Influence of vegetation restoration on runoff and sediment of Yanhe basin
The impact of precipitation changes and water-soil conservation measures on runoff and sediment of Yanhe basin was quantified by using regional averaged annual precipitation,runoff and sediment yield at hydrological stations in the period of 1960-2010.Stream flow and sediment yield were divided into three periods according to the accumulative anomaly method.The double mass curve was adopted to establish the linear regression relationship among the hydrological elements within the compared period.The results show that the obvious change points in runoff and sediment load occurred in 1971 and 1996.The linear model of main hydrological data during 1960-1971 based on the double mass curve have a higher fitting degree (R2 > 0.9).The estimation via the double mass curve indicated that soil and water conservation dominated by vegetation restoration contributed 17.5% and 55.9% to the runoff and sediment load decline,respectively.