论文部分内容阅读
根据延河流域长系列水文资料,对1997—2006年林草植被减洪减沙效应进行重点分析。结果表明:1)与基准期的1956—1969年相比,延河流域1997—2006年汛期降水、径流、输沙量分别减少了15.1%、45.6%和67.2%。截至2006年底,延河流域(含未控区)水土保持措施保存面积37万1 751 hm2,其中林草措施保存面积30万7 412hm2,占82.7%;2)延河流域1997—2006年林草植被年均减少洪水量2 885万m3,年均减沙量1 695万t,分别占水土保持措施年均减洪减沙总量的63.6%和58.2%,其中林地减洪减沙效应最为明显,其减洪减沙量分别是草地和封禁治理措施减洪减沙量之和的4.9和4.7倍;3)1997—2006年延河流域林草植被减洪减沙上升趋势明显,林草植被与工程措施减洪量之比约为64%∶36%,减沙量之比约为58%∶42%。
According to the long series of hydrological data of Yanhe River Basin, this paper focuses on the flood and sediment reduction effects of forest and grassland from 1997 to 2006. The results show that: 1) Compared with the reference period from 1956 to 1969, the precipitation, runoff and sediment load decreased by 15.1%, 45.6% and 67.2% respectively in the flood season from 1997 to 2006 in the Yanhe River Basin. As of the end of 2006, the conservation area of water and soil conservation measures in Yan River Basin (including the uncontrolled area) was 371, 751 hm2, of which the reserve area of forest and grass measures was 300,742hm2, accounting for 82.7%; 2) Vegetation average annual reduction of 28.55 million m3 of floods and annual sediment reduction of 16.95 million tons, accounting for 63.6% and 58.2% of the annual total amount of flood and sediment reduction measures of soil and water conservation, of which the effect of reducing flood and reducing sediment is the most obvious , Respectively. The flood and sediment reduction amounts were 4.9 and 4.7 times of the sum of the flood control and sediment reduction measures of grassland and embargo control measures, respectively. 3) The trend of decreasing flood and sediment in forest and grassland vegetation in Yanhe River valley increased significantly from 1997 to 2006, The ratio of flood reduction to engineering measures is about 64%: 36%, and the ratio of sediment reduction is about 58%: 42%.