Hutubi Remote Sensing Evapotranspiration And Ecological Water Requirement Research

Evapotranspiration includes water from the soil surface erosion and by plant transpiration of whole process, the two evaporation process is performed at the same time. And it is difficult to distinguish them. Evaporation from the surface of the earth can returned to the atmosphere in 70%. In the arid region, the proportion can be as high as 90%. In-depth study on evapotranspiration process and mechanism, help us understand surface energy balance and water balance and also help people to correctly assess the human activity influence on the ecological environment.The evapotranspiration of the Hutubi was estimated by using Landsat8 data and meteorological observations based on SEBS model. Estimated evapotranspiration of Hutubi on April 22 th, June 9th, August 28 th, October 15 th, and then the distribution map of evapotranspiration was retrieved. The results reflect season change, for instance the farmland results are 1.938,3.136, 2.641, 1.314 mmday-1.The overall trend: the northern desert plain <in the central region < the southern mountains.The maximum value in four days appeared in June 9th in southern mountain area of up to 4.128mmday-1. The results show that the SEBS model is of adequate accuracy in estimating the evapotranspiration of Arid and semi-arid climate and can be applied to estimating the daily evapotranspiration on a regional scale.Using the Landsat8(30m) data and GEOEYE-1 data, combined with multi scale remote sensing method to estimate evapotranspiration in Hutubi County which belongs to Northern Slop of the TianShan Mountains. In some areas such as arable on Hutubi river Basin, arable on Juntanghu river Basin and Northern desert ecotone, we take high resolution remote sensing image Geoeye-1( 2m) to compute NDVI and land surface temperature then input them to the SEBS model.The significance of the study is: calculating evapotranspiration results with two kinds of sensor data,study the influence on data fusion effect on inverting remote sensing parameters.Theresults showed that adding some parameters which come from GEOEYE-1 make the estimated value more closer to measured values which come from small lysimeter.The maximum absolute error appears in the bare ground, is 28.5 %, below the 54.8%which using Landsat8 data, indicating that participation in high resolution images helps to improve the efficiency of the model.Using GF-1 image classified into farmland, woodland, desert, grassland and bare land, water and other seven parts, according to the evapotranspiration method to calculate the Hutubi County, grassland, forest land and the main vegetation types in the current situation of ecological water demand, on the watershed ecosystem protection and restoration and policy recommendations are put forward. From the sustainable development of follow the laws of nature, the establishment of harmony between man and nature development policy in order to realize the reasonable arrangement of the water resources optimal allocation and the construction of the ecological environment.