Table 3 Results of PCA method in Ludian area.

Slope

− 0.159

0.74

0.232

0.13

0.556

Slope direction

0.002

− 0.195

0.751

0.6

− 0.12

Distance to stream

0.4

− 0.511

− 0.011

− 0.059

0.709

Distance to fault

0.194

0.122

0.598

− 0.745

− 0.096

NDVI

0.462

0.485

− 0.212

0.153

− 0.11

PGA

− 0.877

− 0.028

− 0.078

− 0.027

0.034

Epicenter distance

0.87

0.058

− 0.054

0.107

− 0.11

Contribution rates/%

28.025

15.714

14.714

13.864

12.301

Accumulative contribution rate/%

28.025

43.739

58.453

72.317

84.618