Quantifying uncertainty and confusion in land change analyses: a case study from central Mexico using MODIS data

Figures & data

Figure 1. Study area location of Lerma–Chapala–Santiago (LCS) watershed, with apparent change and persistence, 2001–2007. For full color versions of the figures in this paper, please see the online version.

Figure 2. Confusion index values across the LCS watershed based on Classification Uncertainty Metrics for Land Cover Classifications, 2001–2007.

Table 1. Legend scheme and area of land cover classes, 2001 and 2007.

Name	Description	Comparable classes in other legend schemes
		MODIS-IGBP	INEGI-UNAM
Water	Open bodies of water mixed with no other type of cover	Water	Bodies of water
Forest	Cover dominated by broadleaf or needle-leaf trees of at least 10 m in stature	Evergreen needle-leaf forest Evergreen broad-leaf forest Deciduous needle-leaf forest Deciduous broad-leaf forest Mixed forest	Conifer forest Broad-leaf forest Mixed conifer and broad-leaf forest Forest plantation Perennial forest
Shrub	Cover dominated by woody or leafy vegetation less than 10 m in stature	Closed shrublands Open shrublands Woody savannas	Deciduous forest Mesophilic forest Shrub (matorral) Mesquite forest
Grass	Cover dominated by natural or pasture grasses, possibly with interspersed trees or shrubby vegetation	Savannas Grasslands Permanent wetlands	Other vegetation Natural pastures Hydrophilic vegetation
Bare soil	Cover absent of vegetation	Barren or sparsely vegetated	Unvegetated area
Urban	Impermeable built environment	Urban and built-up	Human settlements
Crop	Cover dominated by agricultural products	Croplands	Irrigated agriculture Induced pastures
Mosaic	Cover mixed between agricultural or pasture uses and natural vegetation of any type	Cropland/natural vegetation mosaic	Temporal agriculture

Figure 3. Average Mahalanobis typicality values for discrete land cover classes and the entire region.

Table 2. Metrics of classification uncertainty and confusion index for selected sample plots.

Sample	Classification uncertainty, 2001	Classification uncertainty, 2007	Confusion index 2001–2007
Forest-dominated landscape	0.1727	0.2951	0.2797
Forest/agriculture matrix	0.4695	0.5827	0.5876
Multiclass mosaic	0.5460	0.5970	0.6308
Agave agriculture	0.6973	0.7316	0.7700

Table 3. Average metrics of classification uncertainty and confusion index by land cover and transition type across LCS watershed.

Extent of sample	Average classification uncertainty, 2001	Average classification uncertainty, 2007	Average confusion index 2001–2007
All LCS watershed	0.5875	0.5895	0.6457
Persistent
Water	0.4416	0.5233	0.5303
Forest	0.5863	0.6000	0.6547
Shrub	0.5381	0.5391	0.5931
Grass	0.6794	0.6899	0.7426
Bare soil	0.8364	0.8429	0.8773
Urban	0.5588	0.5846	0.6442
Crop	0.4996	0.4659	0.5442
Mosaic	0.5292	0.5422	0.5936
All apparent persistent	0.5502	0.5524	0.6101
All apparent changes	0.6210	0.6229	0.6776

Table 4. Accuracy assessment of land cover classifications.

	Water	Forest	Shrub	Grass	Bare soil	Urban	Crop	Mosaic	Errors of commission (%)	Per-class kappa
2001
Water	1926	0	0	0	0	0	1	0	0.05	0.9995
Forest	8	2158	18	2	0	0	3	205	9.86	0.8846
Shrub	5	4	1075	177	0	0	40	97	24.10	0.7203
Grass	1	0	13	177	0	0	14	15	19.55	0.7890
Bare soil	2	0	6	12	145	0	4	0	14.20	0.8578
Urban	31	0	6	2	0	629	39	0	11.03	0.8890
Crop	34	0	1	51	0	0	2506	68	5.79	0.9226
Mosaic	4	41	13	4	0	0	94	354	40.59	0.5565
Errors of omission (%)	4.23	2.04	5.04	58.35	0.00	0.00	7.22	52.10
			Overall accuracy: 89.83%					Overall kappa: 0.8983
2007
Water	1926	0	0	0	0	0	1	0	0.05	0.9995
Forest	17	2254	7	0	0	0	0	116	5.85	0.9294
Shrub	7	8	1119	40	0	1	103	120	19.96	0.7565
Grass	0	0	34	142	2	0	25	17	35.45	0.6322
Bare soil	2	0	1	6	152	0	8	0	10.06	0.8991
Urban	16	0	0	0	0	637	54	0	9.90	0.9004
Crop	46	0	12	12	0	2	2530	58	4.89	0.9314
Mosaic	3	41	13	7	0	0	109	337	33.92	0.5256
Errors of omission (%)	4.51	2.13	5.65	31.40	1.30	0.47	10.60	47.99
			Overall accuracy: 91.11%					Overall kappa: 0.9110

Table 5. Land cover composition and change by area, 2001–2007.

	Land cover		Land cover change, 2001–2007
Class	2001 Area in km^2 (percent of region)	2007 Area in km^2 (percent of region)	Apparent change 2001–2007 (km^2)	Change as percent of class (%)	Change as percent of region (%)
Water	4832.61	4146.78	−685.83	−14.19	−0.51
	(3.60)	(4.09)
Forest	19,618.08	22,981.14	3363.06	17.14	2.50
	(14.61)	(17.11)
Shrub	23,352.50	24,224.44	871.94	3.73	0.65
	(17.39)	(18.04)
Grass	9901.35	4845.28	−5056.07	−51.06	−3.77
	(7.37)	(3.61)
Bare soil	221.31	376.94	155.63	70.32	0.12
	(0.16)	(0.28)
Urban	823.00	857.99	34.99	4.25	0.03
	(0.61)	(0.64)
Crop	33,870.35	38,588.33	4717.98	13.93	3.51
	(25.22)	(28.74)
Mosaic	41,666.10	38,264.62	−3401.48	−8.16	−2.53
	(31.03)	(28.50)

Table 6. Rank of apparent land cover transitions by impacted area, 2001–2007.

Rank	Transition	Area (km^2)	Percent of LCS (%)
1	Mosaic to forest	5596.15	4.17
2	Mosaic to crop	5165.55	3.85
3	Shrub to mosaic	4119.73	3.07
4	Mosaic to shrub	4047.17	3.01
5	Crop to mosaic	3980.84	2.96
6	Grass to shrub	3158.49	2.35
7	Forest to mosaic	2894.24	2.16
8	Shrub to crop	2567.96	1.91
9	Grass to crop	2489.61	1.85
10	Crop to shrub	1737.02	1.29

Figure 4. Landscape composition and typicality values for select sample parcels.