Influence of revegetation efforts on hydrologic response and erosion, Kaho'olawe Island, Hawai'i

Abstract

Measurements of soil physical and hydrological properties provide the first evaluation of the success of revegetation efforts in reducing surface runoff and accelerated erosion on the largely barren plateau region of Kaho'olawe Island, Hawai'i. Saturated hydraulic conductivity and sorptivity data, collected within four of the largest restoration sites, suggest revegetated areas have significantly higher infiltration capacities compared with those of the bare areas surrounding the project sites. Furthermore, comparison of modeled steady-state infiltration capacity to one-min rainfall intensities demonstrate erosion-producing Horton overland flow is very rare on the vegetated areas compared with the barren landscape. Thus, recently, established vegetation forms zones of high infiltration capable of absorbing both rainwater and surface flow exported from upslope areas. However, the current areal extent and spatial arrangement of vegetation is not sufficient to significantly reduce watershed-scale runoff and erosion. © 1998 John Wiley & Sons, Ltd.