Model Building for Regional Ecological Risk Prediction and Evaluation of Prediction Accuracy

Table 8

Prediction results.

Year	Desired output	Improved BP with PCA		Standard BP without PCA
		Predicted value	Relative error%	Predicted value	Relative error%
2016	3	2.8692	4.36	2.6244	12.52
2017	3	2.9676	1.08	2.7159	9.47
2018	4	3.7928	5.18	3.5788	10.53