Analysis Of Spatial And Temporal Sporadic Evolution In Haihe Basin Evaporation

Water resources problems is a significant strategic issue, which is related to the nationaleconomy, national security and social sustainable development. Water resource affects thehuman beings and their survival environment, ecological environment and national foodsecurity, etc. It has become a significant directional problem which draws the domestic andinternational researcher’s attention. ET is the key parameter of terrestrial ecological process,which conveys the moisture from underlying surface to atmosphere on Watershed scale; it isalso the important factors of watershed water cycle and water resource management.Currently, Drought is a grievous problem. Monitoring and estimate of ET has an importantsignificance to regional planning and water resource management and sustainabledevelopment. Therefore, the study of ET, that is an important way to develop and utilize thewater resources and assess the regional water resources reasonably.This paper make a inversion of ET value of Haihe basin in2010based on the surfaceenergy balance system, by using MODIS data and SEBS model-method and combining withthe practical observation data of weather stations. To calculate the ET value by combining thetraditional Penman-Monteith formula into the surface meteorological data in the Haihe riverbasin, then, verify the calculation results of the remote sensing module.According to NASA DC’s MODIS data, select some remote sensing images (March27,June25, October6, December8) as a typical representative of the spring, summer, autumnand winter, combining them with the practical of the surface meteorological data, make ainversion of ET processing of Haihe river basin on the spatial scales based on the SEBSmodel. The ET value showed an overall trend of increase from north to south on the aspect ofseasonal variation and converged on the spatial distribution that reflected the periodicity.Among that, summer ET value is highest, winter ET value is lowest, the autumn and thespring ET value are similar (the autumn ET value is slightly higher by0.13mm).According to the26observing sites50years of meteorological data in haihe basin from1961to2010, this paper calculated the50years of annual and seasonal average daily OETbased on the Penman-Monteith model and make a temporal and spatial analysis. there is asteady variation of ET0in haihe river basin during recent50years, it has a downward trend ofthe primary period for33years and minor period for18years; from the aspect of space, theinter annual changes of ET0value are significant and present a decreasing trend fromsoutheast to northwest; Summer ET0was the highest in the four seasons, followed by others;and it present a decline trend of four seasons from the southeast to the northwest on the spatial view, and the lowest ET0values are mainly located in the mountain-areas round Hebei,Zhangjiakou city and ShanXi, DaTong.The actual evapotranspiration in March27、June25、October6and December8，2010.Calculated crop method, and the Remote Sensing inversion accuracy verification. Theresult of the accuracy validation in remote sensing inversion used the Penman-Monteithformula is reasonable and reliable, which range of error value about10%.