coverage grassland, unused land. Daily total evapotranspiration hair quantity is as follows: the cultivated land, shrub and woodland, unused land, abandoned farmland, low coverage grassland, woodland, residents, waters. |
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