Spatial and temporal distribution research of evapotranspiration in hairiver basin based on remote sensing

Evaportranspiration is the general name of surface evaporation and plant transpiration, which reflects the condition of “Actual Water Consumption” in regional water resource development. Researching the spatial and temporal distribution of ET and its main influence factors has great significance for water resource management. The remote sensing retrieval has been widely used in obtaining regional ET informations due to its advantage of real-time performance and globe ability. The monthly ET data of Haihe river basin from 2002 to 2005, which were provided through remote sensing model named ETwatch, was used as basic data to describe the characters of ET distribution in this paper. The Haihe river basin had been divided into 4738 units according to administrative division combined with water resource division and land use information, then statistic of ET value was completed for each unit by using ARCGIS software platform. On the base of the analyzing the Haihe river basin ET dataset created above, the general spatial distribution and temporal trend of ET, as well as the influence to ET by land use type in Haihe river basin were described. As the study emphasis, the features of ET of farmland system, construction land system and the forest-grass land system were identified respectively in detail.