【摘要】 为研究近年来植被对黄河各支流来水来沙锐减的贡献,选择植被变化极为显著的延河流域为研究区域,定量化估算植被的减水减沙效益。论文利用Landsat系列遥感影像数据,以及流域的气象水文资料,基于Morgan-Duzant版Morgan-Morgan-Finney(MMF)模型估算流域的径流量与输沙量,分析各植被因子与径流量、输沙量的相关性,并利用相邻时期的植被降雨数据进行情景模拟,以此估算植被与降雨对流域水沙的影响。结果表明:1MMF模型能较好地模拟流域年径流量,输沙量次之;2植被因子与径流量、输沙量空间分布格局上相关性不明显,径流量与间接植被因子(截留率、林下降雨侵蚀力和坡面沉积率)相关性较高,而输沙量与植被覆盖度相关性较高;3植被与降雨的情景模拟表明2000、2006年的植被较前一相邻时期有所改善,使得径流量分别较前期减少45.88%、25.74%,输沙量减少12.10%、27.57%。更多还原

【Abstract】 In order to investigate the contribution of vegetation to the reduction of runoff and sediment yield of the Yellow River in recent years, the Yanhe River catchment, which has experienced significant vegetation changes in last decade, was chosen as the study area. In this paper, the new version of Morgan- Morgan- Finney(MMF) model(Morgan- Duzant version)was used to simulate the impact of land cover changes on the runoff and sediment yield of the catchment, and the effect of vegetation and rainfall on runoff and sediment yield were estimated through scenario simulations of series of vegetation and precipitation. Then a correlation analysis was carried out to explore the relationships between vegetation variables and the runoff and sediment yield in the catchment. The data used in the present study included Landsat remote sensing images, the hydrologic and meteorological data, and DEM data(25 m×25 m) of the catchment. The results showed that: 1) the MMF model provided a better prediction of the average annual runoff volume than the average annual sediment production in the Yanhe River catchment. However, when the impact of terraces and soil-retaining dams was incorporated into the MMF model, it also provided a good prediction of sediment production.2) The relationships between vegetation factors and runoff volume and sediment discharge did not show evident spatial patterns. There was obvious correlation between runoff volume and indirect vegetation variables(such as canopy interception, throughfall eroding force, sediment rate of the slope, et al.), while vegetation cover was more closely related to the sediment discharge. 3) The scenario simulation of 1990, 2000 and 2006 indicated that the vegetation cover of the Yanhe River catchment had been increased greatly in 2006. Compared with 1990 and 2000, the increased vegetation cover reduced the runoff volume by 45.88% and 25.74%,and reduced the sediment discharge by 12.10% and 27.57% in 2006.更多还原