Using remote sensing to assess impacts of land management policies in the Ordos rangelands in China

Figures & data

Figure 1. Location of the study area and distribution of the meteorological stations. The basic administrative unit shown in this figure in Inner Mongolia is Banner, which is similar to the unit “County” in other provinces. The location of meteorological stations are marked by a circle.

Table 1. Multi-temporal satellite images used in this study.

Captors	Scene	Acquisition dates	Spatial resolution	Policy implementation period
Landsat 5 TM		18 August 2010	30 m
Landsat 7 ETM+		07 August 2009	30 m
Landsat 5 TM		10 August 2007	30 m	Current state
Landsat 5 TM		07 August 2006	30 m
Landsat 5 TM		17 August 2004	30 m
Landsat 7 ETM+		20 August 2002	30 m
Landsat 7 ETM+	Path-Row: 129–33	30 August 2000	30 m
Landsat 7 ETM+		12 August 1999	30 m	Initial state of Period 3
Landsat 5 TM		11 August 1996	30 m
Landsat 5 TM		30 August 1991	30 m
Landsat 5 TM		24 August 1989	30 m	Initial state of Period 2
Landsat 5 TM		20 September 1987	30 m
Landsat 3 MSS		21 August 1978	56 m	Initial state of Period 1

Table 2. Overall accuracy of each individual classification.

Image acquisition date	Overall accuracy (%)	Kappa coefficient
21 August 1987	99.65	0.988
24 August 1989	98.70	0.967
12 August 1999	97.39	0.918
10 August 2007	98.91	0.966

Table 3. Features of the selected sites.

Site	Longitude	Latitude	Surface area (ha)	Major features
A	106.6928 E	38.4936 N	2317	Degradation in 1978–1989, recovery due to rotation and sand-control in 1996–2002 and degradation again in 2004–2007
B	107.3907 E	38.3194 N	1094	Protected natural rangeland without disturbance of grazing activity before 2004, but open for grazing since 2005/2006
C	107.3885 E	38.6881 N	1094	Managed grassland area but open for grazing after 2007
D	107.6824 E	38.9754 N	1301	Degradation in 1989–1999, especially in 1996–1999 but recovery after 2002
E	108.280 E	38.68857 N	480	Natural rangeland without significant change and little influenced by grazing in the past 32 years
F	107.637 E	38.61615 N	374	Similar to site E, mostly unmanaged but more or less influenced by grazing and conversion of some grassland patches into pastures after 2004

Figure 2. NDVI trajectories and annual rainfall. Note: (a) and (a′) for Site A; (b) and (b′) for Site B; (c) and (c′) for Site C; (d) and (d′) for site D; (e) and (e′) for Site E, and (f) and (f′) for Site F.

Figure 3. Rangeland biophysical changes in the study area in the period 1978-2007. Note: The figure shows (1) vegetation vigor growth (VGT-G), and (2) vegetation degradation (VGT-D). Sites A, B, C, D, E and F were selected to calibrate the relationship between biophysical feature changes (e.g. NDVI) and rainfall variation.

Table 4. Land cover changes in the study area.

	VGT-G						VGT-D
	Crop & pasture extension		Sand control		Rangeland recovery		Desert extension		Rangeland degradation		Coal mining
Policy implementation periods	Area (km^2)	Rate (km^2 y^−1)	Area (km^2)	Rate (km^2 y^−1)	Area (km^2)	Rate (km^2 y^−1)	Area (km^2)	Rate (km^2 y^−1)	Area (km^2)	Rate (km^2 y^−1)	Area (km^2)	Rate (km^2 y^−1)
1978–1989	81.97	7.45	82.48	7.50	153.28	13.93	80.66	7.33	665.04	60.46	5.93	0.54
1989–1999	215.15	21.52	97.61	9.76	429.26	42.93	78.11	7.81	1429.36	142.94	9.54	0.95
1999–2007	260.57	32.57	418.78	52.35	878.78	109.85	38.28	4.79	114.00	14.25	18.28	2.29

Note: y represents “year”.

Figure 4. Land cover change rates in the observed policy implementation periods.

Figure 5. Specific land use/cover changes in the study area.