Over the last few decades, dramatic land use (LU) and land cover (LC) changes (defined and described in Drigo, 2004, 2006) have taken place in the humid tropics (Chang and Lau, 1993) which have resulted in rapid rates of deforestation. In response, Giambelluca (2002) remarked that hydrologists have traditionally focused on the hydrological impacts of forest conversion to cleared, actively used land, that is, at the respective extremes of this LC taxonomy (e.g. Bruijnzeel, 1990, 1996, 2004; Costa, 2004; Grip et al., 2004). The LC of the tropics is now becoming more fragmented and highly complex, and secondary forest is now emerging as the dominant forest type interspersed with remnants of old-growth forest and other intermediate LCs (Giambelluca, 2002; rigo, 2004; Holscher et al., 2004; Cuo et al., 2008). These intermediate LCs include degraded, previously converted forest land now under various LUs as well as Degraded Forest (Lal, 1987; Scott et al., 2004; Safriel, 2007). The storm runoff hydrology of these intermediate LCs from multi-decades of human occupancy, and ‘forestation’ (afforestation–reforestation, defined in Scott et al., 2004; Wiersum, 1984) of land in various states of degradation, have been much less studied across a range of soils and scales (Giambelluca, 2002; Bruijnzeel, 2004; Holscher et al., 2004; Scott et al., 2004; van Dijk et al., 2007; Ilstedt et al., 2007; Malmer et al., 2010). The need for such attention is emphasized when one considers that globally an increasing proportion of the population in the humid tropics are becoming dependent on these intermediate LCs for their livelihoods and ecosystem services because of decreasing availability and access to less disturbed (or old-growth) tropical forest (Drigo, 2004; Chazdon, 2008). For example within South and Southeast Asia, it was estimated that about 45% of the total land area has been affected by human-induced soil degradation (Eswaran et al., 2001; Scott et al., 2004). At the small scale (1 km2 ); Ziegler et al. (2004, 2007) presented a case study from northern Vietnam that demonstrates the surface hydrologic consequences of landscape fragmentation and a predictive frame-work for restoration scenarios. Contrary to results from controlled, paired experimental research basins (Hewlett and Fortson, 1983; Andreassian, 2004; Bruijnzeel, 2004), there are an increasing number of reports from both degraded and converted tropical forests of the occurrence of Horton-type (infiltration-excess) overland flow IOF, across various scales of investigation (e.g. Pereira, 1989,1991; Sandstrom, 1995, 1996, 1998; Chandler and Walter, 1998; Zhou et al., 2001; Costa et al., 2003; Bruijnzeel, 2004; Ziegler et al., 2004; Chandler, 2006; de Moraes et al., 2006; Cuo et al., 2008;Chaves et al., 2008; Mehta et al., 2008; Zimmermann and Elsenbeer, 2008, 2009). The reason for this dichotomy is that most of the controlled experiments relate to the two-class land-cover taxonomy of Giambelluca (2002) where the various states of resilience of different soils to disturbance have remained high. Further the short duration of most controlled experiments has not captured the hydrological responses to multi-decadal degradation (Bruijnzeel, 1989, 2004; Sandstrom, 1998). Consequently the soils in the controlled experiments have retained comparatively high infiltration rates towards those of pre-disturbed conditions, and so LC change had a minimal effect on the dominant stormflow pathways (Chappell et al., 2007, e.g. sub-surface stormflow, SSF). In the context of the ‘infiltration trade-off’ hypothesis of Bruijnzeel (2004), the preceding description would be fit within the ‘non-degraded scenario’. The principal reason for enhanced IOF is a significant reduction in soil infiltrability (Hillel, 1980) and permeability due to various forms of disturbance at multi-decadal time scales (e.g. Scott et al., 2004). Strictly however in situ measurements made above a water table to represent saturated hydraulic conductivity, Ksat are known as field, saturated hydraulic conductivity, K* because the latter can be as low as 0.5 Ksat (Bouwer, 1966; Talsma and Hallam, 1980; Talsma, 1987). Following Williams and Bonell (1988), K* will be thus adopted in this work. Further K* and ‘permeability’ will be used interchangeably for the same reasons as outlined in Zimmermann and Elsenbeer (2009). A common cause for enhancing the occurrence of IOF is surface soil compaction arising from various trampling pressures such as intensive over-grazing, human pathways and roads (Ziegler et al., 2004; Hamza and Anderson, 2005; Cuo et al., 2008; Zimmermann and Elsenbeer, 2008, 2009). Moreover selected soils in the tropics are particularly vulnerable to significant changes in structure as a result of human disturbance (e.g. Gilmour, 1977; Schaak-Kirchener et al., 2007). Additional causes are the exposure of unprotected soils to high rainfall intensities which can result in raindrop compaction and sealing (Sandstrom, 1998; Grip et al., 2004; Scott et al., 2004).Thus the overall reduction in surface permeability (and thus infiltration) results in a change of the dominant stormflow pathways from SSF (supplemented by SOF) to IOF. It will also affect the vertical percolation (VP) flux in the uppermost soil layers. These circumstances are part of the ’degraded scenario’ of the ‘infiltration trade-off’ hypothesis (Bruijnzeel, 2004).