基于台站和MOD16数据的山东省蒸散及潜在蒸散时空变化

蒸散发的时空格局分析对理解气候变化与水资源之间的相互影响具有重要的作用。本文基于Penman-Monteith公式,利用MODIS全球蒸散发产品(MOD16)及气象站点的蒸发皿观测数据,先对数据精度进行评价,再从空间和时间两个尺度上对数据进行统计分析,系统阐释了2000-2014年山东省地表蒸散(ET)及潜在蒸散(PET)的时空分布特征及其与气象因子的相关性。主要结论为：①山东省不同区域蒸散分布差异明显,地表植被对ET的月际变化趋势有重要影响;②山东省ET及PET年际波动不大,全省ET均值为1529 mm,PET均值为2178 mm,年均ET与PET相对较大的差值说明该省整体相对缺水。③ET及PET的时空变化与诸多气象因子相关,其中与降水及温度的关系最为密切。

Spatiotemporal variations of evapotranspiration and potential evapotranspiration in Shandong Province based on station observations and MOD16

Spatiotemporal pattern analysis of evapotranspiration plays an important role in understanding the interaction between climate change and water resources. Based on the Penman-Monteith formula, this study analyzed the temporal and spatial characteristics of land surface evapotranspiration and its correlation with meteorological factors in Shandong Province from 2000-2014 with the MODIS ET product (MOD16) and the observation data of evaporation dishes at meteorological stations. We first examined the accuracy of MOD16 for Shandong Province and selected 13 weather stations within the province with daily values of atmospheric pressure, temperature, precipitation, evaporation, relative humidity, wind direction, wind speed, sunshine hours, and 0 cm land surface temperature from 2000-2014. Through the analysis of the spatiotemporal correlation between MOD16 potential evapotranspiration (PET) and the observation data of evaporation dishes at the meteorological stations, the effectiveness of the MOD16 PET in the area was verified. Then we used the MRT tool provided by MODLAND to splice MOD16 and convert the projection into longitude and latitude by taking WGS-8 as the reference surface. Finally, based on MOD16 and the meteorological data, the spatiotemporal distribution characteristics of ET and PET from 2000-2014 were analyzed. The main conclusions are as follows. (1) There was plentiful water in the eastern part of Shandong Province while the western part was short of water, which resulted in a clear difference of ET over different areas in the province. (2) The annual fluctuations of ET and PET from 2000-2014 were relatively small. The average value of ET was 1529 mm while that of PET was 2178 mm, which indicates that Shandong Province is a relatively dry area. (3) The correlation analysis between evapotranspiration and meteorological factors indicates that the spatiotemporal variation of evapotranspiration was closely related to many climatic factors, especially the water and heat conditions.