干旱区生态环境知识资源中心

Analysis of spatial patterns of evapotranspiration (ET) and water deficit (WD) is significant in the evaluation of crop growth status and water use efficiency for the Songnen Plain, an important commodity grain product base of China. Spatial patterns of ET and WD in the Songnen Plain of 2008 growing season (from May to September) were mapped by using MODIS products and meteorological data. The results indicated that ET and WD exhibited obvious spatial variation and gradually increased from southwest to east and northeast. Total ET over the Songnen Plain during the 2008 growing season ranged from 182.7mm to 1002.4mm with the mean value of 591.1mm, and WD ranged from -163.0mm to 645.9mm with the mean value of 195.9mm. Average ET and WD for different land covers varied significantly, water-body and wetlands obtained the highest ET and WD values, while grassland got the lowest ET and WD values. Through this study, it would provide some supports for the assessment of crop growth in arid environments of Songnen Plain.