INFLUENCE OF REVEGETATION EFFORTS ON HYDROLOGIC RESPONSE AND EROSION,KAHOOLAWE-ISLAND, HAWAII

Measurements of soil physical and hydrological properties provide the first evaluation of the success of revegetation efforts in reducing su rface runoff and accelerated erosion on the largely barren plateau reg ion of Kaho'olawe Island, Hawai'i. Saturated hydraulic conductivity an d sorptivity data, collected within four of the largest restoration si tes, suggest revegetated areas have significantly higher infiltration capacities compared with those of the bare areas surrounding the proje ct sites. Furthermore, comparison of modeled steady-state infiltration capacity to one-min rainfall intensities demonstrate erosion-producin g Horton overland flow is very rare on the vegetated areas compared wi th the barren landscape. Thus, recently, established vegetation forms zones of high infiltration capable of absorbing both rainwater and sur face flow exported from upslope areas. However, the current areal exte nt and spatial arrangement of vegetation is not sufficient to signific antly reduce watershed-scale runoff and erosion. (C) 1998 John Wiley & Sons, Ltd.