Surface Run-off, Soil Erosion and Slope Instability - Semi-quantitative Approaches for Landslide Assessment and Prediction - page 135

Table 4.9 Hydrological soil group wise land use and land cover and determined curve number (CN) under different hydrological condition for individual
watersheds
Land use/land cover Hydrological soil

group

Hydrological
condition

Curve number
(CN)

Distribution of land uses in individual
watersheds (area in km 2 )
I II III IV V VI

Agricultural land B Poor 74 0.19 0.00 0.00 0.12 0.00 0.00

Settlement Compact D Poor 92 0.07 0.02 0.05 0.00 0.00 0.75

Disperse C Fair 80 0.55 0.02 0.10 0.06 0.06 0.25

Concrete
road

Concrete D Poor 92 0.48 0.11 0.18 0.12 0.00 0.32

Metalled C Fair 80 0.26 0.00 0.05 0.18 0.13 0.12

Dense forest A Good 30 0.80 0.14 0.00 0.00 0.00 0.00

Bared
Surface

Steep slope C Poor 91 0.15 0.00 0.02 0.03 0.03 0.23

Gentle
slope

B Poor 85 0.04 0.00 0.00 0.00 0.00 0.18

Tea garden Up slope B Poor 74 0.98 0.05 0.31 0.41 0.15 0.87

Down slope A Good 62 0.37 0.07 0.30 0.08 0.30 0.24

Mixed forest Up slope B Fair 76 0.62 0.01 0.06 0.03 0.05 0.06

Down slope A Good 58 0.06 0.02 0.00 0.00 0.00 0.12

Degraded
forest

Up slope C Poor 77 0.40 0.12 0.16 0.14 0.14 0.52

Down slope B Poor 66 0.16 0.08 0.00 0.00 0.00 0.18

Open forest Up slope C Fair 73 0.75 0.14 0.09 0.31 0.23 0.37

Down slope B Fair 60 0.28 0.09 0.10 0.06 0.06 0.14

Jungle Up slope C Fair 70 0.73 0.16 0.45 0.04 0.23 0.77

Down slope B Poor 67 0.20 0.21 0.26 0.16 0.13 0.24