IAPRS & SIS, Vol.34, Part 7, "Resource and Environmental Monitoring", Hyderabad, India, 2002
on. The compound value of each sub basin was calculated
based on the sum of all ranks division with the total number of
parameters considered. The prioritization of sub basins was
made based on the compound value. The lowest compound
value is the highest priority, next lower value is the next
priority and so on. The sub basins of 2 and 1 are ranked with 1
and 2, whereas sub basins 11 and 9 are ranked with 18 and 19
(Table.1).
Estimated potential soil loss based approach: The areal
extent of potential erosion under different erosion classes at sub
basin level was carried out. The sub basins at higher elevations
are noticed under severe to extremely severe soil erosion
classes. The sub basins of 10,11 and 19 are mainly under slight
to moderate potential erosion conditions. The analysis of
quantum of potential soil loss in the whole basin reveals that
out of the total quantum of soil loss nearly 67.10 per cent is
only due to extremely severe soil erosion. Based on the
compound values, the sub basins of 17 and 1 are ranked with 1
and 2 whereas the sub basins 10 and 11 are ranked with 18 and
19 (Table.1).
Estimated Actual soil loss based approach: The areal extent
of actual soil erosion under different erosion classes was
worked out at sub basin level. The area analysis reveals that
nearly 21.77, 22.71 and 17.21 per cent of the area is under
extremely severe, very slight and slight erosion classes
respectively. The area analysis of quantum of actual soil loss
shows that the area under extremely potential soil loss reduced
significantly because of the influence of cover and management
factors. Based on the compound values, the sub basins of 1 and
17 are ranked with 1 and 2, whereas sub basins 10 and 11 are
ranked with 18 and 19 (Table.1). However, the ranks of sub
basin 12 is remained same in all the three cases.
Table.1: Prioritization of sub basins based on morphometric,
estimated Potential and Actual soil loss compound
parameters*.
Sbn Mcp Mp | Pcp Psp Acp Asp
1 | 3428 2 |5836| 2 |4766| 1
2. | 2142 1 | Soil 7142051 À
3. {12.0280 42. 133,95 |. 11 (28:01 {40
4 | 6.571 5] 530.80 1. 71 40.84.16
5 8.714 54.22 44.04
Goud 14.005 0. 15. |.28 89.| 13 |. 2334; 12
7: li24223]-13]33s0| 12:1 2590] 11
ael S571 4 1436] 9 013136 |.^8
9..-[417:423 1-19 |-21.58 | 12: | 1882 1.15
102112714] 77171 39721 718 | 652 | 18
11” 1138571 15° 803 | 19 170 | 19
2.013.142). . 16.1 16867 19 | 12209 | 16
13 |10.428| 11 | 39.09 | 10 | 3084 | 9
14 |10428| 10 | 52339 39.80 | 7
15 | 10.000 8 | 5419 [5 17.86 | 13
16 |10.285 2143 14" y oi | 14
17 | 5.142 70:43 back 45:30
18 | 8.714 715078). 9 |4244| 5
19.112.571 14 11179 |. 17. | 714.4 ‘17
656
*Sbn = Sub basin no; Mcp - Morphometric compound
parameter; Mp = Morphometric priority; Pcp = Potential soil
loss compound parameter; Psp = Potential soil loss priority;
Acp = Actual soil loss compound parameter; Asp = Actual soil
loss priority.
Erosion Susceptibility Zoning at Sub basins level
The erosion susceptibility zone map has been generated based
on the ranks of estimated actual soil loss parameters of sub
basins (Fig.2). The sub basins of 1,5 and 17 are prioritized
Vena Basin
Erosion Susceptibility Zones
(Sub basins Prioritization)
Sub basin Priority
EH Extremely severe
Very severe
LL Severe
[77] Moderately severe
[CJ Moderate
[J slight
Very slight
[J Unclassified area
BER Water bodies
Drainage
—— Sub-basins
——— Metalled Road
National Highway
— Railway line
Fig.2. Erosion Susceptibility Zones (Priority sub basins).
under extremely severe soil loss basins based on the quantum of
estimated actual soil loss. These sub basins consist of very
steep slopes, very high drainage density, stream frequency,
texture ratio and lowest form factor. The sub basins numbered
2, 18 and 4 are classified under very severe soil loss priority
basins. These sub basins consist of steep to very steep slopes,
very high drainage density, stream frequency, texture ratio and
lowest form factor. The sub basins of 14, 8 and 13 are classified
under severe soil loss priority basins. These sub basins consists
of gentle to steep slopes, high drainage density, stream
frequency, texture ratio, lowest form factor and elongation
ratio. The sub basins of 3, 7 and 6 are grouped under
moderately severe soil loss priority basins, which are consist of
gentle to steep slopes, moderate drainage density, stream
frequency, texture ratio, lowest form factor and elongation
ratio. The sub basins of 15, 16 and 9 are classified under
moderate soil loss and are consist of moderate to gentle slopes,
moderate drainage density, stream frequency, high texture ratio,
lowest form factor and circulatory ratio. The sub basins of 12,
19 and 10 are classified under slight soil loss priority and are
associated with level slopes, low drainage density and stream
frequency. The sub basin of 11 is classified under very slight
soil loss.
Evaluation of Conservation Measures for Landscape
Management
The multi-criteria overlay analysis was performed in GIS taken
into consideration the weighted potential erosion, slope, soil
depth, texture and land use/land cover layers as input to find out
the priority areas to suggest appropriate soil conservation
measures. In the final composite map based on the range of