IAPRS & SIS, Vol.34, Part 7, "Resource and Environmental Monitoring", Hyderabad, India, 2002 
  
A slope class map showing various slope intervals as per slope 
classification suggested by AISLUS is generated by slicing the 
map into ranges, A 2 0 - 1 % (nearly level), B = 2 - 3% (very 
gently sloping), C = 3-5%(gently sloping), D = 5. 
10% (moderately sloping), E =10- 15%(strongly sloping), F = 
15-25% (moderately steep), G = 25-33%(Steep sloping), H = 
33-50%(very steep), I = >50%( very very steep). Then by 
classifying DEM map into different elevation classes an 
elevation zone map has also been generated. 
Estimation of soil erosion loss 
Soil loss has been quantitatively estimated under GIS 
environment using the universal soil loss formula, 
A R*K*LS*C*P 
Where A = the computed soil loss per unit area in tone per 
hectare per year. 
R = the rainfall erosivity factor; is the number of 
rainfall erosion index units for a particular location. 
K = soil erodability factor; is the soil loss rate erosion 
index unit for a specified soil as measured on a unit 
plot, which is defined as 21.13 meter length of 
uniform 9% slope continuously on a clear tilled 
fallow. 
L = slope-length factor; is the ratio of soil loss from 
the field slope length to that from 21.13 meter length 
under identical conditions. 
S = slope steepness factor; is the ratio of soil loss 
from the field slope gradient to that from 9% slope 
under identical conditions, 
C = crop management factor; is the ratio of soil loss 
from an area with specified cover and management to 
that from an identical area in tilled fallow condition. 
P = land support practice factor; is the ratio of soil 
loss with support practices like contour strip cropping 
etc. Accordingly the areas in different categories of 
erosion classes have been found out under GIS 
environment, as shown in Table 1. Land capability 
class map is then generated by integrating capability 
class of soil (parametric method) topography (slope) 
and soil erosion class map using in the following 
syntax, 
Capability map = Max (soil cap, slope 
cap, ero cap). 
Where soil cap is prepared by reclassifying the parameters 
like soil texture and soil depth as per capability class. 
Slope cap map is derived from DEM by reclassifying 
into slope capability class map ranging from A, B, C, 
D, E, F, G, H, I and accordingly erosion capability 
class map is generated by reclassifying soil loss map 
(derived from USLE model) into EQ, El, E2, E3 & 
E4. 
Land use adjustment map 
The land use adjustment map is generated by integrating 
present land use map and land capability map, which contains 
information essential for making decisions on future land use 
planning adjustment needs, conservation needs and possible 
resettlement etc. The classification criterion for determining 
land use conditions was first worked out. This was prepared by 
comparing present land use with land capability to obtain 
results, which are categorized into, 
Lk W+ : Used within capability but needs soil 
conservation treatment. 
2. W Used within capability, where soil 
conservation treatment is not necessary. 
3. O+ : seriously over used. 
4. O : Over used. 
5, U+ : Under used common lands, which can be 
adjusted for better use i.e. 
resettlement etc. 
6. U : Under used. 
RESULTS AND DISCUSSIONS 
The results obtain from the land use adjustment map suggested 
Six types of land use adjustment classes as explained above. 
Out of the total area the maximum land covering 60.88 96 have 
been found within capability uses without soil conservation 
measures followed by under used common land (public land) 
with an extent of 12.25 95 which can be adjusted suitably for 
better production system and resettlement. The land used within 
capability but needs appropriate soil conservation measures for 
better sustainability are 10.09% whereas 1.86% area have been 
found to be over used necessitating immediate change of 
existing cropping pattern and conservation practices. (Table-2). 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
SI.No. Erosion Class. Area (ha). Area (%). 
1 EO, Nil erosion (0-5 ton / ha/ yr.). 8864.31 29.58 
2. El, Slight erosion (5-12 ton /ha /yr.) 8663.28 28.91 | 
3, E2, Moderate erosion (12-25 ton/ha/yr.). 8497.62 28:25 
4 E3, Severe erosion (25-60 ton/ha/yr.) 3637.47 12.14 
S E4, very severe erosion (60-150 ton/ha/yr.) 303.23 1.01 
Total 29,965.91 
Table 1. Area under various erosion categories 
| SLNo. Symbol Land uses adjustment Class. Area (ha) Area (96) 
1. W+ Used within capability but needs soil 3024.60 10.09 
conservation measures. 
2. W Used within capability, soil conservation 18241.17 60.88 
measures not necessary 
  
  
  
  
  
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