Applications of remote sensing and geographic information systems for urban land-cover change studies in Mongolia

Figures & data

Figure 1. A Mongol ger (a) and a typical example of a ger district in Ulaanbaatar represented in a Quickbird image of 2002 (b) (1-ger and 2-house).

Figure 2. 2001 ETM image of Ulaanbaatar area (red, band 5; green, band 4; blue, panchromatic band). The size of the displayed area is about 28 km × 20 km.

Figure 3. Comparison of the multi-temporal PC images. (a) PC image of 1990 data sets (red, PC1; green, PC2, blue, PC3), (b) PC image of 2001 data sets (red, PC1; green, PC2; blue, PC3).

Table 1. Principal component coefficients.

	PC1	PC2	PC3	PC4	PC5	PC6
Coefficients from SPOT PAN and five bands of the TM
SPOT PAN	0.1699	−0.1732	−0.2545	0.9243	0.1427	−0.0379
TM2	0.1817	−0.3279	−0.2795	−0.1063	−0.1967	0.8551
TM3	0.3127	−0.6001	−0.3482	−0.2379	−0.3176	−0.5131
TM4	0.2929	0.5579	−0.7142	−0.1846	0.2369	−0.0502
TM5	0.7453	0.3260	0.3972	0.0978	−0.4129	0.0136
TM7	0.4459	−0.2910	0.2604	−0.1842	0.7831	0.0359
Eigenvalue	1148.40	114.89	43.71	13.07	7.14	1.38
Variance %	86.43	8.65	3.29	0.98	0.54	0.11
Coefficients from panchromatic and five multi-spectral bands of the ETM
ETM PAN	0.1753	0.0170	−0.4346	−0.8453	−0.2505	0.0508
ETM2	0.2837	−0.4046	−0.2658	0.1454	−0.0237	−0.8144
ETM3	0.4500	−0.6056	−0.1630	0.2486	−0.1684	0.5602
ETM4	0.1260	0.3663	−0.7135	0.2572	0.5086	0.1259
ETM5	0.5917	0.5787	0.1136	0.2201	−0.4994	−0.0645
ETM7	0.5657	−0.0074	0.4378	−0.2962	0.6325	−0.0134
Eigenvalue	1728.17	147.41	46.06	8.81	6.93	3.62
Variance %	89.04	7.59	2.37	0.45	0.36	0.19

Figure 4. Comparison of the classification results for the selected classes. (a) Classified image using 1990 data sets, (b) classified image using 2001 data sets.

Figure 5. A general diagram for the refined parametric classification.

Table 2. Confusion matrix produced for the classified PC images.

Classified data	Reference data
	Building area	Ger area	Forest	Grass land	Soil	Water
PC images of 1990
Building area	1728	102	0	0	28	0
Ger area	129	1674	0	0	41	0
Forest	0	0	1409	21	0	0
Grass land	9	16	36	746	114	3
Soil	43	51	0	57	1957	6
Water	0	0	0	0	8	97
Total	1909	1843	1445	824	2148	106
Overall accuracy = 91.98% (7611/8275)
PC images of 2001
Building area	1802	64	0	0	17	0
Ger area	79	1783	0	0	36	0
Forest	0	0	1387	32	0	0
Grass land	18	12	24	708	109	0
Soil	87	71	0	46	2114	9
Water	0	0	0	0	0	92
Total	1986	1930	1411	786	2276	101
Overall accuracy = 92.89% (7886/8490)

Figure 6. Topographic map of Ulaanbaatar area of 1969, scale 1:50,000. The size of the displayed area is about 28 km × 20 km.

Table 3. The total areas for each class in different years, evaluated from multi-temporal GIS and RS data sets.

Land cover classes	The total areas for each class in different years (ha)
	1969	1990	2001
Building area	2498.92	3996.71	4812.64
Ger area	978.86	2719.65	4304.26
Forest	11896.12	11075.94	10324.26
Grass land	Not available	11626.26	9153.98
Soil	Not available	26273.23	27359.04
Water	1078.84	716.40	454.01
Total	56408.19	56408.19	56408.19