1.西北农林科技大学水土保持研究所；3.CSIROLand and Water GPO Box 1666, Canberra，ACT2601，Australia；2.中国科学院水利部水土保持研究所:712100, 陕西杨凌
Responses of runoff to vegetation alteration at different temporal scale
ZHANG Xiao-Ping-；Gao-Zhao-Liang-；Zhang-Lu-；Li-Dui
1.Institute of Soil and Water Conservation,North-West University of Agriculture and Forest;2.Institute of Soil and Water Conservation,CAS:712100,Yangling,Shaanxi,China;3.CSIRO Land and Water,GPO Box 1666,Canberra,ACT 2601,Australia
Abstract：Vegetation influences the water recycle of land ecological system considerably.Understanding these relationships between vegetation and runoff changes is helpful for regional eco-environmental construction and water resources management.Based on paired catchments and time trend studies a number of studies had been undertaken to establish relationships between vegetation cover and water use.The paper reviews results from that which are focusing on changes at various time scales.At mean annual scale the runoff changes resulted from vegetation alteration can be predicted using Zhang curves.The absolute change of runoff due to vegetation alteration in humid area is larger than that in dry region.While the relative change is reverse.At annual scale,it takes 1520 years or longer in arid region for catchments to reach a new equilibrium following afforestation,and under natural restoration,it takes about hundred years.The vegetation changes have a proportionally larger impact on low flow at seasonal scale.For catchments in arid regions,relative changes in low flow section of the flow duration curve will be much more significant compared with that in high flow section,leading to increased number of zero-flow days;however in humid regions,changes in runoff tend to be much more uniform.
2007, Vol. 5 
