Fusion of Sentinel-1A and Sentinel-2A data for land cover mapping: a case study in the lower Magdalena region, Colombia

Figures & data

Figure 1. Study area (red polygon). Lower Magdalena region, Cundinamarca, Colombia.

Figure 2. Pre-processing and processing chain performed in this study (integrated radar–VNIR dataset).

Table 1. Overall accuracy and kappa index for the SVM, Random Forests and k-NN classifications applied to the three dataset configurations used in the study.

	Dataset
	Integrated Sentinel radar–VNIR layers		Sentinel-1A radar layer		Sentinel-2A VNIR layers
Classification algorithm	Overall accuracy (%)	Kappa	Overall accuracy (%)	Kappa	Overall accuracy (%)	Kappa
Support Vector Machine (Burges, 1998)	88.75	0.86	30.62	0.15	72.5	0.67
Random Forests (Breiman, 2001)	55.50	0.49	20.12	0.02	48.1	0.37
k-Nearest Neighbor (Altman, 1992)	39.37	0.26	16.98	0.02	37.5	0.24

Table 2. Confusion matrix and classification accuracy measures of the integrated datasets SVM-classified map.

	Ground reference
Classification	Forest	Water	Crops	Pastureland	Built	Secondary vegetation/ shrubs	Total	User accuracy (%)	Commission error (%)
Forest	27	0	0	1	0	4	32	84.38	15.62
Water	0	20	0	0	0	0	20	100	0
Crops	0	0	26	2	0	0	28	92.86	7.14
Pastureland	1	0	2	26	1	2	32	81,25	18.75
Built	0	0	0	0	19	0	19	100	0
Secondary vegetation/ shrubs	2	0	2	1	0	24	29	82.76	17.24
Total	30	20	30	30	20	30	n = 160
Producer accuracy (%)	90	100	86,67	86.67	95	80		Overall accuracy	88.75
Omission error (%)	10	0	13,33	13.33	5	20		Kappa	0.86

Burges, C. J. C. (1998). A tutorial on support vector machines for pattern recognition. Data Mining and Knowledge Discovery, 2(2), 121–167. doi: 10.1023/A:1009715923555

 Web of Science ®Google Scholar

Breiman, R. E. (2001). Random forests. Machine Learning, 45, 5–32. doi: 10.1023/A:1010933404324

 Web of Science ®Google Scholar

Altman, N. S. (1992). An introduction to kernel and nearest-neighbor nonparametric regression. The American Statistician, 46(3), 175–185. doi: 10.1080/00031305.1992.10475879

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