Spatial-temporal characters of evapotranspiration in the Yellow River Delta

摘要

Evapotranspiration (ET) is an important variable for water and energy balances on the earth's surface. Surface Energy Balance Algorithm for Land (SEBAL) is an image-processing model that calculates ET over vast areas. In this study, time series of MODIS data in 2009 and meteorological data are used to estimate ET over the Yellow River Delta (YRD) by SEBAL, and then the spatial-temporal characters of ET are analyzed. It shows that, monthly average ET presents a unimodal distribution that the peak value locates in June, ET changes with the corresponding of climate and underlying surface coverage variations over time and season; there are great spatial diversities of ET, Water and beach have a relatively high level of ET which are mainly located in the northeast and northern of the study area. ET in Guangrao County tends to decrease from May to July, and then increase rapidly in August, finally decreases sharply in September and October.