Fig. 4: The slope of water requirement changes for rice cultivation from 2000 to 2020.

The first row is the slope of depth of water requirement changes of rice production for (a) total water requirement (TWR), b green water requirement (GWR), and (c) blue water requirement (BWR). The second row is the slope of volumetric water requirement changes for rice production (that is depth of water requirement multiplied by rice area) for (d) total water requirement (TWV), e green water requirement (GWV), and (f) blue water requirement (BWV). g The slope of area change under rice cultivation. Counties with bold boundaries mean the slope of water requirement or rice area change is significant at the level of 0.05.