|
|
|
Land Degradation Detection, Mapping, and monitoring in the Northwestern part of Hebei Province, China, Using RS and GIS Technologies
Figure 8. County-level Brightness negative change map of the Northwestern
part of Hebei Province during the period from 1987 to 1996
Figure 9. County-level NDVI positive change map of the Northwestern part
of Hebei Province during the period from 1987 to 1996
Figure 10. County-level NDVI negative change map of the Northwestern part
of Hebei Province during the period from 1987 to 1996
Table 4. County-level NDVI results of the Northwestern part of Hebei Province
for the period from 1987 to 1996.
| County CODE |
County
area |
NDVI_P |
NDVI_N |
No-change |
(NDVI_P)-
(NDVI_N)
|
NDV_ P rate |
NDVI_ N rate |
| (km2) |
(km2) |
(%) |
(km2) |
(%) |
(km2) |
(%) |
(%) |
(km2 .yr-1) |
| Chi Cheng (1/2) 2,647.565 |
35.849 |
1.354 |
69.814 |
2.637 |
5,189.468 |
98.005 |
-0.641 |
3.983 |
7.757 |
l |
| Wan Quan |
1,158.246 |
0.839 |
0.072 |
6.667 |
0.576 |
1,150.740 |
99.352 |
-0.503 |
0.093 |
0.741 |
| Zhang Jia Kou |
405.414 |
2.079 |
0.513 |
5.483 |
1.352 |
397.851 |
98.135 |
-0.840 |
0.231 |
0.609 |
| Cong Li (2/3) |
1,555.442 |
40.166 |
2.582 |
132.384 |
8.511 |
2,162.949 |
92.612 |
-3.949 |
4.463 |
14.709 |
| Huai Hua |
1,692.094 |
3.242 |
0.192 |
12.361 |
0.731 |
1,676.491 |
99.078 |
-0.539 |
0.360 |
1.373 |
| Xuan Hua |
2,474.029 |
27.486 |
1.111 |
19.554 |
0.790 |
2,426.990 |
98.099 |
0.321 |
3.054 |
2.173 |
| Huai Lai |
1,855.068 |
71.518 |
3.855 |
25.021 |
1.349 |
1,758.530 |
94.796 |
2.506 |
7.946 |
2.780 |
| Yang Yuan |
1,838.358 |
7.032 |
0.383 |
12.414 |
0.675 |
1,818.912 |
98.942 |
-0.293 |
0.781 |
1.379 |
| Wei Xian |
3,182.889 |
113.031 |
3.551 |
95.482 |
3.000 |
2,974.376 |
93.449 |
0.551 |
12.559 |
10.609 |
| Zhu Lu |
2,788.724 |
215.392 |
7.724 |
54.078 |
1.939 |
2,519.254 |
90.337 |
5.785 |
23.932 |
6.009 |
| Lai Shui (3/4) |
1,230.852 |
163.963 |
13.321 |
43.184 |
3.508 |
1,023.705 |
83.170 |
9.813 |
18.218 |
4.798 |
|
|
|
|
|
|
|
|
|
|
|
| Sum |
20,828.681 |
680.597 |
3.268 |
476.442 |
2.287 |
19,671.64 |
94.445 |
0.980 |
75.621 |
52.937 |
|
|
|
|
|
|
|
|
Average |
6.875 |
4.812 |
Table 5. Correlation matrix and regression equations between the studied indicators for the Northwestern part of Hebei Province
| Correlations Matrix |
|
BT |
GN |
WT |
NDVI |
| BT |
1.0 |
0.084 |
0.003 |
-0.042 |
| GN |
0.084 |
1.0 |
0.144 |
0.704 |
| WT |
0.003 |
0.144 |
1.0 |
0.263 |
| NDVI |
-0.042 |
0.704 |
0.263 |
1.0 |
| Regression equation |
| NDV |
NDVI= 9.31388+0.335838*(GN)R2 =49.517 ** |
| GN |
GN=51.3252+1.47445*(NDVI)R2 =49.517 ** |
| ** |
There is a statistically significant relationship between the variables at the 99% confidence level |
Conclusion
In general view, the study area revealed an increase in tasseled cap greenness indicator, tasseled cap wetness indicator, NDVI values during the study period from 1987 to 1996, which means that there was an increase in the vegetation cover and soil moisture. In the same time showed an decrease in the tasseled cap brightness indicator values, which points to decrease in the soil bareness. By other words, there was a decline in the land degradation in the region during the study period.
This study demonstrates the effectiveness of the remote sensing and GIS technologies in detecting, assessing, mapping, and monitoring the land degradation. The outcome of this type of studies represents a valuable resource for decision makers to guard against land acquisition, and for future development projects in the study area in the Northwestern part of Hebei Province, China.
References
- Chen, G., Z. Dong, and P. Yam. 1996. Desertification: International Research Topics and Research Strategies in China. Exploration of Nature, 15, 1-5 (in Chinese).
- Crist, H.P., and R.C. Cicone 1984. Application of the Tasseled Cap Concept to Simulated Thematic Mapper Data. Photogrammetric Engineering and Remote Sensing, vol. 50(3): 343-352.
- ER Mapper, 1995. ER Mapper Tutorial. Earth Resources mapping Pty Ltd.
- Lambin, E.F. 1994. Modelling deforestation processes (A Review), Tropical ecosystem environment observations by satellites. TREES series B: Research Report no l. EUR15744EN, pp: 45-101.
- Lambin, E.F. 1997. Modelling and Monitoring Land-Cover Changes Processes in Tropical Regions. Progress in Physical Geography, Vol. 21: 375-393.
- Lillesand, T.M., and R.W. Kiefer. 1987. Remote Sensing and Image Interpretation. John Wiley and Sons. New York. p. 599.
Ministry of Civil Affairs and Ministry of Construction. 1992. Encyclopaedia of Chinese Counties. vol. North China, China Social Publishing House, Beijing.
- Rouse, J. W., R. W. Haas, J. A. Schell, D. W. Deering, and J. C. Harlan, 1974. Monitoring the Vernal Advancement and Retrogradation (Greenwave Effect) of Natural Vegetation. NASA/GSFCT Type III Final report, Greenbelt, MD, USA.
- Sun, H., H. Zhou, and P. Wang. 1998. Progress in Research on Degradation Succession of Grasslands. Grassland China, vol.1: 51-56.
- UNCCD, 2002. China National Report to Implement the United Nation's Convention to Combat Desertification. New York.
- Zhu Z.D., and T. Wang. 1993. Trends of Desertification and its Rehabilitation in China. Desertif. Contr. Bull. 22: 27-30.
|
|
|