Abstract
The effect of vegetation on the water recycling of a land ecological system is considerably significant.Understanding the relationship between vegetation and runoff changes will benefit regional eco-environmental and water resources management. Based on paired catchments and time trend studies, a number of studies had been undertaken to establish the relationship between vegetation cover and water yield. We obtained some results from paired watersheds by focusing on changes at various time scales. At the mean annual scale the runoff changes resulting from vegetation alteration can be predicted using Zhang's curves. The absolute change of runoff due to vegetation alteration in a humid area is larger than that in the dry region, while the relative change is reverse. At the annual scale, it takes 15-20 years or longer in the arid region for catchments to reach a new equilibrium after afforestation,and under natural restoration, it takes about a hundred years.The vegetation changes have a proportionally larger impact on low flow at the seasonal scale. For catchments in arid regions,relative changes in low flow sections of the flow duration curve will be much more significant compared with that in the high flow section, leading to increased number of zero-flow days. However, in humid regions, changes in runoff tend to be much more uniform.
基金项目
impact of land use/land cover change on the stream flow and sediment in the He-Long section of the Loess Plateau, China(B183)
International Cooperative project Regional impacts of revegetation on water resources of the Loess Plateau, China()
Middle and Upper Murrumbidgee catchment, Australia(LWR/2002/018)
NETL
NSTL
万方数据