Multi-temporal remote sensing of land cover change and urban sprawl in the coastal city of Yantai, China

Figures & data

Figure 1. Location of Yantai and its color composite imagery obtained on 22 June 2009 (RGB= Landsat TM bands 4, 3, 2).

Table 1. Data types used in this study.

No.	Type of data used	Scale/resolution	Year
1	Land use map	9 m	1996
2	SPOT Pan image	10 m	2003
3	CBERS images	19.5 m	1999, 2009
4	Landsat-4 TM images	30 m	1989
5	Landsat-5 TM images	30 m	2009
6	Landsat-7 ETM+images	30 m	1999
7	Municipal boundary data	1:50,000	2001
8	High-resolution images	1.194329 m	2006
9	Socioeconomic data	Yearly^a	1989–2009

^a Census records.

Figure 2. Digital number values' range of (a) arable land and bare land and (b) arable land and woodland on single date (25 October 2005).

Figure 3. Linear separation of Class 1 and Class 2 in two-dimensional space with SVMc.

Table 2. Land cover classification scheme.

Level 1 Land cover Class	Description
Agriculture	Crop fields and bare crop fields
Extraction	Quarries, sand, and bare soil
Forest	Deciduous forest land, evergreen forest land, mixed forest and grass land, orchards, groves, vineyards, nurseries
Urban	Residential, commercial services, industrial, transportation, communications, mixed urban or build-up land, other urban or built-up land
Water	Permanent open water, lakes, reservoirs, streams, bays, and estuaries

Figure 4. Feature space representation of the first three MNF components of the image acquired on 22 June 2009. Four endmembers, vegetation (e.g. agricultural land, forest and grass), extraction, urban, and water, can be identified according to these feature spaces and their associated interpretations obtained from the original reflectance data.

Table 3. Summary of classification accuracies for 1989, 1999, and 2009.

	MLC		ANN		SVM
Land cover class	Producer's accuracy	User's accuracy	Producer's accuracy	User's accuracy	Producer's accuracy	User's accuracy
a. Summary classification accuracies (%) for 1989
Agriculture	77.93	95.03	82.69	93.89	83.85	93.56
Extraction	98.91	70.98	95.63	93.58	98.36	90.91
Forest	92.51	89.18	82.89	93.94	90.37	94.41
Urban	91.42	98.42	92.47	88.76	92.26	94.23
Water	97.86	78.74	95.00	78.70	95.00	78.24
Overall accuracy	88.14		89.74		91.43
Kappa coefficient	84.49		86.36		88.68
b. Summary classification accuracies (%) for 1999
Agriculture	77.03	95.30	74.62	95.77	78.71	96.08
Extraction	80.52	76.78	93.75	72.86	90.63	72.73
Forest	98.09	90.20	98.63	85.41	98.09	94.72
Urban	95.52	96.46	98.83	96.02	99.22	96.95
Water	97.20	83.20	90.65	94.17	92.52	95.19
Overall accuracy	88.95		89.27		94.08
Kappa coefficient	84.52		84.76		91.62
c. Summary classification accuracies (%) for 2009
Agriculture	88.36	82.66	86.21	83.33	83.62	88.99
Extraction	100.00	70.00	98.48	87.84	98.48	85.53
Forest	92.06	98.38	93.01	97.43	95.65	96.02
Urban	89.87	97.93	97.47	97.88	98.31	95.49
Water	95.79	100	96.26	91.96	96.26	100.00
Overall accuracy	91.68		94.06		94.85
Kappa coefficient	88.88		91.96		92.99

Note: MLC, maximum likelihood classifier; ANN, artificial neural networks; SVM, support vector machine.

Table 4. Change detection error matrix for 1989–2009.

	Classification
Reference class	Change	No-change	Producer's accuracy (%)
Change	291	27	90.94
No-change	99	360	75.16
User's accuracy (%)	74.62	93.02

Overall accuracy: 83.78% Kappa coefficient: 80.13%.

Figure 5. Land cover classification from 1989 to 2009 for Yantai.

Table 5. Summary of land cover area statistics in 1989, 1999, and 2009.

	1989		1999		2009
Land cover class	Area (km^2)	%	Area (km^2)	%	Area (km^2)	%	Relative change from 1989 to 2009 (%)
Agriculture	63.82	35.77	47.01	26.35	51.00	27.91	−20.09
Urban	56.04	31.41	77.59	43.49	91.87	50.28	63.94
Forest	25.16	14.10	38.16	21.39	31.55	17.27	41.30
Water	5.32	2.98	2.30	1.28	7.75	4.24	45.68
Extraction	28.08	15.74	13.36	7.49	0.55	0.30	−98.04

Table 6. Matrices of land cover and change statistics (km²) from 1989 to 2009.

a. 1989–1999
	1999
1989	Water	Agriculture	Extraction	Forest	Urban	1999 Total
Water	1.73	0.33	0.13	0.15	0.10	2.44
Agriculture	0.07	34.13	6.31	1.59	4.86	46.96
Extraction	0.41	6.99	5.03	0.20	0.71	13.34
Forest	0.13	9.32	3.09	20.32	5.24	38.10
Urban	2.99	13.04	13.52	2.90	45.13	77.58
1989 Total	5.32	63.82	28.08	25.16	56.04	178.43
b. 1999–2009
	2009
1999	Water	Agriculture	Extraction	Forest	Urban	2009 Total
Water	1.22	1.56	1.87	0.59	2.51	7.75
Agriculture	0.00	30.07	5.44	10.78	4.71	51.00
Extraction	0.00	0.18	0.07	0.06	0.24	0.55
Forest	0.18	3.02	1.19	23.89	3.27	31.55
Urban	0.90	12.17	4.79	2.84	66.87	87.57
1999 Total	2.30	47.01	13.36	38.16	77.59	178.43
c. 1989–2009
	2009
1989	Water	Agriculture	Extraction	Forest	Urban	2009 Total
Water	1.82	2.34	1.94	0.32	1.33	7.75
Agriculture	0.05	31.40	6.95	5.20	7.40	51.00
Extraction	0.00	0.24	0.15	0.01	0.15	0.55
Forest	0.24	7.03	3.48	17.19	3.62	31.55
Urban	3.21	22.80	15.56	2.45	43.54	87.57
1989 Total	5.32	63.82	28.08	25.16	56.04	178.43

Figure 6. Newly reclaimed region for Yantai Port and related industries, shown in dark red in the left map and magnified in the right.

Figure 7. Urban growth from 1989 to 2009. Non-urban land cover types (agriculture, forest and extraction) that were converted to urban land from 1989 to 1999, and from 1999 to 2009 are highlighted in red and green, respectively.

Figure 8. The relationships between urban area and (a) population, (b) GIP, and (c) infrastructure investment. Yuan is the unit of Chinese currency.