Figure 3
The effects of N fertiliser use, energy consumption and precipitation on the spatial pattern of Ndep in the 1990s.
(a) N fertiliser use (expressed as the volume of effective component). The data on N fertiliser use in provinces were obtained from the China Statistical Yearbook43. (b) Energy consumption (expressed as standard coal). The data on energy consumption in provinces were primarily from the China Energy Statistical Yearbook44. (c) Precipitation. The data on the annual amount of precipitation were obtained from the China Meteorological Administration and included 756 weather stations (Supplementary Fig. S3). The mean Ndep in provinces was obtained from spatial maps of Ndep over China using the Zonal Statistics tool of ArcGIS 10.0 software. Notes: the area of shadowing indicates the provinces with large variations in Ndep when the x-axis variable was relatively constant.
