Quantifying Spatiotemporal Dynamics of Solar Radiation over the Northeast China Based on ACO-BPNN Model and Intensity Analysis

Table 2

Solar radiation classification in NEC.

Levels	Name	Classification threshold (MJ⋅m^−2⋅a^−1)
I	Abundant	≥ 5200
II	Comparatively abundant	5000 ≤ G < 5200
III	Normal	4800 ≤ G < 5000
IV	Poor	G < 4800

. G represents the annual total solar radiation.