Moraes, Jener Fernando 
  
2.4.1 Erosion Risk 
The watershed erosion risk (E) considered the relationship between the Maximum Tolerance of Soil Loss Accepted (T) 
and the Natural Erosion Potential (NEP) according to the formula: 
E= T 3 
NEP e) 
where: NEP = R*K*LS 
2.4.0 Land Use Planning 
Land Use Planning Map was obtained through overlaying Land Use and the Land Capability Map. The Erosion Risk 
Map was considered in this process too. Land Capability classification is a broad grouping of soils based on their 
limitations. It serves as a guide to assess the suitability of land for cultivation, grazing and other uses. It was made a 
comparison between the actual land use and the land use suggested by the land capability classification according to the 
previous limitations of soil physical and chemical properties and slope gradient. This comparison results in another map 
called Land Planning Map that summarizes the 
3 RESULTS 
The land use map obtained through digital image processing and visual interpretation of satellite image and aerial 
photographs is presented in Figure 3. The sugarcane is the main occurrence with 58% of total area, followed by pasture 
with 29%. Others occupations like coffee, banana were observed. The area of native forest is little expressive and 
reduced to 5% of the total area. 
The intensive soil mechanization associated with sugarcane production and the natural limitation (high soil erodibility 
and slope) and the great pressure of occupation requires a soil conservation priorizating in sugarcane areas. 
The soil loss rates varied from 0.1 t.ha™ yr” in forest areas to 30 tha’.yr! in sugarcane areas (Figure 4). Compared to 
the to the maximum tolerance of soil loss (Table 1) mainly average rates for sugarcane (30 tha"yr™) is large and 
should be reduced. This problem is critical in those areas with slope larger than 9%. 
  
  
     
     
  
    
  
  
  
590000 592000 594000 
3 à 
> + + [8 
2 8 
Legend 
Forest 
ES Reforestation 
o Secundary_regrow | 
À + i | Pasture FE 
e [] Sugarcane 8 
N 
W E 
Flood plain 
S 
590000 592000 594000 
  
  
  
Figure 3. Land use map of the area 
The erosion risk map, presented in Figure 5, showed that 5496 of the area presents a medium to high erosion risk and 
approximately 30% of sugarcane production occurs in these areas. 
  
898 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 
35.0 
30.0 
25.0 
20.0 
15.0 
10.0 
Soil loss (t/halyr) 
o © 
(Mn € 
  
Figure 
The Su 
the are 
manage 
present 
plannin 
occupa 
toleran 
occur i 
sugarca 
7618000 
7614000 
  
7 
  
Figure