【摘要】 开展变化环境下新安江上游流域径流变化及其归因的研究,有助于理解湿润区水循环过程对气候变化和人类活动的响应机制。利用实测径流、气象资料和遥感植被指数(NDVI)数据,基于布迪克假设框架的弹性系数法,分析了新安江上游降水、潜在蒸散发(ET0)和植被变化对径流的影响。结果表明:(1)实测径流序列转折点发生在1999年左右。2000-2015年径流深较1983-1999年下降了281 mm,相对变化率为20.8%,且21世纪初期径流下降尤为显著。(2)2000-2015年下垫面参数n较1983-1999年增加了52.5%,植被变化对径流影响显著增强。径流对气候变化更加敏感,且对降水敏感性超过潜在蒸散发。(3)气候变化是径流变化的主导因素,其次为植被变化。气候变化和植被变化分别导致径流深下降了145.37 mm和140.96 mm,贡献率分别为50.77%和49.23%。NDVI在2000年后增加显著(P<0.001),植被变化的水文效应超过了降水和潜在蒸散发,未来长期的植被生态水文效应研究仍需进一步加强。更多还原

【Abstract】 Investigation to the variation of streamflow and its drivers in Xin’an River Basin under changing environment will be beneficial for understanding the geographical heterogeneity of water cycle processes in response to climate change and human activities.Using observed discharge at hydrological stations, meteorological data and remote sensing vegetation index(NDVI), the impact of precipitation, potential evapotranspiration(ET0) and vegetation change on runoff in the upper reaches of Xin’an River were analyzed. Results show that:(1) The changing point of streamflow occurred in 1999. From 2000 to 2015, the runoff depth decreased by 281 mm compared with 1983-1999, and the relative change rate was20.8%, especially significant in the early 21 stcentury.(2) After the changing point, the parameter n increased by 52.5%, and the influence of vegetation change on runoff was significantly enhanced. Streamflow is also more sensitive to precipitation than to ET0.(3)Climate change is the dominant factor for the decrease of runoff, followed by vegetation change. The change of climate and vegetation led to a decrease of runoff by-145.37 and140.96 mm, respectively, with contribution rates of 50.77% and 49.23%, respectively. After2000, The NDVI increasing trend reached a very significant level(P<0.001), and the contribution of vegetation change to runoff exceeded precipitation and ET0 individually.However, the long-term research on eco-hydrology effects of vegetation change needs to be further strengthened.更多还原