Trends in Moisture Index, Farmland Area, and Their Combined Effects on Grain Production in Northern China

Table 1

Area of humid, semiarid, and arid zones in northern China.

Humidity region	1989 (ha)	2008 (ha)	Percent change
Humid areas	283,915,219	219,482,992	−22.7
Semiarid areas	105,227,195	153,469,562	45.8
Arid areas	173,833,567	190,023,428	9.3

Note: minus means decrease.