in the fields and on satellite imagery; and the Table 7. Conservation Measures 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
erosion. The ranking is illustrated in Table 7. 
  
  
  
  
  
  
expressions: 
820 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996 
grades could be modified according to application Rank V Mesure 7| Definition Y-R 
needs. This layer was generated by the Where 
conventional way using the normalized green protective | well developed biological or 
ee CHE engineering measures À 
vegetation index NDVI [1], on ERDAS, which 1s 2 E F 
shown in Figure 3. 2 improving | with certain measures, but not ( 
good, or need time, or further > 
3.5 Land Use Factor development ; 
3 natural no human effort to protect, nor X 
The authors suggest that the land use factor is the significant soil erosion and 
key which determines the soil erosion mechanism. y 
teu 4 excessive | unreasonable land use 
Non-agricu tural and use refers to that where damaging soil, such as respect 
human interfering with the soil erosion overgraze, steep slope 
mechanism is minor. Agricultural land use is cultivation etc y 
where soil erosion mechanisms were greatly 5 destroyed. | soil layers zone, hadlands 
changed by human effort. The ranking of land use W, an 
was based on hybrid criteria that agricultural land ; ; 
y e This thematic map was made by a comprehensive change 
use was ranked by slope change, but the non- chahei 
: ; way. Satellite remotely sensed data does not angi 
agricultural land use ranking was based on ; ; factor: 
: ; BIS provide this sort of information, but airphotos do OT, 
vegetation coverage. The land use ranking is ; 
shown in Table 6 provide some, such as terraced fields. The 
: researchers collected annual reports from the a) Whe 
Table 6. Land Use authorities, then were able to find out where and ex 
: what conservation measures were applied, thus the 
Rank Aland Use Land Type conservation measure map was produced, shown W 
1 paddy land, plain | agriculture in Figure 6. 
crop land W 
2 upland, fallow land, | agriculture 
orchard b) Wh 
: 4. MODELING RATIONALE ) Whe 
3 forest, meadow, none-agriculture gentle. 
dense bush & grass ; : 
4 sparse forest, bush | none-agriculture 4.1 Non-agriculture Land W 
& grass, grass ; 
5 sparse grass, bare | none-agriculture The essence for modeling none-agricultural land 
© > © . . . . . 
soil use, is the inverse relationship between vegetation W 
and slope. This suggests: 
This thematic map was produced by the means of In (1), C 
visual interpretation using color airphoto 1) When vegetation coverage, whatever any 
interpretation, illustrated in Figure 4. TM and type, is high, no soil erosion occurs at any soil on C, 
SPOT imagery available during the dry season any slope, except for mass movement; 
were too poor to generate reliable land use maps. The dyn 
2) As vegetation coverage declines, slope (5), truly 
influence increases; soil eros 
3.6 Conservation Measure Factor soil eros 
3) When vegetation coverage is low, slope The Ys 
Conservation can present the rationality of ^ becomes the dominant factor which effects soil intensity 
human's using land, therefore this factor can erosion. 
describe the manner of human impact on land. Table 7. 
This factor can give hints of future change of soil This rationale is presented in the following Intensity