JAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002 
  
  
like amount and intensity of rainfall, soil erodibility, land cover 
and terrain slope gradient which greatly influence the soil loss 
have been given due weightage. 
3.5.1.1 Rainfall factor (R) : The total geographical area of 
the watershed is only 2980 ha which is quite small and hence it 
was assumed that there would not be much variation in the 
rainfall distribution pattern in the watershed. Ram Babu er al. 
(1978) estimated the erosion index of Nagpur area based on 
rainfall distribution pattern and reported annual rainfall erosion 
index value 483 for the area. The same value has been used for 
the estimation of soil loss in the present study. 
3.5.1.2 Soil Erodibility Factor (K) : The physiography soil 
map prepared after adequate ground truth collection was 
utilized to generate information on soil erodibility factor (K) 
and preparation of soil erodibility map. The soil erodibility 
factor (K) was determined for different soil series in the 
watershed using soil erodibility nomograph (Wischmeier ef al. 
1971). The soil erodibilty factor (K) for different soil series are 
presented in table 2 and soil erodibility map with due weight to 
the association of soil series is shown in figure 5. 
Table 2: Estimated value of soil erodibility (K) factor for 
different soil series 
  
  
  
  
  
  
  
  
  
  
  
  
  
Sr. Identified Sand K value 
No. soil series 
(0.1-2mm) 
1. Khairi-1 2.7 0.181 
2. Khairi-2 8.5 0.219 
3 Khairi-3 22.0 0.205 
4. Khairi-4 24.7 0.156 
5 Panjri 1.6 0.206 
6. Kirmati 5.7 0.206 
7. Shivmarka 7.0 0.230 
  
  
  
Habitation 
  
  
  
728 
Figure 5 : K value map of Nanda-Khairi watershed 
3.5.1.3  Slope-length and steepness factor (LS) :The LS 
factor on each physiographic units were determined based on 
degree and length of slope using nomograph developed by 
Wischmeier et al. (1978). The values of slope-length and 
steepness factor (LS) determined for each physiographic units 
of the watershed have been presented in table 3. The data 
indicates that escarpments have the highest LS values due to 
very steep slopes. The lower alluvial plain had the lowest LS 
value as it was associated with, nearly level (0-1% slopes) and 
have good field bundingsand LS factor map is show in figure 6. 
Table 3: Estimated value of LS factor for different slope 
classes 
  
  
  
  
  
  
  
  
  
  
  
S. Physiography Slope Class (%) | Estimated 
No LS value 
1. Summits/Plateau | Gently 0.40 
sloping(3-5%) 
2. Escarpment Steeply 6.6 
sloping(15-35%) 
3. Upper foot slope | Moderately 0.90 
sloping(5-10%) 
4. Lower foot slope | Gentely 0.40 
sloping(3-5%) 
S. Upper alluvial Very gently 0.20 
plain sloping (1-396) 
6. Lower alluvial Nearly level (0- | 0.11 
plain 1%) 
  
  
  
  
  
[] 011 6.50 
L.] 020 E Habitation 
[] 040 EB nas 
EJ o30 
  
  
  
Figure 6 : LS value map of Nanda-Khairi watershed