关键词: 植被降水利用效率, 净初级生产力, CASA模型, 空间分布, 淮河流域

Abstract: Using MODIS NDVI and meteorological data from 2001 to 2016,the net primary productivity (NPP) of vegetation in the Huaihe River basin was estimated based on CASA (Carnegie-Ames-Stanford Approach) model. In combination with precipitation data, space-time distribution characteristics of precipitation use efficiency (PUE) of vegetation and its response to climate factors were analyzed. Results showed that (1) the average PUE of vegetation in the Huaihe River basin was 0.598 g C/(m2·mm) between 2001 and 2016, showing an overall downward trend; (2) PUE in the Huaihe River basin had been changing regularly, increasing in the north of the basin and decreasing in the south; (3) PUE of different vegetation types in the Huaihe River basin were quite different. Most areas were farmland where PUE was the highest , followed by forest, shrub and meadow; (4) PUE was negatively correlated with precipitation in 99.7% of the Huaihe River basin, it was positively correlated with temperature in 80.1% of the basin; (5) Precipitation was an important factor affecting PUE in the Huaihe River basin.

Key words: precipitation use efficiency, net primary productivity, Carnegie Ames-Stanford Approach model, spatial distribution, Huaihe River basin