Spatio-temporal Variations of Evapotranspiration in Sanjiang Plain Using MOD16 Products
Based on MOD16 products, we analyzed the spatial and temporal characteristics of evapotranspiration (ET) in Sanjiang Plain during 2000─2014by using ArcGIS 10.2 and ENVI 4.5/IDL softwares.After format conversion, projection conversion, resampling and image mosaic process, annual and monthly average ET was estimated. The ET trends were also analyzed. We analyzed temporal and spatial variation of evapotranspiration with different time scales and land use types based on Sanjiang Plain vector data and land use data. Results showed that the mean annual ET of Sanjiang Plain increased slowly with a mean value of 497 mm·a-1, ranging from 447 mm·a-1 to 521 mm·a-1 during 2000─2014. Mean monthly ET presented a significant seasonal difference that the ET peaks occurred in August and the bottom values occurred in January. The spatial distribution of annual ET was generally high over the south of Sanjiang Plain, but low in the north, especially in the high vegetation coverage areas. The areas with insignificant variation were accounted for 88% of the total The pixels with significantly increased ET were mainly distributed in north Jixian urban district, and hilly-mountainous areas in Shuangyashan, while the pixels with significantly decreased ET were mainly distributed in the basin and urban area. The spatial distribution of ET is related to land use types with the order of ET intensity: woodland (46.6 mm) > grassland (34.7 mm) > farmland (34.7 mm) > desert (34.7 mm). This study supplied important information to the water resources management and water use efficiency in Sanjiang Plain.
国家科技期刊平台
NSTL
万方数据
维普
