The Impact of Forest Use and Reforestation on Soil Hydraulic Conductivity in the Western Ghats of India: Implications for Surface and Sub-Surface Hydrology

M.Bonell, B. K. Purandara, B. Venkatesh, Jagdish Krishnaswamy, H. A. K. Acharya, U. V. Singh, R. Jayakumar, N.Chappell  | 2010

Abstract

There is comparatively limited information in the humid tropics on the surface and sub-surface permeability of: (i) forests which have been impacted by multi-decades of human occupancy and (ii) forestation of land in various states of degradation. Even less is known about the dominant stormflow pathways for these respective scenarios. We sampled field saturated hydraulic conductivityK at 23 sites at four depths (0 m, n = 166), (0.10 m, n = 139), 0.45–0.60 m, n = 117, (1.35–1.50 m, n = 117) under less disturbed forest (Forest), disturbed production forest of various local species (Degraded Forest) and tree-plantations (Acacia auriculiformes, 7–10 years old, Tectona grandis, ∼25–30 years old, Casuarina equisetifolia, 12 years old) in the Uttar Kannada district, Karnataka, India, in the Western Ghats. The sampling strategy was also undertaken across three physiographic blocks and under three main soil types. Subsequently the determined K were then linked with rainfall intensity–duration–frequency (IDF) characteristics to infer the dominant stormflow pathways.